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 #define ISCSI_CMD_COMPL_WAIT 5
  87
  88 inline void iscsi_conn_queue_xmit(struct iscsi_conn *conn)
  89 {
  90         struct Scsi_Host *shost = conn->session->host;
  91         struct iscsi_host *ihost = shost_priv(shost);
  92
  93         if (ihost->workq)
  94                 queue_work(ihost->workq, &conn->xmitwork);
  95 }
  96 EXPORT_SYMBOL_GPL(iscsi_conn_queue_xmit);
  97
  98 inline void iscsi_conn_queue_recv(struct iscsi_conn *conn)
  99 {
 100         struct Scsi_Host *shost = conn->session->host;
 101         struct iscsi_host *ihost = shost_priv(shost);
 102
 103         if (ihost->workq && !test_bit(ISCSI_CONN_FLAG_SUSPEND_RX, &conn->flags))
 104                 queue_work(ihost->workq, &conn->recvwork);
 105 }
 106 EXPORT_SYMBOL_GPL(iscsi_conn_queue_recv);
 107
 108 static void __iscsi_update_cmdsn(struct iscsi_session *session,
 109                                  uint32_t exp_cmdsn, uint32_t max_cmdsn)
 110 {
 111         /*
 112          * standard specifies this check for when to update expected and
 113          * max sequence numbers
 114          */
 115         if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
 116                 return;
 117
 118         if (exp_cmdsn != session->exp_cmdsn &&
 119             !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
 120                 session->exp_cmdsn = exp_cmdsn;
 121
 122         if (max_cmdsn != session->max_cmdsn &&
 123             !iscsi_sna_lt(max_cmdsn, session->max_cmdsn))
 124                 session->max_cmdsn = max_cmdsn;
 125 }
 126
 127 void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
 128 {
 129         __iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
 130                              be32_to_cpu(hdr->max_cmdsn));
 131 }
 132 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
 133
 134 /**
 135  * iscsi_prep_data_out_pdu - initialize Data-Out
 136  * @task: scsi command task
 137  * @r2t: R2T info
 138  * @hdr: iscsi data in pdu
 139  *
 140  * Notes:
 141  *      Initialize Data-Out within this R2T sequence and finds
 142  *      proper data_offset within this SCSI command.
 143  *
 144  *      This function is called with connection lock taken.
 145  **/
 146 void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
 147                            struct iscsi_data *hdr)
 148 {
 149         struct iscsi_conn *conn = task->conn;
 150         unsigned int left = r2t->data_length - r2t->sent;
 151
 152         task->hdr_len = sizeof(struct iscsi_data);
 153
 154         memset(hdr, 0, sizeof(struct iscsi_data));
 155         hdr->ttt = r2t->ttt;
 156         hdr->datasn = cpu_to_be32(r2t->datasn);
 157         r2t->datasn++;
 158         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 159         hdr->lun = task->lun;
 160         hdr->itt = task->hdr_itt;
 161         hdr->exp_statsn = r2t->exp_statsn;
 162         hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
 163         if (left > conn->max_xmit_dlength) {
 164                 hton24(hdr->dlength, conn->max_xmit_dlength);
 165                 r2t->data_count = conn->max_xmit_dlength;
 166                 hdr->flags = 0;
 167         } else {
 168                 hton24(hdr->dlength, left);
 169                 r2t->data_count = left;
 170                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 171         }
 172         conn->dataout_pdus_cnt++;
 173 }
 174 EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
 175
 176 static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
 177 {
 178         unsigned exp_len = task->hdr_len + len;
 179
 180         if (exp_len > task->hdr_max) {
 181                 WARN_ON(1);
 182                 return -EINVAL;
 183         }
 184
 185         WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 186         task->hdr_len = exp_len;
 187         return 0;
 188 }
 189
 190 /*
 191  * make an extended cdb AHS
 192  */
 193 static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
 194 {
 195         struct scsi_cmnd *cmd = task->sc;
 196         unsigned rlen, pad_len;
 197         unsigned short ahslength;
 198         struct iscsi_ecdb_ahdr *ecdb_ahdr;
 199         int rc;
 200
 201         ecdb_ahdr = iscsi_next_hdr(task);
 202         rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 203
 204         BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 205         ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 206
 207         pad_len = iscsi_padding(rlen);
 208
 209         rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
 210                            sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 211         if (rc)
 212                 return rc;
 213
 214         if (pad_len)
 215                 memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 216
 217         ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 218         ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 219         ecdb_ahdr->reserved = 0;
 220         memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 221
 222         ISCSI_DBG_SESSION(task->conn->session,
 223                           "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 224                           "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
 225                           "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
 226                           task->hdr_len);
 227         return 0;
 228 }
 229
 230 /**
 231  * iscsi_check_tmf_restrictions - check if a task is affected by TMF
 232  * @task: iscsi task
 233  * @opcode: opcode to check for
 234  *
 235  * During TMF a task has to be checked if it's affected.
 236  * All unrelated I/O can be passed through, but I/O to the
 237  * affected LUN should be restricted.
 238  * If 'fast_abort' is set we won't be sending any I/O to the
 239  * affected LUN.
 240  * Otherwise the target is waiting for all TTTs to be completed,
 241  * so we have to send all outstanding Data-Out PDUs to the target.
 242  */
 243 static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
 244 {
 245         struct iscsi_session *session = task->conn->session;
 246         struct iscsi_tm *tmf = &session->tmhdr;
 247         u64 hdr_lun;
 248
 249         if (session->tmf_state == TMF_INITIAL)
 250                 return 0;
 251
 252         if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
 253                 return 0;
 254
 255         switch (ISCSI_TM_FUNC_VALUE(tmf)) {
 256         case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
 257                 /*
 258                  * Allow PDUs for unrelated LUNs
 259                  */
 260                 hdr_lun = scsilun_to_int(&tmf->lun);
 261                 if (hdr_lun != task->sc->device->lun)
 262                         return 0;
 263                 fallthrough;
 264         case ISCSI_TM_FUNC_TARGET_WARM_RESET:
 265                 /*
 266                  * Fail all SCSI cmd PDUs
 267                  */
 268                 if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
 269                         iscsi_session_printk(KERN_INFO, session,
 270                                              "task [op %x itt 0x%x/0x%x] rejected.\n",
 271                                              opcode, task->itt, task->hdr_itt);
 272                         return -EACCES;
 273                 }
 274                 /*
 275                  * And also all data-out PDUs in response to R2T
 276                  * if fast_abort is set.
 277                  */
 278                 if (session->fast_abort) {
 279                         iscsi_session_printk(KERN_INFO, session,
 280                                              "task [op %x itt 0x%x/0x%x] fast abort.\n",
 281                                              opcode, task->itt, task->hdr_itt);
 282                         return -EACCES;
 283                 }
 284                 break;
 285         case ISCSI_TM_FUNC_ABORT_TASK:
 286                 /*
 287                  * the caller has already checked if the task
 288                  * they want to abort was in the pending queue so if
 289                  * we are here the cmd pdu has gone out already, and
 290                  * we will only hit this for data-outs
 291                  */
 292                 if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
 293                     task->hdr_itt == tmf->rtt) {
 294                         ISCSI_DBG_SESSION(session,
 295                                           "Preventing task %x/%x from sending "
 296                                           "data-out due to abort task in "
 297                                           "progress\n", task->itt,
 298                                           task->hdr_itt);
 299                         return -EACCES;
 300                 }
 301                 break;
 302         }
 303
 304         return 0;
 305 }
 306
 307 /**
 308  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 309  * @task: iscsi task
 310  *
 311  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 312  * fields like dlength or final based on how much data it sends
 313  */
 314 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 315 {
 316         struct iscsi_conn *conn = task->conn;
 317         struct iscsi_session *session = conn->session;
 318         struct scsi_cmnd *sc = task->sc;
 319         struct iscsi_scsi_req *hdr;
 320         unsigned hdrlength, cmd_len, transfer_length;
 321         itt_t itt;
 322         int rc;
 323
 324         rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
 325         if (rc)
 326                 return rc;
 327
 328         if (conn->session->tt->alloc_pdu) {
 329                 rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
 330                 if (rc)
 331                         return rc;
 332         }
 333         hdr = (struct iscsi_scsi_req *)task->hdr;
 334         itt = hdr->itt;
 335         memset(hdr, 0, sizeof(*hdr));
 336
 337         if (session->tt->parse_pdu_itt)
 338                 hdr->itt = task->hdr_itt = itt;
 339         else
 340                 hdr->itt = task->hdr_itt = build_itt(task->itt,
 341                                                      task->conn->session->age);
 342         task->hdr_len = 0;
 343         rc = iscsi_add_hdr(task, sizeof(*hdr));
 344         if (rc)
 345                 return rc;
 346         hdr->opcode = ISCSI_OP_SCSI_CMD;
 347         hdr->flags = ISCSI_ATTR_SIMPLE;
 348         int_to_scsilun(sc->device->lun, &hdr->lun);
 349         task->lun = hdr->lun;
 350         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 351         cmd_len = sc->cmd_len;
 352         if (cmd_len < ISCSI_CDB_SIZE)
 353                 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 354         else if (cmd_len > ISCSI_CDB_SIZE) {
 355                 rc = iscsi_prep_ecdb_ahs(task);
 356                 if (rc)
 357                         return rc;
 358                 cmd_len = ISCSI_CDB_SIZE;
 359         }
 360         memcpy(hdr->cdb, sc->cmnd, cmd_len);
 361
 362         task->imm_count = 0;
 363         if (scsi_get_prot_op(sc) != SCSI_PROT_NORMAL)
 364                 task->protected = true;
 365
 366         transfer_length = scsi_transfer_length(sc);
 367         hdr->data_length = cpu_to_be32(transfer_length);
 368         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 369                 struct iscsi_r2t_info *r2t = &task->unsol_r2t;
 370
 371                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 372                 /*
 373                  * Write counters:
 374                  *
 375                  *      imm_count       bytes to be sent right after
 376                  *                      SCSI PDU Header
 377                  *
 378                  *      unsol_count     bytes(as Data-Out) to be sent
 379                  *                      without R2T ack right after
 380                  *                      immediate data
 381                  *
 382                  *      r2t data_length bytes to be sent via R2T ack's
 383                  *
 384                  *      pad_count       bytes to be sent as zero-padding
 385                  */
 386                 memset(r2t, 0, sizeof(*r2t));
 387
 388                 if (session->imm_data_en) {
 389                         if (transfer_length >= session->first_burst)
 390                                 task->imm_count = min(session->first_burst,
 391                                                         conn->max_xmit_dlength);
 392                         else
 393                                 task->imm_count = min(transfer_length,
 394                                                       conn->max_xmit_dlength);
 395                         hton24(hdr->dlength, task->imm_count);
 396                 } else
 397                         zero_data(hdr->dlength);
 398
 399                 if (!session->initial_r2t_en) {
 400                         r2t->data_length = min(session->first_burst,
 401                                                transfer_length) -
 402                                                task->imm_count;
 403                         r2t->data_offset = task->imm_count;
 404                         r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 405                         r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
 406                 }
 407
 408                 if (!task->unsol_r2t.data_length)
 409                         /* No unsolicit Data-Out's */
 410                         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 411         } else {
 412                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 413                 zero_data(hdr->dlength);
 414
 415                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
 416                         hdr->flags |= ISCSI_FLAG_CMD_READ;
 417         }
 418
 419         /* calculate size of additional header segments (AHSs) */
 420         hdrlength = task->hdr_len - sizeof(*hdr);
 421
 422         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 423         hdrlength /= ISCSI_PAD_LEN;
 424
 425         WARN_ON(hdrlength >= 256);
 426         hdr->hlength = hdrlength & 0xFF;
 427         hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
 428
 429         if (session->tt->init_task && session->tt->init_task(task))
 430                 return -EIO;
 431
 432         task->state = ISCSI_TASK_RUNNING;
 433         session->cmdsn++;
 434
 435         conn->scsicmd_pdus_cnt++;
 436         ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
 437                           "itt 0x%x len %d cmdsn %d win %d]\n",
 438                           sc->sc_data_direction == DMA_TO_DEVICE ?
 439                           "write" : "read", conn->id, sc, sc->cmnd[0],
 440                           task->itt, transfer_length,
 441                           session->cmdsn,
 442                           session->max_cmdsn - session->exp_cmdsn + 1);
 443         return 0;
 444 }
 445
 446 /**
 447  * iscsi_free_task - free a task
 448  * @task: iscsi cmd task
 449  *
 450  * Must be called with session back_lock.
 451  * This function returns the scsi command to scsi-ml or cleans
 452  * up mgmt tasks then returns the task to the pool.
 453  */
 454 static void iscsi_free_task(struct iscsi_task *task)
 455 {
 456         struct iscsi_conn *conn = task->conn;
 457         struct iscsi_session *session = conn->session;
 458         struct scsi_cmnd *sc = task->sc;
 459         int oldstate = task->state;
 460
 461         ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
 462                           task->itt, task->state, task->sc);
 463
 464         session->tt->cleanup_task(task);
 465         task->state = ISCSI_TASK_FREE;
 466         task->sc = NULL;
 467         /*
 468          * login task is preallocated so do not free
 469          */
 470         if (conn->login_task == task)
 471                 return;
 472
 473         kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
 474
 475         if (sc) {
 476                 /* SCSI eh reuses commands to verify us */
 477                 iscsi_cmd(sc)->task = NULL;
 478                 /*
 479                  * queue command may call this to free the task, so
 480                  * it will decide how to return sc to scsi-ml.
 481                  */
 482                 if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
 483                         scsi_done(sc);
 484         }
 485 }
 486
 487 bool iscsi_get_task(struct iscsi_task *task)
 488 {
 489         return refcount_inc_not_zero(&task->refcount);
 490 }
 491 EXPORT_SYMBOL_GPL(iscsi_get_task);
 492
 493 /**
 494  * __iscsi_put_task - drop the refcount on a task
 495  * @task: iscsi_task to drop the refcount on
 496  *
 497  * The back_lock must be held when calling in case it frees the task.
 498  */
 499 void __iscsi_put_task(struct iscsi_task *task)
 500 {
 501         if (refcount_dec_and_test(&task->refcount))
 502                 iscsi_free_task(task);
 503 }
 504 EXPORT_SYMBOL_GPL(__iscsi_put_task);
 505
 506 void iscsi_put_task(struct iscsi_task *task)
 507 {
 508         struct iscsi_session *session = task->conn->session;
 509
 510         if (refcount_dec_and_test(&task->refcount)) {
 511                 spin_lock_bh(&session->back_lock);
 512                 iscsi_free_task(task);
 513                 spin_unlock_bh(&session->back_lock);
 514         }
 515 }
 516 EXPORT_SYMBOL_GPL(iscsi_put_task);
 517
 518 /**
 519  * iscsi_complete_task - finish a task
 520  * @task: iscsi cmd task
 521  * @state: state to complete task with
 522  *
 523  * Must be called with session back_lock.
 524  */
 525 static void iscsi_complete_task(struct iscsi_task *task, int state)
 526 {
 527         struct iscsi_conn *conn = task->conn;
 528
 529         ISCSI_DBG_SESSION(conn->session,
 530                           "complete task itt 0x%x state %d sc %p\n",
 531                           task->itt, task->state, task->sc);
 532         if (task->state == ISCSI_TASK_COMPLETED ||
 533             task->state == ISCSI_TASK_ABRT_TMF ||
 534             task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
 535             task->state == ISCSI_TASK_REQUEUE_SCSIQ)
 536                 return;
 537         WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
 538         task->state = state;
 539
 540         if (READ_ONCE(conn->ping_task) == task)
 541                 WRITE_ONCE(conn->ping_task, NULL);
 542
 543         /* release get from queueing */
 544         __iscsi_put_task(task);
 545 }
 546
 547 /**
 548  * iscsi_complete_scsi_task - finish scsi task normally
 549  * @task: iscsi task for scsi cmd
 550  * @exp_cmdsn: expected cmd sn in cpu format
 551  * @max_cmdsn: max cmd sn in cpu format
 552  *
 553  * This is used when drivers do not need or cannot perform
 554  * lower level pdu processing.
 555  *
 556  * Called with session back_lock
 557  */
 558 void iscsi_complete_scsi_task(struct iscsi_task *task,
 559                               uint32_t exp_cmdsn, uint32_t max_cmdsn)
 560 {
 561         struct iscsi_conn *conn = task->conn;
 562
 563         ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 564
 565         conn->last_recv = jiffies;
 566         __iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 567         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 568 }
 569 EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 570
 571 /*
 572  * Must be called with back and frwd lock
 573  */
 574 static bool cleanup_queued_task(struct iscsi_task *task)
 575 {
 576         struct iscsi_conn *conn = task->conn;
 577         bool early_complete = false;
 578
 579         /*
 580          * We might have raced where we handled a R2T early and got a response
 581          * but have not yet taken the task off the requeue list, then a TMF or
 582          * recovery happened and so we can still see it here.
