drivers/scsi/libiscsi.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * iSCSI lib functions
   4  *
   5  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   6  * Copyright (C) 2004 - 2006 Mike Christie
   7  * Copyright (C) 2004 - 2005 Dmitry Yusupov
   8  * Copyright (C) 2004 - 2005 Alex Aizman
   9  * maintained by open-iscsi@googlegroups.com
  10  */
  11 #include <linux/types.h>
  12 #include <linux/kfifo.h>
  13 #include <linux/delay.h>
  14 #include <linux/log2.h>
  15 #include <linux/slab.h>
  16 #include <linux/sched/signal.h>
  17 #include <linux/module.h>
  18 #include <asm/unaligned.h>
  19 #include <net/tcp.h>
  20 #include <scsi/scsi_cmnd.h>
  21 #include <scsi/scsi_device.h>
  22 #include <scsi/scsi_eh.h>
  23 #include <scsi/scsi_tcq.h>
  24 #include <scsi/scsi_host.h>
  25 #include <scsi/scsi.h>
  26 #include <scsi/iscsi_proto.h>
  27 #include <scsi/scsi_transport.h>
  28 #include <scsi/scsi_transport_iscsi.h>
  29 #include <scsi/libiscsi.h>
  30 #include <trace/events/iscsi.h>
  31
  32 static int iscsi_dbg_lib_conn;
  33 module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
  34                    S_IRUGO | S_IWUSR);
  35 MODULE_PARM_DESC(debug_libiscsi_conn,
  36                  "Turn on debugging for connections in libiscsi module. "
  37                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  38
  39 static int iscsi_dbg_lib_session;
  40 module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
  41                    S_IRUGO | S_IWUSR);
  42 MODULE_PARM_DESC(debug_libiscsi_session,
  43                  "Turn on debugging for sessions in libiscsi module. "
  44                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  45
  46 static int iscsi_dbg_lib_eh;
  47 module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
  48                    S_IRUGO | S_IWUSR);
  49 MODULE_PARM_DESC(debug_libiscsi_eh,
  50                  "Turn on debugging for error handling in libiscsi module. "
  51                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  52
  53 #define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)                  \
  54         do {                                                    \
  55                 if (iscsi_dbg_lib_conn)                         \
  56                         iscsi_conn_printk(KERN_INFO, _conn,     \
  57                                              "%s " dbg_fmt,     \
  58                                              __func__, ##arg);  \
  59                 iscsi_dbg_trace(trace_iscsi_dbg_conn,           \
  60                                 &(_conn)->cls_conn->dev,        \
  61                                 "%s " dbg_fmt, __func__, ##arg);\
  62         } while (0);
  63
  64 #define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)                    \
  65         do {                                                            \
  66                 if (iscsi_dbg_lib_session)                              \
  67                         iscsi_session_printk(KERN_INFO, _session,       \
  68                                              "%s " dbg_fmt,             \
  69                                              __func__, ##arg);          \
  70                 iscsi_dbg_trace(trace_iscsi_dbg_session,                \
  71                                 &(_session)->cls_session->dev,          \
  72                                 "%s " dbg_fmt, __func__, ##arg);        \
  73         } while (0);
  74
  75 #define ISCSI_DBG_EH(_session, dbg_fmt, arg...)                         \
  76         do {                                                            \
  77                 if (iscsi_dbg_lib_eh)                                   \
  78                         iscsi_session_printk(KERN_INFO, _session,       \
  79                                              "%s " dbg_fmt,             \
  80                                              __func__, ##arg);          \
  81                 iscsi_dbg_trace(trace_iscsi_dbg_eh,                     \
  82                                 &(_session)->cls_session->dev,          \
  83                                 "%s " dbg_fmt, __func__, ##arg);        \
  84         } while (0);
  85
  86 inline void iscsi_conn_queue_work(struct iscsi_conn *conn)
  87 {
  88         struct Scsi_Host *shost = conn->session->host;
  89         struct iscsi_host *ihost = shost_priv(shost);
  90
  91         if (ihost->workq)
  92                 queue_work(ihost->workq, &conn->xmitwork);
  93 }
  94 EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
  95
  96 static void __iscsi_update_cmdsn(struct iscsi_session *session,
  97                                  uint32_t exp_cmdsn, uint32_t max_cmdsn)
  98 {
  99         /*
 100          * standard specifies this check for when to update expected and
 101          * max sequence numbers
 102          */
 103         if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
 104                 return;
 105
 106         if (exp_cmdsn != session->exp_cmdsn &&
 107             !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
 108                 session->exp_cmdsn = exp_cmdsn;
 109
 110         if (max_cmdsn != session->max_cmdsn &&
 111             !iscsi_sna_lt(max_cmdsn, session->max_cmdsn))
 112                 session->max_cmdsn = max_cmdsn;
 113 }
 114
 115 void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
 116 {
 117         __iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
 118                              be32_to_cpu(hdr->max_cmdsn));
 119 }
 120 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
 121
 122 /**
 123  * iscsi_prep_data_out_pdu - initialize Data-Out
 124  * @task: scsi command task
 125  * @r2t: R2T info
 126  * @hdr: iscsi data in pdu
 127  *
 128  * Notes:
 129  *      Initialize Data-Out within this R2T sequence and finds
 130  *      proper data_offset within this SCSI command.
 131  *
 132  *      This function is called with connection lock taken.
 133  **/
 134 void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
 135                            struct iscsi_data *hdr)
 136 {
 137         struct iscsi_conn *conn = task->conn;
 138         unsigned int left = r2t->data_length - r2t->sent;
 139
 140         task->hdr_len = sizeof(struct iscsi_data);
 141
 142         memset(hdr, 0, sizeof(struct iscsi_data));
 143         hdr->ttt = r2t->ttt;
 144         hdr->datasn = cpu_to_be32(r2t->datasn);
 145         r2t->datasn++;
 146         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 147         hdr->lun = task->lun;
 148         hdr->itt = task->hdr_itt;
 149         hdr->exp_statsn = r2t->exp_statsn;
 150         hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
 151         if (left > conn->max_xmit_dlength) {
 152                 hton24(hdr->dlength, conn->max_xmit_dlength);
 153                 r2t->data_count = conn->max_xmit_dlength;
 154                 hdr->flags = 0;
 155         } else {
 156                 hton24(hdr->dlength, left);
 157                 r2t->data_count = left;
 158                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 159         }
 160         conn->dataout_pdus_cnt++;
 161 }
 162 EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
 163
 164 static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
 165 {
 166         unsigned exp_len = task->hdr_len + len;
 167
 168         if (exp_len > task->hdr_max) {
 169                 WARN_ON(1);
 170                 return -EINVAL;
 171         }
 172
 173         WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 174         task->hdr_len = exp_len;
 175         return 0;
 176 }
 177
 178 /*
 179  * make an extended cdb AHS
 180  */
 181 static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
 182 {
 183         struct scsi_cmnd *cmd = task->sc;
 184         unsigned rlen, pad_len;
 185         unsigned short ahslength;
 186         struct iscsi_ecdb_ahdr *ecdb_ahdr;
 187         int rc;
 188
 189         ecdb_ahdr = iscsi_next_hdr(task);
 190         rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 191
 192         BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 193         ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 194
 195         pad_len = iscsi_padding(rlen);
 196
 197         rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
 198                            sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 199         if (rc)
 200                 return rc;
 201
 202         if (pad_len)
 203                 memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 204
 205         ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 206         ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 207         ecdb_ahdr->reserved = 0;
 208         memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 209
 210         ISCSI_DBG_SESSION(task->conn->session,
 211                           "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 212                           "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
 213                           "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
 214                           task->hdr_len);
 215         return 0;
 216 }
 217
 218 /**
 219  * iscsi_check_tmf_restrictions - check if a task is affected by TMF
 220  * @task: iscsi task
 221  * @opcode: opcode to check for
 222  *
 223  * During TMF a task has to be checked if it's affected.
 224  * All unrelated I/O can be passed through, but I/O to the
 225  * affected LUN should be restricted.
 226  * If 'fast_abort' is set we won't be sending any I/O to the
 227  * affected LUN.
 228  * Otherwise the target is waiting for all TTTs to be completed,
 229  * so we have to send all outstanding Data-Out PDUs to the target.
 230  */
 231 static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
 232 {
 233         struct iscsi_session *session = task->conn->session;
 234         struct iscsi_tm *tmf = &session->tmhdr;
 235         u64 hdr_lun;
 236
 237         if (session->tmf_state == TMF_INITIAL)
 238                 return 0;
 239
 240         if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
 241                 return 0;
 242
 243         switch (ISCSI_TM_FUNC_VALUE(tmf)) {
 244         case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
 245                 /*
 246                  * Allow PDUs for unrelated LUNs
 247                  */
 248                 hdr_lun = scsilun_to_int(&tmf->lun);
 249                 if (hdr_lun != task->sc->device->lun)
 250                         return 0;
 251                 fallthrough;
 252         case ISCSI_TM_FUNC_TARGET_WARM_RESET:
 253                 /*
 254                  * Fail all SCSI cmd PDUs
 255                  */
 256                 if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
 257                         iscsi_session_printk(KERN_INFO, session,
 258                                              "task [op %x itt 0x%x/0x%x] rejected.\n",
 259                                              opcode, task->itt, task->hdr_itt);
 260                         return -EACCES;
 261                 }
 262                 /*
 263                  * And also all data-out PDUs in response to R2T
 264                  * if fast_abort is set.
 265                  */
 266                 if (session->fast_abort) {
 267                         iscsi_session_printk(KERN_INFO, session,
 268                                              "task [op %x itt 0x%x/0x%x] fast abort.\n",
 269                                              opcode, task->itt, task->hdr_itt);
 270                         return -EACCES;
 271                 }
 272                 break;
 273         case ISCSI_TM_FUNC_ABORT_TASK:
 274                 /*
 275                  * the caller has already checked if the task
 276                  * they want to abort was in the pending queue so if
 277                  * we are here the cmd pdu has gone out already, and
 278                  * we will only hit this for data-outs
 279                  */
 280                 if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
 281                     task->hdr_itt == tmf->rtt) {
 282                         ISCSI_DBG_SESSION(session,
 283                                           "Preventing task %x/%x from sending "
 284                                           "data-out due to abort task in "
 285                                           "progress\n", task->itt,
 286                                           task->hdr_itt);
 287                         return -EACCES;
 288                 }
 289                 break;
 290         }
 291
 292         return 0;
 293 }
 294
 295 /**
 296  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 297  * @task: iscsi task
 298  *
 299  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 300  * fields like dlength or final based on how much data it sends
 301  */
 302 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 303 {
 304         struct iscsi_conn *conn = task->conn;
 305         struct iscsi_session *session = conn->session;
 306         struct scsi_cmnd *sc = task->sc;
 307         struct iscsi_scsi_req *hdr;
 308         unsigned hdrlength, cmd_len, transfer_length;
 309         itt_t itt;
 310         int rc;
 311
 312         rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
 313         if (rc)
 314                 return rc;
 315
 316         if (conn->session->tt->alloc_pdu) {
 317                 rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
 318                 if (rc)
 319                         return rc;
 320         }
 321         hdr = (struct iscsi_scsi_req *)task->hdr;
 322         itt = hdr->itt;
 323         memset(hdr, 0, sizeof(*hdr));
 324
 325         if (session->tt->parse_pdu_itt)
 326                 hdr->itt = task->hdr_itt = itt;
 327         else
 328                 hdr->itt = task->hdr_itt = build_itt(task->itt,
 329                                                      task->conn->session->age);
 330         task->hdr_len = 0;
 331         rc = iscsi_add_hdr(task, sizeof(*hdr));
 332         if (rc)
 333                 return rc;
 334         hdr->opcode = ISCSI_OP_SCSI_CMD;
 335         hdr->flags = ISCSI_ATTR_SIMPLE;
 336         int_to_scsilun(sc->device->lun, &hdr->lun);
 337         task->lun = hdr->lun;
 338         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 339         cmd_len = sc->cmd_len;
 340         if (cmd_len < ISCSI_CDB_SIZE)
 341                 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 342         else if (cmd_len > ISCSI_CDB_SIZE) {
 343                 rc = iscsi_prep_ecdb_ahs(task);
 344                 if (rc)
 345                         return rc;
 346                 cmd_len = ISCSI_CDB_SIZE;
 347         }
 348         memcpy(hdr->cdb, sc->cmnd, cmd_len);
 349
 350         task->imm_count = 0;
 351         if (scsi_get_prot_op(sc) != SCSI_PROT_NORMAL)
 352                 task->protected = true;
 353
 354         transfer_length = scsi_transfer_length(sc);
 355         hdr->data_length = cpu_to_be32(transfer_length);
 356         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 357                 struct iscsi_r2t_info *r2t = &task->unsol_r2t;
 358
 359                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 360                 /*
 361                  * Write counters:
 362                  *
 363                  *      imm_count       bytes to be sent right after
 364                  *                      SCSI PDU Header
 365                  *
 366                  *      unsol_count     bytes(as Data-Out) to be sent
 367                  *                      without R2T ack right after
 368                  *                      immediate data
 369                  *
 370                  *      r2t data_length bytes to be sent via R2T ack's
 371                  *
 372                  *      pad_count       bytes to be sent as zero-padding
 373                  */
 374                 memset(r2t, 0, sizeof(*r2t));
 375
 376                 if (session->imm_data_en) {
 377                         if (transfer_length >= session->first_burst)
 378                                 task->imm_count = min(session->first_burst,
 379                                                         conn->max_xmit_dlength);
 380                         else
 381                                 task->imm_count = min(transfer_length,
 382                                                       conn->max_xmit_dlength);
 383                         hton24(hdr->dlength, task->imm_count);
 384                 } else
 385                         zero_data(hdr->dlength);
 386
 387                 if (!session->initial_r2t_en) {
 388                         r2t->data_length = min(session->first_burst,
 389                                                transfer_length) -
 390                                                task->imm_count;
 391                         r2t->data_offset = task->imm_count;
 392                         r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 393                         r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
 394                 }
 395
 396                 if (!task->unsol_r2t.data_length)
 397                         /* No unsolicit Data-Out's */
 398                         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 399         } else {
 400                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 401                 zero_data(hdr->dlength);
 402
 403                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
 404                         hdr->flags |= ISCSI_FLAG_CMD_READ;
 405         }
 406
 407         /* calculate size of additional header segments (AHSs) */
 408         hdrlength = task->hdr_len - sizeof(*hdr);
 409
 410         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 411         hdrlength /= ISCSI_PAD_LEN;
 412
 413         WARN_ON(hdrlength >= 256);
 414         hdr->hlength = hdrlength & 0xFF;
 415         hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
 416
 417         if (session->tt->init_task && session->tt->init_task(task))
 418                 return -EIO;
 419
 420         task->state = ISCSI_TASK_RUNNING;
 421         session->cmdsn++;
 422
 423         conn->scsicmd_pdus_cnt++;
 424         ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
 425                           "itt 0x%x len %d cmdsn %d win %d]\n",
 426                           sc->sc_data_direction == DMA_TO_DEVICE ?
 427                           "write" : "read", conn->id, sc, sc->cmnd[0],
 428                           task->itt, transfer_length,
 429                           session->cmdsn,
 430                           session->max_cmdsn - session->exp_cmdsn + 1);
 431         return 0;
 432 }
 433
 434 /**
 435  * iscsi_free_task - free a task
 436  * @task: iscsi cmd task
 437  *
 438  * Must be called with session back_lock.
 439  * This function returns the scsi command to scsi-ml or cleans
 440  * up mgmt tasks then returns the task to the pool.
 441  */
 442 static void iscsi_free_task(struct iscsi_task *task)
 443 {
 444         struct iscsi_conn *conn = task->conn;
 445         struct iscsi_session *session = conn->session;
 446         struct scsi_cmnd *sc = task->sc;
 447         int oldstate = task->state;
 448
 449         ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
 450                           task->itt, task->state, task->sc);
 451
 452         session->tt->cleanup_task(task);
 453         task->state = ISCSI_TASK_FREE;
 454         task->sc = NULL;
 455         /*
 456          * login task is preallocated so do not free
 457          */
 458         if (conn->login_task == task)
 459                 return;
 460
 461         kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
 462
 463         if (sc) {
 464                 /* SCSI eh reuses commands to verify us */
 465                 iscsi_cmd(sc)->task = NULL;
 466                 /*
 467                  * queue command may call this to free the task, so
 468                  * it will decide how to return sc to scsi-ml.
