drivers/scsi/libiscsi.c

   1 /*
   2  * iSCSI lib functions
   3  *
   4  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   5  * Copyright (C) 2004 - 2006 Mike Christie
   6  * Copyright (C) 2004 - 2005 Dmitry Yusupov
   7  * Copyright (C) 2004 - 2005 Alex Aizman
   8  * maintained by open-iscsi@googlegroups.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  */
  24 #include <linux/types.h>
  25 #include <linux/kfifo.h>
  26 #include <linux/delay.h>
  27 #include <linux/log2.h>
  28 #include <linux/slab.h>
  29 #include <asm/unaligned.h>
  30 #include <net/tcp.h>
  31 #include <scsi/scsi_cmnd.h>
  32 #include <scsi/scsi_device.h>
  33 #include <scsi/scsi_eh.h>
  34 #include <scsi/scsi_tcq.h>
  35 #include <scsi/scsi_host.h>
  36 #include <scsi/scsi.h>
  37 #include <scsi/iscsi_proto.h>
  38 #include <scsi/scsi_transport.h>
  39 #include <scsi/scsi_transport_iscsi.h>
  40 #include <scsi/libiscsi.h>
  41
  42 static int iscsi_dbg_lib_conn;
  43 module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
  44                    S_IRUGO | S_IWUSR);
  45 MODULE_PARM_DESC(debug_libiscsi_conn,
  46                  "Turn on debugging for connections in libiscsi module. "
  47                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  48
  49 static int iscsi_dbg_lib_session;
  50 module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
  51                    S_IRUGO | S_IWUSR);
  52 MODULE_PARM_DESC(debug_libiscsi_session,
  53                  "Turn on debugging for sessions in libiscsi module. "
  54                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  55
  56 static int iscsi_dbg_lib_eh;
  57 module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
  58                    S_IRUGO | S_IWUSR);
  59 MODULE_PARM_DESC(debug_libiscsi_eh,
  60                  "Turn on debugging for error handling in libiscsi module. "
  61                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  62
  63 #define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)                  \
  64         do {                                                    \
  65                 if (iscsi_dbg_lib_conn)                         \
  66                         iscsi_conn_printk(KERN_INFO, _conn,     \
  67                                              "%s " dbg_fmt,     \
  68                                              __func__, ##arg);  \
  69         } while (0);
  70
  71 #define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)                    \
  72         do {                                                            \
  73                 if (iscsi_dbg_lib_session)                              \
  74                         iscsi_session_printk(KERN_INFO, _session,       \
  75                                              "%s " dbg_fmt,             \
  76                                              __func__, ##arg);          \
  77         } while (0);
  78
  79 #define ISCSI_DBG_EH(_session, dbg_fmt, arg...)                         \
  80         do {                                                            \
  81                 if (iscsi_dbg_lib_eh)                                   \
  82                         iscsi_session_printk(KERN_INFO, _session,       \
  83                                              "%s " dbg_fmt,             \
  84                                              __func__, ##arg);          \
  85         } while (0);
  86
  87 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
  88 #define SNA32_CHECK 2147483648UL
  89
  90 static int iscsi_sna_lt(u32 n1, u32 n2)
  91 {
  92         return n1 != n2 && ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
  93                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
  94 }
  95
  96 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
  97 static int iscsi_sna_lte(u32 n1, u32 n2)
  98 {
  99         return n1 == n2 || ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
 100                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
 101 }
 102
 103 inline void iscsi_conn_queue_work(struct iscsi_conn *conn)
 104 {
 105         struct Scsi_Host *shost = conn->session->host;
 106         struct iscsi_host *ihost = shost_priv(shost);
 107
 108         if (ihost->workq)
 109                 queue_work(ihost->workq, &conn->xmitwork);
 110 }
 111 EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
 112
 113 static void __iscsi_update_cmdsn(struct iscsi_session *session,
 114                                  uint32_t exp_cmdsn, uint32_t max_cmdsn)
 115 {
 116         /*
 117          * standard specifies this check for when to update expected and
 118          * max sequence numbers
 119          */
 120         if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
 121                 return;
 122
 123         if (exp_cmdsn != session->exp_cmdsn &&
 124             !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
 125                 session->exp_cmdsn = exp_cmdsn;
 126
 127         if (max_cmdsn != session->max_cmdsn &&
 128             !iscsi_sna_lt(max_cmdsn, session->max_cmdsn)) {
 129                 session->max_cmdsn = max_cmdsn;
 130                 /*
 131                  * if the window closed with IO queued, then kick the
 132                  * xmit thread
 133                  */
 134                 if (!list_empty(&session->leadconn->cmdqueue) ||
 135                     !list_empty(&session->leadconn->mgmtqueue))
 136                         iscsi_conn_queue_work(session->leadconn);
 137         }
 138 }
 139
 140 void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
 141 {
 142         __iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
 143                              be32_to_cpu(hdr->max_cmdsn));
 144 }
 145 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
 146
 147 /**
 148  * iscsi_prep_data_out_pdu - initialize Data-Out
 149  * @task: scsi command task
 150  * @r2t: R2T info
 151  * @hdr: iscsi data in pdu
 152  *
 153  * Notes:
 154  *      Initialize Data-Out within this R2T sequence and finds
 155  *      proper data_offset within this SCSI command.
 156  *
 157  *      This function is called with connection lock taken.
 158  **/
 159 void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
 160                            struct iscsi_data *hdr)
 161 {
 162         struct iscsi_conn *conn = task->conn;
 163         unsigned int left = r2t->data_length - r2t->sent;
 164
 165         task->hdr_len = sizeof(struct iscsi_data);
 166
 167         memset(hdr, 0, sizeof(struct iscsi_data));
 168         hdr->ttt = r2t->ttt;
 169         hdr->datasn = cpu_to_be32(r2t->datasn);
 170         r2t->datasn++;
 171         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 172         memcpy(hdr->lun, task->lun, sizeof(hdr->lun));
 173         hdr->itt = task->hdr_itt;
 174         hdr->exp_statsn = r2t->exp_statsn;
 175         hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
 176         if (left > conn->max_xmit_dlength) {
 177                 hton24(hdr->dlength, conn->max_xmit_dlength);
 178                 r2t->data_count = conn->max_xmit_dlength;
 179                 hdr->flags = 0;
 180         } else {
 181                 hton24(hdr->dlength, left);
 182                 r2t->data_count = left;
 183                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 184         }
 185         conn->dataout_pdus_cnt++;
 186 }
 187 EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
 188
 189 static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
 190 {
 191         unsigned exp_len = task->hdr_len + len;
 192
 193         if (exp_len > task->hdr_max) {
 194                 WARN_ON(1);
 195                 return -EINVAL;
 196         }
 197
 198         WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 199         task->hdr_len = exp_len;
 200         return 0;
 201 }
 202
 203 /*
 204  * make an extended cdb AHS
 205  */
 206 static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
 207 {
 208         struct scsi_cmnd *cmd = task->sc;
 209         unsigned rlen, pad_len;
 210         unsigned short ahslength;
 211         struct iscsi_ecdb_ahdr *ecdb_ahdr;
 212         int rc;
 213
 214         ecdb_ahdr = iscsi_next_hdr(task);
 215         rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 216
 217         BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 218         ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 219
 220         pad_len = iscsi_padding(rlen);
 221
 222         rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
 223                            sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 224         if (rc)
 225                 return rc;
 226
 227         if (pad_len)
 228                 memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 229
 230         ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 231         ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 232         ecdb_ahdr->reserved = 0;
 233         memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 234
 235         ISCSI_DBG_SESSION(task->conn->session,
 236                           "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 237                           "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
 238                           "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
 239                           task->hdr_len);
 240         return 0;
 241 }
 242
 243 static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
 244 {
 245         struct scsi_cmnd *sc = task->sc;
 246         struct iscsi_rlength_ahdr *rlen_ahdr;
 247         int rc;
 248
 249         rlen_ahdr = iscsi_next_hdr(task);
 250         rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
 251         if (rc)
 252                 return rc;
 253
 254         rlen_ahdr->ahslength =
 255                 cpu_to_be16(sizeof(rlen_ahdr->read_length) +
 256                                                   sizeof(rlen_ahdr->reserved));
 257         rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
 258         rlen_ahdr->reserved = 0;
 259         rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
 260
 261         ISCSI_DBG_SESSION(task->conn->session,
 262                           "bidi-in rlen_ahdr->read_length(%d) "
 263                           "rlen_ahdr->ahslength(%d)\n",
 264                           be32_to_cpu(rlen_ahdr->read_length),
 265                           be16_to_cpu(rlen_ahdr->ahslength));
 266         return 0;
 267 }
 268
 269 /**
 270  * iscsi_check_tmf_restrictions - check if a task is affected by TMF
 271  * @task: iscsi task
 272  * @opcode: opcode to check for
 273  *
 274  * During TMF a task has to be checked if it's affected.
 275  * All unrelated I/O can be passed through, but I/O to the
 276  * affected LUN should be restricted.
 277  * If 'fast_abort' is set we won't be sending any I/O to the
 278  * affected LUN.
 279  * Otherwise the target is waiting for all TTTs to be completed,
 280  * so we have to send all outstanding Data-Out PDUs to the target.
 281  */
 282 static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
 283 {
 284         struct iscsi_conn *conn = task->conn;
 285         struct iscsi_tm *tmf = &conn->tmhdr;
 286         unsigned int hdr_lun;
 287
 288         if (conn->tmf_state == TMF_INITIAL)
 289                 return 0;
 290
 291         if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
 292                 return 0;
 293
 294         switch (ISCSI_TM_FUNC_VALUE(tmf)) {
 295         case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
 296                 /*
 297                  * Allow PDUs for unrelated LUNs
 298                  */
 299                 hdr_lun = scsilun_to_int((struct scsi_lun *)tmf->lun);
 300                 if (hdr_lun != task->sc->device->lun)
 301                         return 0;
 302                 /* fall through */
 303         case ISCSI_TM_FUNC_TARGET_WARM_RESET:
 304                 /*
 305                  * Fail all SCSI cmd PDUs
 306                  */
 307                 if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
 308                         iscsi_conn_printk(KERN_INFO, conn,
 309                                           "task [op %x/%x itt "
 310                                           "0x%x/0x%x] "
 311                                           "rejected.\n",
 312                                           task->hdr->opcode, opcode,
 313                                           task->itt, task->hdr_itt);
 314                         return -EACCES;
 315                 }
 316                 /*
 317                  * And also all data-out PDUs in response to R2T
 318                  * if fast_abort is set.
 319                  */
 320                 if (conn->session->fast_abort) {
 321                         iscsi_conn_printk(KERN_INFO, conn,
 322                                           "task [op %x/%x itt "
 323                                           "0x%x/0x%x] fast abort.\n",
 324                                           task->hdr->opcode, opcode,
 325                                           task->itt, task->hdr_itt);
 326                         return -EACCES;
 327                 }
 328                 break;
 329         case ISCSI_TM_FUNC_ABORT_TASK:
 330                 /*
 331                  * the caller has already checked if the task
 332                  * they want to abort was in the pending queue so if
 333                  * we are here the cmd pdu has gone out already, and
 334                  * we will only hit this for data-outs
 335                  */
 336                 if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
 337                     task->hdr_itt == tmf->rtt) {
 338                         ISCSI_DBG_SESSION(conn->session,
 339                                           "Preventing task %x/%x from sending "
 340                                           "data-out due to abort task in "
 341                                           "progress\n", task->itt,
 342                                           task->hdr_itt);
 343                         return -EACCES;
 344                 }
 345                 break;
 346         }
 347
 348         return 0;
 349 }
 350
 351 /**
 352  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 353  * @task: iscsi task
 354  *
 355  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 356  * fields like dlength or final based on how much data it sends
 357  */
 358 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 359 {
 360         struct iscsi_conn *conn = task->conn;
 361         struct iscsi_session *session = conn->session;
 362         struct scsi_cmnd *sc = task->sc;
 363         struct iscsi_cmd *hdr;
 364         unsigned hdrlength, cmd_len;
 365         itt_t itt;
 366         int rc;
 367
 368         rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
 369         if (rc)
 370                 return rc;
 371
 372         if (conn->session->tt->alloc_pdu) {
 373                 rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
 374                 if (rc)
 375                         return rc;
 376         }
 377         hdr = (struct iscsi_cmd *) task->hdr;
 378         itt = hdr->itt;
 379         memset(hdr, 0, sizeof(*hdr));
 380
 381         if (session->tt->parse_pdu_itt)
 382                 hdr->itt = task->hdr_itt = itt;
 383         else
 384                 hdr->itt = task->hdr_itt = build_itt(task->itt,
 385                                                      task->conn->session->age);
 386         task->hdr_len = 0;
 387         rc = iscsi_add_hdr(task, sizeof(*hdr));
 388         if (rc)
 389                 return rc;
 390         hdr->opcode = ISCSI_OP_SCSI_CMD;
 391         hdr->flags = ISCSI_ATTR_SIMPLE;
 392         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
 393         memcpy(task->lun, hdr->lun, sizeof(task->lun));
 394         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 395         cmd_len = sc->cmd_len;
 396         if (cmd_len < ISCSI_CDB_SIZE)
 397                 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 398         else if (cmd_len > ISCSI_CDB_SIZE) {
 399                 rc = iscsi_prep_ecdb_ahs(task);
 400                 if (rc)
 401                         return rc;
 402                 cmd_len = ISCSI_CDB_SIZE;
 403         }
 404         memcpy(hdr->cdb, sc->cmnd, cmd_len);
 405
 406         task->imm_count = 0;
 407         if (scsi_bidi_cmnd(sc)) {
 408                 hdr->flags |= ISCSI_FLAG_CMD_READ;
 409                 rc = iscsi_prep_bidi_ahs(task);
 410                 if (rc)
 411                         return rc;
 412         }
 413         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 414                 unsigned out_len = scsi_out(sc)->length;
 415                 struct iscsi_r2t_info *r2t = &task->unsol_r2t;
 416
 417                 hdr->data_length = cpu_to_be32(out_len);
 418                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 419                 /*
 420                  * Write counters:
 421                  *
 422                  *      imm_count       bytes to be sent right after
 423                  *                      SCSI PDU Header
 424                  *
 425                  *      unsol_count     bytes(as Data-Out) to be sent
 426                  *                      without R2T ack right after
 427                  *                      immediate data
 428                  *
 429                  *      r2t data_length bytes to be sent via R2T ack's
 430                  *
 431                  *      pad_count       bytes to be sent as zero-padding
 432                  */
 433                 memset(r2t, 0, sizeof(*r2t));
 434
 435                 if (session->imm_data_en) {
 436                         if (out_len >= session->first_burst)
 437                                 task->imm_count = min(session->first_burst,
 438                                                         conn->max_xmit_dlength);
 439                         else
 440                                 task->imm_count = min(out_len,
 441                                                         conn->max_xmit_dlength);
 442                         hton24(hdr->dlength, task->imm_count);
 443                 } else
 444                         zero_data(hdr->dlength);
 445
 446                 if (!session->initial_r2t_en) {
 447                         r2t->data_length = min(session->first_burst, out_len) -
 448                                                task->imm_count;
 449                         r2t->data_offset = task->imm_count;
 450                         r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 451                         r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
 452                 }
 453
 454                 if (!task->unsol_r2t.data_length)
 455                         /* No unsolicit Data-Out's */
 456                         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 457         } else {
 458                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 459                 zero_data(hdr->dlength);
 460                 hdr->data_length = cpu_to_be32(scsi_in(sc)->length);
 461
 462                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
 463                         hdr->flags |= ISCSI_FLAG_CMD_READ;
 464         }
 465
 466         /* calculate size of additional header segments (AHSs) */
 467         hdrlength = task->hdr_len - sizeof(*hdr);
 468
 469         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 470         hdrlength /= ISCSI_PAD_LEN;
 471
 472         WARN_ON(hdrlength >= 256);
 473         hdr->hlength = hdrlength & 0xFF;
 474         hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
 475
 476         if (session->tt->init_task && session->tt->init_task(task))
 477                 return -EIO;
 478
 479         task->state = ISCSI_TASK_RUNNING;
 480         session->cmdsn++;
 481
 482         conn->scsicmd_pdus_cnt++;
 483         ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
 484                           "itt 0x%x len %d bidi_len %d cmdsn %d win %d]\n",
 485                           scsi_bidi_cmnd(sc) ? "bidirectional" :
 486                           sc->sc_data_direction == DMA_TO_DEVICE ?