 583          */
 584         if (task->state == ISCSI_TASK_COMPLETED)
 585                 early_complete = true;
 586
 587         if (!list_empty(&task->running)) {
 588                 list_del_init(&task->running);
 589                 /*
 590                  * If it's on a list but still running this could be cleanup
 591                  * from a TMF or session recovery.
 592                  */
 593                 if (task->state == ISCSI_TASK_RUNNING ||
 594                     task->state == ISCSI_TASK_COMPLETED)
 595                         __iscsi_put_task(task);
 596         }
 597
 598         if (conn->session->running_aborted_task == task) {
 599                 conn->session->running_aborted_task = NULL;
 600                 __iscsi_put_task(task);
 601         }
 602
 603         if (conn->task == task) {
 604                 conn->task = NULL;
 605                 __iscsi_put_task(task);
 606         }
 607
 608         return early_complete;
 609 }
 610
 611 /*
 612  * session back and frwd lock must be held and if not called for a task that
 613  * is still pending or from the xmit thread, then xmit thread must be suspended
 614  */
 615 static void __fail_scsi_task(struct iscsi_task *task, int err)
 616 {
 617         struct iscsi_conn *conn = task->conn;
 618         struct scsi_cmnd *sc;
 619         int state;
 620
 621         if (cleanup_queued_task(task))
 622                 return;
 623
 624         if (task->state == ISCSI_TASK_PENDING) {
 625                 /*
 626                  * cmd never made it to the xmit thread, so we should not count
 627                  * the cmd in the sequencing
 628                  */
 629                 conn->session->queued_cmdsn--;
 630                 /* it was never sent so just complete like normal */
 631                 state = ISCSI_TASK_COMPLETED;
 632         } else if (err == DID_TRANSPORT_DISRUPTED)
 633                 state = ISCSI_TASK_ABRT_SESS_RECOV;
 634         else
 635                 state = ISCSI_TASK_ABRT_TMF;
 636
 637         sc = task->sc;
 638         sc->result = err << 16;
 639         scsi_set_resid(sc, scsi_bufflen(sc));
 640         iscsi_complete_task(task, state);
 641 }
 642
 643 static void fail_scsi_task(struct iscsi_task *task, int err)
 644 {
 645         struct iscsi_session *session = task->conn->session;
 646
 647         spin_lock_bh(&session->back_lock);
 648         __fail_scsi_task(task, err);
 649         spin_unlock_bh(&session->back_lock);
 650 }
 651
 652 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 653                                 struct iscsi_task *task)
 654 {
 655         struct iscsi_session *session = conn->session;
 656         struct iscsi_hdr *hdr = task->hdr;
 657         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 658         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 659
 660         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 661                 return -ENOTCONN;
 662
 663         if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
 664                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 665         /*
 666          * pre-format CmdSN for outgoing PDU.
 667          */
 668         nop->cmdsn = cpu_to_be32(session->cmdsn);
 669         if (hdr->itt != RESERVED_ITT) {
 670                 /*
 671                  * TODO: We always use immediate for normal session pdus.
 672                  * If we start to send tmfs or nops as non-immediate then
 673                  * we should start checking the cmdsn numbers for mgmt tasks.
 674                  *
 675                  * During discovery sessions iscsid sends TEXT as non immediate,
 676                  * but we always only send one PDU at a time.
 677                  */
 678                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 679                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 680                         session->queued_cmdsn++;
 681                         session->cmdsn++;
 682                 }
 683         }
 684
 685         if (session->tt->init_task && session->tt->init_task(task))
 686                 return -EIO;
 687
 688         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 689                 session->state = ISCSI_STATE_LOGGING_OUT;
 690
 691         task->state = ISCSI_TASK_RUNNING;
 692         ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 693                           "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 694                           hdr->itt, task->data_count);
 695         return 0;
 696 }
 697
 698 /**
 699  * iscsi_alloc_mgmt_task - allocate and setup a mgmt task.
 700  * @conn: iscsi conn that the task will be sent on.
 701  * @hdr: iscsi pdu that will be sent.
 702  * @data: buffer for data segment if needed.
 703  * @data_size: length of data in bytes.
 704  */
 705 static struct iscsi_task *
 706 iscsi_alloc_mgmt_task(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 707                       char *data, uint32_t data_size)
 708 {
 709         struct iscsi_session *session = conn->session;
 710         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 711         struct iscsi_task *task;
 712         itt_t itt;
 713
 714         if (session->state == ISCSI_STATE_TERMINATE ||
 715             !test_bit(ISCSI_CONN_FLAG_BOUND, &conn->flags))
 716                 return NULL;
 717
 718         if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 719                 /*
 720                  * Login and Text are sent serially, in
 721                  * request-followed-by-response sequence.
 722                  * Same task can be used. Same ITT must be used.
 723                  * Note that login_task is preallocated at conn_create().
 724                  */
 725                 if (conn->login_task->state != ISCSI_TASK_FREE) {
 726                         iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 727                                           "progress. Cannot start new task.\n");
 728                         return NULL;
 729                 }
 730
 731                 if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
 732                         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);
 733                         return NULL;
 734                 }
 735
 736                 task = conn->login_task;
 737         } else {
 738                 if (session->state != ISCSI_STATE_LOGGED_IN)
 739                         return NULL;
 740
 741                 if (data_size != 0) {
 742                         iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
 743                         return NULL;
 744                 }
 745
 746                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 747                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 748
 749                 if (!kfifo_out(&session->cmdpool.queue,
 750                                  (void*)&task, sizeof(void*)))
 751                         return NULL;
 752         }
 753         /*
 754          * released in complete pdu for task we expect a response for, and
 755          * released by the lld when it has transmitted the task for
 756          * pdus we do not expect a response for.
 757          */
 758         refcount_set(&task->refcount, 1);
 759         task->conn = conn;
 760         task->sc = NULL;
 761         INIT_LIST_HEAD(&task->running);
 762         task->state = ISCSI_TASK_PENDING;
 763
 764         if (data_size) {
 765                 memcpy(task->data, data, data_size);
 766                 task->data_count = data_size;
 767         } else
 768                 task->data_count = 0;
 769
 770         if (conn->session->tt->alloc_pdu) {
 771                 if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 772                         iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 773                                          "pdu for mgmt task.\n");
 774                         goto free_task;
 775                 }
 776         }
 777
 778         itt = task->hdr->itt;
 779         task->hdr_len = sizeof(struct iscsi_hdr);
 780         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 781
 782         if (hdr->itt != RESERVED_ITT) {
 783                 if (session->tt->parse_pdu_itt)
 784                         task->hdr->itt = itt;
 785                 else
 786                         task->hdr->itt = build_itt(task->itt,
 787                                                    task->conn->session->age);
 788         }
 789
 790         return task;
 791
 792 free_task:
 793         iscsi_put_task(task);
 794         return NULL;
 795 }
 796
 797 /**
 798  * iscsi_send_mgmt_task - Send task created with iscsi_alloc_mgmt_task.
 799  * @task: iscsi task to send.
 800  *
 801  * On failure this returns a non-zero error code, and the driver must free
 802  * the task with iscsi_put_task;
 803  */
 804 static int iscsi_send_mgmt_task(struct iscsi_task *task)
 805 {
 806         struct iscsi_conn *conn = task->conn;
 807         struct iscsi_session *session = conn->session;
 808         struct iscsi_host *ihost = shost_priv(conn->session->host);
 809         int rc = 0;
 810
 811         if (!ihost->workq) {
 812                 rc = iscsi_prep_mgmt_task(conn, task);
 813                 if (rc)
 814                         return rc;
 815
 816                 rc = session->tt->xmit_task(task);
 817                 if (rc)
 818                         return rc;
 819         } else {
 820                 list_add_tail(&task->running, &conn->mgmtqueue);
 821                 iscsi_conn_queue_xmit(conn);
 822         }
 823
 824         return 0;
 825 }
 826
 827 static int __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 828                                  char *data, uint32_t data_size)
 829 {
 830         struct iscsi_task *task;
 831         int rc;
 832
 833         task = iscsi_alloc_mgmt_task(conn, hdr, data, data_size);
 834         if (!task)
 835                 return -ENOMEM;
 836
 837         rc = iscsi_send_mgmt_task(task);
 838         if (rc)
 839                 iscsi_put_task(task);
 840         return rc;
 841 }
 842
 843 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 844                         char *data, uint32_t data_size)
 845 {
 846         struct iscsi_conn *conn = cls_conn->dd_data;
 847         struct iscsi_session *session = conn->session;
 848         int err = 0;
 849
 850         spin_lock_bh(&session->frwd_lock);
 851         if (__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 852                 err = -EPERM;
 853         spin_unlock_bh(&session->frwd_lock);
 854         return err;
 855 }
 856 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 857
 858 /**
 859  * iscsi_scsi_cmd_rsp - SCSI Command Response processing
 860  * @conn: iscsi connection
 861  * @hdr: iscsi header
 862  * @task: scsi command task
 863  * @data: cmd data buffer
 864  * @datalen: len of buffer
 865  *
 866  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 867  * then completes the command and task. called under back_lock
 868  **/
 869 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 870                                struct iscsi_task *task, char *data,
 871                                int datalen)
 872 {
 873         struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
 874         struct iscsi_session *session = conn->session;
 875         struct scsi_cmnd *sc = task->sc;
 876
 877         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 878         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 879
 880         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 881
 882         if (task->protected) {
 883                 sector_t sector;
 884                 u8 ascq;
 885
 886                 /**
 887                  * Transports that didn't implement check_protection
 888                  * callback but still published T10-PI support to scsi-mid
 889                  * deserve this BUG_ON.
 890                  **/
 891                 BUG_ON(!session->tt->check_protection);
 892
 893                 ascq = session->tt->check_protection(task, &sector);
 894                 if (ascq) {
 895                         scsi_build_sense(sc, 1, ILLEGAL_REQUEST, 0x10, ascq);
 896                         scsi_set_sense_information(sc->sense_buffer,
 897                                                    SCSI_SENSE_BUFFERSIZE,
 898                                                    sector);
 899                         goto out;
 900                 }
 901         }
 902
 903         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 904                 sc->result = DID_ERROR << 16;
 905                 goto out;
 906         }
 907
 908         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 909                 uint16_t senselen;
 910
 911                 if (datalen < 2) {
 912 invalid_datalen:
 913                         iscsi_conn_printk(KERN_ERR,  conn,
 914                                          "Got CHECK_CONDITION but invalid data "
 915                                          "buffer size of %d\n", datalen);
 916                         sc->result = DID_BAD_TARGET << 16;
 917                         goto out;
 918                 }
 919
 920                 senselen = get_unaligned_be16(data);
 921                 if (datalen < senselen)
 922                         goto invalid_datalen;
 923
 924                 memcpy(sc->sense_buffer, data + 2,
 925                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 926                 ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 927                                   min_t(uint16_t, senselen,
 928                                   SCSI_SENSE_BUFFERSIZE));
 929         }
 930
 931         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 932                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 933                 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 934         }
 935
 936         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 937                            ISCSI_FLAG_CMD_OVERFLOW)) {
 938                 int res_count = be32_to_cpu(rhdr->residual_count);
 939
 940                 if (res_count > 0 &&
 941                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 942                      res_count <= scsi_bufflen(sc)))
 943                         /* write side for bidi or uni-io set_resid */
 944                         scsi_set_resid(sc, res_count);
 945                 else
 946                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 947         }
 948 out:
 949         ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 950                           sc, sc->result, task->itt);
 951         conn->scsirsp_pdus_cnt++;
 952         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 953 }
 954
 955 /**
 956  * iscsi_data_in_rsp - SCSI Data-In Response processing
 957  * @conn: iscsi connection
 958  * @hdr:  iscsi pdu
 959  * @task: scsi command task
 960  *
 961  * iscsi_data_in_rsp sets up the scsi_cmnd fields based on the data received
 962  * then completes the command and task. called under back_lock
 963  **/
 964 static void
 965 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 966                   struct iscsi_task *task)
 967 {
 968         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 969         struct scsi_cmnd *sc = task->sc;
 970
 971         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 972                 return;
 973
 974         iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 975         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 976         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 977         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 978                            ISCSI_FLAG_DATA_OVERFLOW)) {
 979                 int res_count = be32_to_cpu(rhdr->residual_count);
 980
 981                 if (res_count > 0 &&
 982                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 983                      res_count <= sc->sdb.length))
 984                         scsi_set_resid(sc, res_count);
 985                 else
 986                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 987         }
 988
 989         ISCSI_DBG_SESSION(conn->session, "data in with status done "
 990                           "[sc %p res %d itt 0x%x]\n",
 991                           sc, sc->result, task->itt);
 992         conn->scsirsp_pdus_cnt++;
 993         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 994 }
 995
 996 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 997 {
 998         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 999         struct iscsi_session *session = conn->session;
1000
1001         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1002         conn->tmfrsp_pdus_cnt++;
1003
1004         if (session->tmf_state != TMF_QUEUED)
1005                 return;
1006
1007         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
1008                 session->tmf_state = TMF_SUCCESS;
1009         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
1010                 session->tmf_state = TMF_NOT_FOUND;
1011         else
1012                 session->tmf_state = TMF_FAILED;
1013         wake_up(&session->ehwait);
1014 }
1015
1016 static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
1017 {
1018         struct iscsi_nopout hdr;
1019         struct iscsi_task *task;
1020
1021         if (!rhdr) {
1022                 if (READ_ONCE(conn->ping_task))
1023                         return -EINVAL;
1024         }
1025
1026         memset(&hdr, 0, sizeof(struct iscsi_nopout));
1027         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
1028         hdr.flags = ISCSI_FLAG_CMD_FINAL;
1029
1030         if (rhdr) {
1031                 hdr.lun = rhdr->lun;
1032                 hdr.ttt = rhdr->ttt;
1033                 hdr.itt = RESERVED_ITT;
1034         } else
1035                 hdr.ttt = RESERVED_ITT;
1036
1037         task = iscsi_alloc_mgmt_task(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
1038         if (!task)
1039                 return -ENOMEM;
1040
1041         if (!rhdr)
1042                 WRITE_ONCE(conn->ping_task, task);
1043
1044         if (iscsi_send_mgmt_task(task)) {
1045                 if (!rhdr)
1046                         WRITE_ONCE(conn->ping_task, NULL);
1047                 iscsi_put_task(task);
1048
1049                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
1050                 return -EIO;
1051         } else if (!rhdr) {
1052                 /* only track our nops */
1053                 conn->last_ping = jiffies;
1054         }
1055
1056         return 0;
1057 }
1058
1059 /**
1060  * iscsi_nop_out_rsp - SCSI NOP Response processing
1061  * @task: scsi command task
1062  * @nop: the nop structure
1063  * @data: where to put the data
1064  * @datalen: length of data
1065  *
1066  * iscsi_nop_out_rsp handles nop response from use or
1067  * from user space. called under back_lock
1068  **/
1069 static int iscsi_nop_out_rsp(struct iscsi_task *task,
1070                              struct iscsi_nopin *nop, char *data, int datalen)
1071 {
1072         struct iscsi_conn *conn = task->conn;
1073         int rc = 0;
1074
1075         if (READ_ONCE(conn->ping_task) != task) {
1076                 /*
1077                  * If this is not in response to one of our
1078                  * nops then it must be from userspace.
1079                  */
1080                 if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
1081                                    data, datalen))
1082                         rc = ISCSI_ERR_CONN_FAILED;
1083         } else
1084                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1085         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1086         return rc;
1087 }
1088
1089 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1090                                char *data, int datalen)
1091 {
1092         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1093         struct iscsi_hdr rejected_pdu;
1094         int opcode, rc = 0;
1095
1096         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1097
1098         if (ntoh24(reject->dlength) > datalen ||
1099             ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1100                 iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1101                                   "pdu. Invalid data length (pdu dlength "
1102                                   "%u, datalen %d\n", ntoh24(reject->dlength),
1103                                   datalen);
1104                 return ISCSI_ERR_PROTO;
1105         }
1106         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1107         opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1108
1109         switch (reject->reason) {
1110         case ISCSI_REASON_DATA_DIGEST_ERROR:
1111                 iscsi_conn_printk(KERN_ERR, conn,
1112                                   "pdu (op 0x%x itt 0x%x) rejected "
1113                                   "due to DataDigest error.\n",
1114                                   opcode, rejected_pdu.itt);
1115                 break;
1116         case ISCSI_REASON_IMM_CMD_REJECT:
1117                 iscsi_conn_printk(KERN_ERR, conn,
1118                                   "pdu (op 0x%x itt 0x%x) rejected. Too many "
1119                                   "immediate commands.\n",
1120                                   opcode, rejected_pdu.itt);
1121                 /*
1122                  * We only send one TMF at a time so if the target could not
1123                  * handle it, then it should get fixed (RFC mandates that
1124                  * a target can handle one immediate TMF per conn).
