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 <linux/slab.h>
  29 #include <linux/module.h>
  30 #include <asm/unaligned.h>
  31 #include <net/tcp.h>
  32 #include <scsi/scsi_cmnd.h>
  33 #include <scsi/scsi_device.h>
  34 #include <scsi/scsi_eh.h>
  35 #include <scsi/scsi_tcq.h>
  36 #include <scsi/scsi_host.h>
  37 #include <scsi/scsi.h>
  38 #include <scsi/iscsi_proto.h>
  39 #include <scsi/scsi_transport.h>
  40 #include <scsi/scsi_transport_iscsi.h>
  41 #include <scsi/libiscsi.h>
  42
  43 static int iscsi_dbg_lib_conn;
  44 module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
  45                    S_IRUGO | S_IWUSR);
  46 MODULE_PARM_DESC(debug_libiscsi_conn,
  47                  "Turn on debugging for connections in libiscsi module. "
  48                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  49
  50 static int iscsi_dbg_lib_session;
  51 module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
  52                    S_IRUGO | S_IWUSR);
  53 MODULE_PARM_DESC(debug_libiscsi_session,
  54                  "Turn on debugging for sessions in libiscsi module. "
  55                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  56
  57 static int iscsi_dbg_lib_eh;
  58 module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
  59                    S_IRUGO | S_IWUSR);
  60 MODULE_PARM_DESC(debug_libiscsi_eh,
  61                  "Turn on debugging for error handling in libiscsi module. "
  62                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  63
  64 #define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)                  \
  65         do {                                                    \
  66                 if (iscsi_dbg_lib_conn)                         \
  67                         iscsi_conn_printk(KERN_INFO, _conn,     \
  68                                              "%s " dbg_fmt,     \
  69                                              __func__, ##arg);  \
  70         } while (0);
  71
  72 #define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)                    \
  73         do {                                                            \
  74                 if (iscsi_dbg_lib_session)                              \
  75                         iscsi_session_printk(KERN_INFO, _session,       \
  76                                              "%s " dbg_fmt,             \
  77                                              __func__, ##arg);          \
  78         } while (0);
  79
  80 #define ISCSI_DBG_EH(_session, dbg_fmt, arg...)                         \
  81         do {                                                            \
  82                 if (iscsi_dbg_lib_eh)                                   \
  83                         iscsi_session_printk(KERN_INFO, _session,       \
  84                                              "%s " dbg_fmt,             \
  85                                              __func__, ##arg);          \
  86         } while (0);
  87
  88 inline void iscsi_conn_queue_work(struct iscsi_conn *conn)
  89 {
  90         struct Scsi_Host *shost = conn->session->host;
  91         struct iscsi_host *ihost = shost_priv(shost);
  92
  93         if (ihost->workq)
  94                 queue_work(ihost->workq, &conn->xmitwork);
  95 }
  96 EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
  97
  98 static void __iscsi_update_cmdsn(struct iscsi_session *session,
  99                                  uint32_t exp_cmdsn, uint32_t max_cmdsn)
 100 {
 101         /*
 102          * standard specifies this check for when to update expected and
 103          * max sequence numbers
 104          */
 105         if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
 106                 return;
 107
 108         if (exp_cmdsn != session->exp_cmdsn &&
 109             !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
 110                 session->exp_cmdsn = exp_cmdsn;
 111
 112         if (max_cmdsn != session->max_cmdsn &&
 113             !iscsi_sna_lt(max_cmdsn, session->max_cmdsn))
 114                 session->max_cmdsn = max_cmdsn;
 115 }
 116
 117 void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
 118 {
 119         __iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
 120                              be32_to_cpu(hdr->max_cmdsn));
 121 }
 122 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
 123
 124 /**
 125  * iscsi_prep_data_out_pdu - initialize Data-Out
 126  * @task: scsi command task
 127  * @r2t: R2T info
 128  * @hdr: iscsi data in pdu
 129  *
 130  * Notes:
 131  *      Initialize Data-Out within this R2T sequence and finds
 132  *      proper data_offset within this SCSI command.
 133  *
 134  *      This function is called with connection lock taken.
 135  **/
 136 void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
 137                            struct iscsi_data *hdr)
 138 {
 139         struct iscsi_conn *conn = task->conn;
 140         unsigned int left = r2t->data_length - r2t->sent;
 141
 142         task->hdr_len = sizeof(struct iscsi_data);
 143
 144         memset(hdr, 0, sizeof(struct iscsi_data));
 145         hdr->ttt = r2t->ttt;
 146         hdr->datasn = cpu_to_be32(r2t->datasn);
 147         r2t->datasn++;
 148         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 149         hdr->lun = task->lun;
 150         hdr->itt = task->hdr_itt;
 151         hdr->exp_statsn = r2t->exp_statsn;
 152         hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
 153         if (left > conn->max_xmit_dlength) {
 154                 hton24(hdr->dlength, conn->max_xmit_dlength);
 155                 r2t->data_count = conn->max_xmit_dlength;
 156                 hdr->flags = 0;
 157         } else {
 158                 hton24(hdr->dlength, left);
 159                 r2t->data_count = left;
 160                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 161         }
 162         conn->dataout_pdus_cnt++;
 163 }
 164 EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
 165
 166 static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
 167 {
 168         unsigned exp_len = task->hdr_len + len;
 169
 170         if (exp_len > task->hdr_max) {
 171                 WARN_ON(1);
 172                 return -EINVAL;
 173         }
 174
 175         WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 176         task->hdr_len = exp_len;
 177         return 0;
 178 }
 179
 180 /*
 181  * make an extended cdb AHS
 182  */
 183 static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
 184 {
 185         struct scsi_cmnd *cmd = task->sc;
 186         unsigned rlen, pad_len;
 187         unsigned short ahslength;
 188         struct iscsi_ecdb_ahdr *ecdb_ahdr;
 189         int rc;
 190
 191         ecdb_ahdr = iscsi_next_hdr(task);
 192         rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 193
 194         BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 195         ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 196
 197         pad_len = iscsi_padding(rlen);
 198
 199         rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
 200                            sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 201         if (rc)
 202                 return rc;
 203
 204         if (pad_len)
 205                 memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 206
 207         ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 208         ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 209         ecdb_ahdr->reserved = 0;
 210         memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 211
 212         ISCSI_DBG_SESSION(task->conn->session,
 213                           "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 214                           "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
 215                           "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
 216                           task->hdr_len);
 217         return 0;
 218 }
 219
 220 static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
 221 {
 222         struct scsi_cmnd *sc = task->sc;
 223         struct iscsi_rlength_ahdr *rlen_ahdr;
 224         int rc;
 225
 226         rlen_ahdr = iscsi_next_hdr(task);
 227         rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
 228         if (rc)
 229                 return rc;
 230
 231         rlen_ahdr->ahslength =
 232                 cpu_to_be16(sizeof(rlen_ahdr->read_length) +
 233                                                   sizeof(rlen_ahdr->reserved));
 234         rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
 235         rlen_ahdr->reserved = 0;
 236         rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
 237
 238         ISCSI_DBG_SESSION(task->conn->session,
 239                           "bidi-in rlen_ahdr->read_length(%d) "
 240                           "rlen_ahdr->ahslength(%d)\n",
 241                           be32_to_cpu(rlen_ahdr->read_length),
 242                           be16_to_cpu(rlen_ahdr->ahslength));
 243         return 0;
 244 }
 245
 246 /**
 247  * iscsi_check_tmf_restrictions - check if a task is affected by TMF
 248  * @task: iscsi task
 249  * @opcode: opcode to check for
 250  *
 251  * During TMF a task has to be checked if it's affected.
 252  * All unrelated I/O can be passed through, but I/O to the
 253  * affected LUN should be restricted.
 254  * If 'fast_abort' is set we won't be sending any I/O to the
 255  * affected LUN.
 256  * Otherwise the target is waiting for all TTTs to be completed,
 257  * so we have to send all outstanding Data-Out PDUs to the target.
 258  */
 259 static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
 260 {
 261         struct iscsi_conn *conn = task->conn;
 262         struct iscsi_tm *tmf = &conn->tmhdr;
 263         u64 hdr_lun;
 264
 265         if (conn->tmf_state == TMF_INITIAL)
 266                 return 0;
 267
 268         if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
 269                 return 0;
 270
 271         switch (ISCSI_TM_FUNC_VALUE(tmf)) {
 272         case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
 273                 /*
 274                  * Allow PDUs for unrelated LUNs
 275                  */
 276                 hdr_lun = scsilun_to_int(&tmf->lun);
 277                 if (hdr_lun != task->sc->device->lun)
 278                         return 0;
 279                 /* fall through */
 280         case ISCSI_TM_FUNC_TARGET_WARM_RESET:
 281                 /*
 282                  * Fail all SCSI cmd PDUs
 283                  */
 284                 if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
 285                         iscsi_conn_printk(KERN_INFO, conn,
 286                                           "task [op %x itt "
 287                                           "0x%x/0x%x] "
 288                                           "rejected.\n",
 289                                           opcode, task->itt,
 290                                           task->hdr_itt);
 291                         return -EACCES;
 292                 }
 293                 /*
 294                  * And also all data-out PDUs in response to R2T
 295                  * if fast_abort is set.
 296                  */
 297                 if (conn->session->fast_abort) {
 298                         iscsi_conn_printk(KERN_INFO, conn,
 299                                           "task [op %x itt "
 300                                           "0x%x/0x%x] fast abort.\n",
 301                                           opcode, task->itt,
 302                                           task->hdr_itt);
 303                         return -EACCES;
 304                 }
 305                 break;
 306         case ISCSI_TM_FUNC_ABORT_TASK:
 307                 /*
 308                  * the caller has already checked if the task
 309                  * they want to abort was in the pending queue so if
 310                  * we are here the cmd pdu has gone out already, and
 311                  * we will only hit this for data-outs
 312                  */
 313                 if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
 314                     task->hdr_itt == tmf->rtt) {
 315                         ISCSI_DBG_SESSION(conn->session,
 316                                           "Preventing task %x/%x from sending "
 317                                           "data-out due to abort task in "
 318                                           "progress\n", task->itt,
 319                                           task->hdr_itt);
 320                         return -EACCES;
 321                 }
 322                 break;
 323         }
 324
 325         return 0;
 326 }
 327
 328 /**
 329  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 330  * @task: iscsi task
 331  *
 332  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 333  * fields like dlength or final based on how much data it sends
 334  */
 335 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 336 {
 337         struct iscsi_conn *conn = task->conn;
 338         struct iscsi_session *session = conn->session;
 339         struct scsi_cmnd *sc = task->sc;
 340         struct iscsi_scsi_req *hdr;
 341         unsigned hdrlength, cmd_len, transfer_length;
 342         itt_t itt;
 343         int rc;
 344
 345         rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
 346         if (rc)
 347                 return rc;
 348
 349         if (conn->session->tt->alloc_pdu) {
 350                 rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
 351                 if (rc)
 352                         return rc;
 353         }
 354         hdr = (struct iscsi_scsi_req *)task->hdr;
 355         itt = hdr->itt;
 356         memset(hdr, 0, sizeof(*hdr));
 357
 358         if (session->tt->parse_pdu_itt)
 359                 hdr->itt = task->hdr_itt = itt;
 360         else
 361                 hdr->itt = task->hdr_itt = build_itt(task->itt,
 362                                                      task->conn->session->age);
 363         task->hdr_len = 0;
 364         rc = iscsi_add_hdr(task, sizeof(*hdr));
 365         if (rc)
 366                 return rc;
 367         hdr->opcode = ISCSI_OP_SCSI_CMD;
 368         hdr->flags = ISCSI_ATTR_SIMPLE;
 369         int_to_scsilun(sc->device->lun, &hdr->lun);
 370         task->lun = hdr->lun;
 371         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 372         cmd_len = sc->cmd_len;
 373         if (cmd_len < ISCSI_CDB_SIZE)
 374                 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 375         else if (cmd_len > ISCSI_CDB_SIZE) {
 376                 rc = iscsi_prep_ecdb_ahs(task);
 377                 if (rc)
 378                         return rc;
 379                 cmd_len = ISCSI_CDB_SIZE;
 380         }
 381         memcpy(hdr->cdb, sc->cmnd, cmd_len);
 382
 383         task->imm_count = 0;
 384         if (scsi_bidi_cmnd(sc)) {
 385                 hdr->flags |= ISCSI_FLAG_CMD_READ;
 386                 rc = iscsi_prep_bidi_ahs(task);
 387                 if (rc)
 388                         return rc;
 389         }
 390
 391         if (scsi_get_prot_op(sc) != SCSI_PROT_NORMAL)
 392                 task->protected = true;
 393
 394         transfer_length = scsi_transfer_length(sc);
 395         hdr->data_length = cpu_to_be32(transfer_length);
 396         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 397                 struct iscsi_r2t_info *r2t = &task->unsol_r2t;
 398
 399                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 400                 /*
 401                  * Write counters:
 402                  *
 403                  *      imm_count       bytes to be sent right after
 404                  *                      SCSI PDU Header
 405                  *
 406                  *      unsol_count     bytes(as Data-Out) to be sent
 407                  *                      without R2T ack right after
 408                  *                      immediate data
 409                  *
 410                  *      r2t data_length bytes to be sent via R2T ack's
 411                  *
 412                  *      pad_count       bytes to be sent as zero-padding
 413                  */
 414                 memset(r2t, 0, sizeof(*r2t));
 415
 416                 if (session->imm_data_en) {
 417                         if (transfer_length >= session->first_burst)
 418                                 task->imm_count = min(session->first_burst,
 419                                                         conn->max_xmit_dlength);
 420                         else
 421                                 task->imm_count = min(transfer_length,
 422                                                       conn->max_xmit_dlength);
 423                         hton24(hdr->dlength, task->imm_count);
 424                 } else
 425                         zero_data(hdr->dlength);
 426
 427                 if (!session->initial_r2t_en) {
 428                         r2t->data_length = min(session->first_burst,
 429                                                transfer_length) -
 430                                                task->imm_count;
 431                         r2t->data_offset = task->imm_count;
 432                         r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 433                         r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
 434                 }
 435
 436                 if (!task->unsol_r2t.data_length)
 437                         /* No unsolicit Data-Out's */
 438                         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 439         } else {
 440                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 441                 zero_data(hdr->dlength);
 442
 443                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
 444                         hdr->flags |= ISCSI_FLAG_CMD_READ;
 445         }
 446
 447         /* calculate size of additional header segments (AHSs) */
 448         hdrlength = task->hdr_len - sizeof(*hdr);
 449
 450         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 451         hdrlength /= ISCSI_PAD_LEN;
 452
 453         WARN_ON(hdrlength >= 256);
 454         hdr->hlength = hdrlength & 0xFF;
 455         hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
 456
 457         if (session->tt->init_task && session->tt->init_task(task))
 458                 return -EIO;
 459
 460         task->state = ISCSI_TASK_RUNNING;
 461         session->cmdsn++;
 462
 463         conn->scsicmd_pdus_cnt++;
 464         ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
 465                           "itt 0x%x len %d bidi_len %d cmdsn %d win %d]\n",
 466                           scsi_bidi_cmnd(sc) ? "bidirectional" :
 467                           sc->sc_data_direction == DMA_TO_DEVICE ?
 468                           "write" : "read", conn->id, sc, sc->cmnd[0],
 469                           task->itt, transfer_length,
 470                           scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
 471                           session->cmdsn,
 472                           session->max_cmdsn - session->exp_cmdsn + 1);
 473         return 0;
 474 }
 475
 476 /**
 477  * iscsi_free_task - free a task
 478  * @task: iscsi cmd task
 479  *
 480  * Must be called with session back_lock.