 487                           "write" : "read", conn->id, sc, sc->cmnd[0],
 488                           task->itt, scsi_bufflen(sc),
 489                           scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
 490                           session->cmdsn,
 491                           session->max_cmdsn - session->exp_cmdsn + 1);
 492         return 0;
 493 }
 494
 495 /**
 496  * iscsi_free_task - free a task
 497  * @task: iscsi cmd task
 498  *
 499  * Must be called with session lock.
 500  * This function returns the scsi command to scsi-ml or cleans
 501  * up mgmt tasks then returns the task to the pool.
 502  */
 503 static void iscsi_free_task(struct iscsi_task *task)
 504 {
 505         struct iscsi_conn *conn = task->conn;
 506         struct iscsi_session *session = conn->session;
 507         struct scsi_cmnd *sc = task->sc;
 508         int oldstate = task->state;
 509
 510         ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
 511                           task->itt, task->state, task->sc);
 512
 513         session->tt->cleanup_task(task);
 514         task->state = ISCSI_TASK_FREE;
 515         task->sc = NULL;
 516         /*
 517          * login task is preallocated so do not free
 518          */
 519         if (conn->login_task == task)
 520                 return;
 521
 522         kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
 523
 524         if (sc) {
 525                 task->sc = NULL;
 526                 /* SCSI eh reuses commands to verify us */
 527                 sc->SCp.ptr = NULL;
 528                 /*
 529                  * queue command may call this to free the task, so
 530                  * it will decide how to return sc to scsi-ml.
 531                  */
 532                 if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
 533                         sc->scsi_done(sc);
 534         }
 535 }
 536
 537 void __iscsi_get_task(struct iscsi_task *task)
 538 {
 539         atomic_inc(&task->refcount);
 540 }
 541 EXPORT_SYMBOL_GPL(__iscsi_get_task);
 542
 543 void __iscsi_put_task(struct iscsi_task *task)
 544 {
 545         if (atomic_dec_and_test(&task->refcount))
 546                 iscsi_free_task(task);
 547 }
 548 EXPORT_SYMBOL_GPL(__iscsi_put_task);
 549
 550 void iscsi_put_task(struct iscsi_task *task)
 551 {
 552         struct iscsi_session *session = task->conn->session;
 553
 554         spin_lock_bh(&session->lock);
 555         __iscsi_put_task(task);
 556         spin_unlock_bh(&session->lock);
 557 }
 558 EXPORT_SYMBOL_GPL(iscsi_put_task);
 559
 560 /**
 561  * iscsi_complete_task - finish a task
 562  * @task: iscsi cmd task
 563  * @state: state to complete task with
 564  *
 565  * Must be called with session lock.
 566  */
 567 static void iscsi_complete_task(struct iscsi_task *task, int state)
 568 {
 569         struct iscsi_conn *conn = task->conn;
 570
 571         ISCSI_DBG_SESSION(conn->session,
 572                           "complete task itt 0x%x state %d sc %p\n",
 573                           task->itt, task->state, task->sc);
 574         if (task->state == ISCSI_TASK_COMPLETED ||
 575             task->state == ISCSI_TASK_ABRT_TMF ||
 576             task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
 577             task->state == ISCSI_TASK_REQUEUE_SCSIQ)
 578                 return;
 579         WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
 580         task->state = state;
 581
 582         if (!list_empty(&task->running))
 583                 list_del_init(&task->running);
 584
 585         if (conn->task == task)
 586                 conn->task = NULL;
 587
 588         if (conn->ping_task == task)
 589                 conn->ping_task = NULL;
 590
 591         /* release get from queueing */
 592         __iscsi_put_task(task);
 593 }
 594
 595 /**
 596  * iscsi_complete_scsi_task - finish scsi task normally
 597  * @task: iscsi task for scsi cmd
 598  * @exp_cmdsn: expected cmd sn in cpu format
 599  * @max_cmdsn: max cmd sn in cpu format
 600  *
 601  * This is used when drivers do not need or cannot perform
 602  * lower level pdu processing.
 603  *
 604  * Called with session lock
 605  */
 606 void iscsi_complete_scsi_task(struct iscsi_task *task,
 607                               uint32_t exp_cmdsn, uint32_t max_cmdsn)
 608 {
 609         struct iscsi_conn *conn = task->conn;
 610
 611         ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 612
 613         conn->last_recv = jiffies;
 614         __iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 615         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 616 }
 617 EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 618
 619
 620 /*
 621  * session lock must be held and if not called for a task that is
 622  * still pending or from the xmit thread, then xmit thread must
 623  * be suspended.
 624  */
 625 static void fail_scsi_task(struct iscsi_task *task, int err)
 626 {
 627         struct iscsi_conn *conn = task->conn;
 628         struct scsi_cmnd *sc;
 629         int state;
 630
 631         /*
 632          * if a command completes and we get a successful tmf response
 633          * we will hit this because the scsi eh abort code does not take
 634          * a ref to the task.
 635          */
 636         sc = task->sc;
 637         if (!sc)
 638                 return;
 639
 640         if (task->state == ISCSI_TASK_PENDING) {
 641                 /*
 642                  * cmd never made it to the xmit thread, so we should not count
 643                  * the cmd in the sequencing
 644                  */
 645                 conn->session->queued_cmdsn--;
 646                 /* it was never sent so just complete like normal */
 647                 state = ISCSI_TASK_COMPLETED;
 648         } else if (err == DID_TRANSPORT_DISRUPTED)
 649                 state = ISCSI_TASK_ABRT_SESS_RECOV;
 650         else
 651                 state = ISCSI_TASK_ABRT_TMF;
 652
 653         sc->result = err << 16;
 654         if (!scsi_bidi_cmnd(sc))
 655                 scsi_set_resid(sc, scsi_bufflen(sc));
 656         else {
 657                 scsi_out(sc)->resid = scsi_out(sc)->length;
 658                 scsi_in(sc)->resid = scsi_in(sc)->length;
 659         }
 660
 661         iscsi_complete_task(task, state);
 662 }
 663
 664 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 665                                 struct iscsi_task *task)
 666 {
 667         struct iscsi_session *session = conn->session;
 668         struct iscsi_hdr *hdr = task->hdr;
 669         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 670         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 671
 672         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 673                 return -ENOTCONN;
 674
 675         if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
 676                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 677         /*
 678          * pre-format CmdSN for outgoing PDU.
 679          */
 680         nop->cmdsn = cpu_to_be32(session->cmdsn);
 681         if (hdr->itt != RESERVED_ITT) {
 682                 /*
 683                  * TODO: We always use immediate for normal session pdus.
 684                  * If we start to send tmfs or nops as non-immediate then
 685                  * we should start checking the cmdsn numbers for mgmt tasks.
 686                  *
 687                  * During discovery sessions iscsid sends TEXT as non immediate,
 688                  * but we always only send one PDU at a time.
 689                  */
 690                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 691                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 692                         session->queued_cmdsn++;
 693                         session->cmdsn++;
 694                 }
 695         }
 696
 697         if (session->tt->init_task && session->tt->init_task(task))
 698                 return -EIO;
 699
 700         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 701                 session->state = ISCSI_STATE_LOGGING_OUT;
 702
 703         task->state = ISCSI_TASK_RUNNING;
 704         ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 705                           "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 706                           hdr->itt, task->data_count);
 707         return 0;
 708 }
 709
 710 static struct iscsi_task *
 711 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 712                       char *data, uint32_t data_size)
 713 {
 714         struct iscsi_session *session = conn->session;
 715         struct iscsi_host *ihost = shost_priv(session->host);
 716         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 717         struct iscsi_task *task;
 718         itt_t itt;
 719
 720         if (session->state == ISCSI_STATE_TERMINATE)
 721                 return NULL;
 722
 723         if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 724                 /*
 725                  * Login and Text are sent serially, in
 726                  * request-followed-by-response sequence.
 727                  * Same task can be used. Same ITT must be used.
 728                  * Note that login_task is preallocated at conn_create().
 729                  */
 730                 if (conn->login_task->state != ISCSI_TASK_FREE) {
 731                         iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 732                                           "progress. Cannot start new task.\n");
 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                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 742                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 743
 744                 if (!kfifo_out(&session->cmdpool.queue,
 745                                  (void*)&task, sizeof(void*)))
 746                         return NULL;
 747         }
 748         /*
 749          * released in complete pdu for task we expect a response for, and
 750          * released by the lld when it has transmitted the task for
 751          * pdus we do not expect a response for.
 752          */
 753         atomic_set(&task->refcount, 1);
 754         task->conn = conn;
 755         task->sc = NULL;
 756         INIT_LIST_HEAD(&task->running);
 757         task->state = ISCSI_TASK_PENDING;
 758
 759         if (data_size) {
 760                 memcpy(task->data, data, data_size);
 761                 task->data_count = data_size;
 762         } else
 763                 task->data_count = 0;
 764
 765         if (conn->session->tt->alloc_pdu) {
 766                 if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 767                         iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 768                                          "pdu for mgmt task.\n");
 769                         goto free_task;
 770                 }
 771         }
 772
 773         itt = task->hdr->itt;
 774         task->hdr_len = sizeof(struct iscsi_hdr);
 775         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 776
 777         if (hdr->itt != RESERVED_ITT) {
 778                 if (session->tt->parse_pdu_itt)
 779                         task->hdr->itt = itt;
 780                 else
 781                         task->hdr->itt = build_itt(task->itt,
 782                                                    task->conn->session->age);
 783         }
 784
 785         if (!ihost->workq) {
 786                 if (iscsi_prep_mgmt_task(conn, task))
 787                         goto free_task;
 788
 789                 if (session->tt->xmit_task(task))
 790                         goto free_task;
 791         } else {
 792                 list_add_tail(&task->running, &conn->mgmtqueue);
 793                 iscsi_conn_queue_work(conn);
 794         }
 795
 796         return task;
 797
 798 free_task:
 799         __iscsi_put_task(task);
 800         return NULL;
 801 }
 802
 803 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 804                         char *data, uint32_t data_size)
 805 {
 806         struct iscsi_conn *conn = cls_conn->dd_data;
 807         struct iscsi_session *session = conn->session;
 808         int err = 0;
 809
 810         spin_lock_bh(&session->lock);
 811         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 812                 err = -EPERM;
 813         spin_unlock_bh(&session->lock);
 814         return err;
 815 }
 816 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 817
 818 /**
 819  * iscsi_cmd_rsp - SCSI Command Response processing
 820  * @conn: iscsi connection
 821  * @hdr: iscsi header
 822  * @task: scsi command task
 823  * @data: cmd data buffer
 824  * @datalen: len of buffer
 825  *
 826  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 827  * then completes the command and task.