1125                  *
1126                  * For nops-outs, we could have sent more than one if
1127                  * the target is sending us lots of nop-ins
1128                  */
1129                 if (opcode != ISCSI_OP_NOOP_OUT)
1130                         return 0;
1131
1132                 if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1133                         /*
1134                          * nop-out in response to target's nop-out rejected.
1135                          * Just resend.
1136                          */
1137                         /* In RX path we are under back lock */
1138                         spin_unlock(&conn->session->back_lock);
1139                         spin_lock(&conn->session->frwd_lock);
1140                         iscsi_send_nopout(conn,
1141                                           (struct iscsi_nopin*)&rejected_pdu);
1142                         spin_unlock(&conn->session->frwd_lock);
1143                         spin_lock(&conn->session->back_lock);
1144                 } else {
1145                         struct iscsi_task *task;
1146                         /*
1147                          * Our nop as ping got dropped. We know the target
1148                          * and transport are ok so just clean up
1149                          */
1150                         task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1151                         if (!task) {
1152                                 iscsi_conn_printk(KERN_ERR, conn,
1153                                                  "Invalid pdu reject. Could "
1154                                                  "not lookup rejected task.\n");
1155                                 rc = ISCSI_ERR_BAD_ITT;
1156                         } else
1157                                 rc = iscsi_nop_out_rsp(task,
1158                                         (struct iscsi_nopin*)&rejected_pdu,
1159                                         NULL, 0);
1160                 }
1161                 break;
1162         default:
1163                 iscsi_conn_printk(KERN_ERR, conn,
1164                                   "pdu (op 0x%x itt 0x%x) rejected. Reason "
1165                                   "code 0x%x\n", rejected_pdu.opcode,
1166                                   rejected_pdu.itt, reject->reason);
1167                 break;
1168         }
1169         return rc;
1170 }
1171
1172 /**
1173  * iscsi_itt_to_task - look up task by itt
1174  * @conn: iscsi connection
1175  * @itt: itt
1176  *
1177  * This should be used for mgmt tasks like login and nops, or if
1178  * the LDD's itt space does not include the session age.
1179  *
1180  * The session back_lock must be held.
1181  */
1182 struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1183 {
1184         struct iscsi_session *session = conn->session;
1185         int i;
1186
1187         if (itt == RESERVED_ITT)
1188                 return NULL;
1189
1190         if (session->tt->parse_pdu_itt)
1191                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1192         else
1193                 i = get_itt(itt);
1194         if (i >= session->cmds_max)
1195                 return NULL;
1196
1197         return session->cmds[i];
1198 }
1199 EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1200
1201 /**
1202  * __iscsi_complete_pdu - complete pdu
1203  * @conn: iscsi conn
1204  * @hdr: iscsi header
1205  * @data: data buffer
1206  * @datalen: len of data buffer
1207  *
1208  * Completes pdu processing by freeing any resources allocated at
1209  * queuecommand or send generic. session back_lock must be held and verify
1210  * itt must have been called.
1211  */
1212 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1213                          char *data, int datalen)
1214 {
1215         struct iscsi_session *session = conn->session;
1216         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1217         struct iscsi_task *task;
1218         uint32_t itt;
1219
1220         conn->last_recv = jiffies;
1221         rc = iscsi_verify_itt(conn, hdr->itt);
1222         if (rc)
1223                 return rc;
1224
1225         if (hdr->itt != RESERVED_ITT)
1226                 itt = get_itt(hdr->itt);
1227         else
1228                 itt = ~0U;
1229
1230         ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1231                           opcode, conn->id, itt, datalen);
1232
1233         if (itt == ~0U) {
1234                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1235
1236                 switch(opcode) {
1237                 case ISCSI_OP_NOOP_IN:
1238                         if (datalen) {
1239                                 rc = ISCSI_ERR_PROTO;
1240                                 break;
1241                         }
1242
1243                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1244                                 break;
1245
1246                         /* In RX path we are under back lock */
1247                         spin_unlock(&session->back_lock);
1248                         spin_lock(&session->frwd_lock);
1249                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1250                         spin_unlock(&session->frwd_lock);
1251                         spin_lock(&session->back_lock);
1252                         break;
1253                 case ISCSI_OP_REJECT:
1254                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
1255                         break;
1256                 case ISCSI_OP_ASYNC_EVENT:
1257                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1258                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1259                                 rc = ISCSI_ERR_CONN_FAILED;
1260                         break;
1261                 default:
1262                         rc = ISCSI_ERR_BAD_OPCODE;
1263                         break;
1264                 }
1265                 goto out;
1266         }
1267
1268         switch(opcode) {
1269         case ISCSI_OP_SCSI_CMD_RSP:
1270         case ISCSI_OP_SCSI_DATA_IN:
1271                 task = iscsi_itt_to_ctask(conn, hdr->itt);
1272                 if (!task)
1273                         return ISCSI_ERR_BAD_ITT;
1274                 task->last_xfer = jiffies;
1275                 break;
1276         case ISCSI_OP_R2T:
1277                 /*
1278                  * LLD handles R2Ts if they need to.
1279                  */
1280                 return 0;
1281         case ISCSI_OP_LOGOUT_RSP:
1282         case ISCSI_OP_LOGIN_RSP:
1283         case ISCSI_OP_TEXT_RSP:
1284         case ISCSI_OP_SCSI_TMFUNC_RSP:
1285         case ISCSI_OP_NOOP_IN:
1286                 task = iscsi_itt_to_task(conn, hdr->itt);
1287                 if (!task)
1288                         return ISCSI_ERR_BAD_ITT;
1289                 break;
1290         default:
1291                 return ISCSI_ERR_BAD_OPCODE;
1292         }
1293
1294         switch(opcode) {
1295         case ISCSI_OP_SCSI_CMD_RSP:
1296                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1297                 break;
1298         case ISCSI_OP_SCSI_DATA_IN:
1299                 iscsi_data_in_rsp(conn, hdr, task);
1300                 break;
1301         case ISCSI_OP_LOGOUT_RSP:
1302                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1303                 if (datalen) {
1304                         rc = ISCSI_ERR_PROTO;
1305                         break;
1306                 }
1307                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1308                 goto recv_pdu;
1309         case ISCSI_OP_LOGIN_RSP:
1310         case ISCSI_OP_TEXT_RSP:
1311                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1312                 /*
1313                  * login related PDU's exp_statsn is handled in
1314                  * userspace
1315                  */
1316                 goto recv_pdu;
1317         case ISCSI_OP_SCSI_TMFUNC_RSP:
1318                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1319                 if (datalen) {
1320                         rc = ISCSI_ERR_PROTO;
1321                         break;
1322                 }
1323
1324                 iscsi_tmf_rsp(conn, hdr);
1325                 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1326                 break;
1327         case ISCSI_OP_NOOP_IN:
1328                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1329                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1330                         rc = ISCSI_ERR_PROTO;
1331                         break;
1332                 }
1333                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1334
1335                 rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1336                                        data, datalen);
1337                 break;
1338         default:
1339                 rc = ISCSI_ERR_BAD_OPCODE;
1340                 break;
1341         }
1342
1343 out:
1344         return rc;
1345 recv_pdu:
1346         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1347                 rc = ISCSI_ERR_CONN_FAILED;
1348         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1349         return rc;
1350 }
1351 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1352
1353 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1354                        char *data, int datalen)
1355 {
1356         int rc;
1357
1358         spin_lock(&conn->session->back_lock);
1359         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1360         spin_unlock(&conn->session->back_lock);
1361         return rc;
1362 }
1363 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1364
1365 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1366 {
1367         struct iscsi_session *session = conn->session;
1368         int age = 0, i = 0;
1369
1370         if (itt == RESERVED_ITT)
1371                 return 0;
1372
1373         if (session->tt->parse_pdu_itt)
1374                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
1375         else {
1376                 i = get_itt(itt);
1377                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1378         }
1379
1380         if (age != session->age) {
1381                 iscsi_conn_printk(KERN_ERR, conn,
1382                                   "received itt %x expected session age (%x)\n",
1383                                   (__force u32)itt, session->age);
1384                 return ISCSI_ERR_BAD_ITT;
1385         }
1386
1387         if (i >= session->cmds_max) {
1388                 iscsi_conn_printk(KERN_ERR, conn,
1389                                   "received invalid itt index %u (max cmds "
1390                                    "%u.\n", i, session->cmds_max);
1391                 return ISCSI_ERR_BAD_ITT;
1392         }
1393         return 0;
1394 }
1395 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1396
1397 /**
1398  * iscsi_itt_to_ctask - look up ctask by itt
1399  * @conn: iscsi connection
1400  * @itt: itt
1401  *
1402  * This should be used for cmd tasks.
1403  *
1404  * The session back_lock must be held.
1405  */
1406 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1407 {
1408         struct iscsi_task *task;
1409
1410         if (iscsi_verify_itt(conn, itt))
1411                 return NULL;
1412
1413         task = iscsi_itt_to_task(conn, itt);
1414         if (!task || !task->sc)
1415                 return NULL;
1416
1417         if (iscsi_cmd(task->sc)->age != conn->session->age) {
1418                 iscsi_session_printk(KERN_ERR, conn->session,
1419                                   "task's session age %d, expected %d\n",
1420                                   iscsi_cmd(task->sc)->age, conn->session->age);
1421                 return NULL;
1422         }
1423
1424         return task;
1425 }
1426 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1427
1428 void iscsi_session_failure(struct iscsi_session *session,
1429                            enum iscsi_err err)
1430 {
1431         struct iscsi_conn *conn;
1432
1433         spin_lock_bh(&session->frwd_lock);
1434         conn = session->leadconn;
1435         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1436                 spin_unlock_bh(&session->frwd_lock);
1437                 return;
1438         }
1439
1440         iscsi_get_conn(conn->cls_conn);
1441         spin_unlock_bh(&session->frwd_lock);
1442         /*
1443          * if the host is being removed bypass the connection
1444          * recovery initialization because we are going to kill
1445          * the session.
1446          */
1447         if (err == ISCSI_ERR_INVALID_HOST)
1448                 iscsi_conn_error_event(conn->cls_conn, err);
1449         else
1450                 iscsi_conn_failure(conn, err);
1451         iscsi_put_conn(conn->cls_conn);
1452 }
1453 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1454
1455 static bool iscsi_set_conn_failed(struct iscsi_conn *conn)
1456 {
1457         struct iscsi_session *session = conn->session;
1458
1459         if (session->state == ISCSI_STATE_FAILED)
1460                 return false;
1461
1462         if (conn->stop_stage == 0)
1463                 session->state = ISCSI_STATE_FAILED;
1464
1465         set_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags);
1466         set_bit(ISCSI_CONN_FLAG_SUSPEND_RX, &conn->flags);
1467         return true;
1468 }
1469
1470 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1471 {
1472         struct iscsi_session *session = conn->session;
1473         bool needs_evt;
1474
1475         spin_lock_bh(&session->frwd_lock);
1476         needs_evt = iscsi_set_conn_failed(conn);
1477         spin_unlock_bh(&session->frwd_lock);
1478
1479         if (needs_evt)
1480                 iscsi_conn_error_event(conn->cls_conn, err);
1481 }
1482 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1483
1484 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1485 {
1486         struct iscsi_session *session = conn->session;
1487
1488         /*
1489          * Check for iSCSI window and take care of CmdSN wrap-around
1490          */
1491         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1492                 ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1493                                   "%u MaxCmdSN %u CmdSN %u/%u\n",
1494                                   session->exp_cmdsn, session->max_cmdsn,
1495                                   session->cmdsn, session->queued_cmdsn);
1496                 return -ENOSPC;
1497         }
1498         return 0;
1499 }
1500
1501 static int iscsi_xmit_task(struct iscsi_conn *conn, struct iscsi_task *task,
1502                            bool was_requeue)
1503 {
1504         int rc;
1505
1506         if (!conn->task) {
1507                 /*
1508                  * Take a ref so we can access it after xmit_task().
1509                  *
1510                  * This should never fail because the failure paths will have
1511                  * stopped the xmit thread.
1512                  */
1513                 if (!iscsi_get_task(task)) {
1514                         WARN_ON_ONCE(1);
1515                         return 0;
1516                 }
1517         } else {
1518                 /* Already have a ref from when we failed to send it last call */
1519                 conn->task = NULL;
1520         }
1521
1522         /*
1523          * If this was a requeue for a R2T we have an extra ref on the task in
1524          * case a bad target sends a cmd rsp before we have handled the task.
1525          */
1526         if (was_requeue)
1527                 iscsi_put_task(task);
1528
1529         /*
1530          * Do this after dropping the extra ref because if this was a requeue
1531          * it's removed from that list and cleanup_queued_task would miss it.
1532          */
1533         if (test_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags)) {
1534                 /*
1535                  * Save the task and ref in case we weren't cleaning up this
1536                  * task and get woken up again.
1537                  */
1538                 conn->task = task;
1539                 return -ENODATA;
1540         }
1541
1542         spin_unlock_bh(&conn->session->frwd_lock);
1543         rc = conn->session->tt->xmit_task(task);
1544         spin_lock_bh(&conn->session->frwd_lock);
1545         if (!rc) {
1546                 /* done with this task */
1547                 task->last_xfer = jiffies;
1548         } else {
1549                 /*
1550                  * get an extra ref that is released next time we access it
1551                  * as conn->task above.
1552                  */
1553                 iscsi_get_task(task);
1554                 conn->task = task;
1555         }
1556
1557         iscsi_put_task(task);
1558         return rc;
1559 }
1560
1561 /**
1562  * iscsi_requeue_task - requeue task to run from session workqueue
1563  * @task: task to requeue
1564  *
1565  * Callers must have taken a ref to the task that is going to be requeued.
1566  */
1567 void iscsi_requeue_task(struct iscsi_task *task)
1568 {
1569         struct iscsi_conn *conn = task->conn;
1570
1571         /*
1572          * this may be on the requeue list already if the xmit_task callout
1573          * is handling the r2ts while we are adding new ones
1574          */
1575         spin_lock_bh(&conn->session->frwd_lock);
1576         if (list_empty(&task->running)) {
1577                 list_add_tail(&task->running, &conn->requeue);
1578         } else {
1579                 /*
1580                  * Don't need the extra ref since it's already requeued and
1581                  * has a ref.
1582                  */
1583                 iscsi_put_task(task);
1584         }
1585         iscsi_conn_queue_xmit(conn);
1586         spin_unlock_bh(&conn->session->frwd_lock);
1587 }
1588 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1589
1590 /**
1591  * iscsi_data_xmit - xmit any command into the scheduled connection
1592  * @conn: iscsi connection
1593  *
1594  * Notes:
1595  *      The function can return -EAGAIN in which case the caller must
1596  *      re-schedule it again later or recover. '0' return code means
1597  *      successful xmit.
1598  **/
1599 static int iscsi_data_xmit(struct iscsi_conn *conn)
1600 {
1601         struct iscsi_task *task;
1602         int rc = 0;
1603
1604         spin_lock_bh(&conn->session->frwd_lock);
1605         if (test_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags)) {
1606                 ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1607                 spin_unlock_bh(&conn->session->frwd_lock);
1608                 return -ENODATA;
1609         }
1610
1611         if (conn->task) {
1612                 rc = iscsi_xmit_task(conn, conn->task, false);
1613                 if (rc)
1614                         goto done;
1615         }
1616
1617         /*
1618          * process mgmt pdus like nops before commands since we should
1619          * only have one nop-out as a ping from us and targets should not
1620          * overflow us with nop-ins
1621          */
1622 check_mgmt:
1623         while (!list_empty(&conn->mgmtqueue)) {
1624                 task = list_entry(conn->mgmtqueue.next, struct iscsi_task,
1625                                   running);
1626                 list_del_init(&task->running);
1627                 if (iscsi_prep_mgmt_task(conn, task)) {
1628                         /* regular RX path uses back_lock */
1629                         spin_lock_bh(&conn->session->back_lock);
1630                         __iscsi_put_task(task);
1631                         spin_unlock_bh(&conn->session->back_lock);
1632                         continue;
1633                 }
1634                 rc = iscsi_xmit_task(conn, task, false);
1635                 if (rc)
1636                         goto done;
1637         }
1638
1639 check_requeue:
1640         while (!list_empty(&conn->requeue)) {
1641                 /*
1642                  * we always do fastlogout - conn stop code will clean up.