 469                  */
 470                 if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
 471                         scsi_done(sc);
 472         }
 473 }
 474
 475 void __iscsi_get_task(struct iscsi_task *task)
 476 {
 477         refcount_inc(&task->refcount);
 478 }
 479 EXPORT_SYMBOL_GPL(__iscsi_get_task);
 480
 481 void __iscsi_put_task(struct iscsi_task *task)
 482 {
 483         if (refcount_dec_and_test(&task->refcount))
 484                 iscsi_free_task(task);
 485 }
 486 EXPORT_SYMBOL_GPL(__iscsi_put_task);
 487
 488 void iscsi_put_task(struct iscsi_task *task)
 489 {
 490         struct iscsi_session *session = task->conn->session;
 491
 492         /* regular RX path uses back_lock */
 493         spin_lock_bh(&session->back_lock);
 494         __iscsi_put_task(task);
 495         spin_unlock_bh(&session->back_lock);
 496 }
 497 EXPORT_SYMBOL_GPL(iscsi_put_task);
 498
 499 /**
 500  * iscsi_complete_task - finish a task
 501  * @task: iscsi cmd task
 502  * @state: state to complete task with
 503  *
 504  * Must be called with session back_lock.
 505  */
 506 static void iscsi_complete_task(struct iscsi_task *task, int state)
 507 {
 508         struct iscsi_conn *conn = task->conn;
 509
 510         ISCSI_DBG_SESSION(conn->session,
 511                           "complete task itt 0x%x state %d sc %p\n",
 512                           task->itt, task->state, task->sc);
 513         if (task->state == ISCSI_TASK_COMPLETED ||
 514             task->state == ISCSI_TASK_ABRT_TMF ||
 515             task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
 516             task->state == ISCSI_TASK_REQUEUE_SCSIQ)
 517                 return;
 518         WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
 519         task->state = state;
 520
 521         if (READ_ONCE(conn->ping_task) == task)
 522                 WRITE_ONCE(conn->ping_task, NULL);
 523
 524         /* release get from queueing */
 525         __iscsi_put_task(task);
 526 }
 527
 528 /**
 529  * iscsi_complete_scsi_task - finish scsi task normally
 530  * @task: iscsi task for scsi cmd
 531  * @exp_cmdsn: expected cmd sn in cpu format
 532  * @max_cmdsn: max cmd sn in cpu format
 533  *
 534  * This is used when drivers do not need or cannot perform
 535  * lower level pdu processing.
 536  *
 537  * Called with session back_lock
 538  */
 539 void iscsi_complete_scsi_task(struct iscsi_task *task,
 540                               uint32_t exp_cmdsn, uint32_t max_cmdsn)
 541 {
 542         struct iscsi_conn *conn = task->conn;
 543
 544         ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 545
 546         conn->last_recv = jiffies;
 547         __iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 548         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 549 }
 550 EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 551
 552 /*
 553  * Must be called with back and frwd lock
 554  */
 555 static bool cleanup_queued_task(struct iscsi_task *task)
 556 {
 557         struct iscsi_conn *conn = task->conn;
 558         bool early_complete = false;
 559
 560         /* Bad target might have completed task while it was still running */
 561         if (task->state == ISCSI_TASK_COMPLETED)
 562                 early_complete = true;
 563
 564         if (!list_empty(&task->running)) {
 565                 list_del_init(&task->running);
 566                 /*
 567                  * If it's on a list but still running, this could be from
 568                  * a bad target sending a rsp early, cleanup from a TMF, or
 569                  * session recovery.
 570                  */
 571                 if (task->state == ISCSI_TASK_RUNNING ||
 572                     task->state == ISCSI_TASK_COMPLETED)
 573                         __iscsi_put_task(task);
 574         }
 575
 576         if (conn->session->running_aborted_task == task) {
 577                 conn->session->running_aborted_task = NULL;
 578                 __iscsi_put_task(task);
 579         }
 580
 581         if (conn->task == task) {
 582                 conn->task = NULL;
 583                 __iscsi_put_task(task);
 584         }
 585
 586         return early_complete;
 587 }
 588
 589 /*
 590  * session frwd lock must be held and if not called for a task that is still
 591  * pending or from the xmit thread, then xmit thread must be suspended
 592  */
 593 static void fail_scsi_task(struct iscsi_task *task, int err)
 594 {
 595         struct iscsi_conn *conn = task->conn;
 596         struct scsi_cmnd *sc;
 597         int state;
 598
 599         spin_lock_bh(&conn->session->back_lock);
 600         if (cleanup_queued_task(task)) {
 601                 spin_unlock_bh(&conn->session->back_lock);
 602                 return;
 603         }
 604
 605         if (task->state == ISCSI_TASK_PENDING) {
 606                 /*
 607                  * cmd never made it to the xmit thread, so we should not count
 608                  * the cmd in the sequencing
 609                  */
 610                 conn->session->queued_cmdsn--;
 611                 /* it was never sent so just complete like normal */
 612                 state = ISCSI_TASK_COMPLETED;
 613         } else if (err == DID_TRANSPORT_DISRUPTED)
 614                 state = ISCSI_TASK_ABRT_SESS_RECOV;
 615         else
 616                 state = ISCSI_TASK_ABRT_TMF;
 617
 618         sc = task->sc;
 619         sc->result = err << 16;
 620         scsi_set_resid(sc, scsi_bufflen(sc));
 621         iscsi_complete_task(task, state);
 622         spin_unlock_bh(&conn->session->back_lock);
 623 }
 624
 625 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 626                                 struct iscsi_task *task)
 627 {
 628         struct iscsi_session *session = conn->session;
 629         struct iscsi_hdr *hdr = task->hdr;
 630         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 631         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 632
 633         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 634                 return -ENOTCONN;
 635
 636         if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
 637                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 638         /*
 639          * pre-format CmdSN for outgoing PDU.
 640          */
 641         nop->cmdsn = cpu_to_be32(session->cmdsn);
 642         if (hdr->itt != RESERVED_ITT) {
 643                 /*
 644                  * TODO: We always use immediate for normal session pdus.
 645                  * If we start to send tmfs or nops as non-immediate then
 646                  * we should start checking the cmdsn numbers for mgmt tasks.
 647                  *
 648                  * During discovery sessions iscsid sends TEXT as non immediate,
 649                  * but we always only send one PDU at a time.
 650                  */
 651                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 652                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 653                         session->queued_cmdsn++;
 654                         session->cmdsn++;
 655                 }
 656         }
 657
 658         if (session->tt->init_task && session->tt->init_task(task))
 659                 return -EIO;
 660
 661         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 662                 session->state = ISCSI_STATE_LOGGING_OUT;
 663
 664         task->state = ISCSI_TASK_RUNNING;
 665         ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 666                           "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 667                           hdr->itt, task->data_count);
 668         return 0;
 669 }
 670
 671 static struct iscsi_task *
 672 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 673                       char *data, uint32_t data_size)
 674 {
 675         struct iscsi_session *session = conn->session;
 676         struct iscsi_host *ihost = shost_priv(session->host);
 677         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 678         struct iscsi_task *task;
 679         itt_t itt;
 680
 681         if (session->state == ISCSI_STATE_TERMINATE ||
 682             !test_bit(ISCSI_CONN_FLAG_BOUND, &conn->flags))
 683                 return NULL;
 684
 685         if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 686                 /*
 687                  * Login and Text are sent serially, in
 688                  * request-followed-by-response sequence.
 689                  * Same task can be used. Same ITT must be used.
 690                  * Note that login_task is preallocated at conn_create().
 691                  */
 692                 if (conn->login_task->state != ISCSI_TASK_FREE) {
 693                         iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 694                                           "progress. Cannot start new task.\n");
 695                         return NULL;
 696                 }
 697
 698                 if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
 699                         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);
 700                         return NULL;
 701                 }
 702
 703                 task = conn->login_task;
 704         } else {
 705                 if (session->state != ISCSI_STATE_LOGGED_IN)
 706                         return NULL;
 707
 708                 if (data_size != 0) {
 709                         iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
 710                         return NULL;
 711                 }
 712
 713                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 714                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 715
 716                 if (!kfifo_out(&session->cmdpool.queue,
 717                                  (void*)&task, sizeof(void*)))
 718                         return NULL;
 719         }
 720         /*
 721          * released in complete pdu for task we expect a response for, and
 722          * released by the lld when it has transmitted the task for
 723          * pdus we do not expect a response for.
 724          */
 725         refcount_set(&task->refcount, 1);
 726         task->conn = conn;
 727         task->sc = NULL;
 728         INIT_LIST_HEAD(&task->running);
 729         task->state = ISCSI_TASK_PENDING;
 730
 731         if (data_size) {
 732                 memcpy(task->data, data, data_size);
 733                 task->data_count = data_size;
 734         } else
 735                 task->data_count = 0;
 736
 737         if (conn->session->tt->alloc_pdu) {
 738                 if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 739                         iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 740                                          "pdu for mgmt task.\n");
 741                         goto free_task;
 742                 }
 743         }
 744
 745         itt = task->hdr->itt;
 746         task->hdr_len = sizeof(struct iscsi_hdr);
 747         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 748
 749         if (hdr->itt != RESERVED_ITT) {
 750                 if (session->tt->parse_pdu_itt)
 751                         task->hdr->itt = itt;
 752                 else
 753                         task->hdr->itt = build_itt(task->itt,
 754                                                    task->conn->session->age);
 755         }
 756
 757         if (unlikely(READ_ONCE(conn->ping_task) == INVALID_SCSI_TASK))
 758                 WRITE_ONCE(conn->ping_task, task);
 759
 760         if (!ihost->workq) {
 761                 if (iscsi_prep_mgmt_task(conn, task))
 762                         goto free_task;
 763
 764                 if (session->tt->xmit_task(task))
 765                         goto free_task;
 766         } else {
 767                 list_add_tail(&task->running, &conn->mgmtqueue);
 768                 iscsi_conn_queue_work(conn);
 769         }
 770
 771         return task;
 772
 773 free_task:
 774         /* regular RX path uses back_lock */
 775         spin_lock(&session->back_lock);
 776         __iscsi_put_task(task);
 777         spin_unlock(&session->back_lock);
 778         return NULL;
 779 }
 780
 781 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 782                         char *data, uint32_t data_size)
 783 {
 784         struct iscsi_conn *conn = cls_conn->dd_data;
 785         struct iscsi_session *session = conn->session;
 786         int err = 0;
 787
 788         spin_lock_bh(&session->frwd_lock);
 789         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 790                 err = -EPERM;
 791         spin_unlock_bh(&session->frwd_lock);
 792         return err;
 793 }
 794 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 795
 796 /**
 797  * iscsi_scsi_cmd_rsp - SCSI Command Response processing
 798  * @conn: iscsi connection
 799  * @hdr: iscsi header
 800  * @task: scsi command task
 801  * @data: cmd data buffer
 802  * @datalen: len of buffer
 803  *
 804  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 805  * then completes the command and task. called under back_lock
 806  **/
 807 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 808                                struct iscsi_task *task, char *data,
 809                                int datalen)
 810 {
 811         struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
 812         struct iscsi_session *session = conn->session;
 813         struct scsi_cmnd *sc = task->sc;
 814
 815         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 816         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 817
 818         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 819
 820         if (task->protected) {
 821                 sector_t sector;
 822                 u8 ascq;
 823
 824                 /**
 825                  * Transports that didn't implement check_protection
 826                  * callback but still published T10-PI support to scsi-mid
 827                  * deserve this BUG_ON.
 828                  **/
 829                 BUG_ON(!session->tt->check_protection);
 830
 831                 ascq = session->tt->check_protection(task, &sector);
 832                 if (ascq) {
 833                         scsi_build_sense(sc, 1, ILLEGAL_REQUEST, 0x10, ascq);
 834                         scsi_set_sense_information(sc->sense_buffer,
 835                                                    SCSI_SENSE_BUFFERSIZE,
 836                                                    sector);
 837                         goto out;
 838                 }
 839         }
 840
 841         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 842                 sc->result = DID_ERROR << 16;
 843                 goto out;
 844         }
 845
 846         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 847                 uint16_t senselen;
 848
 849                 if (datalen < 2) {
 850 invalid_datalen:
 851                         iscsi_conn_printk(KERN_ERR,  conn,
 852                                          "Got CHECK_CONDITION but invalid data "
 853                                          "buffer size of %d\n", datalen);
 854                         sc->result = DID_BAD_TARGET << 16;
 855                         goto out;
 856                 }
 857
 858                 senselen = get_unaligned_be16(data);
 859                 if (datalen < senselen)
 860                         goto invalid_datalen;
 861
 862                 memcpy(sc->sense_buffer, data + 2,
 863                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 864                 ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 865                                   min_t(uint16_t, senselen,
 866                                   SCSI_SENSE_BUFFERSIZE));
 867         }
 868
 869         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 870                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 871                 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 872         }
 873
 874         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 875                            ISCSI_FLAG_CMD_OVERFLOW)) {
 876                 int res_count = be32_to_cpu(rhdr->residual_count);
 877
 878                 if (res_count > 0 &&
 879                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 880                      res_count <= scsi_bufflen(sc)))
 881                         /* write side for bidi or uni-io set_resid */
 882                         scsi_set_resid(sc, res_count);
 883                 else
 884                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 885         }
 886 out:
 887         ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 888                           sc, sc->result, task->itt);
 889         conn->scsirsp_pdus_cnt++;
 890         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 891 }
 892
 893 /**
 894  * iscsi_data_in_rsp - SCSI Data-In Response processing
 895  * @conn: iscsi connection
 896  * @hdr:  iscsi pdu
 897  * @task: scsi command task
 898  *
 899  * iscsi_data_in_rsp sets up the scsi_cmnd fields based on the data received
 900  * then completes the command and task. called under back_lock
 901  **/
 902 static void
 903 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 904                   struct iscsi_task *task)
 905 {
 906         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 907         struct scsi_cmnd *sc = task->sc;
 908
 909         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 910                 return;
 911
 912         iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 913         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 914         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 915         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 916                            ISCSI_FLAG_DATA_OVERFLOW)) {
 917                 int res_count = be32_to_cpu(rhdr->residual_count);
 918
 919                 if (res_count > 0 &&
 920                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 921                      res_count <= sc->sdb.length))
 922                         scsi_set_resid(sc, res_count);
 923                 else
 924                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 925         }
 926
 927         ISCSI_DBG_SESSION(conn->session, "data in with status done "
 928                           "[sc %p res %d itt 0x%x]\n",
 929                           sc, sc->result, task->itt);
 930         conn->scsirsp_pdus_cnt++;
 931         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 932 }
 933
 934 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 935 {
 936         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 937         struct iscsi_session *session = conn->session;
 938
 939         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 940         conn->tmfrsp_pdus_cnt++;
 941
 942         if (session->tmf_state != TMF_QUEUED)
 943                 return;
 944
 945         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 946                 session->tmf_state = TMF_SUCCESS;
 947         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 948                 session->tmf_state = TMF_NOT_FOUND;
 949         else
 950                 session->tmf_state = TMF_FAILED;
 951         wake_up(&session->ehwait);
 952 }
 953
 954 static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 955 {
 956         struct iscsi_nopout hdr;
 957         struct iscsi_task *task;
 958
 959         if (!rhdr) {
 960                 if (READ_ONCE(conn->ping_task))
 961                         return -EINVAL;
 962                 WRITE_ONCE(conn->ping_task, INVALID_SCSI_TASK);
 963         }
 964
 965         memset(&hdr, 0, sizeof(struct iscsi_nopout));
 966         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 967         hdr.flags = ISCSI_FLAG_CMD_FINAL;
 968
 969         if (rhdr) {
 970                 hdr.lun = rhdr->lun;
 971                 hdr.ttt = rhdr->ttt;
 972                 hdr.itt = RESERVED_ITT;
 973         } else
 974                 hdr.ttt = RESERVED_ITT;
 975
 976         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 977         if (!task) {
 978                 if (!rhdr)
 979                         WRITE_ONCE(conn->ping_task, NULL);
 980                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 981                 return -EIO;
 982         } else if (!rhdr) {
 983                 /* only track our nops */
 984                 conn->last_ping = jiffies;
 985         }
 986
 987         return 0;
 988 }
 989
 990 /**
 991  * iscsi_nop_out_rsp - SCSI NOP Response processing
 992  * @task: scsi command task
 993  * @nop: the nop structure
 994  * @data: where to put the data
 995  * @datalen: length of data
 996  *
 997  * iscsi_nop_out_rsp handles nop response from use or
 998  * from user space. called under back_lock
 999  **/
1000 static int iscsi_nop_out_rsp(struct iscsi_task *task,
1001                              struct iscsi_nopin *nop, char *data, int datalen)
1002 {
1003         struct iscsi_conn *conn = task->conn;
1004         int rc = 0;
1005
1006         if (READ_ONCE(conn->ping_task) != task) {
1007                 /*
1008                  * If this is not in response to one of our
1009                  * nops then it must be from userspace.