 828  **/
 829 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 830                                struct iscsi_task *task, char *data,
 831                                int datalen)
 832 {
 833         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
 834         struct iscsi_session *session = conn->session;
 835         struct scsi_cmnd *sc = task->sc;
 836
 837         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 838         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 839
 840         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 841
 842         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 843                 sc->result = DID_ERROR << 16;
 844                 goto out;
 845         }
 846
 847         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 848                 uint16_t senselen;
 849
 850                 if (datalen < 2) {
 851 invalid_datalen:
 852                         iscsi_conn_printk(KERN_ERR,  conn,
 853                                          "Got CHECK_CONDITION but invalid data "
 854                                          "buffer size of %d\n", datalen);
 855                         sc->result = DID_BAD_TARGET << 16;
 856                         goto out;
 857                 }
 858
 859                 senselen = get_unaligned_be16(data);
 860                 if (datalen < senselen)
 861                         goto invalid_datalen;
 862
 863                 memcpy(sc->sense_buffer, data + 2,
 864                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 865                 ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 866                                   min_t(uint16_t, senselen,
 867                                   SCSI_SENSE_BUFFERSIZE));
 868         }
 869
 870         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 871                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 872                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
 873
 874                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 875                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 876                                  res_count <= scsi_in(sc)->length))
 877                         scsi_in(sc)->resid = res_count;
 878                 else
 879                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 880         }
 881
 882         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 883                            ISCSI_FLAG_CMD_OVERFLOW)) {
 884                 int res_count = be32_to_cpu(rhdr->residual_count);
 885
 886                 if (res_count > 0 &&
 887                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 888                      res_count <= scsi_bufflen(sc)))
 889                         /* write side for bidi or uni-io set_resid */
 890                         scsi_set_resid(sc, res_count);
 891                 else
 892                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 893         }
 894 out:
 895         ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 896                           sc, sc->result, task->itt);
 897         conn->scsirsp_pdus_cnt++;
 898         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 899 }
 900
 901 /**
 902  * iscsi_data_in_rsp - SCSI Data-In Response processing
 903  * @conn: iscsi connection
 904  * @hdr:  iscsi pdu
 905  * @task: scsi command task
 906  **/
 907 static void
 908 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 909                   struct iscsi_task *task)
 910 {
 911         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 912         struct scsi_cmnd *sc = task->sc;
 913
 914         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 915                 return;
 916
 917         iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 918         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 919         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 920         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 921                            ISCSI_FLAG_DATA_OVERFLOW)) {
 922                 int res_count = be32_to_cpu(rhdr->residual_count);
 923
 924                 if (res_count > 0 &&
 925                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 926                      res_count <= scsi_in(sc)->length))
 927                         scsi_in(sc)->resid = res_count;
 928                 else
 929                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 930         }
 931
 932         ISCSI_DBG_SESSION(conn->session, "data in with status done "
 933                           "[sc %p res %d itt 0x%x]\n",
 934                           sc, sc->result, task->itt);
 935         conn->scsirsp_pdus_cnt++;
 936         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 937 }
 938
 939 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 940 {
 941         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 942
 943         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 944         conn->tmfrsp_pdus_cnt++;
 945
 946         if (conn->tmf_state != TMF_QUEUED)
 947                 return;
 948
 949         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 950                 conn->tmf_state = TMF_SUCCESS;
 951         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 952                 conn->tmf_state = TMF_NOT_FOUND;
 953         else
 954                 conn->tmf_state = TMF_FAILED;
 955         wake_up(&conn->ehwait);
 956 }
 957
 958 static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 959 {
 960         struct iscsi_nopout hdr;
 961         struct iscsi_task *task;
 962
 963         if (!rhdr && conn->ping_task)
 964                 return;
 965
 966         memset(&hdr, 0, sizeof(struct iscsi_nopout));
 967         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 968         hdr.flags = ISCSI_FLAG_CMD_FINAL;
 969
 970         if (rhdr) {
 971                 memcpy(hdr.lun, rhdr->lun, 8);
 972                 hdr.ttt = rhdr->ttt;
 973                 hdr.itt = RESERVED_ITT;
 974         } else
 975                 hdr.ttt = RESERVED_ITT;
 976
 977         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 978         if (!task)
 979                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 980         else if (!rhdr) {
 981                 /* only track our nops */
 982                 conn->ping_task = task;
 983                 conn->last_ping = jiffies;
 984         }
 985 }
 986
 987 static int iscsi_nop_out_rsp(struct iscsi_task *task,
 988                              struct iscsi_nopin *nop, char *data, int datalen)
 989 {
 990         struct iscsi_conn *conn = task->conn;
 991         int rc = 0;
 992
 993         if (conn->ping_task != task) {
 994                 /*
 995                  * If this is not in response to one of our
 996                  * nops then it must be from userspace.
 997                  */
 998                 if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
 999                                    data, datalen))
1000                         rc = ISCSI_ERR_CONN_FAILED;
1001         } else
1002                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1003         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1004         return rc;
1005 }
1006
1007 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1008                                char *data, int datalen)
1009 {
1010         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1011         struct iscsi_hdr rejected_pdu;
1012         int opcode, rc = 0;
1013
1014         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1015
1016         if (ntoh24(reject->dlength) > datalen ||
1017             ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1018                 iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1019                                   "pdu. Invalid data length (pdu dlength "
1020                                   "%u, datalen %d\n", ntoh24(reject->dlength),
1021                                   datalen);
1022                 return ISCSI_ERR_PROTO;
1023         }
1024         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1025         opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1026
1027         switch (reject->reason) {
1028         case ISCSI_REASON_DATA_DIGEST_ERROR:
1029                 iscsi_conn_printk(KERN_ERR, conn,
1030                                   "pdu (op 0x%x itt 0x%x) rejected "
1031                                   "due to DataDigest error.\n",
1032                                   rejected_pdu.itt, opcode);
1033                 break;
1034         case ISCSI_REASON_IMM_CMD_REJECT:
1035                 iscsi_conn_printk(KERN_ERR, conn,
1036                                   "pdu (op 0x%x itt 0x%x) rejected. Too many "
1037                                   "immediate commands.\n",
1038                                   rejected_pdu.itt, opcode);
1039                 /*
1040                  * We only send one TMF at a time so if the target could not
1041                  * handle it, then it should get fixed (RFC mandates that
1042                  * a target can handle one immediate TMF per conn).
1043                  *
1044                  * For nops-outs, we could have sent more than one if
1045                  * the target is sending us lots of nop-ins
1046                  */
1047                 if (opcode != ISCSI_OP_NOOP_OUT)
1048                         return 0;
1049
1050                  if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG))
1051                         /*
1052                          * nop-out in response to target's nop-out rejected.
1053                          * Just resend.
1054                          */
1055                         iscsi_send_nopout(conn,
1056                                           (struct iscsi_nopin*)&rejected_pdu);
1057                 else {
1058                         struct iscsi_task *task;
1059                         /*
1060                          * Our nop as ping got dropped. We know the target
1061                          * and transport are ok so just clean up
1062                          */
1063                         task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1064                         if (!task) {
1065                                 iscsi_conn_printk(KERN_ERR, conn,
1066                                                  "Invalid pdu reject. Could "
1067                                                  "not lookup rejected task.\n");
1068                                 rc = ISCSI_ERR_BAD_ITT;
1069                         } else
1070                                 rc = iscsi_nop_out_rsp(task,
1071                                         (struct iscsi_nopin*)&rejected_pdu,
1072                                         NULL, 0);
1073                 }
1074                 break;
1075         default:
1076                 iscsi_conn_printk(KERN_ERR, conn,
1077                                   "pdu (op 0x%x itt 0x%x) rejected. Reason "
1078                                   "code 0x%x\n", rejected_pdu.itt,
1079                                   rejected_pdu.opcode, reject->reason);
1080                 break;
1081         }
1082         return rc;
1083 }
1084
1085 /**
1086  * iscsi_itt_to_task - look up task by itt
1087  * @conn: iscsi connection
1088  * @itt: itt
1089  *
1090  * This should be used for mgmt tasks like login and nops, or if
1091  * the LDD's itt space does not include the session age.
1092  *
1093  * The session lock must be held.
1094  */
1095 struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1096 {
1097         struct iscsi_session *session = conn->session;
1098         int i;
1099
1100         if (itt == RESERVED_ITT)
1101                 return NULL;
1102
1103         if (session->tt->parse_pdu_itt)
1104                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1105         else
1106                 i = get_itt(itt);
1107         if (i >= session->cmds_max)
1108                 return NULL;
1109
1110         return session->cmds[i];
1111 }
1112 EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1113
1114 /**
1115  * __iscsi_complete_pdu - complete pdu
1116  * @conn: iscsi conn
1117  * @hdr: iscsi header
1118  * @data: data buffer
1119  * @datalen: len of data buffer
1120  *
1121  * Completes pdu processing by freeing any resources allocated at
1122  * queuecommand or send generic. session lock must be held and verify
1123  * itt must have been called.
1124  */
1125 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1126                          char *data, int datalen)
1127 {
1128         struct iscsi_session *session = conn->session;
1129         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1130         struct iscsi_task *task;
1131         uint32_t itt;
1132
1133         conn->last_recv = jiffies;
1134         rc = iscsi_verify_itt(conn, hdr->itt);
1135         if (rc)
1136                 return rc;
1137
1138         if (hdr->itt != RESERVED_ITT)
1139                 itt = get_itt(hdr->itt);
1140         else
1141                 itt = ~0U;
1142
1143         ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1144                           opcode, conn->id, itt, datalen);
1145
1146         if (itt == ~0U) {
1147                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1148
1149                 switch(opcode) {
1150                 case ISCSI_OP_NOOP_IN:
1151                         if (datalen) {
1152                                 rc = ISCSI_ERR_PROTO;
1153                                 break;
1154                         }
1155
1156                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1157                                 break;
1158
1159                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1160                         break;
1161                 case ISCSI_OP_REJECT:
1162                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
1163                         break;
1164                 case ISCSI_OP_ASYNC_EVENT:
1165                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1166                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1167                                 rc = ISCSI_ERR_CONN_FAILED;
1168                         break;
1169                 default:
1170                         rc = ISCSI_ERR_BAD_OPCODE;
1171                         break;
1172                 }
1173                 goto out;
1174         }
1175
1176         switch(opcode) {
1177         case ISCSI_OP_SCSI_CMD_RSP:
1178         case ISCSI_OP_SCSI_DATA_IN:
1179                 task = iscsi_itt_to_ctask(conn, hdr->itt);
1180                 if (!task)
1181                         return ISCSI_ERR_BAD_ITT;
1182                 task->last_xfer = jiffies;
1183                 break;
1184         case ISCSI_OP_R2T:
1185                 /*
1186                  * LLD handles R2Ts if they need to.
1187                  */
1188                 return 0;
1189         case ISCSI_OP_LOGOUT_RSP:
1190         case ISCSI_OP_LOGIN_RSP:
1191         case ISCSI_OP_TEXT_RSP:
1192         case ISCSI_OP_SCSI_TMFUNC_RSP:
1193         case ISCSI_OP_NOOP_IN:
1194                 task = iscsi_itt_to_task(conn, hdr->itt);
1195                 if (!task)
1196                         return ISCSI_ERR_BAD_ITT;
1197                 break;
1198         default:
1199                 return ISCSI_ERR_BAD_OPCODE;
1200         }
1201
1202         switch(opcode) {
1203         case ISCSI_OP_SCSI_CMD_RSP:
1204                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1205                 break;
1206         case ISCSI_OP_SCSI_DATA_IN:
1207                 iscsi_data_in_rsp(conn, hdr, task);
1208                 break;
1209         case ISCSI_OP_LOGOUT_RSP:
1210                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1211                 if (datalen) {
1212                         rc = ISCSI_ERR_PROTO;
1213                         break;
1214                 }
1215                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1216                 goto recv_pdu;
1217         case ISCSI_OP_LOGIN_RSP:
1218         case ISCSI_OP_TEXT_RSP:
1219                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1220                 /*
1221                  * login related PDU's exp_statsn is handled in
1222                  * userspace
1223                  */
1224                 goto recv_pdu;
1225         case ISCSI_OP_SCSI_TMFUNC_RSP:
1226                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1227                 if (datalen) {
1228                         rc = ISCSI_ERR_PROTO;
1229                         break;
1230                 }
1231
1232                 iscsi_tmf_rsp(conn, hdr);
1233                 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1234                 break;
1235         case ISCSI_OP_NOOP_IN:
1236                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1237                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1238                         rc = ISCSI_ERR_PROTO;
1239                         break;
1240                 }
1241                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1242
1243                 rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1244                                        data, datalen);
1245                 break;
1246         default:
1247                 rc = ISCSI_ERR_BAD_OPCODE;
1248                 break;
1249         }
1250
1251 out:
1252         return rc;
1253 recv_pdu:
1254         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1255                 rc = ISCSI_ERR_CONN_FAILED;
1256         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1257         return rc;
1258 }
1259 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1260
1261 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1262                        char *data, int datalen)
1263 {
1264         int rc;
1265
1266         spin_lock(&conn->session->lock);
1267         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1268         spin_unlock(&conn->session->lock);
1269         return rc;
1270 }
1271 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1272
1273 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1274 {
1275         struct iscsi_session *session = conn->session;
1276         int age = 0, i = 0;
1277
1278         if (itt == RESERVED_ITT)
1279                 return 0;
1280
1281         if (session->tt->parse_pdu_itt)
1282                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
1283         else {
1284                 i = get_itt(itt);
1285                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1286         }
1287
1288         if (age != session->age) {
1289                 iscsi_conn_printk(KERN_ERR, conn,
1290                                   "received itt %x expected session age (%x)\n",
1291                                   (__force u32)itt, session->age);
1292                 return ISCSI_ERR_BAD_ITT;
1293         }
1294
1295         if (i >= session->cmds_max) {
1296                 iscsi_conn_printk(KERN_ERR, conn,
1297                                   "received invalid itt index %u (max cmds "
1298                                    "%u.\n", i, session->cmds_max);
1299                 return ISCSI_ERR_BAD_ITT;
1300         }
1301         return 0;
1302 }
1303 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1304
1305 /**
1306  * iscsi_itt_to_ctask - look up ctask by itt
1307  * @conn: iscsi connection
1308  * @itt: itt
1309  *
1310  * This should be used for cmd tasks.
1311  *
1312  * The session lock must be held.
1313  */
1314 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1315 {
1316         struct iscsi_task *task;
1317
1318         if (iscsi_verify_itt(conn, itt))
1319                 return NULL;
1320
1321         task = iscsi_itt_to_task(conn, itt);
1322         if (!task || !task->sc)
1323                 return NULL;
1324
1325         if (task->sc->SCp.phase != conn->session->age) {
1326                 iscsi_session_printk(KERN_ERR, conn->session,
1327                                   "task's session age %d, expected %d\n",
1328                                   task->sc->SCp.phase, conn->session->age);
1329                 return NULL;
1330         }
1331
1332         return task;
1333 }
1334 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1335
1336 void iscsi_session_failure(struct iscsi_session *session,
1337                            enum iscsi_err err)
1338 {
1339         struct iscsi_conn *conn;
1340         struct device *dev;
1341
1342         spin_lock_bh(&session->lock);
1343         conn = session->leadconn;
1344         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1345                 spin_unlock_bh(&session->lock);
1346                 return;
1347         }
1348
1349         dev = get_device(&conn->cls_conn->dev);
1350         spin_unlock_bh(&session->lock);
1351         if (!dev)
1352                 return;
1353         /*
1354          * if the host is being removed bypass the connection
1355          * recovery initialization because we are going to kill
1356          * the session.