 481  * This function returns the scsi command to scsi-ml or cleans
 482  * up mgmt tasks then returns the task to the pool.
 483  */
 484 static void iscsi_free_task(struct iscsi_task *task)
 485 {
 486         struct iscsi_conn *conn = task->conn;
 487         struct iscsi_session *session = conn->session;
 488         struct scsi_cmnd *sc = task->sc;
 489         int oldstate = task->state;
 490
 491         ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
 492                           task->itt, task->state, task->sc);
 493
 494         session->tt->cleanup_task(task);
 495         task->state = ISCSI_TASK_FREE;
 496         task->sc = NULL;
 497         /*
 498          * login task is preallocated so do not free
 499          */
 500         if (conn->login_task == task)
 501                 return;
 502
 503         kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
 504
 505         if (sc) {
 506                 /* SCSI eh reuses commands to verify us */
 507                 sc->SCp.ptr = NULL;
 508                 /*
 509                  * queue command may call this to free the task, so
 510                  * it will decide how to return sc to scsi-ml.
 511                  */
 512                 if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
 513                         sc->scsi_done(sc);
 514         }
 515 }
 516
 517 void __iscsi_get_task(struct iscsi_task *task)
 518 {
 519         atomic_inc(&task->refcount);
 520 }
 521 EXPORT_SYMBOL_GPL(__iscsi_get_task);
 522
 523 void __iscsi_put_task(struct iscsi_task *task)
 524 {
 525         if (atomic_dec_and_test(&task->refcount))
 526                 iscsi_free_task(task);
 527 }
 528 EXPORT_SYMBOL_GPL(__iscsi_put_task);
 529
 530 void iscsi_put_task(struct iscsi_task *task)
 531 {
 532         struct iscsi_session *session = task->conn->session;
 533
 534         /* regular RX path uses back_lock */
 535         spin_lock_bh(&session->back_lock);
 536         __iscsi_put_task(task);
 537         spin_unlock_bh(&session->back_lock);
 538 }
 539 EXPORT_SYMBOL_GPL(iscsi_put_task);
 540
 541 /**
 542  * iscsi_complete_task - finish a task
 543  * @task: iscsi cmd task
 544  * @state: state to complete task with
 545  *
 546  * Must be called with session back_lock.
 547  */
 548 static void iscsi_complete_task(struct iscsi_task *task, int state)
 549 {
 550         struct iscsi_conn *conn = task->conn;
 551
 552         ISCSI_DBG_SESSION(conn->session,
 553                           "complete task itt 0x%x state %d sc %p\n",
 554                           task->itt, task->state, task->sc);
 555         if (task->state == ISCSI_TASK_COMPLETED ||
 556             task->state == ISCSI_TASK_ABRT_TMF ||
 557             task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
 558             task->state == ISCSI_TASK_REQUEUE_SCSIQ)
 559                 return;
 560         WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
 561         task->state = state;
 562
 563         spin_lock_bh(&conn->taskqueuelock);
 564         if (!list_empty(&task->running)) {
 565                 pr_debug_once("%s while task on list", __func__);
 566                 list_del_init(&task->running);
 567         }
 568         spin_unlock_bh(&conn->taskqueuelock);
 569
 570         if (conn->task == task)
 571                 conn->task = NULL;
 572
 573         if (READ_ONCE(conn->ping_task) == task)
 574                 WRITE_ONCE(conn->ping_task, NULL);
 575
 576         /* release get from queueing */
 577         __iscsi_put_task(task);
 578 }
 579
 580 /**
 581  * iscsi_complete_scsi_task - finish scsi task normally
 582  * @task: iscsi task for scsi cmd
 583  * @exp_cmdsn: expected cmd sn in cpu format
 584  * @max_cmdsn: max cmd sn in cpu format
 585  *
 586  * This is used when drivers do not need or cannot perform
 587  * lower level pdu processing.
 588  *
 589  * Called with session back_lock
 590  */
 591 void iscsi_complete_scsi_task(struct iscsi_task *task,
 592                               uint32_t exp_cmdsn, uint32_t max_cmdsn)
 593 {
 594         struct iscsi_conn *conn = task->conn;
 595
 596         ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 597
 598         conn->last_recv = jiffies;
 599         __iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 600         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 601 }
 602 EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 603
 604
 605 /*
 606  * session back_lock must be held and if not called for a task that is
 607  * still pending or from the xmit thread, then xmit thread must
 608  * be suspended.
 609  */
 610 static void fail_scsi_task(struct iscsi_task *task, int err)
 611 {
 612         struct iscsi_conn *conn = task->conn;
 613         struct scsi_cmnd *sc;
 614         int state;
 615
 616         /*
 617          * if a command completes and we get a successful tmf response
 618          * we will hit this because the scsi eh abort code does not take
 619          * a ref to the task.
 620          */
 621         sc = task->sc;
 622         if (!sc)
 623                 return;
 624
 625         if (task->state == ISCSI_TASK_PENDING) {
 626                 /*
 627                  * cmd never made it to the xmit thread, so we should not count
 628                  * the cmd in the sequencing
 629                  */
 630                 conn->session->queued_cmdsn--;
 631                 /* it was never sent so just complete like normal */
 632                 state = ISCSI_TASK_COMPLETED;
 633         } else if (err == DID_TRANSPORT_DISRUPTED)
 634                 state = ISCSI_TASK_ABRT_SESS_RECOV;
 635         else
 636                 state = ISCSI_TASK_ABRT_TMF;
 637
 638         sc->result = err << 16;
 639         if (!scsi_bidi_cmnd(sc))
 640                 scsi_set_resid(sc, scsi_bufflen(sc));
 641         else {
 642                 scsi_out(sc)->resid = scsi_out(sc)->length;
 643                 scsi_in(sc)->resid = scsi_in(sc)->length;
 644         }
 645
 646         /* regular RX path uses back_lock */
 647         spin_lock_bh(&conn->session->back_lock);
 648         iscsi_complete_task(task, state);
 649         spin_unlock_bh(&conn->session->back_lock);
 650 }
 651
 652 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 653                                 struct iscsi_task *task)
 654 {
 655         struct iscsi_session *session = conn->session;
 656         struct iscsi_hdr *hdr = task->hdr;
 657         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 658         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 659
 660         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 661                 return -ENOTCONN;
 662
 663         if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
 664                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 665         /*
 666          * pre-format CmdSN for outgoing PDU.
 667          */
 668         nop->cmdsn = cpu_to_be32(session->cmdsn);
 669         if (hdr->itt != RESERVED_ITT) {
 670                 /*
 671                  * TODO: We always use immediate for normal session pdus.
 672                  * If we start to send tmfs or nops as non-immediate then
 673                  * we should start checking the cmdsn numbers for mgmt tasks.
 674                  *
 675                  * During discovery sessions iscsid sends TEXT as non immediate,
 676                  * but we always only send one PDU at a time.
 677                  */
 678                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 679                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 680                         session->queued_cmdsn++;
 681                         session->cmdsn++;
 682                 }
 683         }
 684
 685         if (session->tt->init_task && session->tt->init_task(task))
 686                 return -EIO;
 687
 688         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 689                 session->state = ISCSI_STATE_LOGGING_OUT;
 690
 691         task->state = ISCSI_TASK_RUNNING;
 692         ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 693                           "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 694                           hdr->itt, task->data_count);
 695         return 0;
 696 }
 697
 698 static struct iscsi_task *
 699 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 700                       char *data, uint32_t data_size)
 701 {
 702         struct iscsi_session *session = conn->session;
 703         struct iscsi_host *ihost = shost_priv(session->host);
 704         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 705         struct iscsi_task *task;
 706         itt_t itt;
 707
 708         if (session->state == ISCSI_STATE_TERMINATE)
 709                 return NULL;
 710
 711         if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 712                 /*
 713                  * Login and Text are sent serially, in
 714                  * request-followed-by-response sequence.
 715                  * Same task can be used. Same ITT must be used.
 716                  * Note that login_task is preallocated at conn_create().
 717                  */
 718                 if (conn->login_task->state != ISCSI_TASK_FREE) {
 719                         iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 720                                           "progress. Cannot start new task.\n");
 721                         return NULL;
 722                 }
 723
 724                 if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
 725                         iscsi_conn_printk(KERN_ERR, conn, "Invalid buffer len of %u for login task. Max len is %u\n", data_size, ISCSI_DEF_MAX_RECV_SEG_LEN);
 726                         return NULL;
 727                 }
 728
 729                 task = conn->login_task;
 730         } else {
 731                 if (session->state != ISCSI_STATE_LOGGED_IN)
 732                         return NULL;
 733
 734                 if (data_size != 0) {
 735                         iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
 736                         return NULL;
 737                 }
 738
 739                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 740                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 741
 742                 if (!kfifo_out(&session->cmdpool.queue,
 743                                  (void*)&task, sizeof(void*)))
 744                         return NULL;
 745         }
 746         /*
 747          * released in complete pdu for task we expect a response for, and
 748          * released by the lld when it has transmitted the task for
 749          * pdus we do not expect a response for.
 750          */
 751         atomic_set(&task->refcount, 1);
 752         task->conn = conn;
 753         task->sc = NULL;
 754         INIT_LIST_HEAD(&task->running);
 755         task->state = ISCSI_TASK_PENDING;
 756
 757         if (data_size) {
 758                 memcpy(task->data, data, data_size);
 759                 task->data_count = data_size;
 760         } else
 761                 task->data_count = 0;
 762
 763         if (conn->session->tt->alloc_pdu) {
 764                 if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 765                         iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 766                                          "pdu for mgmt task.\n");
 767                         goto free_task;
 768                 }
 769         }
 770
 771         itt = task->hdr->itt;
 772         task->hdr_len = sizeof(struct iscsi_hdr);
 773         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 774
 775         if (hdr->itt != RESERVED_ITT) {
 776                 if (session->tt->parse_pdu_itt)
 777                         task->hdr->itt = itt;
 778                 else
 779                         task->hdr->itt = build_itt(task->itt,
 780                                                    task->conn->session->age);
 781         }
 782
 783         if (unlikely(READ_ONCE(conn->ping_task) == INVALID_SCSI_TASK))
 784                 WRITE_ONCE(conn->ping_task, task);
 785
 786         if (!ihost->workq) {
 787                 if (iscsi_prep_mgmt_task(conn, task))
 788                         goto free_task;
 789
 790                 if (session->tt->xmit_task(task))
 791                         goto free_task;
 792         } else {
 793                 spin_lock_bh(&conn->taskqueuelock);
 794                 list_add_tail(&task->running, &conn->mgmtqueue);
 795                 spin_unlock_bh(&conn->taskqueuelock);
 796                 iscsi_conn_queue_work(conn);
 797         }
 798
 799         return task;
 800
 801 free_task:
 802         /* regular RX path uses back_lock */
 803         spin_lock(&session->back_lock);
 804         __iscsi_put_task(task);
 805         spin_unlock(&session->back_lock);
 806         return NULL;
 807 }
 808
 809 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 810                         char *data, uint32_t data_size)
 811 {
 812         struct iscsi_conn *conn = cls_conn->dd_data;
 813         struct iscsi_session *session = conn->session;
 814         int err = 0;
 815
 816         spin_lock_bh(&session->frwd_lock);
 817         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 818                 err = -EPERM;
 819         spin_unlock_bh(&session->frwd_lock);
 820         return err;
 821 }
 822 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 823
 824 /**
 825  * iscsi_cmd_rsp - SCSI Command Response processing
 826  * @conn: iscsi connection
 827  * @hdr: iscsi header
 828  * @task: scsi command task
 829  * @data: cmd data buffer
 830  * @datalen: len of buffer
 831  *
 832  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 833  * then completes the command and task.
 834  **/
 835 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 836                                struct iscsi_task *task, char *data,
 837                                int datalen)
 838 {
 839         struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
 840         struct iscsi_session *session = conn->session;
 841         struct scsi_cmnd *sc = task->sc;
 842
 843         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 844         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 845
 846         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 847
 848         if (task->protected) {
 849                 sector_t sector;
 850                 u8 ascq;
 851
 852                 /**
 853                  * Transports that didn't implement check_protection
 854                  * callback but still published T10-PI support to scsi-mid
 855                  * deserve this BUG_ON.
 856                  **/
 857                 BUG_ON(!session->tt->check_protection);
 858
 859                 ascq = session->tt->check_protection(task, &sector);
 860                 if (ascq) {
 861                         sc->result = DRIVER_SENSE << 24 |
 862                                      SAM_STAT_CHECK_CONDITION;
 863                         scsi_build_sense_buffer(1, sc->sense_buffer,
 864                                                 ILLEGAL_REQUEST, 0x10, ascq);
 865                         scsi_set_sense_information(sc->sense_buffer,
 866                                                    SCSI_SENSE_BUFFERSIZE,
 867                                                    sector);
 868                         goto out;
 869                 }
 870         }
 871
 872         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 873                 sc->result = DID_ERROR << 16;
 874                 goto out;
 875         }
 876
 877         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 878                 uint16_t senselen;
 879
 880                 if (datalen < 2) {
 881 invalid_datalen:
 882                         iscsi_conn_printk(KERN_ERR,  conn,
 883                                          "Got CHECK_CONDITION but invalid data "
 884                                          "buffer size of %d\n", datalen);
 885                         sc->result = DID_BAD_TARGET << 16;
 886                         goto out;
 887                 }
 888
 889                 senselen = get_unaligned_be16(data);
 890                 if (datalen < senselen)
 891                         goto invalid_datalen;
 892
 893                 memcpy(sc->sense_buffer, data + 2,
 894                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 895                 ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 896                                   min_t(uint16_t, senselen,
 897                                   SCSI_SENSE_BUFFERSIZE));
 898         }
 899
 900         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 901                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 902                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
 903
 904                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 905                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 906                                  res_count <= scsi_in(sc)->length))
 907                         scsi_in(sc)->resid = res_count;
 908                 else
 909                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 910         }
 911
 912         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 913                            ISCSI_FLAG_CMD_OVERFLOW)) {
 914                 int res_count = be32_to_cpu(rhdr->residual_count);
 915
 916                 if (res_count > 0 &&
 917                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 918                      res_count <= scsi_bufflen(sc)))
 919                         /* write side for bidi or uni-io set_resid */
 920                         scsi_set_resid(sc, res_count);
 921                 else
 922                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 923         }
 924 out:
 925         ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 926                           sc, sc->result, task->itt);
 927         conn->scsirsp_pdus_cnt++;
 928         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 929 }
 930
 931 /**
 932  * iscsi_data_in_rsp - SCSI Data-In Response processing
 933  * @conn: iscsi connection
 934  * @hdr:  iscsi pdu
 935  * @task: scsi command task
 936  **/
 937 static void
 938 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 939                   struct iscsi_task *task)
 940 {
 941         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 942         struct scsi_cmnd *sc = task->sc;
 943
 944         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 945                 return;
 946
 947         iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 948         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 949         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 950         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 951                            ISCSI_FLAG_DATA_OVERFLOW)) {
 952                 int res_count = be32_to_cpu(rhdr->residual_count);
 953
 954                 if (res_count > 0 &&
 955                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 956                      res_count <= scsi_in(sc)->length))
 957                         scsi_in(sc)->resid = res_count;
 958                 else
 959                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 960         }
 961
 962         ISCSI_DBG_SESSION(conn->session, "data in with status done "
 963                           "[sc %p res %d itt 0x%x]\n",
 964                           sc, sc->result, task->itt);
 965         conn->scsirsp_pdus_cnt++;
 966         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 967 }
 968
 969 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 970 {
 971         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 972
 973         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 974         conn->tmfrsp_pdus_cnt++;
 975
 976         if (conn->tmf_state != TMF_QUEUED)
 977                 return;
 978
 979         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 980                 conn->tmf_state = TMF_SUCCESS;
 981         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 982                 conn->tmf_state = TMF_NOT_FOUND;
 983         else
 984                 conn->tmf_state = TMF_FAILED;
 985         wake_up(&conn->ehwait);
 986 }
 987
 988 static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 989 {
 990         struct iscsi_nopout hdr;
 991         struct iscsi_task *task;
 992
 993         if (!rhdr) {
 994                 if (READ_ONCE(conn->ping_task))
 995                         return -EINVAL;
 996                 WRITE_ONCE(conn->ping_task, INVALID_SCSI_TASK);
 997         }
 998
 999         memset(&hdr, 0, sizeof(struct iscsi_nopout));
1000         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
1001         hdr.flags = ISCSI_FLAG_CMD_FINAL;
1002
1003         if (rhdr) {
1004                 hdr.lun = rhdr->lun;
1005                 hdr.ttt = rhdr->ttt;
1006                 hdr.itt = RESERVED_ITT;
1007         } else
1008                 hdr.ttt = RESERVED_ITT;
1009
1010         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
1011         if (!task) {
1012                 if (!rhdr)
1013                         WRITE_ONCE(conn->ping_task, NULL);
1014                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
1015                 return -EIO;
1016         } else if (!rhdr) {
1017                 /* only track our nops */
1018                 conn->last_ping = jiffies;
1019         }
1020
1021         return 0;
1022 }
1023
1024 static int iscsi_nop_out_rsp(struct iscsi_task *task,
1025                              struct iscsi_nopin *nop, char *data, int datalen)
1026 {
1027         struct iscsi_conn *conn = task->conn;
1028         int rc = 0;
1029
1030         if (READ_ONCE(conn->ping_task) != task) {
1031                 /*
1032                  * If this is not in response to one of our
1033                  * nops then it must be from userspace.