1643                  */
1644                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1645                         break;
1646
1647                 task = list_entry(conn->requeue.next, struct iscsi_task,
1648                                   running);
1649
1650                 if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1651                         break;
1652
1653                 list_del_init(&task->running);
1654                 rc = iscsi_xmit_task(conn, task, true);
1655                 if (rc)
1656                         goto done;
1657                 if (!list_empty(&conn->mgmtqueue))
1658                         goto check_mgmt;
1659         }
1660
1661         /* process pending command queue */
1662         while (!list_empty(&conn->cmdqueue)) {
1663                 task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1664                                   running);
1665                 list_del_init(&task->running);
1666                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1667                         fail_scsi_task(task, DID_IMM_RETRY);
1668                         continue;
1669                 }
1670                 rc = iscsi_prep_scsi_cmd_pdu(task);
1671                 if (rc) {
1672                         if (rc == -ENOMEM || rc == -EACCES)
1673                                 fail_scsi_task(task, DID_IMM_RETRY);
1674                         else
1675                                 fail_scsi_task(task, DID_ABORT);
1676                         continue;
1677                 }
1678                 rc = iscsi_xmit_task(conn, task, false);
1679                 if (rc)
1680                         goto done;
1681                 /*
1682                  * we could continuously get new task requests so
1683                  * we need to check the mgmt queue for nops that need to
1684                  * be sent to aviod starvation
1685                  */
1686                 if (!list_empty(&conn->mgmtqueue))
1687                         goto check_mgmt;
1688                 if (!list_empty(&conn->requeue))
1689                         goto check_requeue;
1690         }
1691
1692         spin_unlock_bh(&conn->session->frwd_lock);
1693         return -ENODATA;
1694
1695 done:
1696         spin_unlock_bh(&conn->session->frwd_lock);
1697         return rc;
1698 }
1699
1700 static void iscsi_xmitworker(struct work_struct *work)
1701 {
1702         struct iscsi_conn *conn =
1703                 container_of(work, struct iscsi_conn, xmitwork);
1704         int rc;
1705         /*
1706          * serialize Xmit worker on a per-connection basis.
1707          */
1708         do {
1709                 rc = iscsi_data_xmit(conn);
1710         } while (rc >= 0 || rc == -EAGAIN);
1711 }
1712
1713 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1714                                                   struct scsi_cmnd *sc)
1715 {
1716         struct iscsi_task *task;
1717
1718         if (!kfifo_out(&conn->session->cmdpool.queue,
1719                          (void *) &task, sizeof(void *)))
1720                 return NULL;
1721
1722         iscsi_cmd(sc)->age = conn->session->age;
1723         iscsi_cmd(sc)->task = task;
1724
1725         refcount_set(&task->refcount, 1);
1726         task->state = ISCSI_TASK_PENDING;
1727         task->conn = conn;
1728         task->sc = sc;
1729         task->have_checked_conn = false;
1730         task->last_timeout = jiffies;
1731         task->last_xfer = jiffies;
1732         task->protected = false;
1733         INIT_LIST_HEAD(&task->running);
1734         return task;
1735 }
1736
1737 enum {
1738         FAILURE_BAD_HOST = 1,
1739         FAILURE_SESSION_FAILED,
1740         FAILURE_SESSION_FREED,
1741         FAILURE_WINDOW_CLOSED,
1742         FAILURE_OOM,
1743         FAILURE_SESSION_TERMINATE,
1744         FAILURE_SESSION_IN_RECOVERY,
1745         FAILURE_SESSION_RECOVERY_TIMEOUT,
1746         FAILURE_SESSION_LOGGING_OUT,
1747         FAILURE_SESSION_NOT_READY,
1748 };
1749
1750 int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1751 {
1752         struct iscsi_cls_session *cls_session;
1753         struct iscsi_host *ihost;
1754         int reason = 0;
1755         struct iscsi_session *session;
1756         struct iscsi_conn *conn;
1757         struct iscsi_task *task = NULL;
1758
1759         sc->result = 0;
1760         iscsi_cmd(sc)->task = NULL;
1761
1762         ihost = shost_priv(host);
1763
1764         cls_session = starget_to_session(scsi_target(sc->device));
1765         session = cls_session->dd_data;
1766         spin_lock_bh(&session->frwd_lock);
1767
1768         reason = iscsi_session_chkready(cls_session);
1769         if (reason) {
1770                 sc->result = reason;
1771                 goto fault;
1772         }
1773
1774         if (session->state != ISCSI_STATE_LOGGED_IN) {
1775                 /*
1776                  * to handle the race between when we set the recovery state
1777                  * and block the session we requeue here (commands could
1778                  * be entering our queuecommand while a block is starting
1779                  * up because the block code is not locked)
1780                  */
1781                 switch (session->state) {
1782                 case ISCSI_STATE_FAILED:
1783                         /*
1784                          * cmds should fail during shutdown, if the session
1785                          * state is bad, allowing completion to happen
1786                          */
1787                         if (unlikely(system_state != SYSTEM_RUNNING)) {
1788                                 reason = FAILURE_SESSION_FAILED;
1789                                 sc->result = DID_NO_CONNECT << 16;
1790                                 break;
1791                         }
1792                         fallthrough;
1793                 case ISCSI_STATE_IN_RECOVERY:
1794                         reason = FAILURE_SESSION_IN_RECOVERY;
1795                         sc->result = DID_IMM_RETRY << 16;
1796                         break;
1797                 case ISCSI_STATE_LOGGING_OUT:
1798                         reason = FAILURE_SESSION_LOGGING_OUT;
1799                         sc->result = DID_IMM_RETRY << 16;
1800                         break;
1801                 case ISCSI_STATE_RECOVERY_FAILED:
1802                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1803                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1804                         break;
1805                 case ISCSI_STATE_TERMINATE:
1806                         reason = FAILURE_SESSION_TERMINATE;
1807                         sc->result = DID_NO_CONNECT << 16;
1808                         break;
1809                 default:
1810                         reason = FAILURE_SESSION_FREED;
1811                         sc->result = DID_NO_CONNECT << 16;
1812                 }
1813                 goto fault;
1814         }
1815
1816         conn = session->leadconn;
1817         if (!conn) {
1818                 reason = FAILURE_SESSION_FREED;
1819                 sc->result = DID_NO_CONNECT << 16;
1820                 goto fault;
1821         }
1822
1823         if (test_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags)) {
1824                 reason = FAILURE_SESSION_IN_RECOVERY;
1825                 sc->result = DID_REQUEUE << 16;
1826                 goto fault;
1827         }
1828
1829         if (iscsi_check_cmdsn_window_closed(conn)) {
1830                 reason = FAILURE_WINDOW_CLOSED;
1831                 goto reject;
1832         }
1833
1834         task = iscsi_alloc_task(conn, sc);
1835         if (!task) {
1836                 reason = FAILURE_OOM;
1837                 goto reject;
1838         }
1839
1840         if (!ihost->workq) {
1841                 reason = iscsi_prep_scsi_cmd_pdu(task);
1842                 if (reason) {
1843                         if (reason == -ENOMEM ||  reason == -EACCES) {
1844                                 reason = FAILURE_OOM;
1845                                 goto prepd_reject;
1846                         } else {
1847                                 sc->result = DID_ABORT << 16;
1848                                 goto prepd_fault;
1849                         }
1850                 }
1851                 if (session->tt->xmit_task(task)) {
1852                         session->cmdsn--;
1853                         reason = FAILURE_SESSION_NOT_READY;
1854                         goto prepd_reject;
1855                 }
1856         } else {
1857                 list_add_tail(&task->running, &conn->cmdqueue);
1858                 iscsi_conn_queue_xmit(conn);
1859         }
1860
1861         session->queued_cmdsn++;
1862         spin_unlock_bh(&session->frwd_lock);
1863         return 0;
1864
1865 prepd_reject:
1866         spin_lock_bh(&session->back_lock);
1867         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1868         spin_unlock_bh(&session->back_lock);
1869 reject:
1870         spin_unlock_bh(&session->frwd_lock);
1871         ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1872                           sc->cmnd[0], reason);
1873         return SCSI_MLQUEUE_TARGET_BUSY;
1874
1875 prepd_fault:
1876         spin_lock_bh(&session->back_lock);
1877         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1878         spin_unlock_bh(&session->back_lock);
1879 fault:
1880         spin_unlock_bh(&session->frwd_lock);
1881         ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1882                           sc->cmnd[0], reason);
1883         scsi_set_resid(sc, scsi_bufflen(sc));
1884         scsi_done(sc);
1885         return 0;
1886 }
1887 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1888
1889 int iscsi_target_alloc(struct scsi_target *starget)
1890 {
1891         struct iscsi_cls_session *cls_session = starget_to_session(starget);
1892         struct iscsi_session *session = cls_session->dd_data;
1893
1894         starget->can_queue = session->scsi_cmds_max;
1895         return 0;
1896 }
1897 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1898
1899 static void iscsi_tmf_timedout(struct timer_list *t)
1900 {
1901         struct iscsi_session *session = from_timer(session, t, tmf_timer);
1902
1903         spin_lock(&session->frwd_lock);
1904         if (session->tmf_state == TMF_QUEUED) {
1905                 session->tmf_state = TMF_TIMEDOUT;
1906                 ISCSI_DBG_EH(session, "tmf timedout\n");
1907                 /* unblock eh_abort() */
1908                 wake_up(&session->ehwait);
1909         }
1910         spin_unlock(&session->frwd_lock);
1911 }
1912
1913 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1914                                    struct iscsi_tm *hdr, int age,
1915                                    int timeout)
1916         __must_hold(&session->frwd_lock)
1917 {
1918         struct iscsi_session *session = conn->session;
1919
1920         if (__iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr, NULL, 0)) {
1921                 spin_unlock_bh(&session->frwd_lock);
1922                 iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1923                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1924                 spin_lock_bh(&session->frwd_lock);
1925                 return -EPERM;
1926         }
1927         conn->tmfcmd_pdus_cnt++;
1928         session->tmf_timer.expires = timeout * HZ + jiffies;
1929         add_timer(&session->tmf_timer);
1930         ISCSI_DBG_EH(session, "tmf set timeout\n");
1931
1932         spin_unlock_bh(&session->frwd_lock);
1933         mutex_unlock(&session->eh_mutex);
1934
1935         /*
1936          * block eh thread until:
1937          *
1938          * 1) tmf response
1939          * 2) tmf timeout
1940          * 3) session is terminated or restarted or userspace has
1941          * given up on recovery
1942          */
1943         wait_event_interruptible(session->ehwait, age != session->age ||
1944                                  session->state != ISCSI_STATE_LOGGED_IN ||
1945                                  session->tmf_state != TMF_QUEUED);
1946         if (signal_pending(current))
1947                 flush_signals(current);
1948         del_timer_sync(&session->tmf_timer);
1949
1950         mutex_lock(&session->eh_mutex);
1951         spin_lock_bh(&session->frwd_lock);
1952         /* if the session drops it will clean up the task */
1953         if (age != session->age ||
1954             session->state != ISCSI_STATE_LOGGED_IN)
1955                 return -ENOTCONN;
1956         return 0;
1957 }
1958
1959 /*
1960  * Fail commands. session frwd lock held and xmit thread flushed.
1961  */
1962 static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
1963 {
1964         struct iscsi_session *session = conn->session;
1965         struct iscsi_task *task;
1966         int i;
1967
1968 restart_cmd_loop:
1969         spin_lock_bh(&session->back_lock);
1970         for (i = 0; i < session->cmds_max; i++) {
1971                 task = session->cmds[i];
1972                 if (!task->sc || task->state == ISCSI_TASK_FREE)
1973                         continue;
1974
1975                 if (lun != -1 && lun != task->sc->device->lun)
1976                         continue;
1977                 /*
1978                  * The cmd is completing but if this is called from an eh
1979                  * callout path then when we return scsi-ml owns the cmd. Wait
1980                  * for the completion path to finish freeing the cmd.
1981                  */
1982                 if (!iscsi_get_task(task)) {
1983                         spin_unlock_bh(&session->back_lock);
1984                         spin_unlock_bh(&session->frwd_lock);
1985                         udelay(ISCSI_CMD_COMPL_WAIT);
1986                         spin_lock_bh(&session->frwd_lock);
1987                         goto restart_cmd_loop;
1988                 }
1989
1990                 ISCSI_DBG_SESSION(session,
1991                                   "failing sc %p itt 0x%x state %d\n",
1992                                   task->sc, task->itt, task->state);
1993                 __fail_scsi_task(task, error);
1994                 __iscsi_put_task(task);
1995         }
1996         spin_unlock_bh(&session->back_lock);
1997 }
1998
1999 /**
2000  * iscsi_suspend_queue - suspend iscsi_queuecommand
2001  * @conn: iscsi conn to stop queueing IO on
2002  *
2003  * This grabs the session frwd_lock to make sure no one is in
2004  * xmit_task/queuecommand, and then sets suspend to prevent
2005  * new commands from being queued. This only needs to be called
2006  * by offload drivers that need to sync a path like ep disconnect
2007  * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
2008  * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
2009  */
2010 void iscsi_suspend_queue(struct iscsi_conn *conn)
2011 {
2012         spin_lock_bh(&conn->session->frwd_lock);
2013         set_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags);
2014         spin_unlock_bh(&conn->session->frwd_lock);
2015 }
2016 EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
2017
2018 /**
2019  * iscsi_suspend_tx - suspend iscsi_data_xmit
2020  * @conn: iscsi conn to stop processing IO on.
2021  *
2022  * This function sets the suspend bit to prevent iscsi_data_xmit
2023  * from sending new IO, and if work is queued on the xmit thread
2024  * it will wait for it to be completed.
2025  */
2026 void iscsi_suspend_tx(struct iscsi_conn *conn)
2027 {
2028         struct Scsi_Host *shost = conn->session->host;
2029         struct iscsi_host *ihost = shost_priv(shost);
2030
2031         set_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags);
2032         if (ihost->workq)
2033                 flush_work(&conn->xmitwork);
2034 }
2035 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
2036
2037 static void iscsi_start_tx(struct iscsi_conn *conn)
2038 {
2039         clear_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags);
2040         iscsi_conn_queue_xmit(conn);
2041 }
2042
2043 /**
2044  * iscsi_suspend_rx - Prevent recvwork from running again.
2045  * @conn: iscsi conn to stop.
2046  */
2047 void iscsi_suspend_rx(struct iscsi_conn *conn)
2048 {
2049         struct Scsi_Host *shost = conn->session->host;
2050         struct iscsi_host *ihost = shost_priv(shost);
2051
2052         set_bit(ISCSI_CONN_FLAG_SUSPEND_RX, &conn->flags);
2053         if (ihost->workq)
2054                 flush_work(&conn->recvwork);
2055 }
2056 EXPORT_SYMBOL_GPL(iscsi_suspend_rx);
2057
2058 /*
2059  * We want to make sure a ping is in flight. It has timed out.
2060  * And we are not busy processing a pdu that is making
2061  * progress but got started before the ping and is taking a while
2062  * to complete so the ping is just stuck behind it in a queue.
2063  */
2064 static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
2065 {
2066         if (READ_ONCE(conn->ping_task) &&
2067             time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
2068                            (conn->ping_timeout * HZ), jiffies))
2069                 return 1;
2070         else
2071                 return 0;
2072 }
2073
2074 enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
2075 {
2076         enum blk_eh_timer_return rc = BLK_EH_DONE;
2077         struct iscsi_task *task = NULL, *running_task;
2078         struct iscsi_cls_session *cls_session;
2079         struct iscsi_session *session;
2080         struct iscsi_conn *conn;
2081         int i;
2082
2083         cls_session = starget_to_session(scsi_target(sc->device));
2084         session = cls_session->dd_data;
2085
2086         ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
2087
2088         spin_lock_bh(&session->frwd_lock);
2089         spin_lock(&session->back_lock);
2090         task = iscsi_cmd(sc)->task;
2091         if (!task) {
2092                 /*
2093                  * Raced with completion. Blk layer has taken ownership
2094                  * so let timeout code complete it now.
2095                  */
2096                 rc = BLK_EH_DONE;
2097                 spin_unlock(&session->back_lock);
2098                 goto done;
2099         }
2100         if (!iscsi_get_task(task)) {
2101                 /*
2102                  * Racing with the completion path right now, so give it more
2103                  * time so that path can complete it like normal.