1010                  */
1011                 if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
1012                                    data, datalen))
1013                         rc = ISCSI_ERR_CONN_FAILED;
1014         } else
1015                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1016         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1017         return rc;
1018 }
1019
1020 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1021                                char *data, int datalen)
1022 {
1023         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1024         struct iscsi_hdr rejected_pdu;
1025         int opcode, rc = 0;
1026
1027         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1028
1029         if (ntoh24(reject->dlength) > datalen ||
1030             ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1031                 iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1032                                   "pdu. Invalid data length (pdu dlength "
1033                                   "%u, datalen %d\n", ntoh24(reject->dlength),
1034                                   datalen);
1035                 return ISCSI_ERR_PROTO;
1036         }
1037         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1038         opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1039
1040         switch (reject->reason) {
1041         case ISCSI_REASON_DATA_DIGEST_ERROR:
1042                 iscsi_conn_printk(KERN_ERR, conn,
1043                                   "pdu (op 0x%x itt 0x%x) rejected "
1044                                   "due to DataDigest error.\n",
1045                                   opcode, rejected_pdu.itt);
1046                 break;
1047         case ISCSI_REASON_IMM_CMD_REJECT:
1048                 iscsi_conn_printk(KERN_ERR, conn,
1049                                   "pdu (op 0x%x itt 0x%x) rejected. Too many "
1050                                   "immediate commands.\n",
1051                                   opcode, rejected_pdu.itt);
1052                 /*
1053                  * We only send one TMF at a time so if the target could not
1054                  * handle it, then it should get fixed (RFC mandates that
1055                  * a target can handle one immediate TMF per conn).
1056                  *
1057                  * For nops-outs, we could have sent more than one if
1058                  * the target is sending us lots of nop-ins
1059                  */
1060                 if (opcode != ISCSI_OP_NOOP_OUT)
1061                         return 0;
1062
1063                 if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1064                         /*
1065                          * nop-out in response to target's nop-out rejected.
1066                          * Just resend.
1067                          */
1068                         /* In RX path we are under back lock */
1069                         spin_unlock(&conn->session->back_lock);
1070                         spin_lock(&conn->session->frwd_lock);
1071                         iscsi_send_nopout(conn,
1072                                           (struct iscsi_nopin*)&rejected_pdu);
1073                         spin_unlock(&conn->session->frwd_lock);
1074                         spin_lock(&conn->session->back_lock);
1075                 } else {
1076                         struct iscsi_task *task;
1077                         /*
1078                          * Our nop as ping got dropped. We know the target
1079                          * and transport are ok so just clean up
1080                          */
1081                         task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1082                         if (!task) {
1083                                 iscsi_conn_printk(KERN_ERR, conn,
1084                                                  "Invalid pdu reject. Could "
1085                                                  "not lookup rejected task.\n");
1086                                 rc = ISCSI_ERR_BAD_ITT;
1087                         } else
1088                                 rc = iscsi_nop_out_rsp(task,
1089                                         (struct iscsi_nopin*)&rejected_pdu,
1090                                         NULL, 0);
1091                 }
1092                 break;
1093         default:
1094                 iscsi_conn_printk(KERN_ERR, conn,
1095                                   "pdu (op 0x%x itt 0x%x) rejected. Reason "
1096                                   "code 0x%x\n", rejected_pdu.opcode,
1097                                   rejected_pdu.itt, reject->reason);
1098                 break;
1099         }
1100         return rc;
1101 }
1102
1103 /**
1104  * iscsi_itt_to_task - look up task by itt
1105  * @conn: iscsi connection
1106  * @itt: itt
1107  *
1108  * This should be used for mgmt tasks like login and nops, or if
1109  * the LDD's itt space does not include the session age.
1110  *
1111  * The session back_lock must be held.
1112  */
1113 struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1114 {
1115         struct iscsi_session *session = conn->session;
1116         int i;
1117
1118         if (itt == RESERVED_ITT)
1119                 return NULL;
1120
1121         if (session->tt->parse_pdu_itt)
1122                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1123         else
1124                 i = get_itt(itt);
1125         if (i >= session->cmds_max)
1126                 return NULL;
1127
1128         return session->cmds[i];
1129 }
1130 EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1131
1132 /**
1133  * __iscsi_complete_pdu - complete pdu
1134  * @conn: iscsi conn
1135  * @hdr: iscsi header
1136  * @data: data buffer
1137  * @datalen: len of data buffer
1138  *
1139  * Completes pdu processing by freeing any resources allocated at
1140  * queuecommand or send generic. session back_lock must be held and verify
1141  * itt must have been called.
1142  */
1143 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1144                          char *data, int datalen)
1145 {
1146         struct iscsi_session *session = conn->session;
1147         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1148         struct iscsi_task *task;
1149         uint32_t itt;
1150
1151         conn->last_recv = jiffies;
1152         rc = iscsi_verify_itt(conn, hdr->itt);
1153         if (rc)
1154                 return rc;
1155
1156         if (hdr->itt != RESERVED_ITT)
1157                 itt = get_itt(hdr->itt);
1158         else
1159                 itt = ~0U;
1160
1161         ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1162                           opcode, conn->id, itt, datalen);
1163
1164         if (itt == ~0U) {
1165                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1166
1167                 switch(opcode) {
1168                 case ISCSI_OP_NOOP_IN:
1169                         if (datalen) {
1170                                 rc = ISCSI_ERR_PROTO;
1171                                 break;
1172                         }
1173
1174                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1175                                 break;
1176
1177                         /* In RX path we are under back lock */
1178                         spin_unlock(&session->back_lock);
1179                         spin_lock(&session->frwd_lock);
1180                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1181                         spin_unlock(&session->frwd_lock);
1182                         spin_lock(&session->back_lock);
1183                         break;
1184                 case ISCSI_OP_REJECT:
1185                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
1186                         break;
1187                 case ISCSI_OP_ASYNC_EVENT:
1188                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1189                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1190                                 rc = ISCSI_ERR_CONN_FAILED;
1191                         break;
1192                 default:
1193                         rc = ISCSI_ERR_BAD_OPCODE;
1194                         break;
1195                 }
1196                 goto out;
1197         }
1198
1199         switch(opcode) {
1200         case ISCSI_OP_SCSI_CMD_RSP:
1201         case ISCSI_OP_SCSI_DATA_IN:
1202                 task = iscsi_itt_to_ctask(conn, hdr->itt);
1203                 if (!task)
1204                         return ISCSI_ERR_BAD_ITT;
1205                 task->last_xfer = jiffies;
1206                 break;
1207         case ISCSI_OP_R2T:
1208                 /*
1209                  * LLD handles R2Ts if they need to.
1210                  */
1211                 return 0;
1212         case ISCSI_OP_LOGOUT_RSP:
1213         case ISCSI_OP_LOGIN_RSP:
1214         case ISCSI_OP_TEXT_RSP:
1215         case ISCSI_OP_SCSI_TMFUNC_RSP:
1216         case ISCSI_OP_NOOP_IN:
1217                 task = iscsi_itt_to_task(conn, hdr->itt);
1218                 if (!task)
1219                         return ISCSI_ERR_BAD_ITT;
1220                 break;
1221         default:
1222                 return ISCSI_ERR_BAD_OPCODE;
1223         }
1224
1225         switch(opcode) {
1226         case ISCSI_OP_SCSI_CMD_RSP:
1227                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1228                 break;
1229         case ISCSI_OP_SCSI_DATA_IN:
1230                 iscsi_data_in_rsp(conn, hdr, task);
1231                 break;
1232         case ISCSI_OP_LOGOUT_RSP:
1233                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1234                 if (datalen) {
1235                         rc = ISCSI_ERR_PROTO;
1236                         break;
1237                 }
1238                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1239                 goto recv_pdu;
1240         case ISCSI_OP_LOGIN_RSP:
1241         case ISCSI_OP_TEXT_RSP:
1242                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1243                 /*
1244                  * login related PDU's exp_statsn is handled in
1245                  * userspace
1246                  */
1247                 goto recv_pdu;
1248         case ISCSI_OP_SCSI_TMFUNC_RSP:
1249                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1250                 if (datalen) {
1251                         rc = ISCSI_ERR_PROTO;
1252                         break;
1253                 }
1254
1255                 iscsi_tmf_rsp(conn, hdr);
1256                 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1257                 break;
1258         case ISCSI_OP_NOOP_IN:
1259                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1260                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1261                         rc = ISCSI_ERR_PROTO;
1262                         break;
1263                 }
1264                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1265
1266                 rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1267                                        data, datalen);
1268                 break;
1269         default:
1270                 rc = ISCSI_ERR_BAD_OPCODE;
1271                 break;
1272         }
1273
1274 out:
1275         return rc;
1276 recv_pdu:
1277         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1278                 rc = ISCSI_ERR_CONN_FAILED;
1279         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1280         return rc;
1281 }
1282 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1283
1284 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1285                        char *data, int datalen)
1286 {
1287         int rc;
1288
1289         spin_lock(&conn->session->back_lock);
1290         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1291         spin_unlock(&conn->session->back_lock);
1292         return rc;
1293 }
1294 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1295
1296 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1297 {
1298         struct iscsi_session *session = conn->session;
1299         int age = 0, i = 0;
1300
1301         if (itt == RESERVED_ITT)
1302                 return 0;
1303
1304         if (session->tt->parse_pdu_itt)
1305                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
1306         else {
1307                 i = get_itt(itt);
1308                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1309         }
1310
1311         if (age != session->age) {
1312                 iscsi_conn_printk(KERN_ERR, conn,
1313                                   "received itt %x expected session age (%x)\n",
1314                                   (__force u32)itt, session->age);
1315                 return ISCSI_ERR_BAD_ITT;
1316         }
1317
1318         if (i >= session->cmds_max) {
1319                 iscsi_conn_printk(KERN_ERR, conn,
1320                                   "received invalid itt index %u (max cmds "
1321                                    "%u.\n", i, session->cmds_max);
1322                 return ISCSI_ERR_BAD_ITT;
1323         }
1324         return 0;
1325 }
1326 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1327
1328 /**
1329  * iscsi_itt_to_ctask - look up ctask by itt
1330  * @conn: iscsi connection
1331  * @itt: itt
1332  *
1333  * This should be used for cmd tasks.
1334  *
1335  * The session back_lock must be held.
1336  */
1337 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1338 {
1339         struct iscsi_task *task;
1340
1341         if (iscsi_verify_itt(conn, itt))
1342                 return NULL;
1343
1344         task = iscsi_itt_to_task(conn, itt);
1345         if (!task || !task->sc)
1346                 return NULL;
1347
1348         if (iscsi_cmd(task->sc)->age != conn->session->age) {
1349                 iscsi_session_printk(KERN_ERR, conn->session,
1350                                   "task's session age %d, expected %d\n",
1351                                   iscsi_cmd(task->sc)->age, conn->session->age);
1352                 return NULL;
1353         }
1354
1355         return task;
1356 }
1357 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1358
1359 void iscsi_session_failure(struct iscsi_session *session,
1360                            enum iscsi_err err)
1361 {
1362         struct iscsi_conn *conn;
1363
1364         spin_lock_bh(&session->frwd_lock);
1365         conn = session->leadconn;
1366         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1367                 spin_unlock_bh(&session->frwd_lock);
1368                 return;
1369         }
1370
1371         iscsi_get_conn(conn->cls_conn);
1372         spin_unlock_bh(&session->frwd_lock);
1373         /*
1374          * if the host is being removed bypass the connection
1375          * recovery initialization because we are going to kill
1376          * the session.
1377          */
1378         if (err == ISCSI_ERR_INVALID_HOST)
1379                 iscsi_conn_error_event(conn->cls_conn, err);
1380         else
1381                 iscsi_conn_failure(conn, err);
1382         iscsi_put_conn(conn->cls_conn);
1383 }
1384 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1385
1386 static bool iscsi_set_conn_failed(struct iscsi_conn *conn)
1387 {
1388         struct iscsi_session *session = conn->session;
1389
1390         if (session->state == ISCSI_STATE_FAILED)
1391                 return false;
1392
1393         if (conn->stop_stage == 0)
1394                 session->state = ISCSI_STATE_FAILED;
1395
1396         set_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags);
1397         set_bit(ISCSI_CONN_FLAG_SUSPEND_RX, &conn->flags);
1398         return true;
1399 }
1400
1401 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1402 {
1403         struct iscsi_session *session = conn->session;
1404         bool needs_evt;
1405
1406         spin_lock_bh(&session->frwd_lock);
1407         needs_evt = iscsi_set_conn_failed(conn);
1408         spin_unlock_bh(&session->frwd_lock);
1409
1410         if (needs_evt)
1411                 iscsi_conn_error_event(conn->cls_conn, err);
1412 }
1413 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1414
1415 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1416 {
1417         struct iscsi_session *session = conn->session;
1418
1419         /*
1420          * Check for iSCSI window and take care of CmdSN wrap-around
1421          */
1422         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1423                 ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1424                                   "%u MaxCmdSN %u CmdSN %u/%u\n",
1425                                   session->exp_cmdsn, session->max_cmdsn,
1426                                   session->cmdsn, session->queued_cmdsn);
1427                 return -ENOSPC;
1428         }
1429         return 0;
1430 }
1431
1432 static int iscsi_xmit_task(struct iscsi_conn *conn, struct iscsi_task *task,
1433                            bool was_requeue)
1434 {
1435         int rc;
1436
1437         spin_lock_bh(&conn->session->back_lock);
1438
1439         if (!conn->task) {
1440                 /* Take a ref so we can access it after xmit_task() */
1441                 __iscsi_get_task(task);
1442         } else {
1443                 /* Already have a ref from when we failed to send it last call */
1444                 conn->task = NULL;
1445         }
1446
1447         /*
1448          * If this was a requeue for a R2T we have an extra ref on the task in
1449          * case a bad target sends a cmd rsp before we have handled the task.
1450          */
1451         if (was_requeue)
1452                 __iscsi_put_task(task);
1453
1454         /*
1455          * Do this after dropping the extra ref because if this was a requeue
1456          * it's removed from that list and cleanup_queued_task would miss it.
1457          */
1458         if (test_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags)) {
1459                 /*
1460                  * Save the task and ref in case we weren't cleaning up this
1461                  * task and get woken up again.
1462                  */
1463                 conn->task = task;
1464                 spin_unlock_bh(&conn->session->back_lock);
1465                 return -ENODATA;
1466         }
1467         spin_unlock_bh(&conn->session->back_lock);
1468
1469         spin_unlock_bh(&conn->session->frwd_lock);
1470         rc = conn->session->tt->xmit_task(task);
1471         spin_lock_bh(&conn->session->frwd_lock);
1472         if (!rc) {
1473                 /* done with this task */
1474                 task->last_xfer = jiffies;
1475         }
1476         /* regular RX path uses back_lock */
1477         spin_lock(&conn->session->back_lock);
1478         if (rc && task->state == ISCSI_TASK_RUNNING) {
1479                 /*
1480                  * get an extra ref that is released next time we access it
1481                  * as conn->task above.
1482                  */
1483                 __iscsi_get_task(task);
1484                 conn->task = task;
1485         }
1486
1487         __iscsi_put_task(task);
1488         spin_unlock(&conn->session->back_lock);
1489         return rc;
1490 }
1491
1492 /**
1493  * iscsi_requeue_task - requeue task to run from session workqueue
1494  * @task: task to requeue
1495  *
1496  * Callers must have taken a ref to the task that is going to be requeued.
1497  */
1498 void iscsi_requeue_task(struct iscsi_task *task)
1499 {
1500         struct iscsi_conn *conn = task->conn;
1501
1502         /*
1503          * this may be on the requeue list already if the xmit_task callout
1504          * is handling the r2ts while we are adding new ones
1505          */
1506         spin_lock_bh(&conn->session->frwd_lock);
1507         if (list_empty(&task->running)) {
1508                 list_add_tail(&task->running, &conn->requeue);
1509         } else {
1510                 /*
1511                  * Don't need the extra ref since it's already requeued and
1512                  * has a ref.
