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
 509         ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
 510                           task->itt, task->state, task->sc);
 511
 512         session->tt->cleanup_task(task);
 513         task->state = ISCSI_TASK_FREE;
 514         task->sc = NULL;
 515         /*
 516          * login task is preallocated so do not free
 517          */
 518         if (conn->login_task == task)
 519                 return;
 520
 521         kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
 522
 523         if (sc) {
 524                 task->sc = NULL;
 525                 /* SCSI eh reuses commands to verify us */
 526                 sc->SCp.ptr = NULL;
 527                 /*
 528                  * queue command may call this to free the task, but
 529                  * not have setup the sc callback
 530                  */
 531                 if (sc->scsi_done)
 532                         sc->scsi_done(sc);
 533         }
 534 }
 535
 536 void __iscsi_get_task(struct iscsi_task *task)
 537 {
 538         atomic_inc(&task->refcount);
 539 }
 540 EXPORT_SYMBOL_GPL(__iscsi_get_task);
 541
 542 static void __iscsi_put_task(struct iscsi_task *task)
 543 {
 544         if (atomic_dec_and_test(&task->refcount))
 545                 iscsi_free_task(task);
 546 }
 547
 548 void iscsi_put_task(struct iscsi_task *task)
 549 {
 550         struct iscsi_session *session = task->conn->session;
 551
 552         spin_lock_bh(&session->lock);
 553         __iscsi_put_task(task);
 554         spin_unlock_bh(&session->lock);
 555 }
 556 EXPORT_SYMBOL_GPL(iscsi_put_task);
 557
 558 /**
 559  * iscsi_complete_task - finish a task
 560  * @task: iscsi cmd task
 561  * @state: state to complete task with
 562  *
 563  * Must be called with session lock.
 564  */
 565 static void iscsi_complete_task(struct iscsi_task *task, int state)
 566 {
 567         struct iscsi_conn *conn = task->conn;
 568
 569         ISCSI_DBG_SESSION(conn->session,
 570                           "complete task itt 0x%x state %d sc %p\n",
 571                           task->itt, task->state, task->sc);
 572         if (task->state == ISCSI_TASK_COMPLETED ||
 573             task->state == ISCSI_TASK_ABRT_TMF ||
 574             task->state == ISCSI_TASK_ABRT_SESS_RECOV)
 575                 return;
 576         WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
 577         task->state = state;
 578
 579         if (!list_empty(&task->running))
 580                 list_del_init(&task->running);
 581
 582         if (conn->task == task)
 583                 conn->task = NULL;
 584
 585         if (conn->ping_task == task)
 586                 conn->ping_task = NULL;
 587
 588         /* release get from queueing */
 589         __iscsi_put_task(task);
 590 }
 591
 592 /**
 593  * iscsi_complete_scsi_task - finish scsi task normally
 594  * @task: iscsi task for scsi cmd
 595  * @exp_cmdsn: expected cmd sn in cpu format
 596  * @max_cmdsn: max cmd sn in cpu format
 597  *
 598  * This is used when drivers do not need or cannot perform
 599  * lower level pdu processing.
 600  *
 601  * Called with session lock
 602  */
 603 void iscsi_complete_scsi_task(struct iscsi_task *task,
 604                               uint32_t exp_cmdsn, uint32_t max_cmdsn)
 605 {
 606         struct iscsi_conn *conn = task->conn;
 607
 608         ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 609
 610         conn->last_recv = jiffies;
 611         __iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 612         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 613 }
 614 EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 615
 616
 617 /*
 618  * session lock must be held and if not called for a task that is
 619  * still pending or from the xmit thread, then xmit thread must
 620  * be suspended.
 621  */
 622 static void fail_scsi_task(struct iscsi_task *task, int err)
 623 {
 624         struct iscsi_conn *conn = task->conn;
 625         struct scsi_cmnd *sc;
 626         int state;
 627
 628         /*
 629          * if a command completes and we get a successful tmf response
 630          * we will hit this because the scsi eh abort code does not take
 631          * a ref to the task.