2104                  */
2105                 rc = BLK_EH_RESET_TIMER;
2106                 task = NULL;
2107                 spin_unlock(&session->back_lock);
2108                 goto done;
2109         }
2110         spin_unlock(&session->back_lock);
2111
2112         if (session->state != ISCSI_STATE_LOGGED_IN) {
2113                 /*
2114                  * During shutdown, if session is prematurely disconnected,
2115                  * recovery won't happen and there will be hung cmds. Not
2116                  * handling cmds would trigger EH, also bad in this case.
2117                  * Instead, handle cmd, allow completion to happen and let
2118                  * upper layer to deal with the result.
2119                  */
2120                 if (unlikely(system_state != SYSTEM_RUNNING)) {
2121                         sc->result = DID_NO_CONNECT << 16;
2122                         ISCSI_DBG_EH(session, "sc on shutdown, handled\n");
2123                         rc = BLK_EH_DONE;
2124                         goto done;
2125                 }
2126                 /*
2127                  * We are probably in the middle of iscsi recovery so let
2128                  * that complete and handle the error.
2129                  */
2130                 rc = BLK_EH_RESET_TIMER;
2131                 goto done;
2132         }
2133
2134         conn = session->leadconn;
2135         if (!conn) {
2136                 /* In the middle of shuting down */
2137                 rc = BLK_EH_RESET_TIMER;
2138                 goto done;
2139         }
2140
2141         /*
2142          * If we have sent (at least queued to the network layer) a pdu or
2143          * recvd one for the task since the last timeout ask for
2144          * more time. If on the next timeout we have not made progress
2145          * we can check if it is the task or connection when we send the
2146          * nop as a ping.
2147          */
2148         if (time_after(task->last_xfer, task->last_timeout)) {
2149                 ISCSI_DBG_EH(session, "Command making progress. Asking "
2150                              "scsi-ml for more time to complete. "
2151                              "Last data xfer at %lu. Last timeout was at "
2152                              "%lu\n.", task->last_xfer, task->last_timeout);
2153                 task->have_checked_conn = false;
2154                 rc = BLK_EH_RESET_TIMER;
2155                 goto done;
2156         }
2157
2158         if (!conn->recv_timeout && !conn->ping_timeout)
2159                 goto done;
2160         /*
2161          * if the ping timedout then we are in the middle of cleaning up
2162          * and can let the iscsi eh handle it
2163          */
2164         if (iscsi_has_ping_timed_out(conn)) {
2165                 rc = BLK_EH_RESET_TIMER;
2166                 goto done;
2167         }
2168
2169         spin_lock(&session->back_lock);
2170         for (i = 0; i < conn->session->cmds_max; i++) {
2171                 running_task = conn->session->cmds[i];
2172                 if (!running_task->sc || running_task == task ||
2173                      running_task->state != ISCSI_TASK_RUNNING)
2174                         continue;
2175
2176                 /*
2177                  * Only check if cmds started before this one have made
2178                  * progress, or this could never fail
2179                  */
2180                 if (time_after(running_task->sc->jiffies_at_alloc,
2181                                task->sc->jiffies_at_alloc))
2182                         continue;
2183
2184                 if (time_after(running_task->last_xfer, task->last_timeout)) {
2185                         /*
2186                          * This task has not made progress, but a task
2187                          * started before us has transferred data since
2188                          * we started/last-checked. We could be queueing
2189                          * too many tasks or the LU is bad.
2190                          *
2191                          * If the device is bad the cmds ahead of us on
2192                          * other devs will complete, and this loop will
2193                          * eventually fail starting the scsi eh.
2194                          */
2195                         ISCSI_DBG_EH(session, "Command has not made progress "
2196                                      "but commands ahead of it have. "
2197                                      "Asking scsi-ml for more time to "
2198                                      "complete. Our last xfer vs running task "
2199                                      "last xfer %lu/%lu. Last check %lu.\n",
2200                                      task->last_xfer, running_task->last_xfer,
2201                                      task->last_timeout);
2202                         spin_unlock(&session->back_lock);
2203                         rc = BLK_EH_RESET_TIMER;
2204                         goto done;
2205                 }
2206         }
2207         spin_unlock(&session->back_lock);
2208
2209         /* Assumes nop timeout is shorter than scsi cmd timeout */
2210         if (task->have_checked_conn)
2211                 goto done;
2212
2213         /*
2214          * Checking the transport already or nop from a cmd timeout still
2215          * running
2216          */
2217         if (READ_ONCE(conn->ping_task)) {
2218                 task->have_checked_conn = true;
2219                 rc = BLK_EH_RESET_TIMER;
2220                 goto done;
2221         }
2222
2223         /* Make sure there is a transport check done */
2224         iscsi_send_nopout(conn, NULL);
2225         task->have_checked_conn = true;
2226         rc = BLK_EH_RESET_TIMER;
2227
2228 done:
2229         spin_unlock_bh(&session->frwd_lock);
2230
2231         if (task) {
2232                 task->last_timeout = jiffies;
2233                 iscsi_put_task(task);
2234         }
2235         ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2236                      "timer reset" : "shutdown or nh");
2237         return rc;
2238 }
2239 EXPORT_SYMBOL_GPL(iscsi_eh_cmd_timed_out);
2240
2241 static void iscsi_check_transport_timeouts(struct timer_list *t)
2242 {
2243         struct iscsi_conn *conn = from_timer(conn, t, transport_timer);
2244         struct iscsi_session *session = conn->session;
2245         unsigned long recv_timeout, next_timeout = 0, last_recv;
2246
2247         spin_lock(&session->frwd_lock);
2248         if (session->state != ISCSI_STATE_LOGGED_IN)
2249                 goto done;
2250
2251         recv_timeout = conn->recv_timeout;
2252         if (!recv_timeout)
2253                 goto done;
2254
2255         recv_timeout *= HZ;
2256         last_recv = conn->last_recv;
2257
2258         if (iscsi_has_ping_timed_out(conn)) {
2259                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2260                                   "expired, recv timeout %d, last rx %lu, "
2261                                   "last ping %lu, now %lu\n",
2262                                   conn->ping_timeout, conn->recv_timeout,
2263                                   last_recv, conn->last_ping, jiffies);
2264                 spin_unlock(&session->frwd_lock);
2265                 iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2266                 return;
2267         }
2268
2269         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2270                 /* send a ping to try to provoke some traffic */
2271                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2272                 if (iscsi_send_nopout(conn, NULL))
2273                         next_timeout = jiffies + (1 * HZ);
2274                 else
2275                         next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2276         } else
2277                 next_timeout = last_recv + recv_timeout;
2278
2279         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2280         mod_timer(&conn->transport_timer, next_timeout);
2281 done:
2282         spin_unlock(&session->frwd_lock);
2283 }
2284
2285 /**
2286  * iscsi_conn_unbind - prevent queueing to conn.
2287  * @cls_conn: iscsi conn ep is bound to.
2288  * @is_active: is the conn in use for boot or is this for EH/termination
2289  *
2290  * This must be called by drivers implementing the ep_disconnect callout.
2291  * It disables queueing to the connection from libiscsi in preparation for
2292  * an ep_disconnect call.
2293  */
2294 void iscsi_conn_unbind(struct iscsi_cls_conn *cls_conn, bool is_active)
2295 {
2296         struct iscsi_session *session;
2297         struct iscsi_conn *conn;
2298
2299         if (!cls_conn)
2300                 return;
2301
2302         conn = cls_conn->dd_data;
2303         session = conn->session;
2304         /*
2305          * Wait for iscsi_eh calls to exit. We don't wait for the tmf to
2306          * complete or timeout. The caller just wants to know what's running
2307          * is everything that needs to be cleaned up, and no cmds will be
2308          * queued.
2309          */
2310         mutex_lock(&session->eh_mutex);
2311
2312         iscsi_suspend_queue(conn);
2313         iscsi_suspend_tx(conn);
2314
2315         spin_lock_bh(&session->frwd_lock);
2316         clear_bit(ISCSI_CONN_FLAG_BOUND, &conn->flags);
2317
2318         if (!is_active) {
2319                 /*
2320                  * if logout timed out before userspace could even send a PDU
2321                  * the state might still be in ISCSI_STATE_LOGGED_IN and
2322                  * allowing new cmds and TMFs.
2323                  */
2324                 if (session->state == ISCSI_STATE_LOGGED_IN)
2325                         iscsi_set_conn_failed(conn);
2326         }
2327         spin_unlock_bh(&session->frwd_lock);
2328         mutex_unlock(&session->eh_mutex);
2329 }
2330 EXPORT_SYMBOL_GPL(iscsi_conn_unbind);
2331
2332 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2333                                       struct iscsi_tm *hdr)
2334 {
2335         memset(hdr, 0, sizeof(*hdr));
2336         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2337         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2338         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2339         hdr->lun = task->lun;
2340         hdr->rtt = task->hdr_itt;
2341         hdr->refcmdsn = task->cmdsn;
2342 }
2343
2344 int iscsi_eh_abort(struct scsi_cmnd *sc)
2345 {
2346         struct iscsi_cls_session *cls_session;
2347         struct iscsi_session *session;
2348         struct iscsi_conn *conn;
2349         struct iscsi_task *task;
2350         struct iscsi_tm *hdr;
2351         int age;
2352
2353         cls_session = starget_to_session(scsi_target(sc->device));
2354         session = cls_session->dd_data;
2355
2356         ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2357
2358 completion_check:
2359         mutex_lock(&session->eh_mutex);
2360         spin_lock_bh(&session->frwd_lock);
2361         /*
2362          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2363          * got the command.
2364          */
2365         if (!iscsi_cmd(sc)->task) {
2366                 ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2367                                       "it completed.\n");
2368                 spin_unlock_bh(&session->frwd_lock);
2369                 mutex_unlock(&session->eh_mutex);
2370                 return SUCCESS;
2371         }
2372
2373         /*
2374          * If we are not logged in or we have started a new session
2375          * then let the host reset code handle this
2376          */
2377         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2378             iscsi_cmd(sc)->age != session->age) {
2379                 spin_unlock_bh(&session->frwd_lock);
2380                 mutex_unlock(&session->eh_mutex);
2381                 ISCSI_DBG_EH(session, "failing abort due to dropped "
2382                                   "session.\n");
2383                 return FAILED;
2384         }
2385
2386         spin_lock(&session->back_lock);
2387         task = iscsi_cmd(sc)->task;
2388         if (!task || !task->sc) {
2389                 /* task completed before time out */
2390                 ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2391
2392                 spin_unlock(&session->back_lock);
2393                 spin_unlock_bh(&session->frwd_lock);
2394                 mutex_unlock(&session->eh_mutex);
2395                 return SUCCESS;
2396         }
2397
2398         if (!iscsi_get_task(task)) {
2399                 spin_unlock(&session->back_lock);
2400                 spin_unlock_bh(&session->frwd_lock);
2401                 mutex_unlock(&session->eh_mutex);
2402                 /* We are just about to call iscsi_free_task so wait for it. */
2403                 udelay(ISCSI_CMD_COMPL_WAIT);
2404                 goto completion_check;
2405         }
2406
2407         ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n", sc, task->itt);
2408         conn = session->leadconn;
2409         iscsi_get_conn(conn->cls_conn);
2410         conn->eh_abort_cnt++;
2411         age = session->age;
2412         spin_unlock(&session->back_lock);
2413
2414         if (task->state == ISCSI_TASK_PENDING) {
2415                 fail_scsi_task(task, DID_ABORT);
2416                 goto success;
2417         }
2418
2419         /* only have one tmf outstanding at a time */
2420         if (session->tmf_state != TMF_INITIAL)
2421                 goto failed;
2422         session->tmf_state = TMF_QUEUED;
2423
2424         hdr = &session->tmhdr;
2425         iscsi_prep_abort_task_pdu(task, hdr);
2426
2427         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout))
2428                 goto failed;
2429
2430         switch (session->tmf_state) {
2431         case TMF_SUCCESS:
2432                 spin_unlock_bh(&session->frwd_lock);
2433                 /*
2434                  * stop tx side incase the target had sent a abort rsp but
2435                  * the initiator was still writing out data.
2436                  */
2437                 iscsi_suspend_tx(conn);
2438                 /*
2439                  * we do not stop the recv side because targets have been
2440                  * good and have never sent us a successful tmf response
2441                  * then sent more data for the cmd.
2442                  */
2443                 spin_lock_bh(&session->frwd_lock);
2444                 fail_scsi_task(task, DID_ABORT);
2445                 session->tmf_state = TMF_INITIAL;
2446                 memset(hdr, 0, sizeof(*hdr));
2447                 spin_unlock_bh(&session->frwd_lock);
2448                 iscsi_start_tx(conn);
2449                 goto success_unlocked;
2450         case TMF_TIMEDOUT:
2451                 session->running_aborted_task = task;
2452                 spin_unlock_bh(&session->frwd_lock);
2453                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2454                 goto failed_unlocked;
2455         case TMF_NOT_FOUND:
2456                 if (iscsi_task_is_completed(task)) {
2457                         session->tmf_state = TMF_INITIAL;
2458                         memset(hdr, 0, sizeof(*hdr));
2459                         /* task completed before tmf abort response */
2460                         ISCSI_DBG_EH(session, "sc completed while abort in "
2461                                               "progress\n");
2462                         goto success;
2463                 }
2464                 fallthrough;
2465         default:
2466                 session->tmf_state = TMF_INITIAL;
2467                 goto failed;
2468         }
2469
2470 success:
2471         spin_unlock_bh(&session->frwd_lock);
2472 success_unlocked:
2473         ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2474                      sc, task->itt);
2475         iscsi_put_task(task);
2476         iscsi_put_conn(conn->cls_conn);
2477         mutex_unlock(&session->eh_mutex);
2478         return SUCCESS;
2479
2480 failed:
2481         spin_unlock_bh(&session->frwd_lock);
2482 failed_unlocked:
2483         ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2484                      task ? task->itt : 0);
2485         /*
2486          * The driver might be accessing the task so hold the ref. The conn
2487          * stop cleanup will drop the ref after ep_disconnect so we know the
2488          * driver's no longer touching the task.
2489          */
2490         if (!session->running_aborted_task)
2491                 iscsi_put_task(task);
2492
2493         iscsi_put_conn(conn->cls_conn);
2494         mutex_unlock(&session->eh_mutex);
2495         return FAILED;
2496 }
2497 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2498
2499 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2500 {
2501         memset(hdr, 0, sizeof(*hdr));
2502         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2503         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2504         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2505         int_to_scsilun(sc->device->lun, &hdr->lun);
2506         hdr->rtt = RESERVED_ITT;
2507 }
2508
2509 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2510 {
2511         struct iscsi_cls_session *cls_session;
2512         struct iscsi_session *session;
2513         struct iscsi_conn *conn;
2514         struct iscsi_tm *hdr;
2515         int rc = FAILED;
2516
2517         cls_session = starget_to_session(scsi_target(sc->device));
2518         session = cls_session->dd_data;
2519
2520         ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2521                      sc->device->lun);
2522
2523         mutex_lock(&session->eh_mutex);
2524         spin_lock_bh(&session->frwd_lock);
2525         /*
2526          * Just check if we are not logged in. We cannot check for
2527          * the phase because the reset could come from a ioctl.
2528          */
2529         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2530                 goto unlock;
2531         conn = session->leadconn;
2532
2533         /* only have one tmf outstanding at a time */
2534         if (session->tmf_state != TMF_INITIAL)
2535                 goto unlock;
2536         session->tmf_state = TMF_QUEUED;
2537
2538         hdr = &session->tmhdr;
2539         iscsi_prep_lun_reset_pdu(sc, hdr);
2540
2541         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2542                                     session->lu_reset_timeout)) {
2543                 rc = FAILED;
2544                 goto unlock;
2545         }
2546
2547         switch (session->tmf_state) {
2548         case TMF_SUCCESS:
2549                 break;
2550         case TMF_TIMEDOUT:
2551                 spin_unlock_bh(&session->frwd_lock);
2552                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2553                 goto done;
2554         default:
2555                 session->tmf_state = TMF_INITIAL;
2556                 goto unlock;
2557         }
2558
2559         rc = SUCCESS;
2560         spin_unlock_bh(&session->frwd_lock);
2561
2562         iscsi_suspend_tx(conn);
2563
2564         spin_lock_bh(&session->frwd_lock);
2565         memset(hdr, 0, sizeof(*hdr));
2566         fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2567         session->tmf_state = TMF_INITIAL;
2568         spin_unlock_bh(&session->frwd_lock);
2569
2570         iscsi_start_tx(conn);
2571         goto done;
2572
2573 unlock:
2574         spin_unlock_bh(&session->frwd_lock);
2575 done:
2576         ISCSI_DBG_EH(session, "dev reset result = %s\n",
2577                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2578         mutex_unlock(&session->eh_mutex);
2579         return rc;
2580 }
2581 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2582
2583 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2584 {
2585         struct iscsi_session *session = cls_session->dd_data;
2586
2587         spin_lock_bh(&session->frwd_lock);
2588         if (session->state != ISCSI_STATE_LOGGED_IN) {
2589                 session->state = ISCSI_STATE_RECOVERY_FAILED;
2590                 wake_up(&session->ehwait);
2591         }
2592         spin_unlock_bh(&session->frwd_lock);
2593 }
2594 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2595
2596 /**
2597  * iscsi_eh_session_reset - drop session and attempt relogin
2598  * @sc: scsi command
2599  *
2600  * This function will wait for a relogin, session termination from
2601  * userspace, or a recovery/replacement timeout.