1513                  */
1514                 iscsi_put_task(task);
1515         }
1516         iscsi_conn_queue_work(conn);
1517         spin_unlock_bh(&conn->session->frwd_lock);
1518 }
1519 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1520
1521 /**
1522  * iscsi_data_xmit - xmit any command into the scheduled connection
1523  * @conn: iscsi connection
1524  *
1525  * Notes:
1526  *      The function can return -EAGAIN in which case the caller must
1527  *      re-schedule it again later or recover. '0' return code means
1528  *      successful xmit.
1529  **/
1530 static int iscsi_data_xmit(struct iscsi_conn *conn)
1531 {
1532         struct iscsi_task *task;
1533         int rc = 0;
1534
1535         spin_lock_bh(&conn->session->frwd_lock);
1536         if (test_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags)) {
1537                 ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1538                 spin_unlock_bh(&conn->session->frwd_lock);
1539                 return -ENODATA;
1540         }
1541
1542         if (conn->task) {
1543                 rc = iscsi_xmit_task(conn, conn->task, false);
1544                 if (rc)
1545                         goto done;
1546         }
1547
1548         /*
1549          * process mgmt pdus like nops before commands since we should
1550          * only have one nop-out as a ping from us and targets should not
1551          * overflow us with nop-ins
1552          */
1553 check_mgmt:
1554         while (!list_empty(&conn->mgmtqueue)) {
1555                 task = list_entry(conn->mgmtqueue.next, struct iscsi_task,
1556                                   running);
1557                 list_del_init(&task->running);
1558                 if (iscsi_prep_mgmt_task(conn, task)) {
1559                         /* regular RX path uses back_lock */
1560                         spin_lock_bh(&conn->session->back_lock);
1561                         __iscsi_put_task(task);
1562                         spin_unlock_bh(&conn->session->back_lock);
1563                         continue;
1564                 }
1565                 rc = iscsi_xmit_task(conn, task, false);
1566                 if (rc)
1567                         goto done;
1568         }
1569
1570         /* process pending command queue */
1571         while (!list_empty(&conn->cmdqueue)) {
1572                 task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1573                                   running);
1574                 list_del_init(&task->running);
1575                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1576                         fail_scsi_task(task, DID_IMM_RETRY);
1577                         continue;
1578                 }
1579                 rc = iscsi_prep_scsi_cmd_pdu(task);
1580                 if (rc) {
1581                         if (rc == -ENOMEM || rc == -EACCES)
1582                                 fail_scsi_task(task, DID_IMM_RETRY);
1583                         else
1584                                 fail_scsi_task(task, DID_ABORT);
1585                         continue;
1586                 }
1587                 rc = iscsi_xmit_task(conn, task, false);
1588                 if (rc)
1589                         goto done;
1590                 /*
1591                  * we could continuously get new task requests so
1592                  * we need to check the mgmt queue for nops that need to
1593                  * be sent to aviod starvation
1594                  */
1595                 if (!list_empty(&conn->mgmtqueue))
1596                         goto check_mgmt;
1597         }
1598
1599         while (!list_empty(&conn->requeue)) {
1600                 /*
1601                  * we always do fastlogout - conn stop code will clean up.
1602                  */
1603                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1604                         break;
1605
1606                 task = list_entry(conn->requeue.next, struct iscsi_task,
1607                                   running);
1608
1609                 if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1610                         break;
1611
1612                 list_del_init(&task->running);
1613                 rc = iscsi_xmit_task(conn, task, true);
1614                 if (rc)
1615                         goto done;
1616                 if (!list_empty(&conn->mgmtqueue))
1617                         goto check_mgmt;
1618         }
1619         spin_unlock_bh(&conn->session->frwd_lock);
1620         return -ENODATA;
1621
1622 done:
1623         spin_unlock_bh(&conn->session->frwd_lock);
1624         return rc;
1625 }
1626
1627 static void iscsi_xmitworker(struct work_struct *work)
1628 {
1629         struct iscsi_conn *conn =
1630                 container_of(work, struct iscsi_conn, xmitwork);
1631         int rc;
1632         /*
1633          * serialize Xmit worker on a per-connection basis.
1634          */
1635         do {
1636                 rc = iscsi_data_xmit(conn);
1637         } while (rc >= 0 || rc == -EAGAIN);
1638 }
1639
1640 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1641                                                   struct scsi_cmnd *sc)
1642 {
1643         struct iscsi_task *task;
1644
1645         if (!kfifo_out(&conn->session->cmdpool.queue,
1646                          (void *) &task, sizeof(void *)))
1647                 return NULL;
1648
1649         iscsi_cmd(sc)->age = conn->session->age;
1650         iscsi_cmd(sc)->task = task;
1651
1652         refcount_set(&task->refcount, 1);
1653         task->state = ISCSI_TASK_PENDING;
1654         task->conn = conn;
1655         task->sc = sc;
1656         task->have_checked_conn = false;
1657         task->last_timeout = jiffies;
1658         task->last_xfer = jiffies;
1659         task->protected = false;
1660         INIT_LIST_HEAD(&task->running);
1661         return task;
1662 }
1663
1664 enum {
1665         FAILURE_BAD_HOST = 1,
1666         FAILURE_SESSION_FAILED,
1667         FAILURE_SESSION_FREED,
1668         FAILURE_WINDOW_CLOSED,
1669         FAILURE_OOM,
1670         FAILURE_SESSION_TERMINATE,
1671         FAILURE_SESSION_IN_RECOVERY,
1672         FAILURE_SESSION_RECOVERY_TIMEOUT,
1673         FAILURE_SESSION_LOGGING_OUT,
1674         FAILURE_SESSION_NOT_READY,
1675 };
1676
1677 int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1678 {
1679         struct iscsi_cls_session *cls_session;
1680         struct iscsi_host *ihost;
1681         int reason = 0;
1682         struct iscsi_session *session;
1683         struct iscsi_conn *conn;
1684         struct iscsi_task *task = NULL;
1685
1686         sc->result = 0;
1687         iscsi_cmd(sc)->task = NULL;
1688
1689         ihost = shost_priv(host);
1690
1691         cls_session = starget_to_session(scsi_target(sc->device));
1692         session = cls_session->dd_data;
1693         spin_lock_bh(&session->frwd_lock);
1694
1695         reason = iscsi_session_chkready(cls_session);
1696         if (reason) {
1697                 sc->result = reason;
1698                 goto fault;
1699         }
1700
1701         if (session->state != ISCSI_STATE_LOGGED_IN) {
1702                 /*
1703                  * to handle the race between when we set the recovery state
1704                  * and block the session we requeue here (commands could
1705                  * be entering our queuecommand while a block is starting
1706                  * up because the block code is not locked)
1707                  */
1708                 switch (session->state) {
1709                 case ISCSI_STATE_FAILED:
1710                         /*
1711                          * cmds should fail during shutdown, if the session
1712                          * state is bad, allowing completion to happen
1713                          */
1714                         if (unlikely(system_state != SYSTEM_RUNNING)) {
1715                                 reason = FAILURE_SESSION_FAILED;
1716                                 sc->result = DID_NO_CONNECT << 16;
1717                                 break;
1718                         }
1719                         fallthrough;
1720                 case ISCSI_STATE_IN_RECOVERY:
1721                         reason = FAILURE_SESSION_IN_RECOVERY;
1722                         sc->result = DID_IMM_RETRY << 16;
1723                         break;
1724                 case ISCSI_STATE_LOGGING_OUT:
1725                         reason = FAILURE_SESSION_LOGGING_OUT;
1726                         sc->result = DID_IMM_RETRY << 16;
1727                         break;
1728                 case ISCSI_STATE_RECOVERY_FAILED:
1729                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1730                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1731                         break;
1732                 case ISCSI_STATE_TERMINATE:
1733                         reason = FAILURE_SESSION_TERMINATE;
1734                         sc->result = DID_NO_CONNECT << 16;
1735                         break;
1736                 default:
1737                         reason = FAILURE_SESSION_FREED;
1738                         sc->result = DID_NO_CONNECT << 16;
1739                 }
1740                 goto fault;
1741         }
1742
1743         conn = session->leadconn;
1744         if (!conn) {
1745                 reason = FAILURE_SESSION_FREED;
1746                 sc->result = DID_NO_CONNECT << 16;
1747                 goto fault;
1748         }
1749
1750         if (test_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags)) {
1751                 reason = FAILURE_SESSION_IN_RECOVERY;
1752                 sc->result = DID_REQUEUE << 16;
1753                 goto fault;
1754         }
1755
1756         if (iscsi_check_cmdsn_window_closed(conn)) {
1757                 reason = FAILURE_WINDOW_CLOSED;
1758                 goto reject;
1759         }
1760
1761         task = iscsi_alloc_task(conn, sc);
1762         if (!task) {
1763                 reason = FAILURE_OOM;
1764                 goto reject;
1765         }
1766
1767         if (!ihost->workq) {
1768                 reason = iscsi_prep_scsi_cmd_pdu(task);
1769                 if (reason) {
1770                         if (reason == -ENOMEM ||  reason == -EACCES) {
1771                                 reason = FAILURE_OOM;
1772                                 goto prepd_reject;
1773                         } else {
1774                                 sc->result = DID_ABORT << 16;
1775                                 goto prepd_fault;
1776                         }
1777                 }
1778                 if (session->tt->xmit_task(task)) {
1779                         session->cmdsn--;
1780                         reason = FAILURE_SESSION_NOT_READY;
1781                         goto prepd_reject;
1782                 }
1783         } else {
1784                 list_add_tail(&task->running, &conn->cmdqueue);
1785                 iscsi_conn_queue_work(conn);
1786         }
1787
1788         session->queued_cmdsn++;
1789         spin_unlock_bh(&session->frwd_lock);
1790         return 0;
1791
1792 prepd_reject:
1793         spin_lock_bh(&session->back_lock);
1794         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1795         spin_unlock_bh(&session->back_lock);
1796 reject:
1797         spin_unlock_bh(&session->frwd_lock);
1798         ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1799                           sc->cmnd[0], reason);
1800         return SCSI_MLQUEUE_TARGET_BUSY;
1801
1802 prepd_fault:
1803         spin_lock_bh(&session->back_lock);
1804         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1805         spin_unlock_bh(&session->back_lock);
1806 fault:
1807         spin_unlock_bh(&session->frwd_lock);
1808         ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1809                           sc->cmnd[0], reason);
1810         scsi_set_resid(sc, scsi_bufflen(sc));
1811         scsi_done(sc);
1812         return 0;
1813 }
1814 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1815
1816 int iscsi_target_alloc(struct scsi_target *starget)
1817 {
1818         struct iscsi_cls_session *cls_session = starget_to_session(starget);
1819         struct iscsi_session *session = cls_session->dd_data;
1820
1821         starget->can_queue = session->scsi_cmds_max;
1822         return 0;
1823 }
1824 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1825
1826 static void iscsi_tmf_timedout(struct timer_list *t)
1827 {
1828         struct iscsi_session *session = from_timer(session, t, tmf_timer);
1829
1830         spin_lock(&session->frwd_lock);
1831         if (session->tmf_state == TMF_QUEUED) {
1832                 session->tmf_state = TMF_TIMEDOUT;
1833                 ISCSI_DBG_EH(session, "tmf timedout\n");
1834                 /* unblock eh_abort() */
1835                 wake_up(&session->ehwait);
1836         }
1837         spin_unlock(&session->frwd_lock);
1838 }
1839
1840 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1841                                    struct iscsi_tm *hdr, int age,
1842                                    int timeout)
1843         __must_hold(&session->frwd_lock)
1844 {
1845         struct iscsi_session *session = conn->session;
1846         struct iscsi_task *task;
1847
1848         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1849                                       NULL, 0);
1850         if (!task) {
1851                 spin_unlock_bh(&session->frwd_lock);
1852                 iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1853                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1854                 spin_lock_bh(&session->frwd_lock);
1855                 return -EPERM;
1856         }
1857         conn->tmfcmd_pdus_cnt++;
1858         session->tmf_timer.expires = timeout * HZ + jiffies;
1859         add_timer(&session->tmf_timer);
1860         ISCSI_DBG_EH(session, "tmf set timeout\n");
1861
1862         spin_unlock_bh(&session->frwd_lock);
1863         mutex_unlock(&session->eh_mutex);
1864
1865         /*
1866          * block eh thread until:
1867          *
1868          * 1) tmf response
1869          * 2) tmf timeout
1870          * 3) session is terminated or restarted or userspace has
1871          * given up on recovery
1872          */
1873         wait_event_interruptible(session->ehwait, age != session->age ||
1874                                  session->state != ISCSI_STATE_LOGGED_IN ||
1875                                  session->tmf_state != TMF_QUEUED);
1876         if (signal_pending(current))
1877                 flush_signals(current);
1878         del_timer_sync(&session->tmf_timer);
1879
1880         mutex_lock(&session->eh_mutex);
1881         spin_lock_bh(&session->frwd_lock);
1882         /* if the session drops it will clean up the task */
1883         if (age != session->age ||
1884             session->state != ISCSI_STATE_LOGGED_IN)
1885                 return -ENOTCONN;
1886         return 0;
1887 }
1888
1889 /*
1890  * Fail commands. session frwd lock held and xmit thread flushed.
1891  */
1892 static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
1893 {
1894         struct iscsi_session *session = conn->session;
1895         struct iscsi_task *task;
1896         int i;
1897
1898         spin_lock_bh(&session->back_lock);
1899         for (i = 0; i < session->cmds_max; i++) {
1900                 task = session->cmds[i];
1901                 if (!task->sc || task->state == ISCSI_TASK_FREE)
1902                         continue;
1903
1904                 if (lun != -1 && lun != task->sc->device->lun)
1905                         continue;
1906
1907                 __iscsi_get_task(task);
1908                 spin_unlock_bh(&session->back_lock);
1909
1910                 ISCSI_DBG_SESSION(session,
1911                                   "failing sc %p itt 0x%x state %d\n",
1912                                   task->sc, task->itt, task->state);
1913                 fail_scsi_task(task, error);
1914
1915                 spin_unlock_bh(&session->frwd_lock);
1916                 iscsi_put_task(task);
1917                 spin_lock_bh(&session->frwd_lock);
1918
1919                 spin_lock_bh(&session->back_lock);
1920         }
1921
1922         spin_unlock_bh(&session->back_lock);
1923 }
1924
1925 /**
1926  * iscsi_suspend_queue - suspend iscsi_queuecommand
1927  * @conn: iscsi conn to stop queueing IO on
1928  *
1929  * This grabs the session frwd_lock to make sure no one is in
1930  * xmit_task/queuecommand, and then sets suspend to prevent
1931  * new commands from being queued. This only needs to be called
1932  * by offload drivers that need to sync a path like ep disconnect
1933  * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1934  * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1935  */
1936 void iscsi_suspend_queue(struct iscsi_conn *conn)
1937 {
1938         spin_lock_bh(&conn->session->frwd_lock);
1939         set_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags);
1940         spin_unlock_bh(&conn->session->frwd_lock);
1941 }
1942 EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1943
1944 /**
1945  * iscsi_suspend_tx - suspend iscsi_data_xmit
1946  * @conn: iscsi conn tp stop processing IO on.
1947  *
1948  * This function sets the suspend bit to prevent iscsi_data_xmit
1949  * from sending new IO, and if work is queued on the xmit thread
1950  * it will wait for it to be completed.
1951  */
1952 void iscsi_suspend_tx(struct iscsi_conn *conn)
1953 {
1954         struct Scsi_Host *shost = conn->session->host;
1955         struct iscsi_host *ihost = shost_priv(shost);
1956
1957         set_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags);
1958         if (ihost->workq)
1959                 flush_workqueue(ihost->workq);
1960 }
1961 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1962
1963 static void iscsi_start_tx(struct iscsi_conn *conn)
1964 {
1965         clear_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags);
1966         iscsi_conn_queue_work(conn);
1967 }
1968
1969 /*
1970  * We want to make sure a ping is in flight. It has timed out.
1971  * And we are not busy processing a pdu that is making
1972  * progress but got started before the ping and is taking a while
1973  * to complete so the ping is just stuck behind it in a queue.