1034                  */
1035                 if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
1036                                    data, datalen))
1037                         rc = ISCSI_ERR_CONN_FAILED;
1038         } else
1039                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1040         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1041         return rc;
1042 }
1043
1044 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1045                                char *data, int datalen)
1046 {
1047         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1048         struct iscsi_hdr rejected_pdu;
1049         int opcode, rc = 0;
1050
1051         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1052
1053         if (ntoh24(reject->dlength) > datalen ||
1054             ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1055                 iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1056                                   "pdu. Invalid data length (pdu dlength "
1057                                   "%u, datalen %d\n", ntoh24(reject->dlength),
1058                                   datalen);
1059                 return ISCSI_ERR_PROTO;
1060         }
1061         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1062         opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1063
1064         switch (reject->reason) {
1065         case ISCSI_REASON_DATA_DIGEST_ERROR:
1066                 iscsi_conn_printk(KERN_ERR, conn,
1067                                   "pdu (op 0x%x itt 0x%x) rejected "
1068                                   "due to DataDigest error.\n",
1069                                   opcode, rejected_pdu.itt);
1070                 break;
1071         case ISCSI_REASON_IMM_CMD_REJECT:
1072                 iscsi_conn_printk(KERN_ERR, conn,
1073                                   "pdu (op 0x%x itt 0x%x) rejected. Too many "
1074                                   "immediate commands.\n",
1075                                   opcode, rejected_pdu.itt);
1076                 /*
1077                  * We only send one TMF at a time so if the target could not
1078                  * handle it, then it should get fixed (RFC mandates that
1079                  * a target can handle one immediate TMF per conn).
1080                  *
1081                  * For nops-outs, we could have sent more than one if
1082                  * the target is sending us lots of nop-ins
1083                  */
1084                 if (opcode != ISCSI_OP_NOOP_OUT)
1085                         return 0;
1086
1087                  if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1088                         /*
1089                          * nop-out in response to target's nop-out rejected.
1090                          * Just resend.
1091                          */
1092                         /* In RX path we are under back lock */
1093                         spin_unlock(&conn->session->back_lock);
1094                         spin_lock(&conn->session->frwd_lock);
1095                         iscsi_send_nopout(conn,
1096                                           (struct iscsi_nopin*)&rejected_pdu);
1097                         spin_unlock(&conn->session->frwd_lock);
1098                         spin_lock(&conn->session->back_lock);
1099                 } else {
1100                         struct iscsi_task *task;
1101                         /*
1102                          * Our nop as ping got dropped. We know the target
1103                          * and transport are ok so just clean up
1104                          */
1105                         task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1106                         if (!task) {
1107                                 iscsi_conn_printk(KERN_ERR, conn,
1108                                                  "Invalid pdu reject. Could "
1109                                                  "not lookup rejected task.\n");
1110                                 rc = ISCSI_ERR_BAD_ITT;
1111                         } else
1112                                 rc = iscsi_nop_out_rsp(task,
1113                                         (struct iscsi_nopin*)&rejected_pdu,
1114                                         NULL, 0);
1115                 }
1116                 break;
1117         default:
1118                 iscsi_conn_printk(KERN_ERR, conn,
1119                                   "pdu (op 0x%x itt 0x%x) rejected. Reason "
1120                                   "code 0x%x\n", rejected_pdu.opcode,
1121                                   rejected_pdu.itt, reject->reason);
1122                 break;
1123         }
1124         return rc;
1125 }
1126
1127 /**
1128  * iscsi_itt_to_task - look up task by itt
1129  * @conn: iscsi connection
1130  * @itt: itt
1131  *
1132  * This should be used for mgmt tasks like login and nops, or if
1133  * the LDD's itt space does not include the session age.
1134  *
1135  * The session back_lock must be held.
1136  */
1137 struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1138 {
1139         struct iscsi_session *session = conn->session;
1140         int i;
1141
1142         if (itt == RESERVED_ITT)
1143                 return NULL;
1144
1145         if (session->tt->parse_pdu_itt)
1146                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1147         else
1148                 i = get_itt(itt);
1149         if (i >= session->cmds_max)
1150                 return NULL;
1151
1152         return session->cmds[i];
1153 }
1154 EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1155
1156 /**
1157  * __iscsi_complete_pdu - complete pdu
1158  * @conn: iscsi conn
1159  * @hdr: iscsi header
1160  * @data: data buffer
1161  * @datalen: len of data buffer
1162  *
1163  * Completes pdu processing by freeing any resources allocated at
1164  * queuecommand or send generic. session back_lock must be held and verify
1165  * itt must have been called.
1166  */
1167 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1168                          char *data, int datalen)
1169 {
1170         struct iscsi_session *session = conn->session;
1171         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1172         struct iscsi_task *task;
1173         uint32_t itt;
1174
1175         conn->last_recv = jiffies;
1176         rc = iscsi_verify_itt(conn, hdr->itt);
1177         if (rc)
1178                 return rc;
1179
1180         if (hdr->itt != RESERVED_ITT)
1181                 itt = get_itt(hdr->itt);
1182         else
1183                 itt = ~0U;
1184
1185         ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1186                           opcode, conn->id, itt, datalen);
1187
1188         if (itt == ~0U) {
1189                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1190
1191                 switch(opcode) {
1192                 case ISCSI_OP_NOOP_IN:
1193                         if (datalen) {
1194                                 rc = ISCSI_ERR_PROTO;
1195                                 break;
1196                         }
1197
1198                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1199                                 break;
1200
1201                         /* In RX path we are under back lock */
1202                         spin_unlock(&session->back_lock);
1203                         spin_lock(&session->frwd_lock);
1204                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1205                         spin_unlock(&session->frwd_lock);
1206                         spin_lock(&session->back_lock);
1207                         break;
1208                 case ISCSI_OP_REJECT:
1209                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
1210                         break;
1211                 case ISCSI_OP_ASYNC_EVENT:
1212                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1213                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1214                                 rc = ISCSI_ERR_CONN_FAILED;
1215                         break;
1216                 default:
1217                         rc = ISCSI_ERR_BAD_OPCODE;
1218                         break;
1219                 }
1220                 goto out;
1221         }
1222
1223         switch(opcode) {
1224         case ISCSI_OP_SCSI_CMD_RSP:
1225         case ISCSI_OP_SCSI_DATA_IN:
1226                 task = iscsi_itt_to_ctask(conn, hdr->itt);
1227                 if (!task)
1228                         return ISCSI_ERR_BAD_ITT;
1229                 task->last_xfer = jiffies;
1230                 break;
1231         case ISCSI_OP_R2T:
1232                 /*
1233                  * LLD handles R2Ts if they need to.
1234                  */
1235                 return 0;
1236         case ISCSI_OP_LOGOUT_RSP:
1237         case ISCSI_OP_LOGIN_RSP:
1238         case ISCSI_OP_TEXT_RSP:
1239         case ISCSI_OP_SCSI_TMFUNC_RSP:
1240         case ISCSI_OP_NOOP_IN:
1241                 task = iscsi_itt_to_task(conn, hdr->itt);
1242                 if (!task)
1243                         return ISCSI_ERR_BAD_ITT;
1244                 break;
1245         default:
1246                 return ISCSI_ERR_BAD_OPCODE;
1247         }
1248
1249         switch(opcode) {
1250         case ISCSI_OP_SCSI_CMD_RSP:
1251                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1252                 break;
1253         case ISCSI_OP_SCSI_DATA_IN:
1254                 iscsi_data_in_rsp(conn, hdr, task);
1255                 break;
1256         case ISCSI_OP_LOGOUT_RSP:
1257                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1258                 if (datalen) {
1259                         rc = ISCSI_ERR_PROTO;
1260                         break;
1261                 }
1262                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1263                 goto recv_pdu;
1264         case ISCSI_OP_LOGIN_RSP:
1265         case ISCSI_OP_TEXT_RSP:
1266                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1267                 /*
1268                  * login related PDU's exp_statsn is handled in
1269                  * userspace
1270                  */
1271                 goto recv_pdu;
1272         case ISCSI_OP_SCSI_TMFUNC_RSP:
1273                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1274                 if (datalen) {
1275                         rc = ISCSI_ERR_PROTO;
1276                         break;
1277                 }
1278
1279                 iscsi_tmf_rsp(conn, hdr);
1280                 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1281                 break;
1282         case ISCSI_OP_NOOP_IN:
1283                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1284                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1285                         rc = ISCSI_ERR_PROTO;
1286                         break;
1287                 }
1288                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1289
1290                 rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1291                                        data, datalen);
1292                 break;
1293         default:
1294                 rc = ISCSI_ERR_BAD_OPCODE;
1295                 break;
1296         }
1297
1298 out:
1299         return rc;
1300 recv_pdu:
1301         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1302                 rc = ISCSI_ERR_CONN_FAILED;
1303         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1304         return rc;
1305 }
1306 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1307
1308 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1309                        char *data, int datalen)
1310 {
1311         int rc;
1312
1313         spin_lock(&conn->session->back_lock);
1314         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1315         spin_unlock(&conn->session->back_lock);
1316         return rc;
1317 }
1318 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1319
1320 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1321 {
1322         struct iscsi_session *session = conn->session;
1323         int age = 0, i = 0;
1324
1325         if (itt == RESERVED_ITT)
1326                 return 0;
1327
1328         if (session->tt->parse_pdu_itt)
1329                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
1330         else {
1331                 i = get_itt(itt);
1332                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1333         }
1334
1335         if (age != session->age) {
1336                 iscsi_conn_printk(KERN_ERR, conn,
1337                                   "received itt %x expected session age (%x)\n",
1338                                   (__force u32)itt, session->age);
1339                 return ISCSI_ERR_BAD_ITT;
1340         }
1341
1342         if (i >= session->cmds_max) {
1343                 iscsi_conn_printk(KERN_ERR, conn,
1344                                   "received invalid itt index %u (max cmds "
1345                                    "%u.\n", i, session->cmds_max);
1346                 return ISCSI_ERR_BAD_ITT;
1347         }
1348         return 0;
1349 }
1350 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1351
1352 /**
1353  * iscsi_itt_to_ctask - look up ctask by itt
1354  * @conn: iscsi connection
1355  * @itt: itt
1356  *
1357  * This should be used for cmd tasks.
1358  *
1359  * The session back_lock must be held.
1360  */
1361 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1362 {
1363         struct iscsi_task *task;
1364
1365         if (iscsi_verify_itt(conn, itt))
1366                 return NULL;
1367
1368         task = iscsi_itt_to_task(conn, itt);
1369         if (!task || !task->sc)
1370                 return NULL;
1371
1372         if (task->sc->SCp.phase != conn->session->age) {
1373                 iscsi_session_printk(KERN_ERR, conn->session,
1374                                   "task's session age %d, expected %d\n",
1375                                   task->sc->SCp.phase, conn->session->age);
1376                 return NULL;
1377         }
1378
1379         return task;
1380 }
1381 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1382
1383 void iscsi_session_failure(struct iscsi_session *session,
1384                            enum iscsi_err err)
1385 {
1386         struct iscsi_conn *conn;
1387
1388         spin_lock_bh(&session->frwd_lock);
1389         conn = session->leadconn;
1390         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1391                 spin_unlock_bh(&session->frwd_lock);
1392                 return;
1393         }
1394
1395         iscsi_get_conn(conn->cls_conn);
1396         spin_unlock_bh(&session->frwd_lock);
1397         /*
1398          * if the host is being removed bypass the connection
1399          * recovery initialization because we are going to kill
1400          * the session.
1401          */
1402         if (err == ISCSI_ERR_INVALID_HOST)
1403                 iscsi_conn_error_event(conn->cls_conn, err);
1404         else
1405                 iscsi_conn_failure(conn, err);
1406         iscsi_put_conn(conn->cls_conn);
1407 }
1408 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1409
1410 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1411 {
1412         struct iscsi_session *session = conn->session;
1413
1414         spin_lock_bh(&session->frwd_lock);
1415         if (session->state == ISCSI_STATE_FAILED) {
1416                 spin_unlock_bh(&session->frwd_lock);
1417                 return;
1418         }
1419
1420         if (conn->stop_stage == 0)
1421                 session->state = ISCSI_STATE_FAILED;
1422         spin_unlock_bh(&session->frwd_lock);
1423
1424         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1425         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1426         iscsi_conn_error_event(conn->cls_conn, err);
1427 }
1428 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1429
1430 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1431 {
1432         struct iscsi_session *session = conn->session;
1433
1434         /*
1435          * Check for iSCSI window and take care of CmdSN wrap-around
1436          */
1437         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1438                 ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1439                                   "%u MaxCmdSN %u CmdSN %u/%u\n",
1440                                   session->exp_cmdsn, session->max_cmdsn,
1441                                   session->cmdsn, session->queued_cmdsn);
1442                 return -ENOSPC;
1443         }
1444         return 0;
1445 }
1446
1447 static int iscsi_xmit_task(struct iscsi_conn *conn)
1448 {
1449         struct iscsi_task *task = conn->task;
1450         int rc;
1451
1452         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
1453                 return -ENODATA;
1454
1455         spin_lock_bh(&conn->session->back_lock);
1456         if (conn->task == NULL) {
1457                 spin_unlock_bh(&conn->session->back_lock);
1458                 return -ENODATA;
1459         }
1460         __iscsi_get_task(task);
1461         spin_unlock_bh(&conn->session->back_lock);
1462         spin_unlock_bh(&conn->session->frwd_lock);
1463         rc = conn->session->tt->xmit_task(task);
1464         spin_lock_bh(&conn->session->frwd_lock);
1465         if (!rc) {
1466                 /* done with this task */
1467                 task->last_xfer = jiffies;
1468                 conn->task = NULL;
1469         }
1470         /* regular RX path uses back_lock */
1471         spin_lock(&conn->session->back_lock);
1472         __iscsi_put_task(task);
1473         spin_unlock(&conn->session->back_lock);
1474         return rc;
1475 }
1476
1477 /**
1478  * iscsi_requeue_task - requeue task to run from session workqueue
1479  * @task: task to requeue
1480  *
1481  * LLDs that need to run a task from the session workqueue should call
1482  * this. The session frwd_lock must be held. This should only be called
1483  * by software drivers.