1357          */
1358         if (err == ISCSI_ERR_INVALID_HOST)
1359                 iscsi_conn_error_event(conn->cls_conn, err);
1360         else
1361                 iscsi_conn_failure(conn, err);
1362         put_device(dev);
1363 }
1364 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1365
1366 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1367 {
1368         struct iscsi_session *session = conn->session;
1369
1370         spin_lock_bh(&session->lock);
1371         if (session->state == ISCSI_STATE_FAILED) {
1372                 spin_unlock_bh(&session->lock);
1373                 return;
1374         }
1375
1376         if (conn->stop_stage == 0)
1377                 session->state = ISCSI_STATE_FAILED;
1378         spin_unlock_bh(&session->lock);
1379
1380         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1381         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1382         iscsi_conn_error_event(conn->cls_conn, err);
1383 }
1384 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1385
1386 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1387 {
1388         struct iscsi_session *session = conn->session;
1389
1390         /*
1391          * Check for iSCSI window and take care of CmdSN wrap-around
1392          */
1393         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1394                 ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1395                                   "%u MaxCmdSN %u CmdSN %u/%u\n",
1396                                   session->exp_cmdsn, session->max_cmdsn,
1397                                   session->cmdsn, session->queued_cmdsn);
1398                 return -ENOSPC;
1399         }
1400         return 0;
1401 }
1402
1403 static int iscsi_xmit_task(struct iscsi_conn *conn)
1404 {
1405         struct iscsi_task *task = conn->task;
1406         int rc;
1407
1408         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
1409                 return -ENODATA;
1410
1411         __iscsi_get_task(task);
1412         spin_unlock_bh(&conn->session->lock);
1413         rc = conn->session->tt->xmit_task(task);
1414         spin_lock_bh(&conn->session->lock);
1415         if (!rc) {
1416                 /* done with this task */
1417                 task->last_xfer = jiffies;
1418                 conn->task = NULL;
1419         }
1420         __iscsi_put_task(task);
1421         return rc;
1422 }
1423
1424 /**
1425  * iscsi_requeue_task - requeue task to run from session workqueue
1426  * @task: task to requeue
1427  *
1428  * LLDs that need to run a task from the session workqueue should call
1429  * this. The session lock must be held. This should only be called
1430  * by software drivers.
1431  */
1432 void iscsi_requeue_task(struct iscsi_task *task)
1433 {
1434         struct iscsi_conn *conn = task->conn;
1435
1436         /*
1437          * this may be on the requeue list already if the xmit_task callout
1438          * is handling the r2ts while we are adding new ones
1439          */
1440         if (list_empty(&task->running))
1441                 list_add_tail(&task->running, &conn->requeue);
1442         iscsi_conn_queue_work(conn);
1443 }
1444 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1445
1446 /**
1447  * iscsi_data_xmit - xmit any command into the scheduled connection
1448  * @conn: iscsi connection
1449  *
1450  * Notes:
1451  *      The function can return -EAGAIN in which case the caller must
1452  *      re-schedule it again later or recover. '0' return code means
1453  *      successful xmit.
1454  **/
1455 static int iscsi_data_xmit(struct iscsi_conn *conn)
1456 {
1457         struct iscsi_task *task;
1458         int rc = 0;
1459
1460         spin_lock_bh(&conn->session->lock);
1461         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1462                 ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1463                 spin_unlock_bh(&conn->session->lock);
1464                 return -ENODATA;
1465         }
1466
1467         if (conn->task) {
1468                 rc = iscsi_xmit_task(conn);
1469                 if (rc)
1470                         goto done;
1471         }
1472
1473         /*
1474          * process mgmt pdus like nops before commands since we should
1475          * only have one nop-out as a ping from us and targets should not
1476          * overflow us with nop-ins
1477          */
1478 check_mgmt:
1479         while (!list_empty(&conn->mgmtqueue)) {
1480                 conn->task = list_entry(conn->mgmtqueue.next,
1481                                          struct iscsi_task, running);
1482                 list_del_init(&conn->task->running);
1483                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1484                         __iscsi_put_task(conn->task);
1485                         conn->task = NULL;
1486                         continue;
1487                 }
1488                 rc = iscsi_xmit_task(conn);
1489                 if (rc)
1490                         goto done;
1491         }
1492
1493         /* process pending command queue */
1494         while (!list_empty(&conn->cmdqueue)) {
1495                 conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1496                                         running);
1497                 list_del_init(&conn->task->running);
1498                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1499                         fail_scsi_task(conn->task, DID_IMM_RETRY);
1500                         continue;
1501                 }
1502                 rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1503                 if (rc) {
1504                         if (rc == -ENOMEM || rc == -EACCES) {
1505                                 list_add_tail(&conn->task->running,
1506                                               &conn->cmdqueue);
1507                                 conn->task = NULL;
1508                                 goto done;
1509                         } else
1510                                 fail_scsi_task(conn->task, DID_ABORT);
1511                         continue;
1512                 }
1513                 rc = iscsi_xmit_task(conn);
1514                 if (rc)
1515                         goto done;
1516                 /*
1517                  * we could continuously get new task requests so
1518                  * we need to check the mgmt queue for nops that need to
1519                  * be sent to aviod starvation
1520                  */
1521                 if (!list_empty(&conn->mgmtqueue))
1522                         goto check_mgmt;
1523         }
1524
1525         while (!list_empty(&conn->requeue)) {
1526                 /*
1527                  * we always do fastlogout - conn stop code will clean up.
1528                  */
1529                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1530                         break;
1531
1532                 task = list_entry(conn->requeue.next, struct iscsi_task,
1533                                   running);
1534                 if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1535                         break;
1536
1537                 conn->task = task;
1538                 list_del_init(&conn->task->running);
1539                 conn->task->state = ISCSI_TASK_RUNNING;
1540                 rc = iscsi_xmit_task(conn);
1541                 if (rc)
1542                         goto done;
1543                 if (!list_empty(&conn->mgmtqueue))
1544                         goto check_mgmt;
1545         }
1546         spin_unlock_bh(&conn->session->lock);
1547         return -ENODATA;
1548
1549 done:
1550         spin_unlock_bh(&conn->session->lock);
1551         return rc;
1552 }
1553
1554 static void iscsi_xmitworker(struct work_struct *work)
1555 {
1556         struct iscsi_conn *conn =
1557                 container_of(work, struct iscsi_conn, xmitwork);
1558         int rc;
1559         /*
1560          * serialize Xmit worker on a per-connection basis.
1561          */
1562         do {
1563                 rc = iscsi_data_xmit(conn);
1564         } while (rc >= 0 || rc == -EAGAIN);
1565 }
1566
1567 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1568                                                   struct scsi_cmnd *sc)
1569 {
1570         struct iscsi_task *task;
1571
1572         if (!kfifo_out(&conn->session->cmdpool.queue,
1573                          (void *) &task, sizeof(void *)))
1574                 return NULL;
1575
1576         sc->SCp.phase = conn->session->age;
1577         sc->SCp.ptr = (char *) task;
1578
1579         atomic_set(&task->refcount, 1);
1580         task->state = ISCSI_TASK_PENDING;
1581         task->conn = conn;
1582         task->sc = sc;
1583         task->have_checked_conn = false;
1584         task->last_timeout = jiffies;
1585         task->last_xfer = jiffies;
1586         INIT_LIST_HEAD(&task->running);
1587         return task;
1588 }
1589
1590 enum {
1591         FAILURE_BAD_HOST = 1,
1592         FAILURE_SESSION_FAILED,
1593         FAILURE_SESSION_FREED,
1594         FAILURE_WINDOW_CLOSED,
1595         FAILURE_OOM,
1596         FAILURE_SESSION_TERMINATE,
1597         FAILURE_SESSION_IN_RECOVERY,
1598         FAILURE_SESSION_RECOVERY_TIMEOUT,
1599         FAILURE_SESSION_LOGGING_OUT,
1600         FAILURE_SESSION_NOT_READY,
1601 };
1602
1603 int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1604 {
1605         struct iscsi_cls_session *cls_session;
1606         struct iscsi_host *ihost;
1607         int reason = 0;
1608         struct iscsi_session *session;
1609         struct iscsi_conn *conn;
1610         struct iscsi_task *task = NULL;
1611
1612         sc->result = 0;
1613         sc->SCp.ptr = NULL;
1614
1615         ihost = shost_priv(host);
1616
1617         cls_session = starget_to_session(scsi_target(sc->device));
1618         session = cls_session->dd_data;
1619         spin_lock_bh(&session->lock);
1620
1621         reason = iscsi_session_chkready(cls_session);
1622         if (reason) {
1623                 sc->result = reason;
1624                 goto fault;
1625         }
1626
1627         if (session->state != ISCSI_STATE_LOGGED_IN) {
1628                 /*
1629                  * to handle the race between when we set the recovery state
1630                  * and block the session we requeue here (commands could
1631                  * be entering our queuecommand while a block is starting
1632                  * up because the block code is not locked)
1633                  */
1634                 switch (session->state) {
1635                 case ISCSI_STATE_FAILED:
1636                 case ISCSI_STATE_IN_RECOVERY:
1637                         reason = FAILURE_SESSION_IN_RECOVERY;
1638                         sc->result = DID_IMM_RETRY << 16;
1639                         break;
1640                 case ISCSI_STATE_LOGGING_OUT:
1641                         reason = FAILURE_SESSION_LOGGING_OUT;
1642                         sc->result = DID_IMM_RETRY << 16;
1643                         break;
1644                 case ISCSI_STATE_RECOVERY_FAILED:
1645                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1646                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1647                         break;
1648                 case ISCSI_STATE_TERMINATE:
1649                         reason = FAILURE_SESSION_TERMINATE;
1650                         sc->result = DID_NO_CONNECT << 16;
1651                         break;
1652                 default:
1653                         reason = FAILURE_SESSION_FREED;
1654                         sc->result = DID_NO_CONNECT << 16;
1655                 }
1656                 goto fault;
1657         }
1658
1659         conn = session->leadconn;
1660         if (!conn) {
1661                 reason = FAILURE_SESSION_FREED;
1662                 sc->result = DID_NO_CONNECT << 16;
1663                 goto fault;
1664         }
1665
1666         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1667                 reason = FAILURE_SESSION_IN_RECOVERY;
1668                 sc->result = DID_REQUEUE;
1669                 goto fault;
1670         }
1671
1672         if (iscsi_check_cmdsn_window_closed(conn)) {
1673                 reason = FAILURE_WINDOW_CLOSED;
1674                 goto reject;
1675         }
1676
1677         task = iscsi_alloc_task(conn, sc);
1678         if (!task) {
1679                 reason = FAILURE_OOM;
1680                 goto reject;
1681         }
1682
1683         if (!ihost->workq) {
1684                 reason = iscsi_prep_scsi_cmd_pdu(task);
1685                 if (reason) {
1686                         if (reason == -ENOMEM ||  reason == -EACCES) {
1687                                 reason = FAILURE_OOM;
1688                                 goto prepd_reject;
1689                         } else {
1690                                 sc->result = DID_ABORT << 16;
1691                                 goto prepd_fault;
1692                         }
1693                 }
1694                 if (session->tt->xmit_task(task)) {
1695                         session->cmdsn--;
1696                         reason = FAILURE_SESSION_NOT_READY;
1697                         goto prepd_reject;
1698                 }
1699         } else {
1700                 list_add_tail(&task->running, &conn->cmdqueue);
1701                 iscsi_conn_queue_work(conn);
1702         }
1703
1704         session->queued_cmdsn++;
1705         spin_unlock_bh(&session->lock);
1706         return 0;
1707
1708 prepd_reject:
1709         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1710 reject:
1711         spin_unlock_bh(&session->lock);
1712         ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1713                           sc->cmnd[0], reason);
1714         return SCSI_MLQUEUE_TARGET_BUSY;
1715
1716 prepd_fault:
1717         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1718 fault:
1719         spin_unlock_bh(&session->lock);
1720         ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1721                           sc->cmnd[0], reason);
1722         if (!scsi_bidi_cmnd(sc))
1723                 scsi_set_resid(sc, scsi_bufflen(sc));
1724         else {
1725                 scsi_out(sc)->resid = scsi_out(sc)->length;
1726                 scsi_in(sc)->resid = scsi_in(sc)->length;
1727         }
1728         sc->scsi_done(sc);
1729         return 0;
1730 }
1731 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1732
1733 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth, int reason)
1734 {
1735         switch (reason) {
1736         case SCSI_QDEPTH_DEFAULT:
1737                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1738                 break;
1739         case SCSI_QDEPTH_QFULL:
1740                 scsi_track_queue_full(sdev, depth);
1741                 break;
1742         case SCSI_QDEPTH_RAMP_UP:
1743                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1744                 break;
1745         default:
1746                 return -EOPNOTSUPP;
1747         }
1748         return sdev->queue_depth;
1749 }
1750 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1751
1752 int iscsi_target_alloc(struct scsi_target *starget)
1753 {
1754         struct iscsi_cls_session *cls_session = starget_to_session(starget);
1755         struct iscsi_session *session = cls_session->dd_data;
1756
1757         starget->can_queue = session->scsi_cmds_max;
1758         return 0;
1759 }
1760 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1761
1762 static void iscsi_tmf_timedout(unsigned long data)
1763 {
1764         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1765         struct iscsi_session *session = conn->session;
1766
1767         spin_lock(&session->lock);
1768         if (conn->tmf_state == TMF_QUEUED) {
1769                 conn->tmf_state = TMF_TIMEDOUT;
1770                 ISCSI_DBG_EH(session, "tmf timedout\n");
1771                 /* unblock eh_abort() */
1772                 wake_up(&conn->ehwait);
1773         }
1774         spin_unlock(&session->lock);
1775 }
1776
1777 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1778                                    struct iscsi_tm *hdr, int age,
1779                                    int timeout)
1780 {
1781         struct iscsi_session *session = conn->session;
1782         struct iscsi_task *task;
1783
1784         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1785                                       NULL, 0);
1786         if (!task) {
1787                 spin_unlock_bh(&session->lock);
1788                 iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1789                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1790                 spin_lock_bh(&session->lock);
1791                 return -EPERM;
1792         }
1793         conn->tmfcmd_pdus_cnt++;
1794         conn->tmf_timer.expires = timeout * HZ + jiffies;
1795         conn->tmf_timer.function = iscsi_tmf_timedout;
1796         conn->tmf_timer.data = (unsigned long)conn;
1797         add_timer(&conn->tmf_timer);
1798         ISCSI_DBG_EH(session, "tmf set timeout\n");
1799
1800         spin_unlock_bh(&session->lock);
1801         mutex_unlock(&session->eh_mutex);
1802
1803         /*
1804          * block eh thread until:
1805          *
1806          * 1) tmf response
1807          * 2) tmf timeout
1808          * 3) session is terminated or restarted or userspace has
1809          * given up on recovery
1810          */
1811         wait_event_interruptible(conn->ehwait, age != session->age ||
1812                                  session->state != ISCSI_STATE_LOGGED_IN ||
1813                                  conn->tmf_state != TMF_QUEUED);
1814         if (signal_pending(current))
1815                 flush_signals(current);
1816         del_timer_sync(&conn->tmf_timer);
1817
1818         mutex_lock(&session->eh_mutex);
1819         spin_lock_bh(&session->lock);
1820         /* if the session drops it will clean up the task */
1821         if (age != session->age ||
1822             session->state != ISCSI_STATE_LOGGED_IN)
1823                 return -ENOTCONN;
1824         return 0;
1825 }
1826
1827 /*
1828  * Fail commands. session lock held and recv side suspended and xmit
1829  * thread flushed
1830  */
1831 static void fail_scsi_tasks(struct iscsi_conn *conn, unsigned lun,
1832                             int error)
1833 {
1834         struct iscsi_task *task;
1835         int i;
1836
1837         for (i = 0; i < conn->session->cmds_max; i++) {
1838                 task = conn->session->cmds[i];
1839                 if (!task->sc || task->state == ISCSI_TASK_FREE)
1840                         continue;
1841
1842                 if (lun != -1 && lun != task->sc->device->lun)
1843                         continue;
1844
1845                 ISCSI_DBG_SESSION(conn->session,
1846                                   "failing sc %p itt 0x%x state %d\n",
1847                                   task->sc, task->itt, task->state);
1848                 fail_scsi_task(task, error);
1849         }
1850 }
1851
1852 /**
1853  * iscsi_suspend_queue - suspend iscsi_queuecommand
1854  * @conn: iscsi conn to stop queueing IO on
1855  *
1856  * This grabs the session lock to make sure no one is in
1857  * xmit_task/queuecommand, and then sets suspend to prevent
1858  * new commands from being queued. This only needs to be called
1859  * by offload drivers that need to sync a path like ep disconnect
1860  * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1861  * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1862  */
1863 void iscsi_suspend_queue(struct iscsi_conn *conn)
1864 {
1865         spin_lock_bh(&conn->session->lock);
1866         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1867         spin_unlock_bh(&conn->session->lock);
1868 }
1869 EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1870
1871 /**
1872  * iscsi_suspend_tx - suspend iscsi_data_xmit
1873  * @conn: iscsi conn tp stop processing IO on.