1974  */
1975 static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1976 {
1977         if (READ_ONCE(conn->ping_task) &&
1978             time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1979                            (conn->ping_timeout * HZ), jiffies))
1980                 return 1;
1981         else
1982                 return 0;
1983 }
1984
1985 enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1986 {
1987         enum blk_eh_timer_return rc = BLK_EH_DONE;
1988         struct iscsi_task *task = NULL, *running_task;
1989         struct iscsi_cls_session *cls_session;
1990         struct iscsi_session *session;
1991         struct iscsi_conn *conn;
1992         int i;
1993
1994         cls_session = starget_to_session(scsi_target(sc->device));
1995         session = cls_session->dd_data;
1996
1997         ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1998
1999         spin_lock_bh(&session->frwd_lock);
2000         spin_lock(&session->back_lock);
2001         task = iscsi_cmd(sc)->task;
2002         if (!task) {
2003                 /*
2004                  * Raced with completion. Blk layer has taken ownership
2005                  * so let timeout code complete it now.
2006                  */
2007                 rc = BLK_EH_DONE;
2008                 spin_unlock(&session->back_lock);
2009                 goto done;
2010         }
2011         __iscsi_get_task(task);
2012         spin_unlock(&session->back_lock);
2013
2014         if (session->state != ISCSI_STATE_LOGGED_IN) {
2015                 /*
2016                  * During shutdown, if session is prematurely disconnected,
2017                  * recovery won't happen and there will be hung cmds. Not
2018                  * handling cmds would trigger EH, also bad in this case.
2019                  * Instead, handle cmd, allow completion to happen and let
2020                  * upper layer to deal with the result.
2021                  */
2022                 if (unlikely(system_state != SYSTEM_RUNNING)) {
2023                         sc->result = DID_NO_CONNECT << 16;
2024                         ISCSI_DBG_EH(session, "sc on shutdown, handled\n");
2025                         rc = BLK_EH_DONE;
2026                         goto done;
2027                 }
2028                 /*
2029                  * We are probably in the middle of iscsi recovery so let
2030                  * that complete and handle the error.
2031                  */
2032                 rc = BLK_EH_RESET_TIMER;
2033                 goto done;
2034         }
2035
2036         conn = session->leadconn;
2037         if (!conn) {
2038                 /* In the middle of shuting down */
2039                 rc = BLK_EH_RESET_TIMER;
2040                 goto done;
2041         }
2042
2043         /*
2044          * If we have sent (at least queued to the network layer) a pdu or
2045          * recvd one for the task since the last timeout ask for
2046          * more time. If on the next timeout we have not made progress
2047          * we can check if it is the task or connection when we send the
2048          * nop as a ping.
2049          */
2050         if (time_after(task->last_xfer, task->last_timeout)) {
2051                 ISCSI_DBG_EH(session, "Command making progress. Asking "
2052                              "scsi-ml for more time to complete. "
2053                              "Last data xfer at %lu. Last timeout was at "
2054                              "%lu\n.", task->last_xfer, task->last_timeout);
2055                 task->have_checked_conn = false;
2056                 rc = BLK_EH_RESET_TIMER;
2057                 goto done;
2058         }
2059
2060         if (!conn->recv_timeout && !conn->ping_timeout)
2061                 goto done;
2062         /*
2063          * if the ping timedout then we are in the middle of cleaning up
2064          * and can let the iscsi eh handle it
2065          */
2066         if (iscsi_has_ping_timed_out(conn)) {
2067                 rc = BLK_EH_RESET_TIMER;
2068                 goto done;
2069         }
2070
2071         spin_lock(&session->back_lock);
2072         for (i = 0; i < conn->session->cmds_max; i++) {
2073                 running_task = conn->session->cmds[i];
2074                 if (!running_task->sc || running_task == task ||
2075                      running_task->state != ISCSI_TASK_RUNNING)
2076                         continue;
2077
2078                 /*
2079                  * Only check if cmds started before this one have made
2080                  * progress, or this could never fail
2081                  */
2082                 if (time_after(running_task->sc->jiffies_at_alloc,
2083                                task->sc->jiffies_at_alloc))
2084                         continue;
2085
2086                 if (time_after(running_task->last_xfer, task->last_timeout)) {
2087                         /*
2088                          * This task has not made progress, but a task
2089                          * started before us has transferred data since
2090                          * we started/last-checked. We could be queueing
2091                          * too many tasks or the LU is bad.
2092                          *
2093                          * If the device is bad the cmds ahead of us on
2094                          * other devs will complete, and this loop will
2095                          * eventually fail starting the scsi eh.
2096                          */
2097                         ISCSI_DBG_EH(session, "Command has not made progress "
2098                                      "but commands ahead of it have. "
2099                                      "Asking scsi-ml for more time to "
2100                                      "complete. Our last xfer vs running task "
2101                                      "last xfer %lu/%lu. Last check %lu.\n",
2102                                      task->last_xfer, running_task->last_xfer,
2103                                      task->last_timeout);
2104                         spin_unlock(&session->back_lock);
2105                         rc = BLK_EH_RESET_TIMER;
2106                         goto done;
2107                 }
2108         }
2109         spin_unlock(&session->back_lock);
2110
2111         /* Assumes nop timeout is shorter than scsi cmd timeout */
2112         if (task->have_checked_conn)
2113                 goto done;
2114
2115         /*
2116          * Checking the transport already or nop from a cmd timeout still
2117          * running
2118          */
2119         if (READ_ONCE(conn->ping_task)) {
2120                 task->have_checked_conn = true;
2121                 rc = BLK_EH_RESET_TIMER;
2122                 goto done;
2123         }
2124
2125         /* Make sure there is a transport check done */
2126         iscsi_send_nopout(conn, NULL);
2127         task->have_checked_conn = true;
2128         rc = BLK_EH_RESET_TIMER;
2129
2130 done:
2131         spin_unlock_bh(&session->frwd_lock);
2132
2133         if (task) {
2134                 task->last_timeout = jiffies;
2135                 iscsi_put_task(task);
2136         }
2137         ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2138                      "timer reset" : "shutdown or nh");
2139         return rc;
2140 }
2141 EXPORT_SYMBOL_GPL(iscsi_eh_cmd_timed_out);
2142
2143 static void iscsi_check_transport_timeouts(struct timer_list *t)
2144 {
2145         struct iscsi_conn *conn = from_timer(conn, t, transport_timer);
2146         struct iscsi_session *session = conn->session;
2147         unsigned long recv_timeout, next_timeout = 0, last_recv;
2148
2149         spin_lock(&session->frwd_lock);
2150         if (session->state != ISCSI_STATE_LOGGED_IN)
2151                 goto done;
2152
2153         recv_timeout = conn->recv_timeout;
2154         if (!recv_timeout)
2155                 goto done;
2156
2157         recv_timeout *= HZ;
2158         last_recv = conn->last_recv;
2159
2160         if (iscsi_has_ping_timed_out(conn)) {
2161                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2162                                   "expired, recv timeout %d, last rx %lu, "
2163                                   "last ping %lu, now %lu\n",
2164                                   conn->ping_timeout, conn->recv_timeout,
2165                                   last_recv, conn->last_ping, jiffies);
2166                 spin_unlock(&session->frwd_lock);
2167                 iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2168                 return;
2169         }
2170
2171         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2172                 /* send a ping to try to provoke some traffic */
2173                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2174                 if (iscsi_send_nopout(conn, NULL))
2175                         next_timeout = jiffies + (1 * HZ);
2176                 else
2177                         next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2178         } else
2179                 next_timeout = last_recv + recv_timeout;
2180
2181         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2182         mod_timer(&conn->transport_timer, next_timeout);
2183 done:
2184         spin_unlock(&session->frwd_lock);
2185 }
2186
2187 /**
2188  * iscsi_conn_unbind - prevent queueing to conn.
2189  * @cls_conn: iscsi conn ep is bound to.
2190  * @is_active: is the conn in use for boot or is this for EH/termination
2191  *
2192  * This must be called by drivers implementing the ep_disconnect callout.
2193  * It disables queueing to the connection from libiscsi in preparation for
2194  * an ep_disconnect call.
2195  */
2196 void iscsi_conn_unbind(struct iscsi_cls_conn *cls_conn, bool is_active)
2197 {
2198         struct iscsi_session *session;
2199         struct iscsi_conn *conn;
2200
2201         if (!cls_conn)
2202                 return;
2203
2204         conn = cls_conn->dd_data;
2205         session = conn->session;
2206         /*
2207          * Wait for iscsi_eh calls to exit. We don't wait for the tmf to
2208          * complete or timeout. The caller just wants to know what's running
2209          * is everything that needs to be cleaned up, and no cmds will be
2210          * queued.
2211          */
2212         mutex_lock(&session->eh_mutex);
2213
2214         iscsi_suspend_queue(conn);
2215         iscsi_suspend_tx(conn);
2216
2217         spin_lock_bh(&session->frwd_lock);
2218         clear_bit(ISCSI_CONN_FLAG_BOUND, &conn->flags);
2219
2220         if (!is_active) {
2221                 /*
2222                  * if logout timed out before userspace could even send a PDU
2223                  * the state might still be in ISCSI_STATE_LOGGED_IN and
2224                  * allowing new cmds and TMFs.
2225                  */
2226                 if (session->state == ISCSI_STATE_LOGGED_IN)
2227                         iscsi_set_conn_failed(conn);
2228         }
2229         spin_unlock_bh(&session->frwd_lock);
2230         mutex_unlock(&session->eh_mutex);
2231 }
2232 EXPORT_SYMBOL_GPL(iscsi_conn_unbind);
2233
2234 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2235                                       struct iscsi_tm *hdr)
2236 {
2237         memset(hdr, 0, sizeof(*hdr));
2238         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2239         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2240         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2241         hdr->lun = task->lun;
2242         hdr->rtt = task->hdr_itt;
2243         hdr->refcmdsn = task->cmdsn;
2244 }
2245
2246 int iscsi_eh_abort(struct scsi_cmnd *sc)
2247 {
2248         struct iscsi_cls_session *cls_session;
2249         struct iscsi_session *session;
2250         struct iscsi_conn *conn;
2251         struct iscsi_task *task;
2252         struct iscsi_tm *hdr;
2253         int age;
2254
2255         cls_session = starget_to_session(scsi_target(sc->device));
2256         session = cls_session->dd_data;
2257
2258         ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2259
2260         mutex_lock(&session->eh_mutex);
2261         spin_lock_bh(&session->frwd_lock);
2262         /*
2263          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2264          * got the command.
2265          */
2266         if (!iscsi_cmd(sc)->task) {
2267                 ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2268                                       "it completed.\n");
2269                 spin_unlock_bh(&session->frwd_lock);
2270                 mutex_unlock(&session->eh_mutex);
2271                 return SUCCESS;
2272         }
2273
2274         /*
2275          * If we are not logged in or we have started a new session
2276          * then let the host reset code handle this
2277          */
2278         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2279             iscsi_cmd(sc)->age != session->age) {
2280                 spin_unlock_bh(&session->frwd_lock);
2281                 mutex_unlock(&session->eh_mutex);
2282                 ISCSI_DBG_EH(session, "failing abort due to dropped "
2283                                   "session.\n");
2284                 return FAILED;
2285         }
2286
2287         spin_lock(&session->back_lock);
2288         task = iscsi_cmd(sc)->task;
2289         if (!task || !task->sc) {
2290                 /* task completed before time out */
2291                 ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2292
2293                 spin_unlock(&session->back_lock);
2294                 spin_unlock_bh(&session->frwd_lock);
2295                 mutex_unlock(&session->eh_mutex);
2296                 return SUCCESS;
2297         }
2298
2299         conn = session->leadconn;
2300         iscsi_get_conn(conn->cls_conn);
2301         conn->eh_abort_cnt++;
2302         age = session->age;
2303
2304         ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n", sc, task->itt);
2305         __iscsi_get_task(task);
2306         spin_unlock(&session->back_lock);
2307
2308         if (task->state == ISCSI_TASK_PENDING) {
2309                 fail_scsi_task(task, DID_ABORT);
2310                 goto success;
2311         }
2312
2313         /* only have one tmf outstanding at a time */
2314         if (session->tmf_state != TMF_INITIAL)
2315                 goto failed;
2316         session->tmf_state = TMF_QUEUED;
2317
2318         hdr = &session->tmhdr;
2319         iscsi_prep_abort_task_pdu(task, hdr);
2320
2321         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout))
2322                 goto failed;
2323
2324         switch (session->tmf_state) {
2325         case TMF_SUCCESS:
2326                 spin_unlock_bh(&session->frwd_lock);
2327                 /*
2328                  * stop tx side incase the target had sent a abort rsp but
2329                  * the initiator was still writing out data.
2330                  */
2331                 iscsi_suspend_tx(conn);
2332                 /*
2333                  * we do not stop the recv side because targets have been
2334                  * good and have never sent us a successful tmf response
2335                  * then sent more data for the cmd.
2336                  */
2337                 spin_lock_bh(&session->frwd_lock);
2338                 fail_scsi_task(task, DID_ABORT);
2339                 session->tmf_state = TMF_INITIAL;
2340                 memset(hdr, 0, sizeof(*hdr));
2341                 spin_unlock_bh(&session->frwd_lock);
2342                 iscsi_start_tx(conn);
2343                 goto success_unlocked;
2344         case TMF_TIMEDOUT:
2345                 session->running_aborted_task = task;
2346                 spin_unlock_bh(&session->frwd_lock);
2347                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2348                 goto failed_unlocked;
2349         case TMF_NOT_FOUND:
2350                 if (iscsi_task_is_completed(task)) {
2351                         session->tmf_state = TMF_INITIAL;
2352                         memset(hdr, 0, sizeof(*hdr));
2353                         /* task completed before tmf abort response */
2354                         ISCSI_DBG_EH(session, "sc completed while abort in "
2355                                               "progress\n");
2356                         goto success;
2357                 }
2358                 fallthrough;
2359         default:
2360                 session->tmf_state = TMF_INITIAL;
2361                 goto failed;
2362         }
2363
2364 success:
2365         spin_unlock_bh(&session->frwd_lock);
2366 success_unlocked:
2367         ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2368                      sc, task->itt);
2369         iscsi_put_task(task);
2370         iscsi_put_conn(conn->cls_conn);
2371         mutex_unlock(&session->eh_mutex);
2372         return SUCCESS;
2373
2374 failed:
2375         spin_unlock_bh(&session->frwd_lock);
2376 failed_unlocked:
2377         ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2378                      task ? task->itt : 0);
2379         /*
2380          * The driver might be accessing the task so hold the ref. The conn
2381          * stop cleanup will drop the ref after ep_disconnect so we know the
2382          * driver's no longer touching the task.
2383          */
2384         if (!session->running_aborted_task)
2385                 iscsi_put_task(task);
2386
2387         iscsi_put_conn(conn->cls_conn);
2388         mutex_unlock(&session->eh_mutex);
2389         return FAILED;
2390 }
2391 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2392
2393 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2394 {
2395         memset(hdr, 0, sizeof(*hdr));
2396         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2397         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2398         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2399         int_to_scsilun(sc->device->lun, &hdr->lun);
2400         hdr->rtt = RESERVED_ITT;
2401 }
2402
2403 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2404 {
2405         struct iscsi_cls_session *cls_session;
2406         struct iscsi_session *session;
2407         struct iscsi_conn *conn;
2408         struct iscsi_tm *hdr;
2409         int rc = FAILED;
2410
2411         cls_session = starget_to_session(scsi_target(sc->device));
2412         session = cls_session->dd_data;
2413
2414         ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2415                      sc->device->lun);
2416
2417         mutex_lock(&session->eh_mutex);
2418         spin_lock_bh(&session->frwd_lock);
2419         /*
2420          * Just check if we are not logged in. We cannot check for
2421          * the phase because the reset could come from a ioctl.