1484  */
1485 void iscsi_requeue_task(struct iscsi_task *task)
1486 {
1487         struct iscsi_conn *conn = task->conn;
1488
1489         /*
1490          * this may be on the requeue list already if the xmit_task callout
1491          * is handling the r2ts while we are adding new ones
1492          */
1493         spin_lock_bh(&conn->taskqueuelock);
1494         if (list_empty(&task->running))
1495                 list_add_tail(&task->running, &conn->requeue);
1496         spin_unlock_bh(&conn->taskqueuelock);
1497         iscsi_conn_queue_work(conn);
1498 }
1499 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1500
1501 /**
1502  * iscsi_data_xmit - xmit any command into the scheduled connection
1503  * @conn: iscsi connection
1504  *
1505  * Notes:
1506  *      The function can return -EAGAIN in which case the caller must
1507  *      re-schedule it again later or recover. '0' return code means
1508  *      successful xmit.
1509  **/
1510 static int iscsi_data_xmit(struct iscsi_conn *conn)
1511 {
1512         struct iscsi_task *task;
1513         int rc = 0;
1514
1515         spin_lock_bh(&conn->session->frwd_lock);
1516         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1517                 ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1518                 spin_unlock_bh(&conn->session->frwd_lock);
1519                 return -ENODATA;
1520         }
1521
1522         if (conn->task) {
1523                 rc = iscsi_xmit_task(conn);
1524                 if (rc)
1525                         goto done;
1526         }
1527
1528         /*
1529          * process mgmt pdus like nops before commands since we should
1530          * only have one nop-out as a ping from us and targets should not
1531          * overflow us with nop-ins
1532          */
1533         spin_lock_bh(&conn->taskqueuelock);
1534 check_mgmt:
1535         while (!list_empty(&conn->mgmtqueue)) {
1536                 conn->task = list_entry(conn->mgmtqueue.next,
1537                                          struct iscsi_task, running);
1538                 list_del_init(&conn->task->running);
1539                 spin_unlock_bh(&conn->taskqueuelock);
1540                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1541                         /* regular RX path uses back_lock */
1542                         spin_lock_bh(&conn->session->back_lock);
1543                         __iscsi_put_task(conn->task);
1544                         spin_unlock_bh(&conn->session->back_lock);
1545                         conn->task = NULL;
1546                         spin_lock_bh(&conn->taskqueuelock);
1547                         continue;
1548                 }
1549                 rc = iscsi_xmit_task(conn);
1550                 if (rc)
1551                         goto done;
1552                 spin_lock_bh(&conn->taskqueuelock);
1553         }
1554
1555         /* process pending command queue */
1556         while (!list_empty(&conn->cmdqueue)) {
1557                 conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1558                                         running);
1559                 list_del_init(&conn->task->running);
1560                 spin_unlock_bh(&conn->taskqueuelock);
1561                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1562                         fail_scsi_task(conn->task, DID_IMM_RETRY);
1563                         spin_lock_bh(&conn->taskqueuelock);
1564                         continue;
1565                 }
1566                 rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1567                 if (rc) {
1568                         if (rc == -ENOMEM || rc == -EACCES)
1569                                 fail_scsi_task(conn->task, DID_IMM_RETRY);
1570                         else
1571                                 fail_scsi_task(conn->task, DID_ABORT);
1572                         spin_lock_bh(&conn->taskqueuelock);
1573                         continue;
1574                 }
1575                 rc = iscsi_xmit_task(conn);
1576                 if (rc)
1577                         goto done;
1578                 /*
1579                  * we could continuously get new task requests so
1580                  * we need to check the mgmt queue for nops that need to
1581                  * be sent to aviod starvation
1582                  */
1583                 spin_lock_bh(&conn->taskqueuelock);
1584                 if (!list_empty(&conn->mgmtqueue))
1585                         goto check_mgmt;
1586         }
1587
1588         while (!list_empty(&conn->requeue)) {
1589                 /*
1590                  * we always do fastlogout - conn stop code will clean up.
1591                  */
1592                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1593                         break;
1594
1595                 task = list_entry(conn->requeue.next, struct iscsi_task,
1596                                   running);
1597                 if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1598                         break;
1599
1600                 conn->task = task;
1601                 list_del_init(&conn->task->running);
1602                 conn->task->state = ISCSI_TASK_RUNNING;
1603                 spin_unlock_bh(&conn->taskqueuelock);
1604                 rc = iscsi_xmit_task(conn);
1605                 if (rc)
1606                         goto done;
1607                 spin_lock_bh(&conn->taskqueuelock);
1608                 if (!list_empty(&conn->mgmtqueue))
1609                         goto check_mgmt;
1610         }
1611         spin_unlock_bh(&conn->taskqueuelock);
1612         spin_unlock_bh(&conn->session->frwd_lock);
1613         return -ENODATA;
1614
1615 done:
1616         spin_unlock_bh(&conn->session->frwd_lock);
1617         return rc;
1618 }
1619
1620 static void iscsi_xmitworker(struct work_struct *work)
1621 {
1622         struct iscsi_conn *conn =
1623                 container_of(work, struct iscsi_conn, xmitwork);
1624         int rc;
1625         /*
1626          * serialize Xmit worker on a per-connection basis.
1627          */
1628         do {
1629                 rc = iscsi_data_xmit(conn);
1630         } while (rc >= 0 || rc == -EAGAIN);
1631 }
1632
1633 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1634                                                   struct scsi_cmnd *sc)
1635 {
1636         struct iscsi_task *task;
1637
1638         if (!kfifo_out(&conn->session->cmdpool.queue,
1639                          (void *) &task, sizeof(void *)))
1640                 return NULL;
1641
1642         sc->SCp.phase = conn->session->age;
1643         sc->SCp.ptr = (char *) task;
1644
1645         atomic_set(&task->refcount, 1);
1646         task->state = ISCSI_TASK_PENDING;
1647         task->conn = conn;
1648         task->sc = sc;
1649         task->have_checked_conn = false;
1650         task->last_timeout = jiffies;
1651         task->last_xfer = jiffies;
1652         task->protected = false;
1653         INIT_LIST_HEAD(&task->running);
1654         return task;
1655 }
1656
1657 enum {
1658         FAILURE_BAD_HOST = 1,
1659         FAILURE_SESSION_FAILED,
1660         FAILURE_SESSION_FREED,
1661         FAILURE_WINDOW_CLOSED,
1662         FAILURE_OOM,
1663         FAILURE_SESSION_TERMINATE,
1664         FAILURE_SESSION_IN_RECOVERY,
1665         FAILURE_SESSION_RECOVERY_TIMEOUT,
1666         FAILURE_SESSION_LOGGING_OUT,
1667         FAILURE_SESSION_NOT_READY,
1668 };
1669
1670 int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1671 {
1672         struct iscsi_cls_session *cls_session;
1673         struct iscsi_host *ihost;
1674         int reason = 0;
1675         struct iscsi_session *session;
1676         struct iscsi_conn *conn;
1677         struct iscsi_task *task = NULL;
1678
1679         sc->result = 0;
1680         sc->SCp.ptr = NULL;
1681
1682         ihost = shost_priv(host);
1683
1684         cls_session = starget_to_session(scsi_target(sc->device));
1685         session = cls_session->dd_data;
1686         spin_lock_bh(&session->frwd_lock);
1687
1688         reason = iscsi_session_chkready(cls_session);
1689         if (reason) {
1690                 sc->result = reason;
1691                 goto fault;
1692         }
1693
1694         if (session->state != ISCSI_STATE_LOGGED_IN) {
1695                 /*
1696                  * to handle the race between when we set the recovery state
1697                  * and block the session we requeue here (commands could
1698                  * be entering our queuecommand while a block is starting
1699                  * up because the block code is not locked)
1700                  */
1701                 switch (session->state) {
1702                 case ISCSI_STATE_FAILED:
1703                         /*
1704                          * cmds should fail during shutdown, if the session
1705                          * state is bad, allowing completion to happen
1706                          */
1707                         if (unlikely(system_state != SYSTEM_RUNNING)) {
1708                                 reason = FAILURE_SESSION_FAILED;
1709                                 sc->result = DID_NO_CONNECT << 16;
1710                                 break;
1711                         }
1712                 case ISCSI_STATE_IN_RECOVERY:
1713                         reason = FAILURE_SESSION_IN_RECOVERY;
1714                         sc->result = DID_IMM_RETRY << 16;
1715                         break;
1716                 case ISCSI_STATE_LOGGING_OUT:
1717                         reason = FAILURE_SESSION_LOGGING_OUT;
1718                         sc->result = DID_IMM_RETRY << 16;
1719                         break;
1720                 case ISCSI_STATE_RECOVERY_FAILED:
1721                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1722                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1723                         break;
1724                 case ISCSI_STATE_TERMINATE:
1725                         reason = FAILURE_SESSION_TERMINATE;
1726                         sc->result = DID_NO_CONNECT << 16;
1727                         break;
1728                 default:
1729                         reason = FAILURE_SESSION_FREED;
1730                         sc->result = DID_NO_CONNECT << 16;
1731                 }
1732                 goto fault;
1733         }
1734
1735         conn = session->leadconn;
1736         if (!conn) {
1737                 reason = FAILURE_SESSION_FREED;
1738                 sc->result = DID_NO_CONNECT << 16;
1739                 goto fault;
1740         }
1741
1742         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1743                 reason = FAILURE_SESSION_IN_RECOVERY;
1744                 sc->result = DID_REQUEUE << 16;
1745                 goto fault;
1746         }
1747
1748         if (iscsi_check_cmdsn_window_closed(conn)) {
1749                 reason = FAILURE_WINDOW_CLOSED;
1750                 goto reject;
1751         }
1752
1753         task = iscsi_alloc_task(conn, sc);
1754         if (!task) {
1755                 reason = FAILURE_OOM;
1756                 goto reject;
1757         }
1758
1759         if (!ihost->workq) {
1760                 reason = iscsi_prep_scsi_cmd_pdu(task);
1761                 if (reason) {
1762                         if (reason == -ENOMEM ||  reason == -EACCES) {
1763                                 reason = FAILURE_OOM;
1764                                 goto prepd_reject;
1765                         } else {
1766                                 sc->result = DID_ABORT << 16;
1767                                 goto prepd_fault;
1768                         }
1769                 }
1770                 if (session->tt->xmit_task(task)) {
1771                         session->cmdsn--;
1772                         reason = FAILURE_SESSION_NOT_READY;
1773                         goto prepd_reject;
1774                 }
1775         } else {
1776                 spin_lock_bh(&conn->taskqueuelock);
1777                 list_add_tail(&task->running, &conn->cmdqueue);
1778                 spin_unlock_bh(&conn->taskqueuelock);
1779                 iscsi_conn_queue_work(conn);
1780         }
1781
1782         session->queued_cmdsn++;
1783         spin_unlock_bh(&session->frwd_lock);
1784         return 0;
1785
1786 prepd_reject:
1787         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1788 reject:
1789         spin_unlock_bh(&session->frwd_lock);
1790         ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1791                           sc->cmnd[0], reason);
1792         return SCSI_MLQUEUE_TARGET_BUSY;
1793
1794 prepd_fault:
1795         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1796 fault:
1797         spin_unlock_bh(&session->frwd_lock);
1798         ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1799                           sc->cmnd[0], reason);
1800         if (!scsi_bidi_cmnd(sc))
1801                 scsi_set_resid(sc, scsi_bufflen(sc));
1802         else {
1803                 scsi_out(sc)->resid = scsi_out(sc)->length;
1804                 scsi_in(sc)->resid = scsi_in(sc)->length;
1805         }
1806         sc->scsi_done(sc);
1807         return 0;
1808 }
1809 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1810
1811 int iscsi_target_alloc(struct scsi_target *starget)
1812 {
1813         struct iscsi_cls_session *cls_session = starget_to_session(starget);
1814         struct iscsi_session *session = cls_session->dd_data;
1815
1816         starget->can_queue = session->scsi_cmds_max;
1817         return 0;
1818 }
1819 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1820
1821 static void iscsi_tmf_timedout(unsigned long data)
1822 {
1823         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1824         struct iscsi_session *session = conn->session;
1825
1826         spin_lock(&session->frwd_lock);
1827         if (conn->tmf_state == TMF_QUEUED) {
1828                 conn->tmf_state = TMF_TIMEDOUT;
1829                 ISCSI_DBG_EH(session, "tmf timedout\n");
1830                 /* unblock eh_abort() */
1831                 wake_up(&conn->ehwait);
1832         }
1833         spin_unlock(&session->frwd_lock);
1834 }
1835
1836 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1837                                    struct iscsi_tm *hdr, int age,
1838                                    int timeout)
1839 {
1840         struct iscsi_session *session = conn->session;
1841         struct iscsi_task *task;
1842
1843         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1844                                       NULL, 0);
1845         if (!task) {
1846                 spin_unlock_bh(&session->frwd_lock);
1847                 iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1848                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1849                 spin_lock_bh(&session->frwd_lock);
1850                 return -EPERM;
1851         }
1852         conn->tmfcmd_pdus_cnt++;
1853         conn->tmf_timer.expires = timeout * HZ + jiffies;
1854         conn->tmf_timer.function = iscsi_tmf_timedout;
1855         conn->tmf_timer.data = (unsigned long)conn;
1856         add_timer(&conn->tmf_timer);
1857         ISCSI_DBG_EH(session, "tmf set timeout\n");
1858
1859         spin_unlock_bh(&session->frwd_lock);
1860         mutex_unlock(&session->eh_mutex);
1861
1862         /*
1863          * block eh thread until:
1864          *
1865          * 1) tmf response
1866          * 2) tmf timeout
1867          * 3) session is terminated or restarted or userspace has
1868          * given up on recovery
1869          */
1870         wait_event_interruptible(conn->ehwait, age != session->age ||
1871                                  session->state != ISCSI_STATE_LOGGED_IN ||
1872                                  conn->tmf_state != TMF_QUEUED);
1873         if (signal_pending(current))
1874                 flush_signals(current);
1875         del_timer_sync(&conn->tmf_timer);
1876
1877         mutex_lock(&session->eh_mutex);
1878         spin_lock_bh(&session->frwd_lock);
1879         /* if the session drops it will clean up the task */
1880         if (age != session->age ||
1881             session->state != ISCSI_STATE_LOGGED_IN)
1882                 return -ENOTCONN;
1883         return 0;
1884 }
1885
1886 /*
1887  * Fail commands. session lock held and recv side suspended and xmit
1888  * thread flushed
1889  */
1890 static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
1891 {
1892         struct iscsi_task *task;
1893         int i;
1894
1895         for (i = 0; i < conn->session->cmds_max; i++) {
1896                 task = conn->session->cmds[i];
1897                 if (!task->sc || task->state == ISCSI_TASK_FREE)
1898                         continue;
1899
1900                 if (lun != -1 && lun != task->sc->device->lun)
1901                         continue;
1902
1903                 ISCSI_DBG_SESSION(conn->session,
1904                                   "failing sc %p itt 0x%x state %d\n",
1905                                   task->sc, task->itt, task->state);
1906                 fail_scsi_task(task, error);
1907         }
1908 }
1909
1910 /**
1911  * iscsi_suspend_queue - suspend iscsi_queuecommand
1912  * @conn: iscsi conn to stop queueing IO on
1913  *
1914  * This grabs the session frwd_lock to make sure no one is in
1915  * xmit_task/queuecommand, and then sets suspend to prevent
1916  * new commands from being queued. This only needs to be called
1917  * by offload drivers that need to sync a path like ep disconnect
1918  * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1919  * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1920  */
1921 void iscsi_suspend_queue(struct iscsi_conn *conn)
1922 {
1923         spin_lock_bh(&conn->session->frwd_lock);
1924         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1925         spin_unlock_bh(&conn->session->frwd_lock);
1926 }
1927 EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1928
1929 /**
1930  * iscsi_suspend_tx - suspend iscsi_data_xmit
1931  * @conn: iscsi conn tp stop processing IO on.