1874  *
1875  * This function sets the suspend bit to prevent iscsi_data_xmit
1876  * from sending new IO, and if work is queued on the xmit thread
1877  * it will wait for it to be completed.
1878  */
1879 void iscsi_suspend_tx(struct iscsi_conn *conn)
1880 {
1881         struct Scsi_Host *shost = conn->session->host;
1882         struct iscsi_host *ihost = shost_priv(shost);
1883
1884         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1885         if (ihost->workq)
1886                 flush_workqueue(ihost->workq);
1887 }
1888 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1889
1890 static void iscsi_start_tx(struct iscsi_conn *conn)
1891 {
1892         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1893         iscsi_conn_queue_work(conn);
1894 }
1895
1896 /*
1897  * We want to make sure a ping is in flight. It has timed out.
1898  * And we are not busy processing a pdu that is making
1899  * progress but got started before the ping and is taking a while
1900  * to complete so the ping is just stuck behind it in a queue.
1901  */
1902 static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1903 {
1904         if (conn->ping_task &&
1905             time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1906                            (conn->ping_timeout * HZ), jiffies))
1907                 return 1;
1908         else
1909                 return 0;
1910 }
1911
1912 static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1913 {
1914         enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1915         struct iscsi_task *task = NULL, *running_task;
1916         struct iscsi_cls_session *cls_session;
1917         struct iscsi_session *session;
1918         struct iscsi_conn *conn;
1919         int i;
1920
1921         cls_session = starget_to_session(scsi_target(sc->device));
1922         session = cls_session->dd_data;
1923
1924         ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1925
1926         spin_lock(&session->lock);
1927         if (session->state != ISCSI_STATE_LOGGED_IN) {
1928                 /*
1929                  * We are probably in the middle of iscsi recovery so let
1930                  * that complete and handle the error.
1931                  */
1932                 rc = BLK_EH_RESET_TIMER;
1933                 goto done;
1934         }
1935
1936         conn = session->leadconn;
1937         if (!conn) {
1938                 /* In the middle of shuting down */
1939                 rc = BLK_EH_RESET_TIMER;
1940                 goto done;
1941         }
1942
1943         task = (struct iscsi_task *)sc->SCp.ptr;
1944         if (!task) {
1945                 /*
1946                  * Raced with completion. Just reset timer, and let it
1947                  * complete normally
1948                  */
1949                 rc = BLK_EH_RESET_TIMER;
1950                 goto done;
1951         }
1952
1953         /*
1954          * If we have sent (at least queued to the network layer) a pdu or
1955          * recvd one for the task since the last timeout ask for
1956          * more time. If on the next timeout we have not made progress
1957          * we can check if it is the task or connection when we send the
1958          * nop as a ping.
1959          */
1960         if (time_after(task->last_xfer, task->last_timeout)) {
1961                 ISCSI_DBG_EH(session, "Command making progress. Asking "
1962                              "scsi-ml for more time to complete. "
1963                              "Last data xfer at %lu. Last timeout was at "
1964                              "%lu\n.", task->last_xfer, task->last_timeout);
1965                 task->have_checked_conn = false;
1966                 rc = BLK_EH_RESET_TIMER;
1967                 goto done;
1968         }
1969
1970         if (!conn->recv_timeout && !conn->ping_timeout)
1971                 goto done;
1972         /*
1973          * if the ping timedout then we are in the middle of cleaning up
1974          * and can let the iscsi eh handle it
1975          */
1976         if (iscsi_has_ping_timed_out(conn)) {
1977                 rc = BLK_EH_RESET_TIMER;
1978                 goto done;
1979         }
1980
1981         for (i = 0; i < conn->session->cmds_max; i++) {
1982                 running_task = conn->session->cmds[i];
1983                 if (!running_task->sc || running_task == task ||
1984                      running_task->state != ISCSI_TASK_RUNNING)
1985                         continue;
1986
1987                 /*
1988                  * Only check if cmds started before this one have made
1989                  * progress, or this could never fail
1990                  */
1991                 if (time_after(running_task->sc->jiffies_at_alloc,
1992                                task->sc->jiffies_at_alloc))
1993                         continue;
1994
1995                 if (time_after(running_task->last_xfer, task->last_timeout)) {
1996                         /*
1997                          * This task has not made progress, but a task
1998                          * started before us has transferred data since
1999                          * we started/last-checked. We could be queueing
2000                          * too many tasks or the LU is bad.
2001                          *
2002                          * If the device is bad the cmds ahead of us on
2003                          * other devs will complete, and this loop will
2004                          * eventually fail starting the scsi eh.
2005                          */
2006                         ISCSI_DBG_EH(session, "Command has not made progress "
2007                                      "but commands ahead of it have. "
2008                                      "Asking scsi-ml for more time to "
2009                                      "complete. Our last xfer vs running task "
2010                                      "last xfer %lu/%lu. Last check %lu.\n",
2011                                      task->last_xfer, running_task->last_xfer,
2012                                      task->last_timeout);
2013                         rc = BLK_EH_RESET_TIMER;
2014                         goto done;
2015                 }
2016         }
2017
2018         /* Assumes nop timeout is shorter than scsi cmd timeout */
2019         if (task->have_checked_conn)
2020                 goto done;
2021
2022         /*
2023          * Checking the transport already or nop from a cmd timeout still
2024          * running
2025          */
2026         if (conn->ping_task) {
2027                 task->have_checked_conn = true;
2028                 rc = BLK_EH_RESET_TIMER;
2029                 goto done;
2030         }
2031
2032         /* Make sure there is a transport check done */
2033         iscsi_send_nopout(conn, NULL);
2034         task->have_checked_conn = true;
2035         rc = BLK_EH_RESET_TIMER;
2036
2037 done:
2038         if (task)
2039                 task->last_timeout = jiffies;
2040         spin_unlock(&session->lock);
2041         ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2042                      "timer reset" : "nh");
2043         return rc;
2044 }
2045
2046 static void iscsi_check_transport_timeouts(unsigned long data)
2047 {
2048         struct iscsi_conn *conn = (struct iscsi_conn *)data;
2049         struct iscsi_session *session = conn->session;
2050         unsigned long recv_timeout, next_timeout = 0, last_recv;
2051
2052         spin_lock(&session->lock);
2053         if (session->state != ISCSI_STATE_LOGGED_IN)
2054                 goto done;
2055
2056         recv_timeout = conn->recv_timeout;
2057         if (!recv_timeout)
2058                 goto done;
2059
2060         recv_timeout *= HZ;
2061         last_recv = conn->last_recv;
2062
2063         if (iscsi_has_ping_timed_out(conn)) {
2064                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2065                                   "expired, recv timeout %d, last rx %lu, "
2066                                   "last ping %lu, now %lu\n",
2067                                   conn->ping_timeout, conn->recv_timeout,
2068                                   last_recv, conn->last_ping, jiffies);
2069                 spin_unlock(&session->lock);
2070                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
2071                 return;
2072         }
2073
2074         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2075                 /* send a ping to try to provoke some traffic */
2076                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2077                 iscsi_send_nopout(conn, NULL);
2078                 next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2079         } else
2080                 next_timeout = last_recv + recv_timeout;
2081
2082         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2083         mod_timer(&conn->transport_timer, next_timeout);
2084 done:
2085         spin_unlock(&session->lock);
2086 }
2087
2088 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2089                                       struct iscsi_tm *hdr)
2090 {
2091         memset(hdr, 0, sizeof(*hdr));
2092         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2093         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2094         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2095         memcpy(hdr->lun, task->lun, sizeof(hdr->lun));
2096         hdr->rtt = task->hdr_itt;
2097         hdr->refcmdsn = task->cmdsn;
2098 }
2099
2100 int iscsi_eh_abort(struct scsi_cmnd *sc)
2101 {
2102         struct iscsi_cls_session *cls_session;
2103         struct iscsi_session *session;
2104         struct iscsi_conn *conn;
2105         struct iscsi_task *task;
2106         struct iscsi_tm *hdr;
2107         int rc, age;
2108
2109         cls_session = starget_to_session(scsi_target(sc->device));
2110         session = cls_session->dd_data;
2111
2112         ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2113
2114         mutex_lock(&session->eh_mutex);
2115         spin_lock_bh(&session->lock);
2116         /*
2117          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2118          * got the command.
2119          */
2120         if (!sc->SCp.ptr) {
2121                 ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2122                                       "it completed.\n");
2123                 spin_unlock_bh(&session->lock);
2124                 mutex_unlock(&session->eh_mutex);
2125                 return SUCCESS;
2126         }
2127
2128         /*
2129          * If we are not logged in or we have started a new session
2130          * then let the host reset code handle this
2131          */
2132         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2133             sc->SCp.phase != session->age) {
2134                 spin_unlock_bh(&session->lock);
2135                 mutex_unlock(&session->eh_mutex);
2136                 ISCSI_DBG_EH(session, "failing abort due to dropped "
2137                                   "session.\n");
2138                 return FAILED;
2139         }
2140
2141         conn = session->leadconn;
2142         conn->eh_abort_cnt++;
2143         age = session->age;
2144
2145         task = (struct iscsi_task *)sc->SCp.ptr;
2146         ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2147                      sc, task->itt);
2148
2149         /* task completed before time out */
2150         if (!task->sc) {
2151                 ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2152                 goto success;
2153         }
2154
2155         if (task->state == ISCSI_TASK_PENDING) {
2156                 fail_scsi_task(task, DID_ABORT);
2157                 goto success;
2158         }
2159
2160         /* only have one tmf outstanding at a time */
2161         if (conn->tmf_state != TMF_INITIAL)
2162                 goto failed;
2163         conn->tmf_state = TMF_QUEUED;
2164
2165         hdr = &conn->tmhdr;
2166         iscsi_prep_abort_task_pdu(task, hdr);
2167
2168         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
2169                 rc = FAILED;
2170                 goto failed;
2171         }
2172
2173         switch (conn->tmf_state) {
2174         case TMF_SUCCESS:
2175                 spin_unlock_bh(&session->lock);
2176                 /*
2177                  * stop tx side incase the target had sent a abort rsp but
2178                  * the initiator was still writing out data.
2179                  */
2180                 iscsi_suspend_tx(conn);
2181                 /*
2182                  * we do not stop the recv side because targets have been
2183                  * good and have never sent us a successful tmf response
2184                  * then sent more data for the cmd.