2422          */
2423         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2424                 goto unlock;
2425         conn = session->leadconn;
2426
2427         /* only have one tmf outstanding at a time */
2428         if (session->tmf_state != TMF_INITIAL)
2429                 goto unlock;
2430         session->tmf_state = TMF_QUEUED;
2431
2432         hdr = &session->tmhdr;
2433         iscsi_prep_lun_reset_pdu(sc, hdr);
2434
2435         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2436                                     session->lu_reset_timeout)) {
2437                 rc = FAILED;
2438                 goto unlock;
2439         }
2440
2441         switch (session->tmf_state) {
2442         case TMF_SUCCESS:
2443                 break;
2444         case TMF_TIMEDOUT:
2445                 spin_unlock_bh(&session->frwd_lock);
2446                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2447                 goto done;
2448         default:
2449                 session->tmf_state = TMF_INITIAL;
2450                 goto unlock;
2451         }
2452
2453         rc = SUCCESS;
2454         spin_unlock_bh(&session->frwd_lock);
2455
2456         iscsi_suspend_tx(conn);
2457
2458         spin_lock_bh(&session->frwd_lock);
2459         memset(hdr, 0, sizeof(*hdr));
2460         fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2461         session->tmf_state = TMF_INITIAL;
2462         spin_unlock_bh(&session->frwd_lock);
2463
2464         iscsi_start_tx(conn);
2465         goto done;
2466
2467 unlock:
2468         spin_unlock_bh(&session->frwd_lock);
2469 done:
2470         ISCSI_DBG_EH(session, "dev reset result = %s\n",
2471                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2472         mutex_unlock(&session->eh_mutex);
2473         return rc;
2474 }
2475 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2476
2477 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2478 {
2479         struct iscsi_session *session = cls_session->dd_data;
2480
2481         spin_lock_bh(&session->frwd_lock);
2482         if (session->state != ISCSI_STATE_LOGGED_IN) {
2483                 session->state = ISCSI_STATE_RECOVERY_FAILED;
2484                 wake_up(&session->ehwait);
2485         }
2486         spin_unlock_bh(&session->frwd_lock);
2487 }
2488 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2489
2490 /**
2491  * iscsi_eh_session_reset - drop session and attempt relogin
2492  * @sc: scsi command
2493  *
2494  * This function will wait for a relogin, session termination from
2495  * userspace, or a recovery/replacement timeout.
2496  */
2497 int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2498 {
2499         struct iscsi_cls_session *cls_session;
2500         struct iscsi_session *session;
2501         struct iscsi_conn *conn;
2502
2503         cls_session = starget_to_session(scsi_target(sc->device));
2504         session = cls_session->dd_data;
2505
2506         mutex_lock(&session->eh_mutex);
2507         spin_lock_bh(&session->frwd_lock);
2508         if (session->state == ISCSI_STATE_TERMINATE) {
2509 failed:
2510                 ISCSI_DBG_EH(session,
2511                              "failing session reset: Could not log back into "
2512                              "%s [age %d]\n", session->targetname,
2513                              session->age);
2514                 spin_unlock_bh(&session->frwd_lock);
2515                 mutex_unlock(&session->eh_mutex);
2516                 return FAILED;
2517         }
2518
2519         conn = session->leadconn;
2520         iscsi_get_conn(conn->cls_conn);
2521
2522         spin_unlock_bh(&session->frwd_lock);
2523         mutex_unlock(&session->eh_mutex);
2524
2525         iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2526         iscsi_put_conn(conn->cls_conn);
2527
2528         ISCSI_DBG_EH(session, "wait for relogin\n");
2529         wait_event_interruptible(session->ehwait,
2530                                  session->state == ISCSI_STATE_TERMINATE ||
2531                                  session->state == ISCSI_STATE_LOGGED_IN ||
2532                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
2533         if (signal_pending(current))
2534                 flush_signals(current);
2535
2536         mutex_lock(&session->eh_mutex);
2537         spin_lock_bh(&session->frwd_lock);
2538         if (session->state == ISCSI_STATE_LOGGED_IN) {
2539                 ISCSI_DBG_EH(session,
2540                              "session reset succeeded for %s,%s\n",
2541                              session->targetname, conn->persistent_address);
2542         } else
2543                 goto failed;
2544         spin_unlock_bh(&session->frwd_lock);
2545         mutex_unlock(&session->eh_mutex);
2546         return SUCCESS;
2547 }
2548 EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2549
2550 static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2551 {
2552         memset(hdr, 0, sizeof(*hdr));
2553         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2554         hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2555         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2556         hdr->rtt = RESERVED_ITT;
2557 }
2558
2559 /**
2560  * iscsi_eh_target_reset - reset target
2561  * @sc: scsi command
2562  *
2563  * This will attempt to send a warm target reset.
2564  */
2565 static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2566 {
2567         struct iscsi_cls_session *cls_session;
2568         struct iscsi_session *session;
2569         struct iscsi_conn *conn;
2570         struct iscsi_tm *hdr;
2571         int rc = FAILED;
2572
2573         cls_session = starget_to_session(scsi_target(sc->device));
2574         session = cls_session->dd_data;
2575
2576         ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2577                      session->targetname);
2578
2579         mutex_lock(&session->eh_mutex);
2580         spin_lock_bh(&session->frwd_lock);
2581         /*
2582          * Just check if we are not logged in. We cannot check for
2583          * the phase because the reset could come from a ioctl.
2584          */
2585         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2586                 goto unlock;
2587         conn = session->leadconn;
2588
2589         /* only have one tmf outstanding at a time */
2590         if (session->tmf_state != TMF_INITIAL)
2591                 goto unlock;
2592         session->tmf_state = TMF_QUEUED;
2593
2594         hdr = &session->tmhdr;
2595         iscsi_prep_tgt_reset_pdu(sc, hdr);
2596
2597         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2598                                     session->tgt_reset_timeout)) {
2599                 rc = FAILED;
2600                 goto unlock;
2601         }
2602
2603         switch (session->tmf_state) {
2604         case TMF_SUCCESS:
2605                 break;
2606         case TMF_TIMEDOUT:
2607                 spin_unlock_bh(&session->frwd_lock);
2608                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2609                 goto done;
2610         default:
2611                 session->tmf_state = TMF_INITIAL;
2612                 goto unlock;
2613         }
2614
2615         rc = SUCCESS;
2616         spin_unlock_bh(&session->frwd_lock);
2617
2618         iscsi_suspend_tx(conn);
2619
2620         spin_lock_bh(&session->frwd_lock);
2621         memset(hdr, 0, sizeof(*hdr));
2622         fail_scsi_tasks(conn, -1, DID_ERROR);
2623         session->tmf_state = TMF_INITIAL;
2624         spin_unlock_bh(&session->frwd_lock);
2625
2626         iscsi_start_tx(conn);
2627         goto done;
2628
2629 unlock:
2630         spin_unlock_bh(&session->frwd_lock);
2631 done:
2632         ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2633                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2634         mutex_unlock(&session->eh_mutex);
2635         return rc;
2636 }
2637
2638 /**
2639  * iscsi_eh_recover_target - reset target and possibly the session
2640  * @sc: scsi command
2641  *
2642  * This will attempt to send a warm target reset. If that fails,
2643  * we will escalate to ERL0 session recovery.
2644  */
2645 int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2646 {
2647         int rc;
2648
2649         rc = iscsi_eh_target_reset(sc);
2650         if (rc == FAILED)
2651                 rc = iscsi_eh_session_reset(sc);
2652         return rc;
2653 }
2654 EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2655
2656 /*
2657  * Pre-allocate a pool of @max items of @item_size. By default, the pool
2658  * should be accessed via kfifo_{get,put} on q->queue.
2659  * Optionally, the caller can obtain the array of object pointers
2660  * by passing in a non-NULL @items pointer
2661  */
2662 int
2663 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2664 {
2665         int i, num_arrays = 1;
2666
2667         memset(q, 0, sizeof(*q));
2668
2669         q->max = max;
2670
2671         /* If the user passed an items pointer, he wants a copy of
2672          * the array. */
2673         if (items)
2674                 num_arrays++;
2675         q->pool = kvcalloc(num_arrays * max, sizeof(void *), GFP_KERNEL);
2676         if (q->pool == NULL)
2677                 return -ENOMEM;
2678
2679         kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2680
2681         for (i = 0; i < max; i++) {
2682                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2683                 if (q->pool[i] == NULL) {
2684                         q->max = i;
2685                         goto enomem;
2686                 }
2687                 kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2688         }
2689
2690         if (items) {
2691                 *items = q->pool + max;
2692                 memcpy(*items, q->pool, max * sizeof(void *));
2693         }
2694
2695         return 0;
2696
2697 enomem:
2698         iscsi_pool_free(q);
2699         return -ENOMEM;
2700 }
2701 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2702
2703 void iscsi_pool_free(struct iscsi_pool *q)
2704 {
2705         int i;
2706
2707         for (i = 0; i < q->max; i++)
2708                 kfree(q->pool[i]);
2709         kvfree(q->pool);
2710 }
2711 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2712
2713 int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
2714                                  uint16_t requested_cmds_max)
2715 {
2716         int scsi_cmds, total_cmds = requested_cmds_max;
2717
2718 check:
2719         if (!total_cmds)
2720                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2721         /*
2722          * The iscsi layer needs some tasks for nop handling and tmfs,
2723          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2724          * + 1 command for scsi IO.
2725          */
2726         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2727                 printk(KERN_ERR "iscsi: invalid max cmds of %d. Must be a power of two that is at least %d.\n",
2728                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2729                 return -EINVAL;
2730         }
2731
2732         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2733                 printk(KERN_INFO "iscsi: invalid max cmds of %d. Must be a power of 2 less than or equal to %d. Using %d.\n",
2734                        requested_cmds_max, ISCSI_TOTAL_CMDS_MAX,
2735                        ISCSI_TOTAL_CMDS_MAX);
2736                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2737         }
2738
2739         if (!is_power_of_2(total_cmds)) {
2740                 total_cmds = rounddown_pow_of_two(total_cmds);
2741                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2742                         printk(KERN_ERR "iscsi: invalid max cmds of %d. Must be a power of 2 greater than %d.\n", requested_cmds_max, ISCSI_TOTAL_CMDS_MIN);
2743                         return -EINVAL;
2744                 }
2745
2746                 printk(KERN_INFO "iscsi: invalid max cmds %d. Must be a power of 2. Rounding max cmds down to %d.\n",
2747                        requested_cmds_max, total_cmds);
2748         }
2749
2750         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2751         if (shost->can_queue && scsi_cmds > shost->can_queue) {
2752                 total_cmds = shost->can_queue;
2753
2754                 printk(KERN_INFO "iscsi: requested max cmds %u is higher than driver limit. Using driver limit %u\n",
2755                        requested_cmds_max, shost->can_queue);
2756                 goto check;
2757         }
2758
2759         return scsi_cmds;
2760 }
2761 EXPORT_SYMBOL_GPL(iscsi_host_get_max_scsi_cmds);
2762
2763 /**
2764  * iscsi_host_add - add host to system
2765  * @shost: scsi host
2766  * @pdev: parent device
2767  *
2768  * This should be called by partial offload and software iscsi drivers
2769  * to add a host to the system.
2770  */
2771 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2772 {
2773         if (!shost->can_queue)
2774                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2775
2776         if (!shost->cmd_per_lun)
2777                 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2778
2779         return scsi_add_host(shost, pdev);
2780 }
2781 EXPORT_SYMBOL_GPL(iscsi_host_add);
2782
2783 /**
2784  * iscsi_host_alloc - allocate a host and driver data
2785  * @sht: scsi host template
2786  * @dd_data_size: driver host data size
2787  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2788  *
2789  * This should be called by partial offload and software iscsi drivers.
2790  * To access the driver specific memory use the iscsi_host_priv() macro.
2791  */
2792 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2793                                    int dd_data_size, bool xmit_can_sleep)
2794 {
2795         struct Scsi_Host *shost;
2796         struct iscsi_host *ihost;
2797
2798         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2799         if (!shost)
2800                 return NULL;
2801         ihost = shost_priv(shost);
2802
2803         if (xmit_can_sleep) {
2804                 ihost->workq = alloc_workqueue("iscsi_q_%d",
2805                         WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
2806                         1, shost->host_no);
2807                 if (!ihost->workq)
2808                         goto free_host;
2809         }
2810
2811         spin_lock_init(&ihost->lock);
2812         ihost->state = ISCSI_HOST_SETUP;
2813         ihost->num_sessions = 0;
2814         init_waitqueue_head(&ihost->session_removal_wq);
2815         return shost;
2816
2817 free_host:
2818         scsi_host_put(shost);
2819         return NULL;
2820 }
2821 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2822
2823 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2824 {
2825         iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2826 }
2827
2828 /**
2829  * iscsi_host_remove - remove host and sessions
2830  * @shost: scsi host
2831  *
2832  * If there are any sessions left, this will initiate the removal and wait
2833  * for the completion.
2834  */
2835 void iscsi_host_remove(struct Scsi_Host *shost)
2836 {
2837         struct iscsi_host *ihost = shost_priv(shost);
2838         unsigned long flags;
2839
2840         spin_lock_irqsave(&ihost->lock, flags);
2841         ihost->state = ISCSI_HOST_REMOVED;
2842         spin_unlock_irqrestore(&ihost->lock, flags);
2843
2844         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2845         wait_event_interruptible(ihost->session_removal_wq,
2846                                  ihost->num_sessions == 0);
2847         if (signal_pending(current))
2848                 flush_signals(current);
2849
2850         scsi_remove_host(shost);
2851 }
2852 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2853
2854 void iscsi_host_free(struct Scsi_Host *shost)
2855 {
2856         struct iscsi_host *ihost = shost_priv(shost);
2857
2858         if (ihost->workq)
2859                 destroy_workqueue(ihost->workq);
2860
2861         kfree(ihost->netdev);
2862         kfree(ihost->hwaddress);
2863         kfree(ihost->initiatorname);
2864         scsi_host_put(shost);
2865 }
2866 EXPORT_SYMBOL_GPL(iscsi_host_free);
2867
2868 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2869 {
2870         struct iscsi_host *ihost = shost_priv(shost);
2871         unsigned long flags;
2872
2873         shost = scsi_host_get(shost);
2874         if (!shost) {
2875                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2876                       "of session teardown event because host already "
2877                       "removed.\n");
2878                 return;
2879         }
2880
2881         spin_lock_irqsave(&ihost->lock, flags);
2882         ihost->num_sessions--;
2883         if (ihost->num_sessions == 0)
2884                 wake_up(&ihost->session_removal_wq);
2885         spin_unlock_irqrestore(&ihost->lock, flags);
2886         scsi_host_put(shost);
2887 }
2888
2889 /**
2890  * iscsi_session_setup - create iscsi cls session and host and session
2891  * @iscsit: iscsi transport template
2892  * @shost: scsi host
2893  * @cmds_max: session can queue
2894  * @dd_size: private driver data size, added to session allocation size
2895  * @cmd_task_size: LLD task private data size
2896  * @initial_cmdsn: initial CmdSN
2897  * @id: target ID to add to this session
2898  *
2899  * This can be used by software iscsi_transports that allocate
2900  * a session per scsi host.
2901  *
2902  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2903  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2904  * for nop handling and login/logout requests.