1932  *
1933  * This function sets the suspend bit to prevent iscsi_data_xmit
1934  * from sending new IO, and if work is queued on the xmit thread
1935  * it will wait for it to be completed.
1936  */
1937 void iscsi_suspend_tx(struct iscsi_conn *conn)
1938 {
1939         struct Scsi_Host *shost = conn->session->host;
1940         struct iscsi_host *ihost = shost_priv(shost);
1941
1942         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1943         if (ihost->workq)
1944                 flush_workqueue(ihost->workq);
1945 }
1946 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1947
1948 static void iscsi_start_tx(struct iscsi_conn *conn)
1949 {
1950         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1951         iscsi_conn_queue_work(conn);
1952 }
1953
1954 /*
1955  * We want to make sure a ping is in flight. It has timed out.
1956  * And we are not busy processing a pdu that is making
1957  * progress but got started before the ping and is taking a while
1958  * to complete so the ping is just stuck behind it in a queue.
1959  */
1960 static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1961 {
1962         if (READ_ONCE(conn->ping_task) &&
1963             time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1964                            (conn->ping_timeout * HZ), jiffies))
1965                 return 1;
1966         else
1967                 return 0;
1968 }
1969
1970 static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1971 {
1972         enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1973         struct iscsi_task *task = NULL, *running_task;
1974         struct iscsi_cls_session *cls_session;
1975         struct iscsi_session *session;
1976         struct iscsi_conn *conn;
1977         int i;
1978
1979         cls_session = starget_to_session(scsi_target(sc->device));
1980         session = cls_session->dd_data;
1981
1982         ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1983
1984         spin_lock_bh(&session->frwd_lock);
1985         task = (struct iscsi_task *)sc->SCp.ptr;
1986         if (!task) {
1987                 /*
1988                  * Raced with completion. Blk layer has taken ownership
1989                  * so let timeout code complete it now.
1990                  */
1991                 rc = BLK_EH_HANDLED;
1992                 goto done;
1993         }
1994
1995         if (session->state != ISCSI_STATE_LOGGED_IN) {
1996                 /*
1997                  * During shutdown, if session is prematurely disconnected,
1998                  * recovery won't happen and there will be hung cmds. Not
1999                  * handling cmds would trigger EH, also bad in this case.
2000                  * Instead, handle cmd, allow completion to happen and let
2001                  * upper layer to deal with the result.
2002                  */
2003                 if (unlikely(system_state != SYSTEM_RUNNING)) {
2004                         sc->result = DID_NO_CONNECT << 16;
2005                         ISCSI_DBG_EH(session, "sc on shutdown, handled\n");
2006                         rc = BLK_EH_HANDLED;
2007                         goto done;
2008                 }
2009                 /*
2010                  * We are probably in the middle of iscsi recovery so let
2011                  * that complete and handle the error.
2012                  */
2013                 rc = BLK_EH_RESET_TIMER;
2014                 goto done;
2015         }
2016
2017         conn = session->leadconn;
2018         if (!conn) {
2019                 /* In the middle of shuting down */
2020                 rc = BLK_EH_RESET_TIMER;
2021                 goto done;
2022         }
2023
2024         /*
2025          * If we have sent (at least queued to the network layer) a pdu or
2026          * recvd one for the task since the last timeout ask for
2027          * more time. If on the next timeout we have not made progress
2028          * we can check if it is the task or connection when we send the
2029          * nop as a ping.
2030          */
2031         if (time_after(task->last_xfer, task->last_timeout)) {
2032                 ISCSI_DBG_EH(session, "Command making progress. Asking "
2033                              "scsi-ml for more time to complete. "
2034                              "Last data xfer at %lu. Last timeout was at "
2035                              "%lu\n.", task->last_xfer, task->last_timeout);
2036                 task->have_checked_conn = false;
2037                 rc = BLK_EH_RESET_TIMER;
2038                 goto done;
2039         }
2040
2041         if (!conn->recv_timeout && !conn->ping_timeout)
2042                 goto done;
2043         /*
2044          * if the ping timedout then we are in the middle of cleaning up
2045          * and can let the iscsi eh handle it
2046          */
2047         if (iscsi_has_ping_timed_out(conn)) {
2048                 rc = BLK_EH_RESET_TIMER;
2049                 goto done;
2050         }
2051
2052         for (i = 0; i < conn->session->cmds_max; i++) {
2053                 running_task = conn->session->cmds[i];
2054                 if (!running_task->sc || running_task == task ||
2055                      running_task->state != ISCSI_TASK_RUNNING)
2056                         continue;
2057
2058                 /*
2059                  * Only check if cmds started before this one have made
2060                  * progress, or this could never fail
2061                  */
2062                 if (time_after(running_task->sc->jiffies_at_alloc,
2063                                task->sc->jiffies_at_alloc))
2064                         continue;
2065
2066                 if (time_after(running_task->last_xfer, task->last_timeout)) {
2067                         /*
2068                          * This task has not made progress, but a task
2069                          * started before us has transferred data since
2070                          * we started/last-checked. We could be queueing
2071                          * too many tasks or the LU is bad.
2072                          *
2073                          * If the device is bad the cmds ahead of us on
2074                          * other devs will complete, and this loop will
2075                          * eventually fail starting the scsi eh.
2076                          */
2077                         ISCSI_DBG_EH(session, "Command has not made progress "
2078                                      "but commands ahead of it have. "
2079                                      "Asking scsi-ml for more time to "
2080                                      "complete. Our last xfer vs running task "
2081                                      "last xfer %lu/%lu. Last check %lu.\n",
2082                                      task->last_xfer, running_task->last_xfer,
2083                                      task->last_timeout);
2084                         rc = BLK_EH_RESET_TIMER;
2085                         goto done;
2086                 }
2087         }
2088
2089         /* Assumes nop timeout is shorter than scsi cmd timeout */
2090         if (task->have_checked_conn)
2091                 goto done;
2092
2093         /*
2094          * Checking the transport already or nop from a cmd timeout still
2095          * running
2096          */
2097         if (READ_ONCE(conn->ping_task)) {
2098                 task->have_checked_conn = true;
2099                 rc = BLK_EH_RESET_TIMER;
2100                 goto done;
2101         }
2102
2103         /* Make sure there is a transport check done */
2104         iscsi_send_nopout(conn, NULL);
2105         task->have_checked_conn = true;
2106         rc = BLK_EH_RESET_TIMER;
2107
2108 done:
2109         if (task)
2110                 task->last_timeout = jiffies;
2111         spin_unlock_bh(&session->frwd_lock);
2112         ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2113                      "timer reset" : "shutdown or nh");
2114         return rc;
2115 }
2116
2117 static void iscsi_check_transport_timeouts(unsigned long data)
2118 {
2119         struct iscsi_conn *conn = (struct iscsi_conn *)data;
2120         struct iscsi_session *session = conn->session;
2121         unsigned long recv_timeout, next_timeout = 0, last_recv;
2122
2123         spin_lock(&session->frwd_lock);
2124         if (session->state != ISCSI_STATE_LOGGED_IN)
2125                 goto done;
2126
2127         recv_timeout = conn->recv_timeout;
2128         if (!recv_timeout)
2129                 goto done;
2130
2131         recv_timeout *= HZ;
2132         last_recv = conn->last_recv;
2133
2134         if (iscsi_has_ping_timed_out(conn)) {
2135                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2136                                   "expired, recv timeout %d, last rx %lu, "
2137                                   "last ping %lu, now %lu\n",
2138                                   conn->ping_timeout, conn->recv_timeout,
2139                                   last_recv, conn->last_ping, jiffies);
2140                 spin_unlock(&session->frwd_lock);
2141                 iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2142                 return;
2143         }
2144
2145         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2146                 /* send a ping to try to provoke some traffic */
2147                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2148                 if (iscsi_send_nopout(conn, NULL))
2149                         next_timeout = jiffies + (1 * HZ);
2150                 else
2151                         next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2152         } else
2153                 next_timeout = last_recv + recv_timeout;
2154
2155         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2156         mod_timer(&conn->transport_timer, next_timeout);
2157 done:
2158         spin_unlock(&session->frwd_lock);
2159 }
2160
2161 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2162                                       struct iscsi_tm *hdr)
2163 {
2164         memset(hdr, 0, sizeof(*hdr));
2165         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2166         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2167         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2168         hdr->lun = task->lun;
2169         hdr->rtt = task->hdr_itt;
2170         hdr->refcmdsn = task->cmdsn;
2171 }
2172
2173 int iscsi_eh_abort(struct scsi_cmnd *sc)
2174 {
2175         struct iscsi_cls_session *cls_session;
2176         struct iscsi_session *session;
2177         struct iscsi_conn *conn;
2178         struct iscsi_task *task;
2179         struct iscsi_tm *hdr;
2180         int age;
2181
2182         cls_session = starget_to_session(scsi_target(sc->device));
2183         session = cls_session->dd_data;
2184
2185         ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2186
2187         mutex_lock(&session->eh_mutex);
2188         spin_lock_bh(&session->frwd_lock);
2189         /*
2190          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2191          * got the command.
2192          */
2193         if (!sc->SCp.ptr) {
2194                 ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2195                                       "it completed.\n");
2196                 spin_unlock_bh(&session->frwd_lock);
2197                 mutex_unlock(&session->eh_mutex);
2198                 return SUCCESS;
2199         }
2200
2201         /*
2202          * If we are not logged in or we have started a new session
2203          * then let the host reset code handle this
2204          */
2205         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2206             sc->SCp.phase != session->age) {
2207                 spin_unlock_bh(&session->frwd_lock);
2208                 mutex_unlock(&session->eh_mutex);
2209                 ISCSI_DBG_EH(session, "failing abort due to dropped "
2210                                   "session.\n");
2211                 return FAILED;
2212         }
2213
2214         conn = session->leadconn;
2215         conn->eh_abort_cnt++;
2216         age = session->age;
2217
2218         task = (struct iscsi_task *)sc->SCp.ptr;
2219         ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2220                      sc, task->itt);
2221
2222         /* task completed before time out */
2223         if (!task->sc) {
2224                 ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2225                 goto success;
2226         }
2227
2228         if (task->state == ISCSI_TASK_PENDING) {
2229                 fail_scsi_task(task, DID_ABORT);
2230                 goto success;
2231         }
2232
2233         /* only have one tmf outstanding at a time */
2234         if (conn->tmf_state != TMF_INITIAL)
2235                 goto failed;
2236         conn->tmf_state = TMF_QUEUED;
2237
2238         hdr = &conn->tmhdr;
2239         iscsi_prep_abort_task_pdu(task, hdr);
2240
2241         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout))
2242                 goto failed;
2243
2244         switch (conn->tmf_state) {
2245         case TMF_SUCCESS:
2246                 spin_unlock_bh(&session->frwd_lock);
2247                 /*
2248                  * stop tx side incase the target had sent a abort rsp but
2249                  * the initiator was still writing out data.
2250                  */
2251                 iscsi_suspend_tx(conn);
2252                 /*
2253                  * we do not stop the recv side because targets have been
2254                  * good and have never sent us a successful tmf response
2255                  * then sent more data for the cmd.
2256                  */
2257                 spin_lock_bh(&session->frwd_lock);
2258                 fail_scsi_task(task, DID_ABORT);
2259                 conn->tmf_state = TMF_INITIAL;
2260                 memset(hdr, 0, sizeof(*hdr));
2261                 spin_unlock_bh(&session->frwd_lock);
2262                 iscsi_start_tx(conn);
2263                 goto success_unlocked;
2264         case TMF_TIMEDOUT:
2265                 spin_unlock_bh(&session->frwd_lock);
2266                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2267                 goto failed_unlocked;
2268         case TMF_NOT_FOUND:
2269                 if (!sc->SCp.ptr) {
2270                         conn->tmf_state = TMF_INITIAL;
2271                         memset(hdr, 0, sizeof(*hdr));
2272                         /* task completed before tmf abort response */
2273                         ISCSI_DBG_EH(session, "sc completed while abort in "
2274                                               "progress\n");
2275                         goto success;
2276                 }
2277                 /* fall through */
2278         default:
2279                 conn->tmf_state = TMF_INITIAL;
2280                 goto failed;
2281         }
2282
2283 success:
2284         spin_unlock_bh(&session->frwd_lock);
2285 success_unlocked:
2286         ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2287                      sc, task->itt);
2288         mutex_unlock(&session->eh_mutex);
2289         return SUCCESS;
2290
2291 failed:
2292         spin_unlock_bh(&session->frwd_lock);
2293 failed_unlocked:
2294         ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2295                      task ? task->itt : 0);
2296         mutex_unlock(&session->eh_mutex);
2297         return FAILED;
2298 }
2299 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2300
2301 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2302 {
2303         memset(hdr, 0, sizeof(*hdr));
2304         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2305         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2306         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2307         int_to_scsilun(sc->device->lun, &hdr->lun);
2308         hdr->rtt = RESERVED_ITT;
2309 }
2310
2311 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2312 {
2313         struct iscsi_cls_session *cls_session;
2314         struct iscsi_session *session;
2315         struct iscsi_conn *conn;
2316         struct iscsi_tm *hdr;
2317         int rc = FAILED;
2318
2319         cls_session = starget_to_session(scsi_target(sc->device));
2320         session = cls_session->dd_data;
2321
2322         ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2323                      sc->device->lun);
2324
2325         mutex_lock(&session->eh_mutex);
2326         spin_lock_bh(&session->frwd_lock);
2327         /*
2328          * Just check if we are not logged in. We cannot check for
2329          * the phase because the reset could come from a ioctl.
2330          */
2331         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2332                 goto unlock;
2333         conn = session->leadconn;
2334
2335         /* only have one tmf outstanding at a time */
2336         if (conn->tmf_state != TMF_INITIAL)
2337                 goto unlock;
2338         conn->tmf_state = TMF_QUEUED;
2339
2340         hdr = &conn->tmhdr;
2341         iscsi_prep_lun_reset_pdu(sc, hdr);
2342
2343         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2344                                     session->lu_reset_timeout)) {
2345                 rc = FAILED;
2346                 goto unlock;
2347         }
2348
2349         switch (conn->tmf_state) {
2350         case TMF_SUCCESS:
2351                 break;
2352         case TMF_TIMEDOUT:
2353                 spin_unlock_bh(&session->frwd_lock);
2354                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2355                 goto done;
2356         default:
2357                 conn->tmf_state = TMF_INITIAL;
2358                 goto unlock;
2359         }
2360
2361         rc = SUCCESS;
2362         spin_unlock_bh(&session->frwd_lock);
2363
2364         iscsi_suspend_tx(conn);
2365
2366         spin_lock_bh(&session->frwd_lock);
2367         memset(hdr, 0, sizeof(*hdr));
2368         fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2369         conn->tmf_state = TMF_INITIAL;
2370         spin_unlock_bh(&session->frwd_lock);
2371
2372         iscsi_start_tx(conn);
2373         goto done;
2374
2375 unlock:
2376         spin_unlock_bh(&session->frwd_lock);
2377 done:
2378         ISCSI_DBG_EH(session, "dev reset result = %s\n",
2379                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2380         mutex_unlock(&session->eh_mutex);
2381         return rc;
2382 }
2383 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2384
2385 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2386 {
2387         struct iscsi_session *session = cls_session->dd_data;
2388
2389         spin_lock_bh(&session->frwd_lock);
2390         if (session->state != ISCSI_STATE_LOGGED_IN) {
2391                 session->state = ISCSI_STATE_RECOVERY_FAILED;
2392                 if (session->leadconn)
2393                         wake_up(&session->leadconn->ehwait);
2394         }
2395         spin_unlock_bh(&session->frwd_lock);
2396 }
2397 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2398
2399 /**
2400  * iscsi_eh_session_reset - drop session and attempt relogin
2401  * @sc: scsi command
2402  *
2403  * This function will wait for a relogin, session termination from
2404  * userspace, or a recovery/replacement timeout.