2185                  */
2186                 spin_lock_bh(&session->lock);
2187                 fail_scsi_task(task, DID_ABORT);
2188                 conn->tmf_state = TMF_INITIAL;
2189                 memset(hdr, 0, sizeof(*hdr));
2190                 spin_unlock_bh(&session->lock);
2191                 iscsi_start_tx(conn);
2192                 goto success_unlocked;
2193         case TMF_TIMEDOUT:
2194                 spin_unlock_bh(&session->lock);
2195                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2196                 goto failed_unlocked;
2197         case TMF_NOT_FOUND:
2198                 if (!sc->SCp.ptr) {
2199                         conn->tmf_state = TMF_INITIAL;
2200                         memset(hdr, 0, sizeof(*hdr));
2201                         /* task completed before tmf abort response */
2202                         ISCSI_DBG_EH(session, "sc completed while abort in "
2203                                               "progress\n");
2204                         goto success;
2205                 }
2206                 /* fall through */
2207         default:
2208                 conn->tmf_state = TMF_INITIAL;
2209                 goto failed;
2210         }
2211
2212 success:
2213         spin_unlock_bh(&session->lock);
2214 success_unlocked:
2215         ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2216                      sc, task->itt);
2217         mutex_unlock(&session->eh_mutex);
2218         return SUCCESS;
2219
2220 failed:
2221         spin_unlock_bh(&session->lock);
2222 failed_unlocked:
2223         ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2224                      task ? task->itt : 0);
2225         mutex_unlock(&session->eh_mutex);
2226         return FAILED;
2227 }
2228 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2229
2230 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2231 {
2232         memset(hdr, 0, sizeof(*hdr));
2233         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2234         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2235         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2236         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
2237         hdr->rtt = RESERVED_ITT;
2238 }
2239
2240 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2241 {
2242         struct iscsi_cls_session *cls_session;
2243         struct iscsi_session *session;
2244         struct iscsi_conn *conn;
2245         struct iscsi_tm *hdr;
2246         int rc = FAILED;
2247
2248         cls_session = starget_to_session(scsi_target(sc->device));
2249         session = cls_session->dd_data;
2250
2251         ISCSI_DBG_EH(session, "LU Reset [sc %p lun %u]\n", sc, sc->device->lun);
2252
2253         mutex_lock(&session->eh_mutex);
2254         spin_lock_bh(&session->lock);
2255         /*
2256          * Just check if we are not logged in. We cannot check for
2257          * the phase because the reset could come from a ioctl.
2258          */
2259         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2260                 goto unlock;
2261         conn = session->leadconn;
2262
2263         /* only have one tmf outstanding at a time */
2264         if (conn->tmf_state != TMF_INITIAL)
2265                 goto unlock;
2266         conn->tmf_state = TMF_QUEUED;
2267
2268         hdr = &conn->tmhdr;
2269         iscsi_prep_lun_reset_pdu(sc, hdr);
2270
2271         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2272                                     session->lu_reset_timeout)) {
2273                 rc = FAILED;
2274                 goto unlock;
2275         }
2276
2277         switch (conn->tmf_state) {
2278         case TMF_SUCCESS:
2279                 break;
2280         case TMF_TIMEDOUT:
2281                 spin_unlock_bh(&session->lock);
2282                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2283                 goto done;
2284         default:
2285                 conn->tmf_state = TMF_INITIAL;
2286                 goto unlock;
2287         }
2288
2289         rc = SUCCESS;
2290         spin_unlock_bh(&session->lock);
2291
2292         iscsi_suspend_tx(conn);
2293
2294         spin_lock_bh(&session->lock);
2295         memset(hdr, 0, sizeof(*hdr));
2296         fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2297         conn->tmf_state = TMF_INITIAL;
2298         spin_unlock_bh(&session->lock);
2299
2300         iscsi_start_tx(conn);
2301         goto done;
2302
2303 unlock:
2304         spin_unlock_bh(&session->lock);
2305 done:
2306         ISCSI_DBG_EH(session, "dev reset result = %s\n",
2307                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2308         mutex_unlock(&session->eh_mutex);
2309         return rc;
2310 }
2311 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2312
2313 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2314 {
2315         struct iscsi_session *session = cls_session->dd_data;
2316
2317         spin_lock_bh(&session->lock);
2318         if (session->state != ISCSI_STATE_LOGGED_IN) {
2319                 session->state = ISCSI_STATE_RECOVERY_FAILED;
2320                 if (session->leadconn)
2321                         wake_up(&session->leadconn->ehwait);
2322         }
2323         spin_unlock_bh(&session->lock);
2324 }
2325 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2326
2327 /**
2328  * iscsi_eh_session_reset - drop session and attempt relogin
2329  * @sc: scsi command
2330  *
2331  * This function will wait for a relogin, session termination from
2332  * userspace, or a recovery/replacement timeout.
2333  */
2334 int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2335 {
2336         struct iscsi_cls_session *cls_session;
2337         struct iscsi_session *session;
2338         struct iscsi_conn *conn;
2339
2340         cls_session = starget_to_session(scsi_target(sc->device));
2341         session = cls_session->dd_data;
2342         conn = session->leadconn;
2343
2344         mutex_lock(&session->eh_mutex);
2345         spin_lock_bh(&session->lock);
2346         if (session->state == ISCSI_STATE_TERMINATE) {
2347 failed:
2348                 ISCSI_DBG_EH(session,
2349                              "failing session reset: Could not log back into "
2350                              "%s, %s [age %d]\n", session->targetname,
2351                              conn->persistent_address, session->age);
2352                 spin_unlock_bh(&session->lock);
2353                 mutex_unlock(&session->eh_mutex);
2354                 return FAILED;
2355         }
2356
2357         spin_unlock_bh(&session->lock);
2358         mutex_unlock(&session->eh_mutex);
2359         /*
2360          * we drop the lock here but the leadconn cannot be destoyed while
2361          * we are in the scsi eh
2362          */
2363         iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2364
2365         ISCSI_DBG_EH(session, "wait for relogin\n");
2366         wait_event_interruptible(conn->ehwait,
2367                                  session->state == ISCSI_STATE_TERMINATE ||
2368                                  session->state == ISCSI_STATE_LOGGED_IN ||
2369                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
2370         if (signal_pending(current))
2371                 flush_signals(current);
2372
2373         mutex_lock(&session->eh_mutex);
2374         spin_lock_bh(&session->lock);
2375         if (session->state == ISCSI_STATE_LOGGED_IN) {
2376                 ISCSI_DBG_EH(session,
2377                              "session reset succeeded for %s,%s\n",
2378                              session->targetname, conn->persistent_address);
2379         } else
2380                 goto failed;
2381         spin_unlock_bh(&session->lock);
2382         mutex_unlock(&session->eh_mutex);
2383         return SUCCESS;
2384 }
2385 EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2386
2387 static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2388 {
2389         memset(hdr, 0, sizeof(*hdr));
2390         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2391         hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2392         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2393         hdr->rtt = RESERVED_ITT;
2394 }
2395
2396 /**
2397  * iscsi_eh_target_reset - reset target
2398  * @sc: scsi command
2399  *
2400  * This will attempt to send a warm target reset.
2401  */
2402 int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2403 {
2404         struct iscsi_cls_session *cls_session;
2405         struct iscsi_session *session;
2406         struct iscsi_conn *conn;
2407         struct iscsi_tm *hdr;
2408         int rc = FAILED;
2409
2410         cls_session = starget_to_session(scsi_target(sc->device));
2411         session = cls_session->dd_data;
2412
2413         ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2414                      session->targetname);
2415
2416         mutex_lock(&session->eh_mutex);
2417         spin_lock_bh(&session->lock);
2418         /*
2419          * Just check if we are not logged in. We cannot check for
2420          * the phase because the reset could come from a ioctl.
2421          */
2422         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2423                 goto unlock;
2424         conn = session->leadconn;
2425
2426         /* only have one tmf outstanding at a time */
2427         if (conn->tmf_state != TMF_INITIAL)
2428                 goto unlock;
2429         conn->tmf_state = TMF_QUEUED;
2430
2431         hdr = &conn->tmhdr;
2432         iscsi_prep_tgt_reset_pdu(sc, hdr);
2433
2434         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2435                                     session->tgt_reset_timeout)) {
2436                 rc = FAILED;
2437                 goto unlock;
2438         }
2439
2440         switch (conn->tmf_state) {
2441         case TMF_SUCCESS:
2442                 break;
2443         case TMF_TIMEDOUT:
2444                 spin_unlock_bh(&session->lock);
2445                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2446                 goto done;
2447         default:
2448                 conn->tmf_state = TMF_INITIAL;
2449                 goto unlock;
2450         }
2451
2452         rc = SUCCESS;
2453         spin_unlock_bh(&session->lock);
2454
2455         iscsi_suspend_tx(conn);
2456
2457         spin_lock_bh(&session->lock);
2458         memset(hdr, 0, sizeof(*hdr));
2459         fail_scsi_tasks(conn, -1, DID_ERROR);
2460         conn->tmf_state = TMF_INITIAL;
2461         spin_unlock_bh(&session->lock);
2462
2463         iscsi_start_tx(conn);
2464         goto done;
2465
2466 unlock:
2467         spin_unlock_bh(&session->lock);
2468 done:
2469         ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2470                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2471         mutex_unlock(&session->eh_mutex);
2472         return rc;
2473 }
2474 EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
2475
2476 /**
2477  * iscsi_eh_recover_target - reset target and possibly the session
2478  * @sc: scsi command
2479  *
2480  * This will attempt to send a warm target reset. If that fails,
2481  * we will escalate to ERL0 session recovery.
2482  */
2483 int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2484 {
2485         int rc;
2486
2487         rc = iscsi_eh_target_reset(sc);
2488         if (rc == FAILED)
2489                 rc = iscsi_eh_session_reset(sc);
2490         return rc;
2491 }
2492 EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2493
2494 /*
2495  * Pre-allocate a pool of @max items of @item_size. By default, the pool
2496  * should be accessed via kfifo_{get,put} on q->queue.
2497  * Optionally, the caller can obtain the array of object pointers
2498  * by passing in a non-NULL @items pointer
2499  */
2500 int
2501 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2502 {
2503         int i, num_arrays = 1;
2504
2505         memset(q, 0, sizeof(*q));
2506
2507         q->max = max;
2508
2509         /* If the user passed an items pointer, he wants a copy of
2510          * the array. */
2511         if (items)
2512                 num_arrays++;
2513         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
2514         if (q->pool == NULL)
2515                 return -ENOMEM;
2516
2517         kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2518
2519         for (i = 0; i < max; i++) {
2520                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2521                 if (q->pool[i] == NULL) {
2522                         q->max = i;
2523                         goto enomem;
2524                 }
2525                 kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2526         }
2527
2528         if (items) {
2529                 *items = q->pool + max;
2530                 memcpy(*items, q->pool, max * sizeof(void *));
2531         }
2532
2533         return 0;
2534
2535 enomem:
2536         iscsi_pool_free(q);
2537         return -ENOMEM;
2538 }
2539 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2540
2541 void iscsi_pool_free(struct iscsi_pool *q)
2542 {
2543         int i;
2544
2545         for (i = 0; i < q->max; i++)
2546                 kfree(q->pool[i]);
2547         kfree(q->pool);
2548 }
2549 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2550
2551 /**
2552  * iscsi_host_add - add host to system
2553  * @shost: scsi host
2554  * @pdev: parent device
2555  *
2556  * This should be called by partial offload and software iscsi drivers
2557  * to add a host to the system.
2558  */
2559 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2560 {
2561         if (!shost->can_queue)
2562                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2563
2564         if (!shost->cmd_per_lun)
2565                 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2566
2567         if (!shost->transportt->eh_timed_out)
2568                 shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
2569         return scsi_add_host(shost, pdev);
2570 }
2571 EXPORT_SYMBOL_GPL(iscsi_host_add);
2572
2573 /**
2574  * iscsi_host_alloc - allocate a host and driver data
2575  * @sht: scsi host template
2576  * @dd_data_size: driver host data size
2577  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2578  *
2579  * This should be called by partial offload and software iscsi drivers.
2580  * To access the driver specific memory use the iscsi_host_priv() macro.
2581  */
2582 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2583                                    int dd_data_size, bool xmit_can_sleep)
2584 {
2585         struct Scsi_Host *shost;
2586         struct iscsi_host *ihost;
2587
2588         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2589         if (!shost)
2590                 return NULL;
2591         ihost = shost_priv(shost);
2592
2593         if (xmit_can_sleep) {
2594                 snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2595                         "iscsi_q_%d", shost->host_no);
2596                 ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2597                 if (!ihost->workq)
2598                         goto free_host;
2599         }
2600
2601         spin_lock_init(&ihost->lock);
2602         ihost->state = ISCSI_HOST_SETUP;
2603         ihost->num_sessions = 0;
2604         init_waitqueue_head(&ihost->session_removal_wq);
2605         return shost;
2606
2607 free_host:
2608         scsi_host_put(shost);
2609         return NULL;
2610 }
2611 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2612
2613 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2614 {
2615         iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2616 }
2617
2618 /**
2619  * iscsi_host_remove - remove host and sessions
2620  * @shost: scsi host
2621  *
2622  * If there are any sessions left, this will initiate the removal and wait
2623  * for the completion.