2602  */
2603 int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2604 {
2605         struct iscsi_cls_session *cls_session;
2606         struct iscsi_session *session;
2607         struct iscsi_conn *conn;
2608
2609         cls_session = starget_to_session(scsi_target(sc->device));
2610         session = cls_session->dd_data;
2611
2612         mutex_lock(&session->eh_mutex);
2613         spin_lock_bh(&session->frwd_lock);
2614         if (session->state == ISCSI_STATE_TERMINATE) {
2615 failed:
2616                 ISCSI_DBG_EH(session,
2617                              "failing session reset: Could not log back into "
2618                              "%s [age %d]\n", session->targetname,
2619                              session->age);
2620                 spin_unlock_bh(&session->frwd_lock);
2621                 mutex_unlock(&session->eh_mutex);
2622                 return FAILED;
2623         }
2624
2625         conn = session->leadconn;
2626         iscsi_get_conn(conn->cls_conn);
2627
2628         spin_unlock_bh(&session->frwd_lock);
2629         mutex_unlock(&session->eh_mutex);
2630
2631         iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2632         iscsi_put_conn(conn->cls_conn);
2633
2634         ISCSI_DBG_EH(session, "wait for relogin\n");
2635         wait_event_interruptible(session->ehwait,
2636                                  session->state == ISCSI_STATE_TERMINATE ||
2637                                  session->state == ISCSI_STATE_LOGGED_IN ||
2638                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
2639         if (signal_pending(current))
2640                 flush_signals(current);
2641
2642         mutex_lock(&session->eh_mutex);
2643         spin_lock_bh(&session->frwd_lock);
2644         if (session->state == ISCSI_STATE_LOGGED_IN) {
2645                 ISCSI_DBG_EH(session,
2646                              "session reset succeeded for %s,%s\n",
2647                              session->targetname, conn->persistent_address);
2648         } else
2649                 goto failed;
2650         spin_unlock_bh(&session->frwd_lock);
2651         mutex_unlock(&session->eh_mutex);
2652         return SUCCESS;
2653 }
2654 EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2655
2656 static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2657 {
2658         memset(hdr, 0, sizeof(*hdr));
2659         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2660         hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2661         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2662         hdr->rtt = RESERVED_ITT;
2663 }
2664
2665 /**
2666  * iscsi_eh_target_reset - reset target
2667  * @sc: scsi command
2668  *
2669  * This will attempt to send a warm target reset.
2670  */
2671 static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2672 {
2673         struct iscsi_cls_session *cls_session;
2674         struct iscsi_session *session;
2675         struct iscsi_conn *conn;
2676         struct iscsi_tm *hdr;
2677         int rc = FAILED;
2678
2679         cls_session = starget_to_session(scsi_target(sc->device));
2680         session = cls_session->dd_data;
2681
2682         ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2683                      session->targetname);
2684
2685         mutex_lock(&session->eh_mutex);
2686         spin_lock_bh(&session->frwd_lock);
2687         /*
2688          * Just check if we are not logged in. We cannot check for
2689          * the phase because the reset could come from a ioctl.
2690          */
2691         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2692                 goto unlock;
2693         conn = session->leadconn;
2694
2695         /* only have one tmf outstanding at a time */
2696         if (session->tmf_state != TMF_INITIAL)
2697                 goto unlock;
2698         session->tmf_state = TMF_QUEUED;
2699
2700         hdr = &session->tmhdr;
2701         iscsi_prep_tgt_reset_pdu(sc, hdr);
2702
2703         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2704                                     session->tgt_reset_timeout)) {
2705                 rc = FAILED;
2706                 goto unlock;
2707         }
2708
2709         switch (session->tmf_state) {
2710         case TMF_SUCCESS:
2711                 break;
2712         case TMF_TIMEDOUT:
2713                 spin_unlock_bh(&session->frwd_lock);
2714                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2715                 goto done;
2716         default:
2717                 session->tmf_state = TMF_INITIAL;
2718                 goto unlock;
2719         }
2720
2721         rc = SUCCESS;
2722         spin_unlock_bh(&session->frwd_lock);
2723
2724         iscsi_suspend_tx(conn);
2725
2726         spin_lock_bh(&session->frwd_lock);
2727         memset(hdr, 0, sizeof(*hdr));
2728         fail_scsi_tasks(conn, -1, DID_ERROR);
2729         session->tmf_state = TMF_INITIAL;
2730         spin_unlock_bh(&session->frwd_lock);
2731
2732         iscsi_start_tx(conn);
2733         goto done;
2734
2735 unlock:
2736         spin_unlock_bh(&session->frwd_lock);
2737 done:
2738         ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2739                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2740         mutex_unlock(&session->eh_mutex);
2741         return rc;
2742 }
2743
2744 /**
2745  * iscsi_eh_recover_target - reset target and possibly the session
2746  * @sc: scsi command
2747  *
2748  * This will attempt to send a warm target reset. If that fails,
2749  * we will escalate to ERL0 session recovery.
2750  */
2751 int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2752 {
2753         int rc;
2754
2755         rc = iscsi_eh_target_reset(sc);
2756         if (rc == FAILED)
2757                 rc = iscsi_eh_session_reset(sc);
2758         return rc;
2759 }
2760 EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2761
2762 /*
2763  * Pre-allocate a pool of @max items of @item_size. By default, the pool
2764  * should be accessed via kfifo_{get,put} on q->queue.
2765  * Optionally, the caller can obtain the array of object pointers
2766  * by passing in a non-NULL @items pointer
2767  */
2768 int
2769 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2770 {
2771         int i, num_arrays = 1;
2772
2773         memset(q, 0, sizeof(*q));
2774
2775         q->max = max;
2776
2777         /* If the user passed an items pointer, he wants a copy of
2778          * the array. */
2779         if (items)
2780                 num_arrays++;
2781         q->pool = kvcalloc(num_arrays * max, sizeof(void *), GFP_KERNEL);
2782         if (q->pool == NULL)
2783                 return -ENOMEM;
2784
2785         kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2786
2787         for (i = 0; i < max; i++) {
2788                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2789                 if (q->pool[i] == NULL) {
2790                         q->max = i;
2791                         goto enomem;
2792                 }
2793                 kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2794         }
2795
2796         if (items) {
2797                 *items = q->pool + max;
2798                 memcpy(*items, q->pool, max * sizeof(void *));
2799         }
2800
2801         return 0;
2802
2803 enomem:
2804         iscsi_pool_free(q);
2805         return -ENOMEM;
2806 }
2807 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2808
2809 void iscsi_pool_free(struct iscsi_pool *q)
2810 {
2811         int i;
2812
2813         for (i = 0; i < q->max; i++)
2814                 kfree(q->pool[i]);
2815         kvfree(q->pool);
2816 }
2817 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2818
2819 int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
2820                                  uint16_t requested_cmds_max)
2821 {
2822         int scsi_cmds, total_cmds = requested_cmds_max;
2823
2824 check:
2825         if (!total_cmds)
2826                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2827         /*
2828          * The iscsi layer needs some tasks for nop handling and tmfs,
2829          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2830          * + 1 command for scsi IO.
2831          */
2832         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2833                 printk(KERN_ERR "iscsi: invalid max cmds of %d. Must be a power of two that is at least %d.\n",
2834                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2835                 return -EINVAL;
2836         }
2837
2838         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2839                 printk(KERN_INFO "iscsi: invalid max cmds of %d. Must be a power of 2 less than or equal to %d. Using %d.\n",
2840                        requested_cmds_max, ISCSI_TOTAL_CMDS_MAX,
2841                        ISCSI_TOTAL_CMDS_MAX);
2842                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2843         }
2844
2845         if (!is_power_of_2(total_cmds)) {
2846                 total_cmds = rounddown_pow_of_two(total_cmds);
2847                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2848                         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);
2849                         return -EINVAL;
2850                 }
2851
2852                 printk(KERN_INFO "iscsi: invalid max cmds %d. Must be a power of 2. Rounding max cmds down to %d.\n",
2853                        requested_cmds_max, total_cmds);
2854         }
2855
2856         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2857         if (shost->can_queue && scsi_cmds > shost->can_queue) {
2858                 total_cmds = shost->can_queue;
2859
2860                 printk(KERN_INFO "iscsi: requested max cmds %u is higher than driver limit. Using driver limit %u\n",
2861                        requested_cmds_max, shost->can_queue);
2862                 goto check;
2863         }
2864
2865         return scsi_cmds;
2866 }
2867 EXPORT_SYMBOL_GPL(iscsi_host_get_max_scsi_cmds);
2868
2869 /**
2870  * iscsi_host_add - add host to system
2871  * @shost: scsi host
2872  * @pdev: parent device
2873  *
2874  * This should be called by partial offload and software iscsi drivers
2875  * to add a host to the system.
2876  */
2877 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2878 {
2879         if (!shost->can_queue)
2880                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2881
2882         if (!shost->cmd_per_lun)
2883                 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2884
2885         return scsi_add_host(shost, pdev);
2886 }
2887 EXPORT_SYMBOL_GPL(iscsi_host_add);
2888
2889 /**
2890  * iscsi_host_alloc - allocate a host and driver data
2891  * @sht: scsi host template
2892  * @dd_data_size: driver host data size
2893  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2894  *
2895  * This should be called by partial offload and software iscsi drivers.
2896  * To access the driver specific memory use the iscsi_host_priv() macro.
2897  */
2898 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2899                                    int dd_data_size, bool xmit_can_sleep)
2900 {
2901         struct Scsi_Host *shost;
2902         struct iscsi_host *ihost;
2903
2904         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2905         if (!shost)
2906                 return NULL;
2907         ihost = shost_priv(shost);
2908
2909         if (xmit_can_sleep) {
2910                 ihost->workq = alloc_workqueue("iscsi_q_%d",
2911                         WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
2912                         1, shost->host_no);
2913                 if (!ihost->workq)
2914                         goto free_host;
2915         }
2916
2917         spin_lock_init(&ihost->lock);
2918         ihost->state = ISCSI_HOST_SETUP;
2919         ihost->num_sessions = 0;
2920         init_waitqueue_head(&ihost->session_removal_wq);
2921         return shost;
2922
2923 free_host:
2924         scsi_host_put(shost);
2925         return NULL;
2926 }
2927 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2928
2929 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2930 {
2931         iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2932 }
2933
2934 /**
2935  * iscsi_host_remove - remove host and sessions
2936  * @shost: scsi host
2937  * @is_shutdown: true if called from a driver shutdown callout
2938  *
2939  * If there are any sessions left, this will initiate the removal and wait
2940  * for the completion.
2941  */
2942 void iscsi_host_remove(struct Scsi_Host *shost, bool is_shutdown)
2943 {
2944         struct iscsi_host *ihost = shost_priv(shost);
2945         unsigned long flags;
2946
2947         spin_lock_irqsave(&ihost->lock, flags);
2948         ihost->state = ISCSI_HOST_REMOVED;
2949         spin_unlock_irqrestore(&ihost->lock, flags);
2950
2951         if (!is_shutdown)
2952                 iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2953         else
2954                 iscsi_host_for_each_session(shost, iscsi_force_destroy_session);
2955
2956         wait_event_interruptible(ihost->session_removal_wq,
2957                                  ihost->num_sessions == 0);
2958         if (signal_pending(current))
2959                 flush_signals(current);
2960
2961         scsi_remove_host(shost);
2962 }
2963 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2964
2965 void iscsi_host_free(struct Scsi_Host *shost)
2966 {
2967         struct iscsi_host *ihost = shost_priv(shost);
2968
2969         if (ihost->workq)
2970                 destroy_workqueue(ihost->workq);
2971
2972         kfree(ihost->netdev);
2973         kfree(ihost->hwaddress);
2974         kfree(ihost->initiatorname);
2975         scsi_host_put(shost);
2976 }
2977 EXPORT_SYMBOL_GPL(iscsi_host_free);
2978
2979 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2980 {
2981         struct iscsi_host *ihost = shost_priv(shost);
2982         unsigned long flags;
2983
2984         shost = scsi_host_get(shost);
2985         if (!shost) {
2986                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2987                       "of session teardown event because host already "
2988                       "removed.\n");
2989                 return;
2990         }
2991
2992         spin_lock_irqsave(&ihost->lock, flags);
2993         ihost->num_sessions--;
2994         if (ihost->num_sessions == 0)
2995                 wake_up(&ihost->session_removal_wq);
2996         spin_unlock_irqrestore(&ihost->lock, flags);
2997         scsi_host_put(shost);
2998 }
2999
3000 /**
3001  * iscsi_session_setup - create iscsi cls session and host and session
3002  * @iscsit: iscsi transport template
3003  * @shost: scsi host
3004  * @cmds_max: session can queue
3005  * @dd_size: private driver data size, added to session allocation size
3006  * @cmd_task_size: LLD task private data size
3007  * @initial_cmdsn: initial CmdSN
3008  * @id: target ID to add to this session
3009  *
3010  * This can be used by software iscsi_transports that allocate
3011  * a session per scsi host.
3012  *
3013  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
3014  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
3015  * for nop handling and login/logout requests.
3016  */
3017 struct iscsi_cls_session *
3018 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
3019                     uint16_t cmds_max, int dd_size, int cmd_task_size,
3020                     uint32_t initial_cmdsn, unsigned int id)
3021 {
3022         struct iscsi_host *ihost = shost_priv(shost);
3023         struct iscsi_session *session;
3024         struct iscsi_cls_session *cls_session;
3025         int cmd_i, scsi_cmds;
3026         unsigned long flags;
3027
3028         spin_lock_irqsave(&ihost->lock, flags);
3029         if (ihost->state == ISCSI_HOST_REMOVED) {
3030                 spin_unlock_irqrestore(&ihost->lock, flags);
3031                 return NULL;
3032         }
3033         ihost->num_sessions++;
3034         spin_unlock_irqrestore(&ihost->lock, flags);
3035
3036         scsi_cmds = iscsi_host_get_max_scsi_cmds(shost, cmds_max);
3037         if (scsi_cmds < 0)
3038                 goto dec_session_count;
3039
3040         cls_session = iscsi_alloc_session(shost, iscsit,
3041                                           sizeof(struct iscsi_session) +
3042                                           dd_size);
3043         if (!cls_session)
3044                 goto dec_session_count;
3045         session = cls_session->dd_data;
3046         session->cls_session = cls_session;
3047         session->host = shost;
3048         session->state = ISCSI_STATE_FREE;
3049         session->fast_abort = 1;
3050         session->tgt_reset_timeout = 30;
3051         session->lu_reset_timeout = 15;
3052         session->abort_timeout = 10;
3053         session->scsi_cmds_max = scsi_cmds;
3054         session->cmds_max = scsi_cmds + ISCSI_MGMT_CMDS_MAX;
3055         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
3056         session->exp_cmdsn = initial_cmdsn + 1;
3057         session->max_cmdsn = initial_cmdsn + 1;
3058         session->max_r2t = 1;
3059         session->tt = iscsit;
3060         session->dd_data = cls_session->dd_data + sizeof(*session);
3061
3062         session->tmf_state = TMF_INITIAL;
3063         timer_setup(&session->tmf_timer, iscsi_tmf_timedout, 0);
3064         mutex_init(&session->eh_mutex);
3065         init_waitqueue_head(&session->ehwait);
3066
3067         spin_lock_init(&session->frwd_lock);
3068         spin_lock_init(&session->back_lock);
3069
3070         /* initialize SCSI PDU commands pool */
3071         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
3072                             (void***)&session->cmds,
3073                             cmd_task_size + sizeof(struct iscsi_task)))
3074                 goto cmdpool_alloc_fail;
3075
3076         /* pre-format cmds pool with ITT */
3077         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
3078                 struct iscsi_task *task = session->cmds[cmd_i];
3079
3080                 if (cmd_task_size)
3081                         task->dd_data = &task[1];
3082                 task->itt = cmd_i;
3083                 task->state = ISCSI_TASK_FREE;
3084                 INIT_LIST_HEAD(&task->running);
3085         }
3086
3087         if (!try_module_get(iscsit->owner))
3088                 goto module_get_fail;
3089
3090         if (iscsi_add_session(cls_session, id))
3091                 goto cls_session_fail;
3092
3093         return cls_session;
3094
3095 cls_session_fail:
3096         module_put(iscsit->owner);
3097 module_get_fail:
3098         iscsi_pool_free(&session->cmdpool);
3099 cmdpool_alloc_fail:
3100         iscsi_free_session(cls_session);
3101 dec_session_count:
3102         iscsi_host_dec_session_cnt(shost);
3103         return NULL;
3104 }
3105 EXPORT_SYMBOL_GPL(iscsi_session_setup);
3106
3107 /*
3108  * issi_session_remove - Remove session from iSCSI class.