2405  */
2406 int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2407 {
2408         struct iscsi_cls_session *cls_session;
2409         struct iscsi_session *session;
2410         struct iscsi_conn *conn;
2411
2412         cls_session = starget_to_session(scsi_target(sc->device));
2413         session = cls_session->dd_data;
2414         conn = session->leadconn;
2415
2416         mutex_lock(&session->eh_mutex);
2417         spin_lock_bh(&session->frwd_lock);
2418         if (session->state == ISCSI_STATE_TERMINATE) {
2419 failed:
2420                 ISCSI_DBG_EH(session,
2421                              "failing session reset: Could not log back into "
2422                              "%s [age %d]\n", session->targetname,
2423                              session->age);
2424                 spin_unlock_bh(&session->frwd_lock);
2425                 mutex_unlock(&session->eh_mutex);
2426                 return FAILED;
2427         }
2428
2429         spin_unlock_bh(&session->frwd_lock);
2430         mutex_unlock(&session->eh_mutex);
2431         /*
2432          * we drop the lock here but the leadconn cannot be destoyed while
2433          * we are in the scsi eh
2434          */
2435         iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2436
2437         ISCSI_DBG_EH(session, "wait for relogin\n");
2438         wait_event_interruptible(conn->ehwait,
2439                                  session->state == ISCSI_STATE_TERMINATE ||
2440                                  session->state == ISCSI_STATE_LOGGED_IN ||
2441                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
2442         if (signal_pending(current))
2443                 flush_signals(current);
2444
2445         mutex_lock(&session->eh_mutex);
2446         spin_lock_bh(&session->frwd_lock);
2447         if (session->state == ISCSI_STATE_LOGGED_IN) {
2448                 ISCSI_DBG_EH(session,
2449                              "session reset succeeded for %s,%s\n",
2450                              session->targetname, conn->persistent_address);
2451         } else
2452                 goto failed;
2453         spin_unlock_bh(&session->frwd_lock);
2454         mutex_unlock(&session->eh_mutex);
2455         return SUCCESS;
2456 }
2457 EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2458
2459 static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2460 {
2461         memset(hdr, 0, sizeof(*hdr));
2462         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2463         hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2464         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2465         hdr->rtt = RESERVED_ITT;
2466 }
2467
2468 /**
2469  * iscsi_eh_target_reset - reset target
2470  * @sc: scsi command
2471  *
2472  * This will attempt to send a warm target reset.
2473  */
2474 static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2475 {
2476         struct iscsi_cls_session *cls_session;
2477         struct iscsi_session *session;
2478         struct iscsi_conn *conn;
2479         struct iscsi_tm *hdr;
2480         int rc = FAILED;
2481
2482         cls_session = starget_to_session(scsi_target(sc->device));
2483         session = cls_session->dd_data;
2484
2485         ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2486                      session->targetname);
2487
2488         mutex_lock(&session->eh_mutex);
2489         spin_lock_bh(&session->frwd_lock);
2490         /*
2491          * Just check if we are not logged in. We cannot check for
2492          * the phase because the reset could come from a ioctl.
2493          */
2494         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2495                 goto unlock;
2496         conn = session->leadconn;
2497
2498         /* only have one tmf outstanding at a time */
2499         if (conn->tmf_state != TMF_INITIAL)
2500                 goto unlock;
2501         conn->tmf_state = TMF_QUEUED;
2502
2503         hdr = &conn->tmhdr;
2504         iscsi_prep_tgt_reset_pdu(sc, hdr);
2505
2506         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2507                                     session->tgt_reset_timeout)) {
2508                 rc = FAILED;
2509                 goto unlock;
2510         }
2511
2512         switch (conn->tmf_state) {
2513         case TMF_SUCCESS:
2514                 break;
2515         case TMF_TIMEDOUT:
2516                 spin_unlock_bh(&session->frwd_lock);
2517                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2518                 goto done;
2519         default:
2520                 conn->tmf_state = TMF_INITIAL;
2521                 goto unlock;
2522         }
2523
2524         rc = SUCCESS;
2525         spin_unlock_bh(&session->frwd_lock);
2526
2527         iscsi_suspend_tx(conn);
2528
2529         spin_lock_bh(&session->frwd_lock);
2530         memset(hdr, 0, sizeof(*hdr));
2531         fail_scsi_tasks(conn, -1, DID_ERROR);
2532         conn->tmf_state = TMF_INITIAL;
2533         spin_unlock_bh(&session->frwd_lock);
2534
2535         iscsi_start_tx(conn);
2536         goto done;
2537
2538 unlock:
2539         spin_unlock_bh(&session->frwd_lock);
2540 done:
2541         ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2542                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2543         mutex_unlock(&session->eh_mutex);
2544         return rc;
2545 }
2546
2547 /**
2548  * iscsi_eh_recover_target - reset target and possibly the session
2549  * @sc: scsi command
2550  *
2551  * This will attempt to send a warm target reset. If that fails,
2552  * we will escalate to ERL0 session recovery.
2553  */
2554 int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2555 {
2556         int rc;
2557
2558         rc = iscsi_eh_target_reset(sc);
2559         if (rc == FAILED)
2560                 rc = iscsi_eh_session_reset(sc);
2561         return rc;
2562 }
2563 EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2564
2565 /*
2566  * Pre-allocate a pool of @max items of @item_size. By default, the pool
2567  * should be accessed via kfifo_{get,put} on q->queue.
2568  * Optionally, the caller can obtain the array of object pointers
2569  * by passing in a non-NULL @items pointer
2570  */
2571 int
2572 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2573 {
2574         int i, num_arrays = 1;
2575
2576         memset(q, 0, sizeof(*q));
2577
2578         q->max = max;
2579
2580         /* If the user passed an items pointer, he wants a copy of
2581          * the array. */
2582         if (items)
2583                 num_arrays++;
2584         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
2585         if (q->pool == NULL)
2586                 return -ENOMEM;
2587
2588         kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2589
2590         for (i = 0; i < max; i++) {
2591                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2592                 if (q->pool[i] == NULL) {
2593                         q->max = i;
2594                         goto enomem;
2595                 }
2596                 kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2597         }
2598
2599         if (items) {
2600                 *items = q->pool + max;
2601                 memcpy(*items, q->pool, max * sizeof(void *));
2602         }
2603
2604         return 0;
2605
2606 enomem:
2607         iscsi_pool_free(q);
2608         return -ENOMEM;
2609 }
2610 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2611
2612 void iscsi_pool_free(struct iscsi_pool *q)
2613 {
2614         int i;
2615
2616         for (i = 0; i < q->max; i++)
2617                 kfree(q->pool[i]);
2618         kfree(q->pool);
2619 }
2620 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2621
2622 /**
2623  * iscsi_host_add - add host to system
2624  * @shost: scsi host
2625  * @pdev: parent device
2626  *
2627  * This should be called by partial offload and software iscsi drivers
2628  * to add a host to the system.
2629  */
2630 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2631 {
2632         if (!shost->can_queue)
2633                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2634
2635         if (!shost->cmd_per_lun)
2636                 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2637
2638         if (!shost->transportt->eh_timed_out)
2639                 shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
2640         return scsi_add_host(shost, pdev);
2641 }
2642 EXPORT_SYMBOL_GPL(iscsi_host_add);
2643
2644 /**
2645  * iscsi_host_alloc - allocate a host and driver data
2646  * @sht: scsi host template
2647  * @dd_data_size: driver host data size
2648  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2649  *
2650  * This should be called by partial offload and software iscsi drivers.
2651  * To access the driver specific memory use the iscsi_host_priv() macro.
2652  */
2653 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2654                                    int dd_data_size, bool xmit_can_sleep)
2655 {
2656         struct Scsi_Host *shost;
2657         struct iscsi_host *ihost;
2658
2659         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2660         if (!shost)
2661                 return NULL;
2662         ihost = shost_priv(shost);
2663
2664         if (xmit_can_sleep) {
2665                 snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2666                         "iscsi_q_%d", shost->host_no);
2667                 ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2668                 if (!ihost->workq)
2669                         goto free_host;
2670         }
2671
2672         spin_lock_init(&ihost->lock);
2673         ihost->state = ISCSI_HOST_SETUP;
2674         ihost->num_sessions = 0;
2675         init_waitqueue_head(&ihost->session_removal_wq);
2676         return shost;
2677
2678 free_host:
2679         scsi_host_put(shost);
2680         return NULL;
2681 }
2682 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2683
2684 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2685 {
2686         iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2687 }
2688
2689 /**
2690  * iscsi_host_remove - remove host and sessions
2691  * @shost: scsi host
2692  *
2693  * If there are any sessions left, this will initiate the removal and wait
2694  * for the completion.
2695  */
2696 void iscsi_host_remove(struct Scsi_Host *shost)
2697 {
2698         struct iscsi_host *ihost = shost_priv(shost);
2699         unsigned long flags;
2700
2701         spin_lock_irqsave(&ihost->lock, flags);
2702         ihost->state = ISCSI_HOST_REMOVED;
2703         spin_unlock_irqrestore(&ihost->lock, flags);
2704
2705         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2706         wait_event_interruptible(ihost->session_removal_wq,
2707                                  ihost->num_sessions == 0);
2708         if (signal_pending(current))
2709                 flush_signals(current);
2710
2711         scsi_remove_host(shost);
2712         if (ihost->workq)
2713                 destroy_workqueue(ihost->workq);
2714 }
2715 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2716
2717 void iscsi_host_free(struct Scsi_Host *shost)
2718 {
2719         struct iscsi_host *ihost = shost_priv(shost);
2720
2721         kfree(ihost->netdev);
2722         kfree(ihost->hwaddress);
2723         kfree(ihost->initiatorname);
2724         scsi_host_put(shost);
2725 }
2726 EXPORT_SYMBOL_GPL(iscsi_host_free);
2727
2728 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2729 {
2730         struct iscsi_host *ihost = shost_priv(shost);
2731         unsigned long flags;
2732
2733         shost = scsi_host_get(shost);
2734         if (!shost) {
2735                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2736                       "of session teardown event because host already "
2737                       "removed.\n");
2738                 return;
2739         }
2740
2741         spin_lock_irqsave(&ihost->lock, flags);
2742         ihost->num_sessions--;
2743         if (ihost->num_sessions == 0)
2744                 wake_up(&ihost->session_removal_wq);
2745         spin_unlock_irqrestore(&ihost->lock, flags);
2746         scsi_host_put(shost);
2747 }
2748
2749 /**
2750  * iscsi_session_setup - create iscsi cls session and host and session
2751  * @iscsit: iscsi transport template
2752  * @shost: scsi host
2753  * @cmds_max: session can queue
2754  * @cmd_task_size: LLD task private data size
2755  * @initial_cmdsn: initial CmdSN
2756  *
2757  * This can be used by software iscsi_transports that allocate
2758  * a session per scsi host.
2759  *
2760  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2761  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2762  * for nop handling and login/logout requests.
2763  */
2764 struct iscsi_cls_session *
2765 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2766                     uint16_t cmds_max, int dd_size, int cmd_task_size,
2767                     uint32_t initial_cmdsn, unsigned int id)
2768 {
2769         struct iscsi_host *ihost = shost_priv(shost);
2770         struct iscsi_session *session;
2771         struct iscsi_cls_session *cls_session;
2772         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2773         unsigned long flags;
2774
2775         spin_lock_irqsave(&ihost->lock, flags);
2776         if (ihost->state == ISCSI_HOST_REMOVED) {
2777                 spin_unlock_irqrestore(&ihost->lock, flags);
2778                 return NULL;
2779         }
2780         ihost->num_sessions++;
2781         spin_unlock_irqrestore(&ihost->lock, flags);
2782
2783         if (!total_cmds)
2784                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2785         /*
2786          * The iscsi layer needs some tasks for nop handling and tmfs,
2787          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2788          * + 1 command for scsi IO.
2789          */
2790         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2791                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2792                        "must be a power of two that is at least %d.\n",
2793                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2794                 goto dec_session_count;
2795         }
2796
2797         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2798                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2799                        "must be a power of 2 less than or equal to %d.\n",
2800                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2801                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2802         }
2803
2804         if (!is_power_of_2(total_cmds)) {
2805                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2806                        "must be a power of 2.\n", total_cmds);
2807                 total_cmds = rounddown_pow_of_two(total_cmds);
2808                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2809                         return NULL;
2810                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2811                        total_cmds);
2812         }
2813         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2814
2815         cls_session = iscsi_alloc_session(shost, iscsit,
2816                                           sizeof(struct iscsi_session) +
2817                                           dd_size);
2818         if (!cls_session)
2819                 goto dec_session_count;
2820         session = cls_session->dd_data;
2821         session->cls_session = cls_session;
2822         session->host = shost;
2823         session->state = ISCSI_STATE_FREE;
2824         session->fast_abort = 1;
2825         session->tgt_reset_timeout = 30;
2826         session->lu_reset_timeout = 15;
2827         session->abort_timeout = 10;
2828         session->scsi_cmds_max = scsi_cmds;
2829         session->cmds_max = total_cmds;
2830         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2831         session->exp_cmdsn = initial_cmdsn + 1;
2832         session->max_cmdsn = initial_cmdsn + 1;
2833         session->max_r2t = 1;
2834         session->tt = iscsit;
2835         session->dd_data = cls_session->dd_data + sizeof(*session);
2836
2837         mutex_init(&session->eh_mutex);
2838         spin_lock_init(&session->frwd_lock);
2839         spin_lock_init(&session->back_lock);
2840
2841         /* initialize SCSI PDU commands pool */
2842         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2843                             (void***)&session->cmds,
2844                             cmd_task_size + sizeof(struct iscsi_task)))
2845                 goto cmdpool_alloc_fail;
2846
2847         /* pre-format cmds pool with ITT */
2848         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2849                 struct iscsi_task *task = session->cmds[cmd_i];
2850
2851                 if (cmd_task_size)
2852                         task->dd_data = &task[1];
2853                 task->itt = cmd_i;
2854                 task->state = ISCSI_TASK_FREE;
2855                 INIT_LIST_HEAD(&task->running);
2856         }
2857
2858         if (!try_module_get(iscsit->owner))
2859                 goto module_get_fail;
2860
2861         if (iscsi_add_session(cls_session, id))
2862                 goto cls_session_fail;
2863
2864         return cls_session;
2865
2866 cls_session_fail:
2867         module_put(iscsit->owner);
2868 module_get_fail:
2869         iscsi_pool_free(&session->cmdpool);
2870 cmdpool_alloc_fail:
2871         iscsi_free_session(cls_session);
2872 dec_session_count:
2873         iscsi_host_dec_session_cnt(shost);
2874         return NULL;
2875 }
2876 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2877
2878 /**
2879  * iscsi_session_teardown - destroy session, host, and cls_session
2880  * @cls_session: iscsi session
2881  *
2882  * The driver must have called iscsi_remove_session before
2883  * calling this.