2905  */
2906 struct iscsi_cls_session *
2907 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2908                     uint16_t cmds_max, int dd_size, int cmd_task_size,
2909                     uint32_t initial_cmdsn, unsigned int id)
2910 {
2911         struct iscsi_host *ihost = shost_priv(shost);
2912         struct iscsi_session *session;
2913         struct iscsi_cls_session *cls_session;
2914         int cmd_i, scsi_cmds;
2915         unsigned long flags;
2916
2917         spin_lock_irqsave(&ihost->lock, flags);
2918         if (ihost->state == ISCSI_HOST_REMOVED) {
2919                 spin_unlock_irqrestore(&ihost->lock, flags);
2920                 return NULL;
2921         }
2922         ihost->num_sessions++;
2923         spin_unlock_irqrestore(&ihost->lock, flags);
2924
2925         scsi_cmds = iscsi_host_get_max_scsi_cmds(shost, cmds_max);
2926         if (scsi_cmds < 0)
2927                 goto dec_session_count;
2928
2929         cls_session = iscsi_alloc_session(shost, iscsit,
2930                                           sizeof(struct iscsi_session) +
2931                                           dd_size);
2932         if (!cls_session)
2933                 goto dec_session_count;
2934         session = cls_session->dd_data;
2935         session->cls_session = cls_session;
2936         session->host = shost;
2937         session->state = ISCSI_STATE_FREE;
2938         session->fast_abort = 1;
2939         session->tgt_reset_timeout = 30;
2940         session->lu_reset_timeout = 15;
2941         session->abort_timeout = 10;
2942         session->scsi_cmds_max = scsi_cmds;
2943         session->cmds_max = scsi_cmds + ISCSI_MGMT_CMDS_MAX;
2944         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2945         session->exp_cmdsn = initial_cmdsn + 1;
2946         session->max_cmdsn = initial_cmdsn + 1;
2947         session->max_r2t = 1;
2948         session->tt = iscsit;
2949         session->dd_data = cls_session->dd_data + sizeof(*session);
2950
2951         session->tmf_state = TMF_INITIAL;
2952         timer_setup(&session->tmf_timer, iscsi_tmf_timedout, 0);
2953         mutex_init(&session->eh_mutex);
2954         init_waitqueue_head(&session->ehwait);
2955
2956         spin_lock_init(&session->frwd_lock);
2957         spin_lock_init(&session->back_lock);
2958
2959         /* initialize SCSI PDU commands pool */
2960         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2961                             (void***)&session->cmds,
2962                             cmd_task_size + sizeof(struct iscsi_task)))
2963                 goto cmdpool_alloc_fail;
2964
2965         /* pre-format cmds pool with ITT */
2966         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2967                 struct iscsi_task *task = session->cmds[cmd_i];
2968
2969                 if (cmd_task_size)
2970                         task->dd_data = &task[1];
2971                 task->itt = cmd_i;
2972                 task->state = ISCSI_TASK_FREE;
2973                 INIT_LIST_HEAD(&task->running);
2974         }
2975
2976         if (!try_module_get(iscsit->owner))
2977                 goto module_get_fail;
2978
2979         if (iscsi_add_session(cls_session, id))
2980                 goto cls_session_fail;
2981
2982         return cls_session;
2983
2984 cls_session_fail:
2985         module_put(iscsit->owner);
2986 module_get_fail:
2987         iscsi_pool_free(&session->cmdpool);
2988 cmdpool_alloc_fail:
2989         iscsi_free_session(cls_session);
2990 dec_session_count:
2991         iscsi_host_dec_session_cnt(shost);
2992         return NULL;
2993 }
2994 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2995
2996 /**
2997  * iscsi_session_teardown - destroy session, host, and cls_session
2998  * @cls_session: iscsi session
2999  */
3000 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
3001 {
3002         struct iscsi_session *session = cls_session->dd_data;
3003         struct module *owner = cls_session->transport->owner;
3004         struct Scsi_Host *shost = session->host;
3005
3006         iscsi_remove_session(cls_session);
3007
3008         iscsi_pool_free(&session->cmdpool);
3009         kfree(session->password);
3010         kfree(session->password_in);
3011         kfree(session->username);
3012         kfree(session->username_in);
3013         kfree(session->targetname);
3014         kfree(session->targetalias);
3015         kfree(session->initiatorname);
3016         kfree(session->boot_root);
3017         kfree(session->boot_nic);
3018         kfree(session->boot_target);
3019         kfree(session->ifacename);
3020         kfree(session->portal_type);
3021         kfree(session->discovery_parent_type);
3022
3023         iscsi_free_session(cls_session);
3024
3025         iscsi_host_dec_session_cnt(shost);
3026         module_put(owner);
3027 }
3028 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
3029
3030 /**
3031  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
3032  * @cls_session: iscsi_cls_session
3033  * @dd_size: private driver data size
3034  * @conn_idx: cid
3035  */
3036 struct iscsi_cls_conn *
3037 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
3038                  uint32_t conn_idx)
3039 {
3040         struct iscsi_session *session = cls_session->dd_data;
3041         struct iscsi_conn *conn;
3042         struct iscsi_cls_conn *cls_conn;
3043         char *data;
3044         int err;
3045
3046         cls_conn = iscsi_alloc_conn(cls_session, sizeof(*conn) + dd_size,
3047                                      conn_idx);
3048         if (!cls_conn)
3049                 return NULL;
3050         conn = cls_conn->dd_data;
3051
3052         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
3053         conn->session = session;
3054         conn->cls_conn = cls_conn;
3055         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
3056         conn->id = conn_idx;
3057         conn->exp_statsn = 0;
3058
3059         timer_setup(&conn->transport_timer, iscsi_check_transport_timeouts, 0);
3060
3061         INIT_LIST_HEAD(&conn->mgmtqueue);
3062         INIT_LIST_HEAD(&conn->cmdqueue);
3063         INIT_LIST_HEAD(&conn->requeue);
3064         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
3065
3066         /* allocate login_task used for the login/text sequences */
3067         spin_lock_bh(&session->frwd_lock);
3068         if (!kfifo_out(&session->cmdpool.queue,
3069                          (void*)&conn->login_task,
3070                          sizeof(void*))) {
3071                 spin_unlock_bh(&session->frwd_lock);
3072                 goto login_task_alloc_fail;
3073         }
3074         spin_unlock_bh(&session->frwd_lock);
3075
3076         data = (char *) __get_free_pages(GFP_KERNEL,
3077                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3078         if (!data)
3079                 goto login_task_data_alloc_fail;
3080         conn->login_task->data = conn->data = data;
3081
3082         err = iscsi_add_conn(cls_conn);
3083         if (err)
3084                 goto login_task_add_dev_fail;
3085
3086         return cls_conn;
3087
3088 login_task_add_dev_fail:
3089         free_pages((unsigned long) conn->data,
3090                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3091
3092 login_task_data_alloc_fail:
3093         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3094                     sizeof(void*));
3095 login_task_alloc_fail:
3096         iscsi_put_conn(cls_conn);
3097         return NULL;
3098 }
3099 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
3100
3101 /**
3102  * iscsi_conn_teardown - teardown iscsi connection
3103  * @cls_conn: iscsi class connection
3104  *
3105  * TODO: we may need to make this into a two step process
3106  * like scsi-mls remove + put host
3107  */
3108 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
3109 {
3110         struct iscsi_conn *conn = cls_conn->dd_data;
3111         struct iscsi_session *session = conn->session;
3112
3113         iscsi_remove_conn(cls_conn);
3114
3115         del_timer_sync(&conn->transport_timer);
3116
3117         mutex_lock(&session->eh_mutex);
3118         spin_lock_bh(&session->frwd_lock);
3119         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
3120         if (session->leadconn == conn) {
3121                 /*
3122                  * leading connection? then give up on recovery.
3123                  */
3124                 session->state = ISCSI_STATE_TERMINATE;
3125                 wake_up(&session->ehwait);
3126         }
3127         spin_unlock_bh(&session->frwd_lock);
3128
3129         /* flush queued up work because we free the connection below */
3130         iscsi_suspend_tx(conn);
3131
3132         spin_lock_bh(&session->frwd_lock);
3133         free_pages((unsigned long) conn->data,
3134                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3135         kfree(conn->persistent_address);
3136         kfree(conn->local_ipaddr);
3137         /* regular RX path uses back_lock */
3138         spin_lock_bh(&session->back_lock);
3139         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3140                     sizeof(void*));
3141         spin_unlock_bh(&session->back_lock);
3142         if (session->leadconn == conn)
3143                 session->leadconn = NULL;
3144         spin_unlock_bh(&session->frwd_lock);
3145         mutex_unlock(&session->eh_mutex);
3146
3147         iscsi_put_conn(cls_conn);
3148 }
3149 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
3150
3151 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
3152 {
3153         struct iscsi_conn *conn = cls_conn->dd_data;
3154         struct iscsi_session *session = conn->session;
3155
3156         if (!session) {
3157                 iscsi_conn_printk(KERN_ERR, conn,
3158                                   "can't start unbound connection\n");
3159                 return -EPERM;
3160         }
3161
3162         if ((session->imm_data_en || !session->initial_r2t_en) &&
3163              session->first_burst > session->max_burst) {
3164                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
3165                                   "first_burst %d max_burst %d\n",
3166                                   session->first_burst, session->max_burst);
3167                 return -EINVAL;
3168         }
3169
3170         if (conn->ping_timeout && !conn->recv_timeout) {
3171                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3172                                   "zero. Using 5 seconds\n.");
3173                 conn->recv_timeout = 5;
3174         }
3175
3176         if (conn->recv_timeout && !conn->ping_timeout) {
3177                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3178                                   "zero. Using 5 seconds.\n");
3179                 conn->ping_timeout = 5;
3180         }
3181
3182         spin_lock_bh(&session->frwd_lock);
3183         conn->c_stage = ISCSI_CONN_STARTED;
3184         session->state = ISCSI_STATE_LOGGED_IN;
3185         session->queued_cmdsn = session->cmdsn;
3186
3187         conn->last_recv = jiffies;
3188         conn->last_ping = jiffies;
3189         if (conn->recv_timeout && conn->ping_timeout)
3190                 mod_timer(&conn->transport_timer,
3191                           jiffies + (conn->recv_timeout * HZ));
3192
3193         switch(conn->stop_stage) {
3194         case STOP_CONN_RECOVER:
3195                 /*
3196                  * unblock eh_abort() if it is blocked. re-try all
3197                  * commands after successful recovery
3198                  */
3199                 conn->stop_stage = 0;
3200                 session->tmf_state = TMF_INITIAL;
3201                 session->age++;
3202                 if (session->age == 16)
3203                         session->age = 0;
3204                 break;
3205         case STOP_CONN_TERM:
3206                 conn->stop_stage = 0;
3207                 break;
3208         default:
3209                 break;
3210         }
3211         spin_unlock_bh(&session->frwd_lock);
3212
3213         iscsi_unblock_session(session->cls_session);
3214         wake_up(&session->ehwait);
3215         return 0;
3216 }
3217 EXPORT_SYMBOL_GPL(iscsi_conn_start);
3218
3219 static void
3220 fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3221 {
3222         struct iscsi_task *task;
3223         int i, state;
3224
3225         for (i = 0; i < conn->session->cmds_max; i++) {
3226                 task = conn->session->cmds[i];
3227                 if (task->sc)
3228                         continue;
3229
3230                 if (task->state == ISCSI_TASK_FREE)
3231                         continue;
3232
3233                 ISCSI_DBG_SESSION(conn->session,
3234                                   "failing mgmt itt 0x%x state %d\n",
3235                                   task->itt, task->state);
3236
3237                 spin_lock_bh(&session->back_lock);
3238                 if (cleanup_queued_task(task)) {
3239                         spin_unlock_bh(&session->back_lock);
3240                         continue;
3241                 }
3242
3243                 state = ISCSI_TASK_ABRT_SESS_RECOV;
3244                 if (task->state == ISCSI_TASK_PENDING)
3245                         state = ISCSI_TASK_COMPLETED;
3246                 iscsi_complete_task(task, state);
3247                 spin_unlock_bh(&session->back_lock);
3248         }
3249 }
3250
3251 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3252 {
3253         struct iscsi_conn *conn = cls_conn->dd_data;
3254         struct iscsi_session *session = conn->session;
3255         int old_stop_stage;
3256
3257         mutex_lock(&session->eh_mutex);
3258         spin_lock_bh(&session->frwd_lock);
3259         if (conn->stop_stage == STOP_CONN_TERM) {
3260                 spin_unlock_bh(&session->frwd_lock);
3261                 mutex_unlock(&session->eh_mutex);
3262                 return;
3263         }
3264
3265         /*
3266          * When this is called for the in_login state, we only want to clean
3267          * up the login task and connection. We do not need to block and set
3268          * the recovery state again
3269          */
3270         if (flag == STOP_CONN_TERM)
3271                 session->state = ISCSI_STATE_TERMINATE;
3272         else if (conn->stop_stage != STOP_CONN_RECOVER)
3273                 session->state = ISCSI_STATE_IN_RECOVERY;
3274
3275         old_stop_stage = conn->stop_stage;
3276         conn->stop_stage = flag;
3277         spin_unlock_bh(&session->frwd_lock);
3278
3279         del_timer_sync(&conn->transport_timer);
3280         iscsi_suspend_tx(conn);
3281
3282         spin_lock_bh(&session->frwd_lock);
3283         conn->c_stage = ISCSI_CONN_STOPPED;
3284         spin_unlock_bh(&session->frwd_lock);
3285
3286         /*
3287          * for connection level recovery we should not calculate
3288          * header digest. conn->hdr_size used for optimization
3289          * in hdr_extract() and will be re-negotiated at
3290          * set_param() time.
3291          */
3292         if (flag == STOP_CONN_RECOVER) {
3293                 conn->hdrdgst_en = 0;
3294                 conn->datadgst_en = 0;
3295                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
3296                     old_stop_stage != STOP_CONN_RECOVER) {
3297                         ISCSI_DBG_SESSION(session, "blocking session\n");
3298                         iscsi_block_session(session->cls_session);
3299                 }
3300         }
3301
3302         /*
3303          * flush queues.
3304          */
3305         spin_lock_bh(&session->frwd_lock);
3306         fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3307         fail_mgmt_tasks(session, conn);
3308         memset(&session->tmhdr, 0, sizeof(session->tmhdr));
3309         spin_unlock_bh(&session->frwd_lock);
3310         mutex_unlock(&session->eh_mutex);
3311 }
3312 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3313
3314 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3315                     struct iscsi_cls_conn *cls_conn, int is_leading)
3316 {
3317         struct iscsi_session *session = cls_session->dd_data;
3318         struct iscsi_conn *conn = cls_conn->dd_data;
3319
3320         spin_lock_bh(&session->frwd_lock);
3321         if (is_leading)
3322                 session->leadconn = conn;
3323
3324         set_bit(ISCSI_CONN_FLAG_BOUND, &conn->flags);
3325         spin_unlock_bh(&session->frwd_lock);
3326
3327         /*
3328          * The target could have reduced it's window size between logins, so
3329          * we have to reset max/exp cmdsn so we can see the new values.
3330          */
3331         spin_lock_bh(&session->back_lock);
3332         session->max_cmdsn = session->exp_cmdsn = session->cmdsn + 1;
3333         spin_unlock_bh(&session->back_lock);
3334         /*
3335          * Unblock xmitworker(), Login Phase will pass through.