2624  */
2625 void iscsi_host_remove(struct Scsi_Host *shost)
2626 {
2627         struct iscsi_host *ihost = shost_priv(shost);
2628         unsigned long flags;
2629
2630         spin_lock_irqsave(&ihost->lock, flags);
2631         ihost->state = ISCSI_HOST_REMOVED;
2632         spin_unlock_irqrestore(&ihost->lock, flags);
2633
2634         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2635         wait_event_interruptible(ihost->session_removal_wq,
2636                                  ihost->num_sessions == 0);
2637         if (signal_pending(current))
2638                 flush_signals(current);
2639
2640         scsi_remove_host(shost);
2641         if (ihost->workq)
2642                 destroy_workqueue(ihost->workq);
2643 }
2644 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2645
2646 void iscsi_host_free(struct Scsi_Host *shost)
2647 {
2648         struct iscsi_host *ihost = shost_priv(shost);
2649
2650         kfree(ihost->netdev);
2651         kfree(ihost->hwaddress);
2652         kfree(ihost->initiatorname);
2653         scsi_host_put(shost);
2654 }
2655 EXPORT_SYMBOL_GPL(iscsi_host_free);
2656
2657 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2658 {
2659         struct iscsi_host *ihost = shost_priv(shost);
2660         unsigned long flags;
2661
2662         shost = scsi_host_get(shost);
2663         if (!shost) {
2664                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2665                       "of session teardown event because host already "
2666                       "removed.\n");
2667                 return;
2668         }
2669
2670         spin_lock_irqsave(&ihost->lock, flags);
2671         ihost->num_sessions--;
2672         if (ihost->num_sessions == 0)
2673                 wake_up(&ihost->session_removal_wq);
2674         spin_unlock_irqrestore(&ihost->lock, flags);
2675         scsi_host_put(shost);
2676 }
2677
2678 /**
2679  * iscsi_session_setup - create iscsi cls session and host and session
2680  * @iscsit: iscsi transport template
2681  * @shost: scsi host
2682  * @cmds_max: session can queue
2683  * @cmd_task_size: LLD task private data size
2684  * @initial_cmdsn: initial CmdSN
2685  *
2686  * This can be used by software iscsi_transports that allocate
2687  * a session per scsi host.
2688  *
2689  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2690  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2691  * for nop handling and login/logout requests.
2692  */
2693 struct iscsi_cls_session *
2694 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2695                     uint16_t cmds_max, int dd_size, int cmd_task_size,
2696                     uint32_t initial_cmdsn, unsigned int id)
2697 {
2698         struct iscsi_host *ihost = shost_priv(shost);
2699         struct iscsi_session *session;
2700         struct iscsi_cls_session *cls_session;
2701         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2702         unsigned long flags;
2703
2704         spin_lock_irqsave(&ihost->lock, flags);
2705         if (ihost->state == ISCSI_HOST_REMOVED) {
2706                 spin_unlock_irqrestore(&ihost->lock, flags);
2707                 return NULL;
2708         }
2709         ihost->num_sessions++;
2710         spin_unlock_irqrestore(&ihost->lock, flags);
2711
2712         if (!total_cmds)
2713                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2714         /*
2715          * The iscsi layer needs some tasks for nop handling and tmfs,
2716          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2717          * + 1 command for scsi IO.
2718          */
2719         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2720                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2721                        "must be a power of two that is at least %d.\n",
2722                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2723                 goto dec_session_count;
2724         }
2725
2726         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2727                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2728                        "must be a power of 2 less than or equal to %d.\n",
2729                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2730                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2731         }
2732
2733         if (!is_power_of_2(total_cmds)) {
2734                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2735                        "must be a power of 2.\n", total_cmds);
2736                 total_cmds = rounddown_pow_of_two(total_cmds);
2737                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2738                         return NULL;
2739                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2740                        total_cmds);
2741         }
2742         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2743
2744         cls_session = iscsi_alloc_session(shost, iscsit,
2745                                           sizeof(struct iscsi_session) +
2746                                           dd_size);
2747         if (!cls_session)
2748                 goto dec_session_count;
2749         session = cls_session->dd_data;
2750         session->cls_session = cls_session;
2751         session->host = shost;
2752         session->state = ISCSI_STATE_FREE;
2753         session->fast_abort = 1;
2754         session->tgt_reset_timeout = 30;
2755         session->lu_reset_timeout = 15;
2756         session->abort_timeout = 10;
2757         session->scsi_cmds_max = scsi_cmds;
2758         session->cmds_max = total_cmds;
2759         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2760         session->exp_cmdsn = initial_cmdsn + 1;
2761         session->max_cmdsn = initial_cmdsn + 1;
2762         session->max_r2t = 1;
2763         session->tt = iscsit;
2764         session->dd_data = cls_session->dd_data + sizeof(*session);
2765         mutex_init(&session->eh_mutex);
2766         spin_lock_init(&session->lock);
2767
2768         /* initialize SCSI PDU commands pool */
2769         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2770                             (void***)&session->cmds,
2771                             cmd_task_size + sizeof(struct iscsi_task)))
2772                 goto cmdpool_alloc_fail;
2773
2774         /* pre-format cmds pool with ITT */
2775         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2776                 struct iscsi_task *task = session->cmds[cmd_i];
2777
2778                 if (cmd_task_size)
2779                         task->dd_data = &task[1];
2780                 task->itt = cmd_i;
2781                 task->state = ISCSI_TASK_FREE;
2782                 INIT_LIST_HEAD(&task->running);
2783         }
2784
2785         if (!try_module_get(iscsit->owner))
2786                 goto module_get_fail;
2787
2788         if (iscsi_add_session(cls_session, id))
2789                 goto cls_session_fail;
2790
2791         return cls_session;
2792
2793 cls_session_fail:
2794         module_put(iscsit->owner);
2795 module_get_fail:
2796         iscsi_pool_free(&session->cmdpool);
2797 cmdpool_alloc_fail:
2798         iscsi_free_session(cls_session);
2799 dec_session_count:
2800         iscsi_host_dec_session_cnt(shost);
2801         return NULL;
2802 }
2803 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2804
2805 /**
2806  * iscsi_session_teardown - destroy session, host, and cls_session
2807  * @cls_session: iscsi session
2808  *
2809  * The driver must have called iscsi_remove_session before
2810  * calling this.
2811  */
2812 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2813 {
2814         struct iscsi_session *session = cls_session->dd_data;
2815         struct module *owner = cls_session->transport->owner;
2816         struct Scsi_Host *shost = session->host;
2817
2818         iscsi_pool_free(&session->cmdpool);
2819
2820         kfree(session->password);
2821         kfree(session->password_in);
2822         kfree(session->username);
2823         kfree(session->username_in);
2824         kfree(session->targetname);
2825         kfree(session->initiatorname);
2826         kfree(session->ifacename);
2827
2828         iscsi_destroy_session(cls_session);
2829         iscsi_host_dec_session_cnt(shost);
2830         module_put(owner);
2831 }
2832 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2833
2834 /**
2835  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2836  * @cls_session: iscsi_cls_session
2837  * @dd_size: private driver data size
2838  * @conn_idx: cid
2839  */
2840 struct iscsi_cls_conn *
2841 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2842                  uint32_t conn_idx)
2843 {
2844         struct iscsi_session *session = cls_session->dd_data;
2845         struct iscsi_conn *conn;
2846         struct iscsi_cls_conn *cls_conn;
2847         char *data;
2848
2849         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2850                                      conn_idx);
2851         if (!cls_conn)
2852                 return NULL;
2853         conn = cls_conn->dd_data;
2854         memset(conn, 0, sizeof(*conn) + dd_size);
2855
2856         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2857         conn->session = session;
2858         conn->cls_conn = cls_conn;
2859         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2860         conn->id = conn_idx;
2861         conn->exp_statsn = 0;
2862         conn->tmf_state = TMF_INITIAL;
2863
2864         init_timer(&conn->transport_timer);
2865         conn->transport_timer.data = (unsigned long)conn;
2866         conn->transport_timer.function = iscsi_check_transport_timeouts;
2867
2868         INIT_LIST_HEAD(&conn->mgmtqueue);
2869         INIT_LIST_HEAD(&conn->cmdqueue);
2870         INIT_LIST_HEAD(&conn->requeue);
2871         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2872
2873         /* allocate login_task used for the login/text sequences */
2874         spin_lock_bh(&session->lock);
2875         if (!kfifo_out(&session->cmdpool.queue,
2876                          (void*)&conn->login_task,
2877                          sizeof(void*))) {
2878                 spin_unlock_bh(&session->lock);
2879                 goto login_task_alloc_fail;
2880         }
2881         spin_unlock_bh(&session->lock);
2882
2883         data = (char *) __get_free_pages(GFP_KERNEL,
2884                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2885         if (!data)
2886                 goto login_task_data_alloc_fail;
2887         conn->login_task->data = conn->data = data;
2888
2889         init_timer(&conn->tmf_timer);
2890         init_waitqueue_head(&conn->ehwait);
2891
2892         return cls_conn;
2893
2894 login_task_data_alloc_fail:
2895         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2896                     sizeof(void*));
2897 login_task_alloc_fail:
2898         iscsi_destroy_conn(cls_conn);
2899         return NULL;
2900 }
2901 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2902
2903 /**
2904  * iscsi_conn_teardown - teardown iscsi connection
2905  * cls_conn: iscsi class connection
2906  *
2907  * TODO: we may need to make this into a two step process
2908  * like scsi-mls remove + put host
2909  */
2910 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2911 {
2912         struct iscsi_conn *conn = cls_conn->dd_data;
2913         struct iscsi_session *session = conn->session;
2914         unsigned long flags;
2915
2916         del_timer_sync(&conn->transport_timer);
2917
2918         spin_lock_bh(&session->lock);
2919         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2920         if (session->leadconn == conn) {
2921                 /*
2922                  * leading connection? then give up on recovery.
2923                  */
2924                 session->state = ISCSI_STATE_TERMINATE;
2925                 wake_up(&conn->ehwait);
2926         }
2927         spin_unlock_bh(&session->lock);
2928
2929         /*
2930          * Block until all in-progress commands for this connection
2931          * time out or fail.
2932          */
2933         for (;;) {
2934                 spin_lock_irqsave(session->host->host_lock, flags);
2935                 if (!session->host->host_busy) { /* OK for ERL == 0 */
2936                         spin_unlock_irqrestore(session->host->host_lock, flags);
2937                         break;
2938                 }
2939                 spin_unlock_irqrestore(session->host->host_lock, flags);
2940                 msleep_interruptible(500);
2941                 iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2942                                   "host_busy %d host_failed %d\n",
2943                                   session->host->host_busy,
2944                                   session->host->host_failed);
2945                 /*
2946                  * force eh_abort() to unblock
2947                  */
2948                 wake_up(&conn->ehwait);
2949         }
2950
2951         /* flush queued up work because we free the connection below */
2952         iscsi_suspend_tx(conn);
2953
2954         spin_lock_bh(&session->lock);
2955         free_pages((unsigned long) conn->data,
2956                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2957         kfree(conn->persistent_address);
2958         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2959                     sizeof(void*));
2960         if (session->leadconn == conn)
2961                 session->leadconn = NULL;
2962         spin_unlock_bh(&session->lock);
2963
2964         iscsi_destroy_conn(cls_conn);
2965 }
2966 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2967
2968 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2969 {
2970         struct iscsi_conn *conn = cls_conn->dd_data;
2971         struct iscsi_session *session = conn->session;
2972
2973         if (!session) {
2974                 iscsi_conn_printk(KERN_ERR, conn,
2975                                   "can't start unbound connection\n");
2976                 return -EPERM;
2977         }
2978
2979         if ((session->imm_data_en || !session->initial_r2t_en) &&
2980              session->first_burst > session->max_burst) {
2981                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2982                                   "first_burst %d max_burst %d\n",
2983                                   session->first_burst, session->max_burst);
2984                 return -EINVAL;
2985         }
2986
2987         if (conn->ping_timeout && !conn->recv_timeout) {
2988                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
2989                                   "zero. Using 5 seconds\n.");
2990                 conn->recv_timeout = 5;
2991         }
2992
2993         if (conn->recv_timeout && !conn->ping_timeout) {
2994                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
2995                                   "zero. Using 5 seconds.\n");
2996                 conn->ping_timeout = 5;
2997         }
2998
2999         spin_lock_bh(&session->lock);
3000         conn->c_stage = ISCSI_CONN_STARTED;
3001         session->state = ISCSI_STATE_LOGGED_IN;
3002         session->queued_cmdsn = session->cmdsn;
3003
3004         conn->last_recv = jiffies;
3005         conn->last_ping = jiffies;
3006         if (conn->recv_timeout && conn->ping_timeout)
3007                 mod_timer(&conn->transport_timer,
3008                           jiffies + (conn->recv_timeout * HZ));
3009
3010         switch(conn->stop_stage) {
3011         case STOP_CONN_RECOVER:
3012                 /*
3013                  * unblock eh_abort() if it is blocked. re-try all
3014                  * commands after successful recovery
3015                  */
3016                 conn->stop_stage = 0;
3017                 conn->tmf_state = TMF_INITIAL;
3018                 session->age++;
3019                 if (session->age == 16)
3020                         session->age = 0;
3021                 break;
3022         case STOP_CONN_TERM:
3023                 conn->stop_stage = 0;
3024                 break;
3025         default:
3026                 break;
3027         }
3028         spin_unlock_bh(&session->lock);
3029
3030         iscsi_unblock_session(session->cls_session);
3031         wake_up(&conn->ehwait);
3032         return 0;
3033 }
3034 EXPORT_SYMBOL_GPL(iscsi_conn_start);
3035
3036 static void
3037 fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3038 {
3039         struct iscsi_task *task;
3040         int i, state;
3041
3042         for (i = 0; i < conn->session->cmds_max; i++) {
3043                 task = conn->session->cmds[i];
3044                 if (task->sc)
3045                         continue;
3046
3047                 if (task->state == ISCSI_TASK_FREE)
3048                         continue;
3049
3050                 ISCSI_DBG_SESSION(conn->session,
3051                                   "failing mgmt itt 0x%x state %d\n",
3052                                   task->itt, task->state);
3053                 state = ISCSI_TASK_ABRT_SESS_RECOV;
3054                 if (task->state == ISCSI_TASK_PENDING)
3055                         state = ISCSI_TASK_COMPLETED;
3056                 iscsi_complete_task(task, state);
3057
3058         }
3059 }
3060
3061 static void iscsi_start_session_recovery(struct iscsi_session *session,
3062                                          struct iscsi_conn *conn, int flag)
3063 {
3064         int old_stop_stage;
3065
3066         mutex_lock(&session->eh_mutex);
3067         spin_lock_bh(&session->lock);
3068         if (conn->stop_stage == STOP_CONN_TERM) {
3069                 spin_unlock_bh(&session->lock);
3070                 mutex_unlock(&session->eh_mutex);
3071                 return;
3072         }
3073
3074         /*
3075          * When this is called for the in_login state, we only want to clean
3076          * up the login task and connection. We do not need to block and set
3077          * the recovery state again
3078          */
3079         if (flag == STOP_CONN_TERM)
3080                 session->state = ISCSI_STATE_TERMINATE;
3081         else if (conn->stop_stage != STOP_CONN_RECOVER)
3082                 session->state = ISCSI_STATE_IN_RECOVERY;
3083
3084         old_stop_stage = conn->stop_stage;
3085         conn->stop_stage = flag;
3086         spin_unlock_bh(&session->lock);
3087
3088         del_timer_sync(&conn->transport_timer);
3089         iscsi_suspend_tx(conn);
3090
3091         spin_lock_bh(&session->lock);
3092         conn->c_stage = ISCSI_CONN_STOPPED;
3093         spin_unlock_bh(&session->lock);
3094
3095         /*
3096          * for connection level recovery we should not calculate
3097          * header digest. conn->hdr_size used for optimization
3098          * in hdr_extract() and will be re-negotiated at
3099          * set_param() time.