2884  */
2885 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2886 {
2887         struct iscsi_session *session = cls_session->dd_data;
2888         struct module *owner = cls_session->transport->owner;
2889         struct Scsi_Host *shost = session->host;
2890
2891         iscsi_pool_free(&session->cmdpool);
2892
2893         kfree(session->password);
2894         kfree(session->password_in);
2895         kfree(session->username);
2896         kfree(session->username_in);
2897         kfree(session->targetname);
2898         kfree(session->targetalias);
2899         kfree(session->initiatorname);
2900         kfree(session->boot_root);
2901         kfree(session->boot_nic);
2902         kfree(session->boot_target);
2903         kfree(session->ifacename);
2904         kfree(session->portal_type);
2905         kfree(session->discovery_parent_type);
2906
2907         iscsi_destroy_session(cls_session);
2908         iscsi_host_dec_session_cnt(shost);
2909         module_put(owner);
2910 }
2911 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2912
2913 /**
2914  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2915  * @cls_session: iscsi_cls_session
2916  * @dd_size: private driver data size
2917  * @conn_idx: cid
2918  */
2919 struct iscsi_cls_conn *
2920 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2921                  uint32_t conn_idx)
2922 {
2923         struct iscsi_session *session = cls_session->dd_data;
2924         struct iscsi_conn *conn;
2925         struct iscsi_cls_conn *cls_conn;
2926         char *data;
2927
2928         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2929                                      conn_idx);
2930         if (!cls_conn)
2931                 return NULL;
2932         conn = cls_conn->dd_data;
2933         memset(conn, 0, sizeof(*conn) + dd_size);
2934
2935         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2936         conn->session = session;
2937         conn->cls_conn = cls_conn;
2938         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2939         conn->id = conn_idx;
2940         conn->exp_statsn = 0;
2941         conn->tmf_state = TMF_INITIAL;
2942
2943         init_timer(&conn->transport_timer);
2944         conn->transport_timer.data = (unsigned long)conn;
2945         conn->transport_timer.function = iscsi_check_transport_timeouts;
2946
2947         INIT_LIST_HEAD(&conn->mgmtqueue);
2948         INIT_LIST_HEAD(&conn->cmdqueue);
2949         INIT_LIST_HEAD(&conn->requeue);
2950         spin_lock_init(&conn->taskqueuelock);
2951         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2952
2953         /* allocate login_task used for the login/text sequences */
2954         spin_lock_bh(&session->frwd_lock);
2955         if (!kfifo_out(&session->cmdpool.queue,
2956                          (void*)&conn->login_task,
2957                          sizeof(void*))) {
2958                 spin_unlock_bh(&session->frwd_lock);
2959                 goto login_task_alloc_fail;
2960         }
2961         spin_unlock_bh(&session->frwd_lock);
2962
2963         data = (char *) __get_free_pages(GFP_KERNEL,
2964                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2965         if (!data)
2966                 goto login_task_data_alloc_fail;
2967         conn->login_task->data = conn->data = data;
2968
2969         init_timer(&conn->tmf_timer);
2970         init_waitqueue_head(&conn->ehwait);
2971
2972         return cls_conn;
2973
2974 login_task_data_alloc_fail:
2975         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2976                     sizeof(void*));
2977 login_task_alloc_fail:
2978         iscsi_destroy_conn(cls_conn);
2979         return NULL;
2980 }
2981 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2982
2983 /**
2984  * iscsi_conn_teardown - teardown iscsi connection
2985  * cls_conn: iscsi class connection
2986  *
2987  * TODO: we may need to make this into a two step process
2988  * like scsi-mls remove + put host
2989  */
2990 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2991 {
2992         struct iscsi_conn *conn = cls_conn->dd_data;
2993         struct iscsi_session *session = conn->session;
2994
2995         del_timer_sync(&conn->transport_timer);
2996
2997         mutex_lock(&session->eh_mutex);
2998         spin_lock_bh(&session->frwd_lock);
2999         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
3000         if (session->leadconn == conn) {
3001                 /*
3002                  * leading connection? then give up on recovery.
3003                  */
3004                 session->state = ISCSI_STATE_TERMINATE;
3005                 wake_up(&conn->ehwait);
3006         }
3007         spin_unlock_bh(&session->frwd_lock);
3008
3009         /* flush queued up work because we free the connection below */
3010         iscsi_suspend_tx(conn);
3011
3012         spin_lock_bh(&session->frwd_lock);
3013         free_pages((unsigned long) conn->data,
3014                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3015         kfree(conn->persistent_address);
3016         kfree(conn->local_ipaddr);
3017         /* regular RX path uses back_lock */
3018         spin_lock_bh(&session->back_lock);
3019         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3020                     sizeof(void*));
3021         spin_unlock_bh(&session->back_lock);
3022         if (session->leadconn == conn)
3023                 session->leadconn = NULL;
3024         spin_unlock_bh(&session->frwd_lock);
3025         mutex_unlock(&session->eh_mutex);
3026
3027         iscsi_destroy_conn(cls_conn);
3028 }
3029 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
3030
3031 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
3032 {
3033         struct iscsi_conn *conn = cls_conn->dd_data;
3034         struct iscsi_session *session = conn->session;
3035
3036         if (!session) {
3037                 iscsi_conn_printk(KERN_ERR, conn,
3038                                   "can't start unbound connection\n");
3039                 return -EPERM;
3040         }
3041
3042         if ((session->imm_data_en || !session->initial_r2t_en) &&
3043              session->first_burst > session->max_burst) {
3044                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
3045                                   "first_burst %d max_burst %d\n",
3046                                   session->first_burst, session->max_burst);
3047                 return -EINVAL;
3048         }
3049
3050         if (conn->ping_timeout && !conn->recv_timeout) {
3051                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3052                                   "zero. Using 5 seconds\n.");
3053                 conn->recv_timeout = 5;
3054         }
3055
3056         if (conn->recv_timeout && !conn->ping_timeout) {
3057                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3058                                   "zero. Using 5 seconds.\n");
3059                 conn->ping_timeout = 5;
3060         }
3061
3062         spin_lock_bh(&session->frwd_lock);
3063         conn->c_stage = ISCSI_CONN_STARTED;
3064         session->state = ISCSI_STATE_LOGGED_IN;
3065         session->queued_cmdsn = session->cmdsn;
3066
3067         conn->last_recv = jiffies;
3068         conn->last_ping = jiffies;
3069         if (conn->recv_timeout && conn->ping_timeout)
3070                 mod_timer(&conn->transport_timer,
3071                           jiffies + (conn->recv_timeout * HZ));
3072
3073         switch(conn->stop_stage) {
3074         case STOP_CONN_RECOVER:
3075                 /*
3076                  * unblock eh_abort() if it is blocked. re-try all
3077                  * commands after successful recovery
3078                  */
3079                 conn->stop_stage = 0;
3080                 conn->tmf_state = TMF_INITIAL;
3081                 session->age++;
3082                 if (session->age == 16)
3083                         session->age = 0;
3084                 break;
3085         case STOP_CONN_TERM:
3086                 conn->stop_stage = 0;
3087                 break;
3088         default:
3089                 break;
3090         }
3091         spin_unlock_bh(&session->frwd_lock);
3092
3093         iscsi_unblock_session(session->cls_session);
3094         wake_up(&conn->ehwait);
3095         return 0;
3096 }
3097 EXPORT_SYMBOL_GPL(iscsi_conn_start);
3098
3099 static void
3100 fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3101 {
3102         struct iscsi_task *task;
3103         int i, state;
3104
3105         for (i = 0; i < conn->session->cmds_max; i++) {
3106                 task = conn->session->cmds[i];
3107                 if (task->sc)
3108                         continue;
3109
3110                 if (task->state == ISCSI_TASK_FREE)
3111                         continue;
3112
3113                 ISCSI_DBG_SESSION(conn->session,
3114                                   "failing mgmt itt 0x%x state %d\n",
3115                                   task->itt, task->state);
3116                 state = ISCSI_TASK_ABRT_SESS_RECOV;
3117                 if (task->state == ISCSI_TASK_PENDING)
3118                         state = ISCSI_TASK_COMPLETED;
3119                 iscsi_complete_task(task, state);
3120
3121         }
3122 }
3123
3124 static void iscsi_start_session_recovery(struct iscsi_session *session,
3125                                          struct iscsi_conn *conn, int flag)
3126 {
3127         int old_stop_stage;
3128
3129         mutex_lock(&session->eh_mutex);
3130         spin_lock_bh(&session->frwd_lock);
3131         if (conn->stop_stage == STOP_CONN_TERM) {
3132                 spin_unlock_bh(&session->frwd_lock);
3133                 mutex_unlock(&session->eh_mutex);
3134                 return;
3135         }
3136
3137         /*
3138          * When this is called for the in_login state, we only want to clean
3139          * up the login task and connection. We do not need to block and set
3140          * the recovery state again
3141          */
3142         if (flag == STOP_CONN_TERM)
3143                 session->state = ISCSI_STATE_TERMINATE;
3144         else if (conn->stop_stage != STOP_CONN_RECOVER)
3145                 session->state = ISCSI_STATE_IN_RECOVERY;
3146
3147         old_stop_stage = conn->stop_stage;
3148         conn->stop_stage = flag;
3149         spin_unlock_bh(&session->frwd_lock);
3150
3151         del_timer_sync(&conn->transport_timer);
3152         iscsi_suspend_tx(conn);
3153
3154         spin_lock_bh(&session->frwd_lock);
3155         conn->c_stage = ISCSI_CONN_STOPPED;
3156         spin_unlock_bh(&session->frwd_lock);
3157
3158         /*
3159          * for connection level recovery we should not calculate
3160          * header digest. conn->hdr_size used for optimization
3161          * in hdr_extract() and will be re-negotiated at
3162          * set_param() time.
3163          */
3164         if (flag == STOP_CONN_RECOVER) {
3165                 conn->hdrdgst_en = 0;
3166                 conn->datadgst_en = 0;
3167                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
3168                     old_stop_stage != STOP_CONN_RECOVER) {
3169                         ISCSI_DBG_SESSION(session, "blocking session\n");
3170                         iscsi_block_session(session->cls_session);
3171                 }
3172         }
3173
3174         /*
3175          * flush queues.
3176          */
3177         spin_lock_bh(&session->frwd_lock);
3178         fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3179         fail_mgmt_tasks(session, conn);
3180         memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3181         spin_unlock_bh(&session->frwd_lock);
3182         mutex_unlock(&session->eh_mutex);
3183 }
3184
3185 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3186 {
3187         struct iscsi_conn *conn = cls_conn->dd_data;
3188         struct iscsi_session *session = conn->session;
3189
3190         switch (flag) {
3191         case STOP_CONN_RECOVER:
3192         case STOP_CONN_TERM:
3193                 iscsi_start_session_recovery(session, conn, flag);
3194                 break;
3195         default:
3196                 iscsi_conn_printk(KERN_ERR, conn,
3197                                   "invalid stop flag %d\n", flag);
3198         }
3199 }
3200 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3201
3202 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3203                     struct iscsi_cls_conn *cls_conn, int is_leading)
3204 {
3205         struct iscsi_session *session = cls_session->dd_data;
3206         struct iscsi_conn *conn = cls_conn->dd_data;
3207
3208         spin_lock_bh(&session->frwd_lock);
3209         if (is_leading)
3210                 session->leadconn = conn;
3211         spin_unlock_bh(&session->frwd_lock);
3212
3213         /*
3214          * Unblock xmitworker(), Login Phase will pass through.