3336          */
3337         clear_bit(ISCSI_CONN_FLAG_SUSPEND_RX, &conn->flags);
3338         clear_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags);
3339         return 0;
3340 }
3341 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3342
3343 int iscsi_switch_str_param(char **param, char *new_val_buf)
3344 {
3345         char *new_val;
3346
3347         if (*param) {
3348                 if (!strcmp(*param, new_val_buf))
3349                         return 0;
3350         }
3351
3352         new_val = kstrdup(new_val_buf, GFP_NOIO);
3353         if (!new_val)
3354                 return -ENOMEM;
3355
3356         kfree(*param);
3357         *param = new_val;
3358         return 0;
3359 }
3360 EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3361
3362 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3363                     enum iscsi_param param, char *buf, int buflen)
3364 {
3365         struct iscsi_conn *conn = cls_conn->dd_data;
3366         struct iscsi_session *session = conn->session;
3367         int val;
3368
3369         switch(param) {
3370         case ISCSI_PARAM_FAST_ABORT:
3371                 sscanf(buf, "%d", &session->fast_abort);
3372                 break;
3373         case ISCSI_PARAM_ABORT_TMO:
3374                 sscanf(buf, "%d", &session->abort_timeout);
3375                 break;
3376         case ISCSI_PARAM_LU_RESET_TMO:
3377                 sscanf(buf, "%d", &session->lu_reset_timeout);
3378                 break;
3379         case ISCSI_PARAM_TGT_RESET_TMO:
3380                 sscanf(buf, "%d", &session->tgt_reset_timeout);
3381                 break;
3382         case ISCSI_PARAM_PING_TMO:
3383                 sscanf(buf, "%d", &conn->ping_timeout);
3384                 break;
3385         case ISCSI_PARAM_RECV_TMO:
3386                 sscanf(buf, "%d", &conn->recv_timeout);
3387                 break;
3388         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3389                 sscanf(buf, "%d", &conn->max_recv_dlength);
3390                 break;
3391         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3392                 sscanf(buf, "%d", &conn->max_xmit_dlength);
3393                 break;
3394         case ISCSI_PARAM_HDRDGST_EN:
3395                 sscanf(buf, "%d", &conn->hdrdgst_en);
3396                 break;
3397         case ISCSI_PARAM_DATADGST_EN:
3398                 sscanf(buf, "%d", &conn->datadgst_en);
3399                 break;
3400         case ISCSI_PARAM_INITIAL_R2T_EN:
3401                 sscanf(buf, "%d", &session->initial_r2t_en);
3402                 break;
3403         case ISCSI_PARAM_MAX_R2T:
3404                 sscanf(buf, "%hu", &session->max_r2t);
3405                 break;
3406         case ISCSI_PARAM_IMM_DATA_EN:
3407                 sscanf(buf, "%d", &session->imm_data_en);
3408                 break;
3409         case ISCSI_PARAM_FIRST_BURST:
3410                 sscanf(buf, "%d", &session->first_burst);
3411                 break;
3412         case ISCSI_PARAM_MAX_BURST:
3413                 sscanf(buf, "%d", &session->max_burst);
3414                 break;
3415         case ISCSI_PARAM_PDU_INORDER_EN:
3416                 sscanf(buf, "%d", &session->pdu_inorder_en);
3417                 break;
3418         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3419                 sscanf(buf, "%d", &session->dataseq_inorder_en);
3420                 break;
3421         case ISCSI_PARAM_ERL:
3422                 sscanf(buf, "%d", &session->erl);
3423                 break;
3424         case ISCSI_PARAM_EXP_STATSN:
3425                 sscanf(buf, "%u", &conn->exp_statsn);
3426                 break;
3427         case ISCSI_PARAM_USERNAME:
3428                 return iscsi_switch_str_param(&session->username, buf);
3429         case ISCSI_PARAM_USERNAME_IN:
3430                 return iscsi_switch_str_param(&session->username_in, buf);
3431         case ISCSI_PARAM_PASSWORD:
3432                 return iscsi_switch_str_param(&session->password, buf);
3433         case ISCSI_PARAM_PASSWORD_IN:
3434                 return iscsi_switch_str_param(&session->password_in, buf);
3435         case ISCSI_PARAM_TARGET_NAME:
3436                 return iscsi_switch_str_param(&session->targetname, buf);
3437         case ISCSI_PARAM_TARGET_ALIAS:
3438                 return iscsi_switch_str_param(&session->targetalias, buf);
3439         case ISCSI_PARAM_TPGT:
3440                 sscanf(buf, "%d", &session->tpgt);
3441                 break;
3442         case ISCSI_PARAM_PERSISTENT_PORT:
3443                 sscanf(buf, "%d", &conn->persistent_port);
3444                 break;
3445         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3446                 return iscsi_switch_str_param(&conn->persistent_address, buf);
3447         case ISCSI_PARAM_IFACE_NAME:
3448                 return iscsi_switch_str_param(&session->ifacename, buf);
3449         case ISCSI_PARAM_INITIATOR_NAME:
3450                 return iscsi_switch_str_param(&session->initiatorname, buf);
3451         case ISCSI_PARAM_BOOT_ROOT:
3452                 return iscsi_switch_str_param(&session->boot_root, buf);
3453         case ISCSI_PARAM_BOOT_NIC:
3454                 return iscsi_switch_str_param(&session->boot_nic, buf);
3455         case ISCSI_PARAM_BOOT_TARGET:
3456                 return iscsi_switch_str_param(&session->boot_target, buf);
3457         case ISCSI_PARAM_PORTAL_TYPE:
3458                 return iscsi_switch_str_param(&session->portal_type, buf);
3459         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3460                 return iscsi_switch_str_param(&session->discovery_parent_type,
3461                                               buf);
3462         case ISCSI_PARAM_DISCOVERY_SESS:
3463                 sscanf(buf, "%d", &val);
3464                 session->discovery_sess = !!val;
3465                 break;
3466         case ISCSI_PARAM_LOCAL_IPADDR:
3467                 return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3468         default:
3469                 return -ENOSYS;
3470         }
3471
3472         return 0;
3473 }
3474 EXPORT_SYMBOL_GPL(iscsi_set_param);
3475
3476 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3477                             enum iscsi_param param, char *buf)
3478 {
3479         struct iscsi_session *session = cls_session->dd_data;
3480         int len;
3481
3482         switch(param) {
3483         case ISCSI_PARAM_FAST_ABORT:
3484                 len = sysfs_emit(buf, "%d\n", session->fast_abort);
3485                 break;
3486         case ISCSI_PARAM_ABORT_TMO:
3487                 len = sysfs_emit(buf, "%d\n", session->abort_timeout);
3488                 break;
3489         case ISCSI_PARAM_LU_RESET_TMO:
3490                 len = sysfs_emit(buf, "%d\n", session->lu_reset_timeout);
3491                 break;
3492         case ISCSI_PARAM_TGT_RESET_TMO:
3493                 len = sysfs_emit(buf, "%d\n", session->tgt_reset_timeout);
3494                 break;
3495         case ISCSI_PARAM_INITIAL_R2T_EN:
3496                 len = sysfs_emit(buf, "%d\n", session->initial_r2t_en);
3497                 break;
3498         case ISCSI_PARAM_MAX_R2T:
3499                 len = sysfs_emit(buf, "%hu\n", session->max_r2t);
3500                 break;
3501         case ISCSI_PARAM_IMM_DATA_EN:
3502                 len = sysfs_emit(buf, "%d\n", session->imm_data_en);
3503                 break;
3504         case ISCSI_PARAM_FIRST_BURST:
3505                 len = sysfs_emit(buf, "%u\n", session->first_burst);
3506                 break;
3507         case ISCSI_PARAM_MAX_BURST:
3508                 len = sysfs_emit(buf, "%u\n", session->max_burst);
3509                 break;
3510         case ISCSI_PARAM_PDU_INORDER_EN:
3511                 len = sysfs_emit(buf, "%d\n", session->pdu_inorder_en);
3512                 break;
3513         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3514                 len = sysfs_emit(buf, "%d\n", session->dataseq_inorder_en);
3515                 break;
3516         case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3517                 len = sysfs_emit(buf, "%d\n", session->def_taskmgmt_tmo);
3518                 break;
3519         case ISCSI_PARAM_ERL:
3520                 len = sysfs_emit(buf, "%d\n", session->erl);
3521                 break;
3522         case ISCSI_PARAM_TARGET_NAME:
3523                 len = sysfs_emit(buf, "%s\n", session->targetname);
3524                 break;
3525         case ISCSI_PARAM_TARGET_ALIAS:
3526                 len = sysfs_emit(buf, "%s\n", session->targetalias);
3527                 break;
3528         case ISCSI_PARAM_TPGT:
3529                 len = sysfs_emit(buf, "%d\n", session->tpgt);
3530                 break;
3531         case ISCSI_PARAM_USERNAME:
3532                 len = sysfs_emit(buf, "%s\n", session->username);
3533                 break;
3534         case ISCSI_PARAM_USERNAME_IN:
3535                 len = sysfs_emit(buf, "%s\n", session->username_in);
3536                 break;
3537         case ISCSI_PARAM_PASSWORD:
3538                 len = sysfs_emit(buf, "%s\n", session->password);
3539                 break;
3540         case ISCSI_PARAM_PASSWORD_IN:
3541                 len = sysfs_emit(buf, "%s\n", session->password_in);
3542                 break;
3543         case ISCSI_PARAM_IFACE_NAME:
3544                 len = sysfs_emit(buf, "%s\n", session->ifacename);
3545                 break;
3546         case ISCSI_PARAM_INITIATOR_NAME:
3547                 len = sysfs_emit(buf, "%s\n", session->initiatorname);
3548                 break;
3549         case ISCSI_PARAM_BOOT_ROOT:
3550                 len = sysfs_emit(buf, "%s\n", session->boot_root);
3551                 break;
3552         case ISCSI_PARAM_BOOT_NIC:
3553                 len = sysfs_emit(buf, "%s\n", session->boot_nic);
3554                 break;
3555         case ISCSI_PARAM_BOOT_TARGET:
3556                 len = sysfs_emit(buf, "%s\n", session->boot_target);
3557                 break;
3558         case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3559                 len = sysfs_emit(buf, "%u\n", session->auto_snd_tgt_disable);
3560                 break;
3561         case ISCSI_PARAM_DISCOVERY_SESS:
3562                 len = sysfs_emit(buf, "%u\n", session->discovery_sess);
3563                 break;
3564         case ISCSI_PARAM_PORTAL_TYPE:
3565                 len = sysfs_emit(buf, "%s\n", session->portal_type);
3566                 break;
3567         case ISCSI_PARAM_CHAP_AUTH_EN:
3568                 len = sysfs_emit(buf, "%u\n", session->chap_auth_en);
3569                 break;
3570         case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3571                 len = sysfs_emit(buf, "%u\n", session->discovery_logout_en);
3572                 break;
3573         case ISCSI_PARAM_BIDI_CHAP_EN:
3574                 len = sysfs_emit(buf, "%u\n", session->bidi_chap_en);
3575                 break;
3576         case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3577                 len = sysfs_emit(buf, "%u\n", session->discovery_auth_optional);
3578                 break;
3579         case ISCSI_PARAM_DEF_TIME2WAIT:
3580                 len = sysfs_emit(buf, "%d\n", session->time2wait);
3581                 break;
3582         case ISCSI_PARAM_DEF_TIME2RETAIN:
3583                 len = sysfs_emit(buf, "%d\n", session->time2retain);
3584                 break;
3585         case ISCSI_PARAM_TSID:
3586                 len = sysfs_emit(buf, "%u\n", session->tsid);
3587                 break;
3588         case ISCSI_PARAM_ISID:
3589                 len = sysfs_emit(buf, "%02x%02x%02x%02x%02x%02x\n",
3590                               session->isid[0], session->isid[1],
3591                               session->isid[2], session->isid[3],
3592                               session->isid[4], session->isid[5]);
3593                 break;
3594         case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3595                 len = sysfs_emit(buf, "%u\n", session->discovery_parent_idx);
3596                 break;
3597         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3598                 if (session->discovery_parent_type)
3599                         len = sysfs_emit(buf, "%s\n",
3600                                       session->discovery_parent_type);
3601                 else
3602                         len = sysfs_emit(buf, "\n");
3603                 break;
3604         default:
3605                 return -ENOSYS;
3606         }
3607
3608         return len;
3609 }
3610 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3611
3612 int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3613                               enum iscsi_param param, char *buf)
3614 {
3615         struct sockaddr_in6 *sin6 = NULL;
3616         struct sockaddr_in *sin = NULL;
3617         int len;
3618
3619         switch (addr->ss_family) {
3620         case AF_INET:
3621                 sin = (struct sockaddr_in *)addr;
3622                 break;
3623         case AF_INET6:
3624                 sin6 = (struct sockaddr_in6 *)addr;
3625                 break;
3626         default:
3627                 return -EINVAL;
3628         }
3629
3630         switch (param) {
3631         case ISCSI_PARAM_CONN_ADDRESS:
3632         case ISCSI_HOST_PARAM_IPADDRESS:
3633                 if (sin)
3634                         len = sysfs_emit(buf, "%pI4\n", &sin->sin_addr.s_addr);
3635                 else
3636                         len = sysfs_emit(buf, "%pI6\n", &sin6->sin6_addr);
3637                 break;
3638         case ISCSI_PARAM_CONN_PORT:
3639         case ISCSI_PARAM_LOCAL_PORT:
3640                 if (sin)
3641                         len = sysfs_emit(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3642                 else
3643                         len = sysfs_emit(buf, "%hu\n",
3644                                       be16_to_cpu(sin6->sin6_port));
3645                 break;
3646         default:
3647                 return -EINVAL;
3648         }
3649
3650         return len;
3651 }
3652 EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3653
3654 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3655                          enum iscsi_param param, char *buf)
3656 {
3657         struct iscsi_conn *conn = cls_conn->dd_data;
3658         int len;
3659
3660         switch(param) {
3661         case ISCSI_PARAM_PING_TMO:
3662                 len = sysfs_emit(buf, "%u\n", conn->ping_timeout);
3663                 break;
3664         case ISCSI_PARAM_RECV_TMO:
3665                 len = sysfs_emit(buf, "%u\n", conn->recv_timeout);
3666                 break;
3667         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3668                 len = sysfs_emit(buf, "%u\n", conn->max_recv_dlength);
3669                 break;
3670         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3671                 len = sysfs_emit(buf, "%u\n", conn->max_xmit_dlength);
3672                 break;
3673         case ISCSI_PARAM_HDRDGST_EN:
3674                 len = sysfs_emit(buf, "%d\n", conn->hdrdgst_en);
3675                 break;
3676         case ISCSI_PARAM_DATADGST_EN:
3677                 len = sysfs_emit(buf, "%d\n", conn->datadgst_en);
3678                 break;
3679         case ISCSI_PARAM_IFMARKER_EN:
3680                 len = sysfs_emit(buf, "%d\n", conn->ifmarker_en);
3681                 break;
3682         case ISCSI_PARAM_OFMARKER_EN:
3683                 len = sysfs_emit(buf, "%d\n", conn->ofmarker_en);
3684                 break;
3685         case ISCSI_PARAM_EXP_STATSN:
3686                 len = sysfs_emit(buf, "%u\n", conn->exp_statsn);
3687                 break;
3688         case ISCSI_PARAM_PERSISTENT_PORT:
3689                 len = sysfs_emit(buf, "%d\n", conn->persistent_port);
3690                 break;
3691         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3692                 len = sysfs_emit(buf, "%s\n", conn->persistent_address);
3693                 break;
3694         case ISCSI_PARAM_STATSN:
3695                 len = sysfs_emit(buf, "%u\n", conn->statsn);
3696                 break;
3697         case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3698                 len = sysfs_emit(buf, "%u\n", conn->max_segment_size);
3699                 break;
3700         case ISCSI_PARAM_KEEPALIVE_TMO:
3701                 len = sysfs_emit(buf, "%u\n", conn->keepalive_tmo);
3702                 break;
3703         case ISCSI_PARAM_LOCAL_PORT:
3704                 len = sysfs_emit(buf, "%u\n", conn->local_port);
3705                 break;
3706         case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3707                 len = sysfs_emit(buf, "%u\n", conn->tcp_timestamp_stat);
3708                 break;
3709         case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3710                 len = sysfs_emit(buf, "%u\n", conn->tcp_nagle_disable);
3711                 break;
3712         case ISCSI_PARAM_TCP_WSF_DISABLE:
3713                 len = sysfs_emit(buf, "%u\n", conn->tcp_wsf_disable);
3714                 break;
3715         case ISCSI_PARAM_TCP_TIMER_SCALE:
3716                 len = sysfs_emit(buf, "%u\n", conn->tcp_timer_scale);
3717                 break;
3718         case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3719                 len = sysfs_emit(buf, "%u\n", conn->tcp_timestamp_en);
3720                 break;
3721         case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3722                 len = sysfs_emit(buf, "%u\n", conn->fragment_disable);
3723                 break;
3724         case ISCSI_PARAM_IPV4_TOS:
3725                 len = sysfs_emit(buf, "%u\n", conn->ipv4_tos);
3726                 break;
3727         case ISCSI_PARAM_IPV6_TC:
3728                 len = sysfs_emit(buf, "%u\n", conn->ipv6_traffic_class);
3729                 break;
3730         case ISCSI_PARAM_IPV6_FLOW_LABEL:
3731                 len = sysfs_emit(buf, "%u\n", conn->ipv6_flow_label);
3732                 break;
3733         case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3734                 len = sysfs_emit(buf, "%u\n", conn->is_fw_assigned_ipv6);
3735                 break;
3736         case ISCSI_PARAM_TCP_XMIT_WSF:
3737                 len = sysfs_emit(buf, "%u\n", conn->tcp_xmit_wsf);
3738                 break;
3739         case ISCSI_PARAM_TCP_RECV_WSF:
3740                 len = sysfs_emit(buf, "%u\n", conn->tcp_recv_wsf);
3741                 break;
3742         case ISCSI_PARAM_LOCAL_IPADDR:
3743                 len = sysfs_emit(buf, "%s\n", conn->local_ipaddr);
3744                 break;
3745         default:
3746                 return -ENOSYS;
3747         }
3748
3749         return len;
3750 }
3751 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3752
3753 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3754                          char *buf)
3755 {
3756         struct iscsi_host *ihost = shost_priv(shost);
3757         int len;
3758
3759         switch (param) {
3760         case ISCSI_HOST_PARAM_NETDEV_NAME:
3761                 len = sysfs_emit(buf, "%s\n", ihost->netdev);
3762                 break;
3763         case ISCSI_HOST_PARAM_HWADDRESS:
3764                 len = sysfs_emit(buf, "%s\n", ihost->hwaddress);
3765                 break;
3766         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3767                 len = sysfs_emit(buf, "%s\n", ihost->initiatorname);
3768                 break;
3769         default:
3770                 return -ENOSYS;
3771         }
3772
3773         return len;
3774 }
3775 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3776
3777 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3778                          char *buf, int buflen)
3779 {
3780         struct iscsi_host *ihost = shost_priv(shost);
3781
3782         switch (param) {
3783         case ISCSI_HOST_PARAM_NETDEV_NAME:
3784                 return iscsi_switch_str_param(&ihost->netdev, buf);
3785         case ISCSI_HOST_PARAM_HWADDRESS:
3786                 return iscsi_switch_str_param(&ihost->hwaddress, buf);
3787         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3788                 return iscsi_switch_str_param(&ihost->initiatorname, buf);
3789         default:
3790                 return -ENOSYS;
3791         }
3792
3793         return 0;
3794 }
3795 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3796
3797 MODULE_AUTHOR("Mike Christie");
3798 MODULE_DESCRIPTION("iSCSI library functions");
3799 MODULE_LICENSE("GPL");