3100          */
3101         if (flag == STOP_CONN_RECOVER) {
3102                 conn->hdrdgst_en = 0;
3103                 conn->datadgst_en = 0;
3104                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
3105                     old_stop_stage != STOP_CONN_RECOVER) {
3106                         ISCSI_DBG_SESSION(session, "blocking session\n");
3107                         iscsi_block_session(session->cls_session);
3108                 }
3109         }
3110
3111         /*
3112          * flush queues.
3113          */
3114         spin_lock_bh(&session->lock);
3115         fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3116         fail_mgmt_tasks(session, conn);
3117         memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3118         spin_unlock_bh(&session->lock);
3119         mutex_unlock(&session->eh_mutex);
3120 }
3121
3122 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3123 {
3124         struct iscsi_conn *conn = cls_conn->dd_data;
3125         struct iscsi_session *session = conn->session;
3126
3127         switch (flag) {
3128         case STOP_CONN_RECOVER:
3129         case STOP_CONN_TERM:
3130                 iscsi_start_session_recovery(session, conn, flag);
3131                 break;
3132         default:
3133                 iscsi_conn_printk(KERN_ERR, conn,
3134                                   "invalid stop flag %d\n", flag);
3135         }
3136 }
3137 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3138
3139 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3140                     struct iscsi_cls_conn *cls_conn, int is_leading)
3141 {
3142         struct iscsi_session *session = cls_session->dd_data;
3143         struct iscsi_conn *conn = cls_conn->dd_data;
3144
3145         spin_lock_bh(&session->lock);
3146         if (is_leading)
3147                 session->leadconn = conn;
3148         spin_unlock_bh(&session->lock);
3149
3150         /*
3151          * Unblock xmitworker(), Login Phase will pass through.
3152          */
3153         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3154         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3155         return 0;
3156 }
3157 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3158
3159 static int iscsi_switch_str_param(char **param, char *new_val_buf)
3160 {
3161         char *new_val;
3162
3163         if (*param) {
3164                 if (!strcmp(*param, new_val_buf))
3165                         return 0;
3166         }
3167
3168         new_val = kstrdup(new_val_buf, GFP_NOIO);
3169         if (!new_val)
3170                 return -ENOMEM;
3171
3172         kfree(*param);
3173         *param = new_val;
3174         return 0;
3175 }
3176
3177 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3178                     enum iscsi_param param, char *buf, int buflen)
3179 {
3180         struct iscsi_conn *conn = cls_conn->dd_data;
3181         struct iscsi_session *session = conn->session;
3182         uint32_t value;
3183
3184         switch(param) {
3185         case ISCSI_PARAM_FAST_ABORT:
3186                 sscanf(buf, "%d", &session->fast_abort);
3187                 break;
3188         case ISCSI_PARAM_ABORT_TMO:
3189                 sscanf(buf, "%d", &session->abort_timeout);
3190                 break;
3191         case ISCSI_PARAM_LU_RESET_TMO:
3192                 sscanf(buf, "%d", &session->lu_reset_timeout);
3193                 break;
3194         case ISCSI_PARAM_TGT_RESET_TMO:
3195                 sscanf(buf, "%d", &session->tgt_reset_timeout);
3196                 break;
3197         case ISCSI_PARAM_PING_TMO:
3198                 sscanf(buf, "%d", &conn->ping_timeout);
3199                 break;
3200         case ISCSI_PARAM_RECV_TMO:
3201                 sscanf(buf, "%d", &conn->recv_timeout);
3202                 break;
3203         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3204                 sscanf(buf, "%d", &conn->max_recv_dlength);
3205                 break;
3206         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3207                 sscanf(buf, "%d", &conn->max_xmit_dlength);
3208                 break;
3209         case ISCSI_PARAM_HDRDGST_EN:
3210                 sscanf(buf, "%d", &conn->hdrdgst_en);
3211                 break;
3212         case ISCSI_PARAM_DATADGST_EN:
3213                 sscanf(buf, "%d", &conn->datadgst_en);
3214                 break;
3215         case ISCSI_PARAM_INITIAL_R2T_EN:
3216                 sscanf(buf, "%d", &session->initial_r2t_en);
3217                 break;
3218         case ISCSI_PARAM_MAX_R2T:
3219                 sscanf(buf, "%d", &session->max_r2t);
3220                 break;
3221         case ISCSI_PARAM_IMM_DATA_EN:
3222                 sscanf(buf, "%d", &session->imm_data_en);
3223                 break;
3224         case ISCSI_PARAM_FIRST_BURST:
3225                 sscanf(buf, "%d", &session->first_burst);
3226                 break;
3227         case ISCSI_PARAM_MAX_BURST:
3228                 sscanf(buf, "%d", &session->max_burst);
3229                 break;
3230         case ISCSI_PARAM_PDU_INORDER_EN:
3231                 sscanf(buf, "%d", &session->pdu_inorder_en);
3232                 break;
3233         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3234                 sscanf(buf, "%d", &session->dataseq_inorder_en);
3235                 break;
3236         case ISCSI_PARAM_ERL:
3237                 sscanf(buf, "%d", &session->erl);
3238                 break;
3239         case ISCSI_PARAM_IFMARKER_EN:
3240                 sscanf(buf, "%d", &value);
3241                 BUG_ON(value);
3242                 break;
3243         case ISCSI_PARAM_OFMARKER_EN:
3244                 sscanf(buf, "%d", &value);
3245                 BUG_ON(value);
3246                 break;
3247         case ISCSI_PARAM_EXP_STATSN:
3248                 sscanf(buf, "%u", &conn->exp_statsn);
3249                 break;
3250         case ISCSI_PARAM_USERNAME:
3251                 return iscsi_switch_str_param(&session->username, buf);
3252         case ISCSI_PARAM_USERNAME_IN:
3253                 return iscsi_switch_str_param(&session->username_in, buf);
3254         case ISCSI_PARAM_PASSWORD:
3255                 return iscsi_switch_str_param(&session->password, buf);
3256         case ISCSI_PARAM_PASSWORD_IN:
3257                 return iscsi_switch_str_param(&session->password_in, buf);
3258         case ISCSI_PARAM_TARGET_NAME:
3259                 return iscsi_switch_str_param(&session->targetname, buf);
3260         case ISCSI_PARAM_TPGT:
3261                 sscanf(buf, "%d", &session->tpgt);
3262                 break;
3263         case ISCSI_PARAM_PERSISTENT_PORT:
3264                 sscanf(buf, "%d", &conn->persistent_port);
3265                 break;
3266         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3267                 return iscsi_switch_str_param(&conn->persistent_address, buf);
3268         case ISCSI_PARAM_IFACE_NAME:
3269                 return iscsi_switch_str_param(&session->ifacename, buf);
3270         case ISCSI_PARAM_INITIATOR_NAME:
3271                 return iscsi_switch_str_param(&session->initiatorname, buf);
3272         default:
3273                 return -ENOSYS;
3274         }
3275
3276         return 0;
3277 }
3278 EXPORT_SYMBOL_GPL(iscsi_set_param);
3279
3280 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3281                             enum iscsi_param param, char *buf)
3282 {
3283         struct iscsi_session *session = cls_session->dd_data;
3284         int len;
3285
3286         switch(param) {
3287         case ISCSI_PARAM_FAST_ABORT:
3288                 len = sprintf(buf, "%d\n", session->fast_abort);
3289                 break;
3290         case ISCSI_PARAM_ABORT_TMO:
3291                 len = sprintf(buf, "%d\n", session->abort_timeout);
3292                 break;
3293         case ISCSI_PARAM_LU_RESET_TMO:
3294                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
3295                 break;
3296         case ISCSI_PARAM_TGT_RESET_TMO:
3297                 len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
3298                 break;
3299         case ISCSI_PARAM_INITIAL_R2T_EN:
3300                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
3301                 break;
3302         case ISCSI_PARAM_MAX_R2T:
3303                 len = sprintf(buf, "%hu\n", session->max_r2t);
3304                 break;
3305         case ISCSI_PARAM_IMM_DATA_EN:
3306                 len = sprintf(buf, "%d\n", session->imm_data_en);
3307                 break;
3308         case ISCSI_PARAM_FIRST_BURST:
3309                 len = sprintf(buf, "%u\n", session->first_burst);
3310                 break;
3311         case ISCSI_PARAM_MAX_BURST:
3312                 len = sprintf(buf, "%u\n", session->max_burst);
3313                 break;
3314         case ISCSI_PARAM_PDU_INORDER_EN:
3315                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
3316                 break;
3317         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3318                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
3319                 break;
3320         case ISCSI_PARAM_ERL:
3321                 len = sprintf(buf, "%d\n", session->erl);
3322                 break;
3323         case ISCSI_PARAM_TARGET_NAME:
3324                 len = sprintf(buf, "%s\n", session->targetname);
3325                 break;
3326         case ISCSI_PARAM_TPGT:
3327                 len = sprintf(buf, "%d\n", session->tpgt);
3328                 break;
3329         case ISCSI_PARAM_USERNAME:
3330                 len = sprintf(buf, "%s\n", session->username);
3331                 break;
3332         case ISCSI_PARAM_USERNAME_IN:
3333                 len = sprintf(buf, "%s\n", session->username_in);
3334                 break;
3335         case ISCSI_PARAM_PASSWORD:
3336                 len = sprintf(buf, "%s\n", session->password);
3337                 break;
3338         case ISCSI_PARAM_PASSWORD_IN:
3339                 len = sprintf(buf, "%s\n", session->password_in);
3340                 break;
3341         case ISCSI_PARAM_IFACE_NAME:
3342                 len = sprintf(buf, "%s\n", session->ifacename);
3343                 break;
3344         case ISCSI_PARAM_INITIATOR_NAME:
3345                 len = sprintf(buf, "%s\n", session->initiatorname);
3346                 break;
3347         default:
3348                 return -ENOSYS;
3349         }
3350
3351         return len;
3352 }
3353 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3354
3355 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3356                          enum iscsi_param param, char *buf)
3357 {
3358         struct iscsi_conn *conn = cls_conn->dd_data;
3359         int len;
3360
3361         switch(param) {
3362         case ISCSI_PARAM_PING_TMO:
3363                 len = sprintf(buf, "%u\n", conn->ping_timeout);
3364                 break;
3365         case ISCSI_PARAM_RECV_TMO:
3366                 len = sprintf(buf, "%u\n", conn->recv_timeout);
3367                 break;
3368         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3369                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
3370                 break;
3371         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3372                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
3373                 break;
3374         case ISCSI_PARAM_HDRDGST_EN:
3375                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
3376                 break;
3377         case ISCSI_PARAM_DATADGST_EN:
3378                 len = sprintf(buf, "%d\n", conn->datadgst_en);
3379                 break;
3380         case ISCSI_PARAM_IFMARKER_EN:
3381                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
3382                 break;
3383         case ISCSI_PARAM_OFMARKER_EN:
3384                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
3385                 break;
3386         case ISCSI_PARAM_EXP_STATSN:
3387                 len = sprintf(buf, "%u\n", conn->exp_statsn);
3388                 break;
3389         case ISCSI_PARAM_PERSISTENT_PORT:
3390                 len = sprintf(buf, "%d\n", conn->persistent_port);
3391                 break;
3392         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3393                 len = sprintf(buf, "%s\n", conn->persistent_address);
3394                 break;
3395         default:
3396                 return -ENOSYS;
3397         }
3398
3399         return len;
3400 }
3401 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3402
3403 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3404                          char *buf)
3405 {
3406         struct iscsi_host *ihost = shost_priv(shost);
3407         int len;
3408
3409         switch (param) {
3410         case ISCSI_HOST_PARAM_NETDEV_NAME:
3411                 len = sprintf(buf, "%s\n", ihost->netdev);
3412                 break;
3413         case ISCSI_HOST_PARAM_HWADDRESS:
3414                 len = sprintf(buf, "%s\n", ihost->hwaddress);
3415                 break;
3416         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3417                 len = sprintf(buf, "%s\n", ihost->initiatorname);
3418                 break;
3419         case ISCSI_HOST_PARAM_IPADDRESS:
3420                 len = sprintf(buf, "%s\n", ihost->local_address);
3421                 break;
3422         default:
3423                 return -ENOSYS;
3424         }
3425
3426         return len;
3427 }
3428 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3429
3430 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3431                          char *buf, int buflen)
3432 {
3433         struct iscsi_host *ihost = shost_priv(shost);
3434
3435         switch (param) {
3436         case ISCSI_HOST_PARAM_NETDEV_NAME:
3437                 return iscsi_switch_str_param(&ihost->netdev, buf);
3438         case ISCSI_HOST_PARAM_HWADDRESS:
3439                 return iscsi_switch_str_param(&ihost->hwaddress, buf);
3440         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3441                 return iscsi_switch_str_param(&ihost->initiatorname, buf);
3442         default:
3443                 return -ENOSYS;
3444         }
3445
3446         return 0;
3447 }
3448 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3449
3450 MODULE_AUTHOR("Mike Christie");
3451 MODULE_DESCRIPTION("iSCSI library functions");
3452 MODULE_LICENSE("GPL");