3215          */
3216         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3217         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3218         return 0;
3219 }
3220 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3221
3222 int iscsi_switch_str_param(char **param, char *new_val_buf)
3223 {
3224         char *new_val;
3225
3226         if (*param) {
3227                 if (!strcmp(*param, new_val_buf))
3228                         return 0;
3229         }
3230
3231         new_val = kstrdup(new_val_buf, GFP_NOIO);
3232         if (!new_val)
3233                 return -ENOMEM;
3234
3235         kfree(*param);
3236         *param = new_val;
3237         return 0;
3238 }
3239 EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3240
3241 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3242                     enum iscsi_param param, char *buf, int buflen)
3243 {
3244         struct iscsi_conn *conn = cls_conn->dd_data;
3245         struct iscsi_session *session = conn->session;
3246         int val;
3247
3248         switch(param) {
3249         case ISCSI_PARAM_FAST_ABORT:
3250                 sscanf(buf, "%d", &session->fast_abort);
3251                 break;
3252         case ISCSI_PARAM_ABORT_TMO:
3253                 sscanf(buf, "%d", &session->abort_timeout);
3254                 break;
3255         case ISCSI_PARAM_LU_RESET_TMO:
3256                 sscanf(buf, "%d", &session->lu_reset_timeout);
3257                 break;
3258         case ISCSI_PARAM_TGT_RESET_TMO:
3259                 sscanf(buf, "%d", &session->tgt_reset_timeout);
3260                 break;
3261         case ISCSI_PARAM_PING_TMO:
3262                 sscanf(buf, "%d", &conn->ping_timeout);
3263                 break;
3264         case ISCSI_PARAM_RECV_TMO:
3265                 sscanf(buf, "%d", &conn->recv_timeout);
3266                 break;
3267         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3268                 sscanf(buf, "%d", &conn->max_recv_dlength);
3269                 break;
3270         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3271                 sscanf(buf, "%d", &conn->max_xmit_dlength);
3272                 break;
3273         case ISCSI_PARAM_HDRDGST_EN:
3274                 sscanf(buf, "%d", &conn->hdrdgst_en);
3275                 break;
3276         case ISCSI_PARAM_DATADGST_EN:
3277                 sscanf(buf, "%d", &conn->datadgst_en);
3278                 break;
3279         case ISCSI_PARAM_INITIAL_R2T_EN:
3280                 sscanf(buf, "%d", &session->initial_r2t_en);
3281                 break;
3282         case ISCSI_PARAM_MAX_R2T:
3283                 sscanf(buf, "%hu", &session->max_r2t);
3284                 break;
3285         case ISCSI_PARAM_IMM_DATA_EN:
3286                 sscanf(buf, "%d", &session->imm_data_en);
3287                 break;
3288         case ISCSI_PARAM_FIRST_BURST:
3289                 sscanf(buf, "%d", &session->first_burst);
3290                 break;
3291         case ISCSI_PARAM_MAX_BURST:
3292                 sscanf(buf, "%d", &session->max_burst);
3293                 break;
3294         case ISCSI_PARAM_PDU_INORDER_EN:
3295                 sscanf(buf, "%d", &session->pdu_inorder_en);
3296                 break;
3297         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3298                 sscanf(buf, "%d", &session->dataseq_inorder_en);
3299                 break;
3300         case ISCSI_PARAM_ERL:
3301                 sscanf(buf, "%d", &session->erl);
3302                 break;
3303         case ISCSI_PARAM_EXP_STATSN:
3304                 sscanf(buf, "%u", &conn->exp_statsn);
3305                 break;
3306         case ISCSI_PARAM_USERNAME:
3307                 return iscsi_switch_str_param(&session->username, buf);
3308         case ISCSI_PARAM_USERNAME_IN:
3309                 return iscsi_switch_str_param(&session->username_in, buf);
3310         case ISCSI_PARAM_PASSWORD:
3311                 return iscsi_switch_str_param(&session->password, buf);
3312         case ISCSI_PARAM_PASSWORD_IN:
3313                 return iscsi_switch_str_param(&session->password_in, buf);
3314         case ISCSI_PARAM_TARGET_NAME:
3315                 return iscsi_switch_str_param(&session->targetname, buf);
3316         case ISCSI_PARAM_TARGET_ALIAS:
3317                 return iscsi_switch_str_param(&session->targetalias, buf);
3318         case ISCSI_PARAM_TPGT:
3319                 sscanf(buf, "%d", &session->tpgt);
3320                 break;
3321         case ISCSI_PARAM_PERSISTENT_PORT:
3322                 sscanf(buf, "%d", &conn->persistent_port);
3323                 break;
3324         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3325                 return iscsi_switch_str_param(&conn->persistent_address, buf);
3326         case ISCSI_PARAM_IFACE_NAME:
3327                 return iscsi_switch_str_param(&session->ifacename, buf);
3328         case ISCSI_PARAM_INITIATOR_NAME:
3329                 return iscsi_switch_str_param(&session->initiatorname, buf);
3330         case ISCSI_PARAM_BOOT_ROOT:
3331                 return iscsi_switch_str_param(&session->boot_root, buf);
3332         case ISCSI_PARAM_BOOT_NIC:
3333                 return iscsi_switch_str_param(&session->boot_nic, buf);
3334         case ISCSI_PARAM_BOOT_TARGET:
3335                 return iscsi_switch_str_param(&session->boot_target, buf);
3336         case ISCSI_PARAM_PORTAL_TYPE:
3337                 return iscsi_switch_str_param(&session->portal_type, buf);
3338         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3339                 return iscsi_switch_str_param(&session->discovery_parent_type,
3340                                               buf);
3341         case ISCSI_PARAM_DISCOVERY_SESS:
3342                 sscanf(buf, "%d", &val);
3343                 session->discovery_sess = !!val;
3344                 break;
3345         case ISCSI_PARAM_LOCAL_IPADDR:
3346                 return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3347         default:
3348                 return -ENOSYS;
3349         }
3350
3351         return 0;
3352 }
3353 EXPORT_SYMBOL_GPL(iscsi_set_param);
3354
3355 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3356                             enum iscsi_param param, char *buf)
3357 {
3358         struct iscsi_session *session = cls_session->dd_data;
3359         int len;
3360
3361         switch(param) {
3362         case ISCSI_PARAM_FAST_ABORT:
3363                 len = sysfs_emit(buf, "%d\n", session->fast_abort);
3364                 break;
3365         case ISCSI_PARAM_ABORT_TMO:
3366                 len = sysfs_emit(buf, "%d\n", session->abort_timeout);
3367                 break;
3368         case ISCSI_PARAM_LU_RESET_TMO:
3369                 len = sysfs_emit(buf, "%d\n", session->lu_reset_timeout);
3370                 break;
3371         case ISCSI_PARAM_TGT_RESET_TMO:
3372                 len = sysfs_emit(buf, "%d\n", session->tgt_reset_timeout);
3373                 break;
3374         case ISCSI_PARAM_INITIAL_R2T_EN:
3375                 len = sysfs_emit(buf, "%d\n", session->initial_r2t_en);
3376                 break;
3377         case ISCSI_PARAM_MAX_R2T:
3378                 len = sysfs_emit(buf, "%hu\n", session->max_r2t);
3379                 break;
3380         case ISCSI_PARAM_IMM_DATA_EN:
3381                 len = sysfs_emit(buf, "%d\n", session->imm_data_en);
3382                 break;
3383         case ISCSI_PARAM_FIRST_BURST:
3384                 len = sysfs_emit(buf, "%u\n", session->first_burst);
3385                 break;
3386         case ISCSI_PARAM_MAX_BURST:
3387                 len = sysfs_emit(buf, "%u\n", session->max_burst);
3388                 break;
3389         case ISCSI_PARAM_PDU_INORDER_EN:
3390                 len = sysfs_emit(buf, "%d\n", session->pdu_inorder_en);
3391                 break;
3392         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3393                 len = sysfs_emit(buf, "%d\n", session->dataseq_inorder_en);
3394                 break;
3395         case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3396                 len = sysfs_emit(buf, "%d\n", session->def_taskmgmt_tmo);
3397                 break;
3398         case ISCSI_PARAM_ERL:
3399                 len = sysfs_emit(buf, "%d\n", session->erl);
3400                 break;
3401         case ISCSI_PARAM_TARGET_NAME:
3402                 len = sysfs_emit(buf, "%s\n", session->targetname);
3403                 break;
3404         case ISCSI_PARAM_TARGET_ALIAS:
3405                 len = sysfs_emit(buf, "%s\n", session->targetalias);
3406                 break;
3407         case ISCSI_PARAM_TPGT:
3408                 len = sysfs_emit(buf, "%d\n", session->tpgt);
3409                 break;
3410         case ISCSI_PARAM_USERNAME:
3411                 len = sysfs_emit(buf, "%s\n", session->username);
3412                 break;
3413         case ISCSI_PARAM_USERNAME_IN:
3414                 len = sysfs_emit(buf, "%s\n", session->username_in);
3415                 break;
3416         case ISCSI_PARAM_PASSWORD:
3417                 len = sysfs_emit(buf, "%s\n", session->password);
3418                 break;
3419         case ISCSI_PARAM_PASSWORD_IN:
3420                 len = sysfs_emit(buf, "%s\n", session->password_in);
3421                 break;
3422         case ISCSI_PARAM_IFACE_NAME:
3423                 len = sysfs_emit(buf, "%s\n", session->ifacename);
3424                 break;
3425         case ISCSI_PARAM_INITIATOR_NAME:
3426                 len = sysfs_emit(buf, "%s\n", session->initiatorname);
3427                 break;
3428         case ISCSI_PARAM_BOOT_ROOT:
3429                 len = sysfs_emit(buf, "%s\n", session->boot_root);
3430                 break;
3431         case ISCSI_PARAM_BOOT_NIC:
3432                 len = sysfs_emit(buf, "%s\n", session->boot_nic);
3433                 break;
3434         case ISCSI_PARAM_BOOT_TARGET:
3435                 len = sysfs_emit(buf, "%s\n", session->boot_target);
3436                 break;
3437         case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3438                 len = sysfs_emit(buf, "%u\n", session->auto_snd_tgt_disable);
3439                 break;
3440         case ISCSI_PARAM_DISCOVERY_SESS:
3441                 len = sysfs_emit(buf, "%u\n", session->discovery_sess);
3442                 break;
3443         case ISCSI_PARAM_PORTAL_TYPE:
3444                 len = sysfs_emit(buf, "%s\n", session->portal_type);
3445                 break;
3446         case ISCSI_PARAM_CHAP_AUTH_EN:
3447                 len = sysfs_emit(buf, "%u\n", session->chap_auth_en);
3448                 break;
3449         case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3450                 len = sysfs_emit(buf, "%u\n", session->discovery_logout_en);
3451                 break;
3452         case ISCSI_PARAM_BIDI_CHAP_EN:
3453                 len = sysfs_emit(buf, "%u\n", session->bidi_chap_en);
3454                 break;
3455         case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3456                 len = sysfs_emit(buf, "%u\n", session->discovery_auth_optional);
3457                 break;
3458         case ISCSI_PARAM_DEF_TIME2WAIT:
3459                 len = sysfs_emit(buf, "%d\n", session->time2wait);
3460                 break;
3461         case ISCSI_PARAM_DEF_TIME2RETAIN:
3462                 len = sysfs_emit(buf, "%d\n", session->time2retain);
3463                 break;
3464         case ISCSI_PARAM_TSID:
3465                 len = sysfs_emit(buf, "%u\n", session->tsid);
3466                 break;
3467         case ISCSI_PARAM_ISID:
3468                 len = sysfs_emit(buf, "%02x%02x%02x%02x%02x%02x\n",
3469                               session->isid[0], session->isid[1],
3470                               session->isid[2], session->isid[3],
3471                               session->isid[4], session->isid[5]);
3472                 break;
3473         case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3474                 len = sysfs_emit(buf, "%u\n", session->discovery_parent_idx);
3475                 break;
3476         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3477                 if (session->discovery_parent_type)
3478                         len = sysfs_emit(buf, "%s\n",
3479                                       session->discovery_parent_type);
3480                 else
3481                         len = sysfs_emit(buf, "\n");
3482                 break;
3483         default:
3484                 return -ENOSYS;
3485         }
3486
3487         return len;
3488 }
3489 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3490
3491 int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3492                               enum iscsi_param param, char *buf)
3493 {
3494         struct sockaddr_in6 *sin6 = NULL;
3495         struct sockaddr_in *sin = NULL;
3496         int len;
3497
3498         switch (addr->ss_family) {
3499         case AF_INET:
3500                 sin = (struct sockaddr_in *)addr;
3501                 break;
3502         case AF_INET6:
3503                 sin6 = (struct sockaddr_in6 *)addr;
3504                 break;
3505         default:
3506                 return -EINVAL;
3507         }
3508
3509         switch (param) {
3510         case ISCSI_PARAM_CONN_ADDRESS:
3511         case ISCSI_HOST_PARAM_IPADDRESS:
3512                 if (sin)
3513                         len = sysfs_emit(buf, "%pI4\n", &sin->sin_addr.s_addr);
3514                 else
3515                         len = sysfs_emit(buf, "%pI6\n", &sin6->sin6_addr);
3516                 break;
3517         case ISCSI_PARAM_CONN_PORT:
3518         case ISCSI_PARAM_LOCAL_PORT:
3519                 if (sin)
3520                         len = sysfs_emit(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3521                 else
3522                         len = sysfs_emit(buf, "%hu\n",
3523                                       be16_to_cpu(sin6->sin6_port));
3524                 break;
3525         default:
3526                 return -EINVAL;
3527         }
3528
3529         return len;
3530 }
3531 EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3532
3533 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3534                          enum iscsi_param param, char *buf)
3535 {
3536         struct iscsi_conn *conn = cls_conn->dd_data;
3537         int len;
3538
3539         switch(param) {
3540         case ISCSI_PARAM_PING_TMO:
3541                 len = sysfs_emit(buf, "%u\n", conn->ping_timeout);
3542                 break;
3543         case ISCSI_PARAM_RECV_TMO:
3544                 len = sysfs_emit(buf, "%u\n", conn->recv_timeout);
3545                 break;
3546         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3547                 len = sysfs_emit(buf, "%u\n", conn->max_recv_dlength);
3548                 break;
3549         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3550                 len = sysfs_emit(buf, "%u\n", conn->max_xmit_dlength);
3551                 break;
3552         case ISCSI_PARAM_HDRDGST_EN:
3553                 len = sysfs_emit(buf, "%d\n", conn->hdrdgst_en);
3554                 break;
3555         case ISCSI_PARAM_DATADGST_EN:
3556                 len = sysfs_emit(buf, "%d\n", conn->datadgst_en);
3557                 break;
3558         case ISCSI_PARAM_IFMARKER_EN:
3559                 len = sysfs_emit(buf, "%d\n", conn->ifmarker_en);
3560                 break;
3561         case ISCSI_PARAM_OFMARKER_EN:
3562                 len = sysfs_emit(buf, "%d\n", conn->ofmarker_en);
3563                 break;
3564         case ISCSI_PARAM_EXP_STATSN:
3565                 len = sysfs_emit(buf, "%u\n", conn->exp_statsn);
3566                 break;
3567         case ISCSI_PARAM_PERSISTENT_PORT:
3568                 len = sysfs_emit(buf, "%d\n", conn->persistent_port);
3569                 break;
3570         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3571                 len = sysfs_emit(buf, "%s\n", conn->persistent_address);
3572                 break;
3573         case ISCSI_PARAM_STATSN:
3574                 len = sysfs_emit(buf, "%u\n", conn->statsn);
3575                 break;
3576         case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3577                 len = sysfs_emit(buf, "%u\n", conn->max_segment_size);
3578                 break;
3579         case ISCSI_PARAM_KEEPALIVE_TMO:
3580                 len = sysfs_emit(buf, "%u\n", conn->keepalive_tmo);
3581                 break;
3582         case ISCSI_PARAM_LOCAL_PORT:
3583                 len = sysfs_emit(buf, "%u\n", conn->local_port);
3584                 break;
3585         case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3586                 len = sysfs_emit(buf, "%u\n", conn->tcp_timestamp_stat);
3587                 break;
3588         case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3589                 len = sysfs_emit(buf, "%u\n", conn->tcp_nagle_disable);
3590                 break;
3591         case ISCSI_PARAM_TCP_WSF_DISABLE:
3592                 len = sysfs_emit(buf, "%u\n", conn->tcp_wsf_disable);
3593                 break;
3594         case ISCSI_PARAM_TCP_TIMER_SCALE:
3595                 len = sysfs_emit(buf, "%u\n", conn->tcp_timer_scale);
3596                 break;
3597         case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3598                 len = sysfs_emit(buf, "%u\n", conn->tcp_timestamp_en);
3599                 break;
3600         case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3601                 len = sysfs_emit(buf, "%u\n", conn->fragment_disable);
3602                 break;
3603         case ISCSI_PARAM_IPV4_TOS:
3604                 len = sysfs_emit(buf, "%u\n", conn->ipv4_tos);
3605                 break;
3606         case ISCSI_PARAM_IPV6_TC:
3607                 len = sysfs_emit(buf, "%u\n", conn->ipv6_traffic_class);
3608                 break;
3609         case ISCSI_PARAM_IPV6_FLOW_LABEL:
3610                 len = sysfs_emit(buf, "%u\n", conn->ipv6_flow_label);
3611                 break;
3612         case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3613                 len = sysfs_emit(buf, "%u\n", conn->is_fw_assigned_ipv6);
3614                 break;
3615         case ISCSI_PARAM_TCP_XMIT_WSF:
3616                 len = sysfs_emit(buf, "%u\n", conn->tcp_xmit_wsf);
3617                 break;
3618         case ISCSI_PARAM_TCP_RECV_WSF:
3619                 len = sysfs_emit(buf, "%u\n", conn->tcp_recv_wsf);
3620                 break;
3621         case ISCSI_PARAM_LOCAL_IPADDR:
3622                 len = sysfs_emit(buf, "%s\n", conn->local_ipaddr);
3623                 break;
3624         default:
3625                 return -ENOSYS;
3626         }
3627
3628         return len;
3629 }
3630 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3631
3632 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3633                          char *buf)
3634 {
3635         struct iscsi_host *ihost = shost_priv(shost);
3636         int len;
3637
3638         switch (param) {
3639         case ISCSI_HOST_PARAM_NETDEV_NAME:
3640                 len = sysfs_emit(buf, "%s\n", ihost->netdev);
3641                 break;
3642         case ISCSI_HOST_PARAM_HWADDRESS:
3643                 len = sysfs_emit(buf, "%s\n", ihost->hwaddress);
3644                 break;
3645         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3646                 len = sysfs_emit(buf, "%s\n", ihost->initiatorname);
3647                 break;
3648         default:
3649                 return -ENOSYS;
3650         }
3651
3652         return len;
3653 }
3654 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3655
3656 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3657                          char *buf, int buflen)
3658 {
3659         struct iscsi_host *ihost = shost_priv(shost);
3660
3661         switch (param) {
3662         case ISCSI_HOST_PARAM_NETDEV_NAME:
3663                 return iscsi_switch_str_param(&ihost->netdev, buf);
3664         case ISCSI_HOST_PARAM_HWADDRESS:
3665                 return iscsi_switch_str_param(&ihost->hwaddress, buf);
3666         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3667                 return iscsi_switch_str_param(&ihost->initiatorname, buf);
3668         default:
3669                 return -ENOSYS;
3670         }
3671
3672         return 0;
3673 }
3674 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3675
3676 MODULE_AUTHOR("Mike Christie");
3677 MODULE_DESCRIPTION("iSCSI library functions");
3678 MODULE_LICENSE("GPL");