3109  */
3110 void iscsi_session_remove(struct iscsi_cls_session *cls_session)
3111 {
3112         struct iscsi_session *session = cls_session->dd_data;
3113         struct Scsi_Host *shost = session->host;
3114
3115         iscsi_remove_session(cls_session);
3116         /*
3117          * host removal only has to wait for its children to be removed from
3118          * sysfs, and iscsi_tcp needs to do iscsi_host_remove before freeing
3119          * the session, so drop the session count here.
3120          */
3121         iscsi_host_dec_session_cnt(shost);
3122 }
3123 EXPORT_SYMBOL_GPL(iscsi_session_remove);
3124
3125 /**
3126  * iscsi_session_free - Free iscsi session and it's resources
3127  * @cls_session: iscsi session
3128  */
3129 void iscsi_session_free(struct iscsi_cls_session *cls_session)
3130 {
3131         struct iscsi_session *session = cls_session->dd_data;
3132         struct module *owner = cls_session->transport->owner;
3133
3134         iscsi_pool_free(&session->cmdpool);
3135         kfree(session->password);
3136         kfree(session->password_in);
3137         kfree(session->username);
3138         kfree(session->username_in);
3139         kfree(session->targetname);
3140         kfree(session->targetalias);
3141         kfree(session->initiatorname);
3142         kfree(session->boot_root);
3143         kfree(session->boot_nic);
3144         kfree(session->boot_target);
3145         kfree(session->ifacename);
3146         kfree(session->portal_type);
3147         kfree(session->discovery_parent_type);
3148
3149         iscsi_free_session(cls_session);
3150         module_put(owner);
3151 }
3152 EXPORT_SYMBOL_GPL(iscsi_session_free);
3153
3154 /**
3155  * iscsi_session_teardown - destroy session and cls_session
3156  * @cls_session: iscsi session
3157  */
3158 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
3159 {
3160         iscsi_session_remove(cls_session);
3161         iscsi_session_free(cls_session);
3162 }
3163 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
3164
3165 /**
3166  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
3167  * @cls_session: iscsi_cls_session
3168  * @dd_size: private driver data size
3169  * @conn_idx: cid
3170  */
3171 struct iscsi_cls_conn *
3172 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
3173                  uint32_t conn_idx)
3174 {
3175         struct iscsi_session *session = cls_session->dd_data;
3176         struct iscsi_conn *conn;
3177         struct iscsi_cls_conn *cls_conn;
3178         char *data;
3179         int err;
3180
3181         cls_conn = iscsi_alloc_conn(cls_session, sizeof(*conn) + dd_size,
3182                                      conn_idx);
3183         if (!cls_conn)
3184                 return NULL;
3185         conn = cls_conn->dd_data;
3186
3187         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
3188         conn->session = session;
3189         conn->cls_conn = cls_conn;
3190         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
3191         conn->id = conn_idx;
3192         conn->exp_statsn = 0;
3193
3194         timer_setup(&conn->transport_timer, iscsi_check_transport_timeouts, 0);
3195
3196         INIT_LIST_HEAD(&conn->mgmtqueue);
3197         INIT_LIST_HEAD(&conn->cmdqueue);
3198         INIT_LIST_HEAD(&conn->requeue);
3199         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
3200
3201         /* allocate login_task used for the login/text sequences */
3202         spin_lock_bh(&session->frwd_lock);
3203         if (!kfifo_out(&session->cmdpool.queue,
3204                          (void*)&conn->login_task,
3205                          sizeof(void*))) {
3206                 spin_unlock_bh(&session->frwd_lock);
3207                 goto login_task_alloc_fail;
3208         }
3209         spin_unlock_bh(&session->frwd_lock);
3210
3211         data = (char *) __get_free_pages(GFP_KERNEL,
3212                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3213         if (!data)
3214                 goto login_task_data_alloc_fail;
3215         conn->login_task->data = conn->data = data;
3216
3217         err = iscsi_add_conn(cls_conn);
3218         if (err)
3219                 goto login_task_add_dev_fail;
3220
3221         return cls_conn;
3222
3223 login_task_add_dev_fail:
3224         free_pages((unsigned long) conn->data,
3225                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3226
3227 login_task_data_alloc_fail:
3228         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3229                     sizeof(void*));
3230 login_task_alloc_fail:
3231         iscsi_put_conn(cls_conn);
3232         return NULL;
3233 }
3234 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
3235
3236 /**
3237  * iscsi_conn_teardown - teardown iscsi connection
3238  * @cls_conn: iscsi class connection
3239  *
3240  * TODO: we may need to make this into a two step process
3241  * like scsi-mls remove + put host
3242  */
3243 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
3244 {
3245         struct iscsi_conn *conn = cls_conn->dd_data;
3246         struct iscsi_session *session = conn->session;
3247
3248         iscsi_remove_conn(cls_conn);
3249
3250         del_timer_sync(&conn->transport_timer);
3251
3252         mutex_lock(&session->eh_mutex);
3253         spin_lock_bh(&session->frwd_lock);
3254         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
3255         if (session->leadconn == conn) {
3256                 /*
3257                  * leading connection? then give up on recovery.
3258                  */
3259                 session->state = ISCSI_STATE_TERMINATE;
3260                 wake_up(&session->ehwait);
3261         }
3262         spin_unlock_bh(&session->frwd_lock);
3263
3264         /* flush queued up work because we free the connection below */
3265         iscsi_suspend_tx(conn);
3266
3267         spin_lock_bh(&session->frwd_lock);
3268         free_pages((unsigned long) conn->data,
3269                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3270         kfree(conn->persistent_address);
3271         kfree(conn->local_ipaddr);
3272         /* regular RX path uses back_lock */
3273         spin_lock_bh(&session->back_lock);
3274         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3275                     sizeof(void*));
3276         spin_unlock_bh(&session->back_lock);
3277         if (session->leadconn == conn)
3278                 session->leadconn = NULL;
3279         spin_unlock_bh(&session->frwd_lock);
3280         mutex_unlock(&session->eh_mutex);
3281
3282         iscsi_put_conn(cls_conn);
3283 }
3284 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
3285
3286 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
3287 {
3288         struct iscsi_conn *conn = cls_conn->dd_data;
3289         struct iscsi_session *session = conn->session;
3290
3291         if (!session) {
3292                 iscsi_conn_printk(KERN_ERR, conn,
3293                                   "can't start unbound connection\n");
3294                 return -EPERM;
3295         }
3296
3297         if ((session->imm_data_en || !session->initial_r2t_en) &&
3298              session->first_burst > session->max_burst) {
3299                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
3300                                   "first_burst %d max_burst %d\n",
3301                                   session->first_burst, session->max_burst);
3302                 return -EINVAL;
3303         }
3304
3305         if (conn->ping_timeout && !conn->recv_timeout) {
3306                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3307                                   "zero. Using 5 seconds\n.");
3308                 conn->recv_timeout = 5;
3309         }
3310
3311         if (conn->recv_timeout && !conn->ping_timeout) {
3312                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3313                                   "zero. Using 5 seconds.\n");
3314                 conn->ping_timeout = 5;
3315         }
3316
3317         spin_lock_bh(&session->frwd_lock);
3318         conn->c_stage = ISCSI_CONN_STARTED;
3319         session->state = ISCSI_STATE_LOGGED_IN;
3320         session->queued_cmdsn = session->cmdsn;
3321
3322         conn->last_recv = jiffies;
3323         conn->last_ping = jiffies;
3324         if (conn->recv_timeout && conn->ping_timeout)
3325                 mod_timer(&conn->transport_timer,
3326                           jiffies + (conn->recv_timeout * HZ));
3327
3328         switch(conn->stop_stage) {
3329         case STOP_CONN_RECOVER:
3330                 /*
3331                  * unblock eh_abort() if it is blocked. re-try all
3332                  * commands after successful recovery
3333                  */
3334                 conn->stop_stage = 0;
3335                 session->tmf_state = TMF_INITIAL;
3336                 session->age++;
3337                 if (session->age == 16)
3338                         session->age = 0;
3339                 break;
3340         case STOP_CONN_TERM:
3341                 conn->stop_stage = 0;
3342                 break;
3343         default:
3344                 break;
3345         }
3346         spin_unlock_bh(&session->frwd_lock);
3347
3348         iscsi_unblock_session(session->cls_session);
3349         wake_up(&session->ehwait);
3350         return 0;
3351 }
3352 EXPORT_SYMBOL_GPL(iscsi_conn_start);
3353
3354 static void
3355 fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3356 {
3357         struct iscsi_task *task;
3358         int i, state;
3359
3360         for (i = 0; i < conn->session->cmds_max; i++) {
3361                 task = conn->session->cmds[i];
3362                 if (task->sc)
3363                         continue;
3364
3365                 if (task->state == ISCSI_TASK_FREE)
3366                         continue;
3367
3368                 ISCSI_DBG_SESSION(conn->session,
3369                                   "failing mgmt itt 0x%x state %d\n",
3370                                   task->itt, task->state);
3371
3372                 spin_lock_bh(&session->back_lock);
3373                 if (cleanup_queued_task(task)) {
3374                         spin_unlock_bh(&session->back_lock);
3375                         continue;
3376                 }
3377
3378                 state = ISCSI_TASK_ABRT_SESS_RECOV;
3379                 if (task->state == ISCSI_TASK_PENDING)
3380                         state = ISCSI_TASK_COMPLETED;
3381                 iscsi_complete_task(task, state);
3382                 spin_unlock_bh(&session->back_lock);
3383         }
3384 }
3385
3386 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3387 {
3388         struct iscsi_conn *conn = cls_conn->dd_data;
3389         struct iscsi_session *session = conn->session;
3390         int old_stop_stage;
3391
3392         mutex_lock(&session->eh_mutex);
3393         spin_lock_bh(&session->frwd_lock);
3394         if (conn->stop_stage == STOP_CONN_TERM) {
3395                 spin_unlock_bh(&session->frwd_lock);
3396                 mutex_unlock(&session->eh_mutex);
3397                 return;
3398         }
3399
3400         /*
3401          * When this is called for the in_login state, we only want to clean
3402          * up the login task and connection. We do not need to block and set
3403          * the recovery state again
3404          */
3405         if (flag == STOP_CONN_TERM)
3406                 session->state = ISCSI_STATE_TERMINATE;
3407         else if (conn->stop_stage != STOP_CONN_RECOVER)
3408                 session->state = ISCSI_STATE_IN_RECOVERY;
3409
3410         old_stop_stage = conn->stop_stage;
3411         conn->stop_stage = flag;
3412         spin_unlock_bh(&session->frwd_lock);
3413
3414         del_timer_sync(&conn->transport_timer);
3415         iscsi_suspend_tx(conn);
3416
3417         spin_lock_bh(&session->frwd_lock);
3418         conn->c_stage = ISCSI_CONN_STOPPED;
3419         spin_unlock_bh(&session->frwd_lock);
3420
3421         /*
3422          * for connection level recovery we should not calculate
3423          * header digest. conn->hdr_size used for optimization
3424          * in hdr_extract() and will be re-negotiated at
3425          * set_param() time.
3426          */
3427         if (flag == STOP_CONN_RECOVER) {
3428                 conn->hdrdgst_en = 0;
3429                 conn->datadgst_en = 0;
3430                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
3431                     old_stop_stage != STOP_CONN_RECOVER) {
3432                         ISCSI_DBG_SESSION(session, "blocking session\n");
3433                         iscsi_block_session(session->cls_session);
3434                 }
3435         }
3436
3437         /*
3438          * flush queues.
3439          */
3440         spin_lock_bh(&session->frwd_lock);
3441         fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3442         fail_mgmt_tasks(session, conn);
3443         memset(&session->tmhdr, 0, sizeof(session->tmhdr));
3444         spin_unlock_bh(&session->frwd_lock);
3445         mutex_unlock(&session->eh_mutex);
3446 }
3447 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3448
3449 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3450                     struct iscsi_cls_conn *cls_conn, int is_leading)
3451 {
3452         struct iscsi_session *session = cls_session->dd_data;
3453         struct iscsi_conn *conn = cls_conn->dd_data;
3454
3455         spin_lock_bh(&session->frwd_lock);
3456         if (is_leading)
3457                 session->leadconn = conn;
3458
3459         set_bit(ISCSI_CONN_FLAG_BOUND, &conn->flags);
3460         spin_unlock_bh(&session->frwd_lock);
3461
3462         /*
3463          * The target could have reduced it's window size between logins, so
3464          * we have to reset max/exp cmdsn so we can see the new values.
3465          */
3466         spin_lock_bh(&session->back_lock);
3467         session->max_cmdsn = session->exp_cmdsn = session->cmdsn + 1;
3468         spin_unlock_bh(&session->back_lock);
3469         /*
3470          * Unblock xmitworker(), Login Phase will pass through.
3471          */
3472         clear_bit(ISCSI_CONN_FLAG_SUSPEND_RX, &conn->flags);
3473         clear_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags);
3474         return 0;
3475 }
3476 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3477
3478 int iscsi_switch_str_param(char **param, char *new_val_buf)
3479 {
3480         char *new_val;
3481
3482         if (*param) {
3483                 if (!strcmp(*param, new_val_buf))
3484                         return 0;
3485         }
3486
3487         new_val = kstrdup(new_val_buf, GFP_NOIO);
3488         if (!new_val)
3489                 return -ENOMEM;
3490
3491         kfree(*param);
3492         *param = new_val;
3493         return 0;
3494 }
3495 EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3496
3497 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3498                     enum iscsi_param param, char *buf, int buflen)
3499 {
3500         struct iscsi_conn *conn = cls_conn->dd_data;
3501         struct iscsi_session *session = conn->session;
3502         int val;
3503
3504         switch(param) {
3505         case ISCSI_PARAM_FAST_ABORT:
3506                 sscanf(buf, "%d", &session->fast_abort);
3507                 break;
3508         case ISCSI_PARAM_ABORT_TMO:
3509                 sscanf(buf, "%d", &session->abort_timeout);
3510                 break;
3511         case ISCSI_PARAM_LU_RESET_TMO:
3512                 sscanf(buf, "%d", &session->lu_reset_timeout);
3513                 break;
3514         case ISCSI_PARAM_TGT_RESET_TMO:
3515                 sscanf(buf, "%d", &session->tgt_reset_timeout);
3516                 break;
3517         case ISCSI_PARAM_PING_TMO:
3518                 sscanf(buf, "%d", &conn->ping_timeout);
3519                 break;
3520         case ISCSI_PARAM_RECV_TMO:
3521                 sscanf(buf, "%d", &conn->recv_timeout);
3522                 break;
3523         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3524                 sscanf(buf, "%d", &conn->max_recv_dlength);
3525                 break;
3526         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3527                 sscanf(buf, "%d", &conn->max_xmit_dlength);
3528                 break;
3529         case ISCSI_PARAM_HDRDGST_EN:
3530                 sscanf(buf, "%d", &conn->hdrdgst_en);
3531                 break;
3532         case ISCSI_PARAM_DATADGST_EN:
3533                 sscanf(buf, "%d", &conn->datadgst_en);
3534                 break;
3535         case ISCSI_PARAM_INITIAL_R2T_EN:
3536                 sscanf(buf, "%d", &session->initial_r2t_en);
3537                 break;
3538         case ISCSI_PARAM_MAX_R2T:
3539                 sscanf(buf, "%hu", &session->max_r2t);
3540                 break;
3541         case ISCSI_PARAM_IMM_DATA_EN:
3542                 sscanf(buf, "%d", &session->imm_data_en);
3543                 break;
3544         case ISCSI_PARAM_FIRST_BURST:
3545                 sscanf(buf, "%d", &session->first_burst);
3546                 break;
3547         case ISCSI_PARAM_MAX_BURST:
3548                 sscanf(buf, "%d", &session->max_burst);
3549                 break;
3550         case ISCSI_PARAM_PDU_INORDER_EN:
3551                 sscanf(buf, "%d", &session->pdu_inorder_en);
3552                 break;
3553         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3554                 sscanf(buf, "%d", &session->dataseq_inorder_en);
3555                 break;
3556         case ISCSI_PARAM_ERL:
3557                 sscanf(buf, "%d", &session->erl);
3558                 break;
3559         case ISCSI_PARAM_EXP_STATSN:
3560                 sscanf(buf, "%u", &conn->exp_statsn);
3561                 break;
3562         case ISCSI_PARAM_USERNAME:
3563                 return iscsi_switch_str_param(&session->username, buf);
3564         case ISCSI_PARAM_USERNAME_IN:
3565                 return iscsi_switch_str_param(&session->username_in, buf);
3566         case ISCSI_PARAM_PASSWORD:
3567                 return iscsi_switch_str_param(&session->password, buf);
3568         case ISCSI_PARAM_PASSWORD_IN:
3569                 return iscsi_switch_str_param(&session->password_in, buf);
3570         case ISCSI_PARAM_TARGET_NAME:
3571                 return iscsi_switch_str_param(&session->targetname, buf);
3572         case ISCSI_PARAM_TARGET_ALIAS:
3573                 return iscsi_switch_str_param(&session->targetalias, buf);
3574         case ISCSI_PARAM_TPGT:
3575                 sscanf(buf, "%d", &session->tpgt);
3576                 break;
3577         case ISCSI_PARAM_PERSISTENT_PORT:
3578                 sscanf(buf, "%d", &conn->persistent_port);
3579                 break;
3580         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3581                 return iscsi_switch_str_param(&conn->persistent_address, buf);
3582         case ISCSI_PARAM_IFACE_NAME:
3583                 return iscsi_switch_str_param(&session->ifacename, buf);
3584         case ISCSI_PARAM_INITIATOR_NAME:
3585                 return iscsi_switch_str_param(&session->initiatorname, buf);
3586         case ISCSI_PARAM_BOOT_ROOT:
3587                 return iscsi_switch_str_param(&session->boot_root, buf);
3588         case ISCSI_PARAM_BOOT_NIC:
3589                 return iscsi_switch_str_param(&session->boot_nic, buf);
3590         case ISCSI_PARAM_BOOT_TARGET:
3591                 return iscsi_switch_str_param(&session->boot_target, buf);
3592         case ISCSI_PARAM_PORTAL_TYPE:
3593                 return iscsi_switch_str_param(&session->portal_type, buf);
3594         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3595                 return iscsi_switch_str_param(&session->discovery_parent_type,
3596                                               buf);
3597         case ISCSI_PARAM_DISCOVERY_SESS:
3598                 sscanf(buf, "%d", &val);
3599                 session->discovery_sess = !!val;
3600                 break;
3601         case ISCSI_PARAM_LOCAL_IPADDR:
3602                 return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3603         default:
3604                 return -ENOSYS;
3605         }
3606
3607         return 0;
3608 }
3609 EXPORT_SYMBOL_GPL(iscsi_set_param);
3610
3611 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3612                             enum iscsi_param param, char *buf)
3613 {
3614         struct iscsi_session *session = cls_session->dd_data;
3615         int len;
3616
3617         switch(param) {
3618         case ISCSI_PARAM_FAST_ABORT:
3619                 len = sysfs_emit(buf, "%d\n", session->fast_abort);
3620                 break;
3621         case ISCSI_PARAM_ABORT_TMO:
3622                 len = sysfs_emit(buf, "%d\n", session->abort_timeout);
3623                 break;
3624         case ISCSI_PARAM_LU_RESET_TMO:
3625                 len = sysfs_emit(buf, "%d\n", session->lu_reset_timeout);
3626                 break;
3627         case ISCSI_PARAM_TGT_RESET_TMO:
3628                 len = sysfs_emit(buf, "%d\n", session->tgt_reset_timeout);
3629                 break;
3630         case ISCSI_PARAM_INITIAL_R2T_EN:
3631                 len = sysfs_emit(buf, "%d\n", session->initial_r2t_en);
3632                 break;
3633         case ISCSI_PARAM_MAX_R2T:
3634                 len = sysfs_emit(buf, "%hu\n", session->max_r2t);
3635                 break;
3636         case ISCSI_PARAM_IMM_DATA_EN:
3637                 len = sysfs_emit(buf, "%d\n", session->imm_data_en);
3638                 break;
3639         case ISCSI_PARAM_FIRST_BURST:
3640                 len = sysfs_emit(buf, "%u\n", session->first_burst);
3641                 break;
3642         case ISCSI_PARAM_MAX_BURST:
3643                 len = sysfs_emit(buf, "%u\n", session->max_burst);
3644                 break;
3645         case ISCSI_PARAM_PDU_INORDER_EN:
3646                 len = sysfs_emit(buf, "%d\n", session->pdu_inorder_en);
3647                 break;
3648         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3649                 len = sysfs_emit(buf, "%d\n", session->dataseq_inorder_en);
3650                 break;
3651         case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3652                 len = sysfs_emit(buf, "%d\n", session->def_taskmgmt_tmo);
3653                 break;
3654         case ISCSI_PARAM_ERL:
3655                 len = sysfs_emit(buf, "%d\n", session->erl);
3656                 break;
3657         case ISCSI_PARAM_TARGET_NAME:
3658                 len = sysfs_emit(buf, "%s\n", session->targetname);
3659                 break;
3660         case ISCSI_PARAM_TARGET_ALIAS:
3661                 len = sysfs_emit(buf, "%s\n", session->targetalias);
3662                 break;
3663         case ISCSI_PARAM_TPGT:
3664                 len = sysfs_emit(buf, "%d\n", session->tpgt);
3665                 break;
3666         case ISCSI_PARAM_USERNAME:
3667                 len = sysfs_emit(buf, "%s\n", session->username);
3668                 break;
3669         case ISCSI_PARAM_USERNAME_IN:
3670                 len = sysfs_emit(buf, "%s\n", session->username_in);
3671                 break;
3672         case ISCSI_PARAM_PASSWORD:
3673                 len = sysfs_emit(buf, "%s\n", session->password);
3674                 break;
3675         case ISCSI_PARAM_PASSWORD_IN:
3676                 len = sysfs_emit(buf, "%s\n", session->password_in);
3677                 break;
3678         case ISCSI_PARAM_IFACE_NAME:
3679                 len = sysfs_emit(buf, "%s\n", session->ifacename);
3680                 break;
3681         case ISCSI_PARAM_INITIATOR_NAME:
3682                 len = sysfs_emit(buf, "%s\n", session->initiatorname);
3683                 break;
3684         case ISCSI_PARAM_BOOT_ROOT:
3685                 len = sysfs_emit(buf, "%s\n", session->boot_root);
3686                 break;
3687         case ISCSI_PARAM_BOOT_NIC:
3688                 len = sysfs_emit(buf, "%s\n", session->boot_nic);
3689                 break;
3690         case ISCSI_PARAM_BOOT_TARGET:
3691                 len = sysfs_emit(buf, "%s\n", session->boot_target);
3692                 break;
3693         case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3694                 len = sysfs_emit(buf, "%u\n", session->auto_snd_tgt_disable);
3695                 break;
3696         case ISCSI_PARAM_DISCOVERY_SESS:
3697                 len = sysfs_emit(buf, "%u\n", session->discovery_sess);
3698                 break;
3699         case ISCSI_PARAM_PORTAL_TYPE:
3700                 len = sysfs_emit(buf, "%s\n", session->portal_type);
3701                 break;
3702         case ISCSI_PARAM_CHAP_AUTH_EN:
3703                 len = sysfs_emit(buf, "%u\n", session->chap_auth_en);
3704                 break;
3705         case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3706                 len = sysfs_emit(buf, "%u\n", session->discovery_logout_en);
3707                 break;
3708         case ISCSI_PARAM_BIDI_CHAP_EN:
3709                 len = sysfs_emit(buf, "%u\n", session->bidi_chap_en);
3710                 break;
3711         case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3712                 len = sysfs_emit(buf, "%u\n", session->discovery_auth_optional);
3713                 break;
3714         case ISCSI_PARAM_DEF_TIME2WAIT:
3715                 len = sysfs_emit(buf, "%d\n", session->time2wait);
3716                 break;
3717         case ISCSI_PARAM_DEF_TIME2RETAIN:
3718                 len = sysfs_emit(buf, "%d\n", session->time2retain);
3719                 break;
3720         case ISCSI_PARAM_TSID:
3721                 len = sysfs_emit(buf, "%u\n", session->tsid);
3722                 break;
3723         case ISCSI_PARAM_ISID:
3724                 len = sysfs_emit(buf, "%02x%02x%02x%02x%02x%02x\n",
3725                               session->isid[0], session->isid[1],
3726                               session->isid[2], session->isid[3],
3727                               session->isid[4], session->isid[5]);
3728                 break;
3729         case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3730                 len = sysfs_emit(buf, "%u\n", session->discovery_parent_idx);
3731                 break;
3732         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3733                 if (session->discovery_parent_type)
3734                         len = sysfs_emit(buf, "%s\n",
3735                                       session->discovery_parent_type);
3736                 else
3737                         len = sysfs_emit(buf, "\n");
3738                 break;
3739         default:
3740                 return -ENOSYS;
3741         }
3742
3743         return len;
3744 }
3745 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3746
3747 int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3748                               enum iscsi_param param, char *buf)
3749 {
3750         struct sockaddr_in6 *sin6 = NULL;
3751         struct sockaddr_in *sin = NULL;
3752         int len;
3753
3754         switch (addr->ss_family) {
3755         case AF_INET:
3756                 sin = (struct sockaddr_in *)addr;
3757                 break;
3758         case AF_INET6:
3759                 sin6 = (struct sockaddr_in6 *)addr;
3760                 break;
3761         default:
3762                 return -EINVAL;
3763         }
3764
3765         switch (param) {
3766         case ISCSI_PARAM_CONN_ADDRESS:
3767         case ISCSI_HOST_PARAM_IPADDRESS:
3768                 if (sin)
3769                         len = sysfs_emit(buf, "%pI4\n", &sin->sin_addr.s_addr);
3770                 else
3771                         len = sysfs_emit(buf, "%pI6\n", &sin6->sin6_addr);
3772                 break;
3773         case ISCSI_PARAM_CONN_PORT:
3774         case ISCSI_PARAM_LOCAL_PORT:
3775                 if (sin)
3776                         len = sysfs_emit(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3777                 else
3778                         len = sysfs_emit(buf, "%hu\n",
3779                                       be16_to_cpu(sin6->sin6_port));
3780                 break;
3781         default:
3782                 return -EINVAL;
3783         }
3784
3785         return len;
3786 }
3787 EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3788
3789 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3790                          enum iscsi_param param, char *buf)
3791 {
3792         struct iscsi_conn *conn = cls_conn->dd_data;
3793         int len;
3794
3795         switch(param) {
3796         case ISCSI_PARAM_PING_TMO:
3797                 len = sysfs_emit(buf, "%u\n", conn->ping_timeout);
3798                 break;
3799         case ISCSI_PARAM_RECV_TMO:
3800                 len = sysfs_emit(buf, "%u\n", conn->recv_timeout);
3801                 break;
3802         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3803                 len = sysfs_emit(buf, "%u\n", conn->max_recv_dlength);
3804                 break;
3805         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3806                 len = sysfs_emit(buf, "%u\n", conn->max_xmit_dlength);
3807                 break;
3808         case ISCSI_PARAM_HDRDGST_EN:
3809                 len = sysfs_emit(buf, "%d\n", conn->hdrdgst_en);
3810                 break;
3811         case ISCSI_PARAM_DATADGST_EN:
3812                 len = sysfs_emit(buf, "%d\n", conn->datadgst_en);
3813                 break;
3814         case ISCSI_PARAM_IFMARKER_EN:
3815                 len = sysfs_emit(buf, "%d\n", conn->ifmarker_en);
3816                 break;
3817         case ISCSI_PARAM_OFMARKER_EN:
3818                 len = sysfs_emit(buf, "%d\n", conn->ofmarker_en);
3819                 break;
3820         case ISCSI_PARAM_EXP_STATSN:
3821                 len = sysfs_emit(buf, "%u\n", conn->exp_statsn);
3822                 break;
3823         case ISCSI_PARAM_PERSISTENT_PORT:
3824                 len = sysfs_emit(buf, "%d\n", conn->persistent_port);
3825                 break;
3826         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3827                 len = sysfs_emit(buf, "%s\n", conn->persistent_address);
3828                 break;
3829         case ISCSI_PARAM_STATSN:
3830                 len = sysfs_emit(buf, "%u\n", conn->statsn);
3831                 break;
3832         case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3833                 len = sysfs_emit(buf, "%u\n", conn->max_segment_size);
3834                 break;
3835         case ISCSI_PARAM_KEEPALIVE_TMO:
3836                 len = sysfs_emit(buf, "%u\n", conn->keepalive_tmo);
3837                 break;
3838         case ISCSI_PARAM_LOCAL_PORT:
3839                 len = sysfs_emit(buf, "%u\n", conn->local_port);
3840                 break;
3841         case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3842                 len = sysfs_emit(buf, "%u\n", conn->tcp_timestamp_stat);
3843                 break;
3844         case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3845                 len = sysfs_emit(buf, "%u\n", conn->tcp_nagle_disable);
3846                 break;
3847         case ISCSI_PARAM_TCP_WSF_DISABLE:
3848                 len = sysfs_emit(buf, "%u\n", conn->tcp_wsf_disable);
3849                 break;
3850         case ISCSI_PARAM_TCP_TIMER_SCALE:
3851                 len = sysfs_emit(buf, "%u\n", conn->tcp_timer_scale);
3852                 break;
3853         case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3854                 len = sysfs_emit(buf, "%u\n", conn->tcp_timestamp_en);
3855                 break;
3856         case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3857                 len = sysfs_emit(buf, "%u\n", conn->fragment_disable);
3858                 break;
3859         case ISCSI_PARAM_IPV4_TOS:
3860                 len = sysfs_emit(buf, "%u\n", conn->ipv4_tos);
3861                 break;
3862         case ISCSI_PARAM_IPV6_TC:
3863                 len = sysfs_emit(buf, "%u\n", conn->ipv6_traffic_class);
3864                 break;
3865         case ISCSI_PARAM_IPV6_FLOW_LABEL:
3866                 len = sysfs_emit(buf, "%u\n", conn->ipv6_flow_label);
3867                 break;
3868         case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3869                 len = sysfs_emit(buf, "%u\n", conn->is_fw_assigned_ipv6);
3870                 break;
3871         case ISCSI_PARAM_TCP_XMIT_WSF:
3872                 len = sysfs_emit(buf, "%u\n", conn->tcp_xmit_wsf);
3873                 break;
3874         case ISCSI_PARAM_TCP_RECV_WSF:
3875                 len = sysfs_emit(buf, "%u\n", conn->tcp_recv_wsf);
3876                 break;
3877         case ISCSI_PARAM_LOCAL_IPADDR:
3878                 len = sysfs_emit(buf, "%s\n", conn->local_ipaddr);
3879                 break;
3880         default:
3881                 return -ENOSYS;
3882         }
3883
3884         return len;
3885 }
3886 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3887
3888 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3889                          char *buf)
3890 {
3891         struct iscsi_host *ihost = shost_priv(shost);
3892         int len;
3893
3894         switch (param) {
3895         case ISCSI_HOST_PARAM_NETDEV_NAME:
3896                 len = sysfs_emit(buf, "%s\n", ihost->netdev);
3897                 break;
3898         case ISCSI_HOST_PARAM_HWADDRESS:
3899                 len = sysfs_emit(buf, "%s\n", ihost->hwaddress);
3900                 break;
3901         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3902                 len = sysfs_emit(buf, "%s\n", ihost->initiatorname);
3903                 break;
3904         default:
3905                 return -ENOSYS;
3906         }
3907
3908         return len;
3909 }
3910 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3911
3912 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3913                          char *buf, int buflen)
3914 {
3915         struct iscsi_host *ihost = shost_priv(shost);
3916
3917         switch (param) {
3918         case ISCSI_HOST_PARAM_NETDEV_NAME:
3919                 return iscsi_switch_str_param(&ihost->netdev, buf);
3920         case ISCSI_HOST_PARAM_HWADDRESS:
3921                 return iscsi_switch_str_param(&ihost->hwaddress, buf);
3922         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3923                 return iscsi_switch_str_param(&ihost->initiatorname, buf);
3924         default:
3925                 return -ENOSYS;
3926         }
3927
3928         return 0;
3929 }
3930 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3931
3932 MODULE_AUTHOR("Mike Christie");
3933 MODULE_DESCRIPTION("iSCSI library functions");
3934 MODULE_LICENSE("GPL");