 632          */
 633         sc = task->sc;
 634         if (!sc)
 635                 return;
 636
 637         if (task->state == ISCSI_TASK_PENDING) {
 638                 /*
 639                  * cmd never made it to the xmit thread, so we should not count
 640                  * the cmd in the sequencing
 641                  */
 642                 conn->session->queued_cmdsn--;
 643                 /* it was never sent so just complete like normal */
 644                 state = ISCSI_TASK_COMPLETED;
 645         } else if (err == DID_TRANSPORT_DISRUPTED)
 646                 state = ISCSI_TASK_ABRT_SESS_RECOV;
 647         else
 648                 state = ISCSI_TASK_ABRT_TMF;
 649
 650         sc->result = err << 16;
 651         if (!scsi_bidi_cmnd(sc))
 652                 scsi_set_resid(sc, scsi_bufflen(sc));
 653         else {
 654                 scsi_out(sc)->resid = scsi_out(sc)->length;
 655                 scsi_in(sc)->resid = scsi_in(sc)->length;
 656         }
 657
 658         iscsi_complete_task(task, state);
 659 }
 660
 661 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 662                                 struct iscsi_task *task)
 663 {
 664         struct iscsi_session *session = conn->session;
 665         struct iscsi_hdr *hdr = task->hdr;
 666         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 667         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 668
 669         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 670                 return -ENOTCONN;
 671
 672         if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
 673                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 674         /*
 675          * pre-format CmdSN for outgoing PDU.
 676          */
 677         nop->cmdsn = cpu_to_be32(session->cmdsn);
 678         if (hdr->itt != RESERVED_ITT) {
 679                 /*
 680                  * TODO: We always use immediate for normal session pdus.
 681                  * If we start to send tmfs or nops as non-immediate then
 682                  * we should start checking the cmdsn numbers for mgmt tasks.
 683                  *
 684                  * During discovery sessions iscsid sends TEXT as non immediate,
 685                  * but we always only send one PDU at a time.
 686                  */
 687                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 688                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 689                         session->queued_cmdsn++;
 690                         session->cmdsn++;
 691                 }
 692         }
 693
 694         if (session->tt->init_task && session->tt->init_task(task))
 695                 return -EIO;
 696
 697         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 698                 session->state = ISCSI_STATE_LOGGING_OUT;
 699
 700         task->state = ISCSI_TASK_RUNNING;
 701         ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 702                           "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 703                           hdr->itt, task->data_count);
 704         return 0;
 705 }
 706
 707 static struct iscsi_task *
 708 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 709                       char *data, uint32_t data_size)
 710 {
 711         struct iscsi_session *session = conn->session;
 712         struct iscsi_host *ihost = shost_priv(session->host);
 713         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 714         struct iscsi_task *task;
 715         itt_t itt;
 716
 717         if (session->state == ISCSI_STATE_TERMINATE)
 718                 return NULL;
 719
 720         if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 721                 /*
 722                  * Login and Text are sent serially, in
 723                  * request-followed-by-response sequence.
 724                  * Same task can be used. Same ITT must be used.
 725                  * Note that login_task is preallocated at conn_create().
 726                  */
 727                 if (conn->login_task->state != ISCSI_TASK_FREE) {
 728                         iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 729                                           "progress. Cannot start new task.\n");
 730                         return NULL;
 731                 }
 732
 733                 task = conn->login_task;
 734         } else {
 735                 if (session->state != ISCSI_STATE_LOGGED_IN)
 736                         return NULL;
 737
 738                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 739                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 740
 741                 if (!kfifo_out(&session->cmdpool.queue,
 742                                  (void*)&task, sizeof(void*)))
 743                         return NULL;
 744         }
 745         /*
 746          * released in complete pdu for task we expect a response for, and
 747          * released by the lld when it has transmitted the task for
 748          * pdus we do not expect a response for.
 749          */
 750         atomic_set(&task->refcount, 1);
 751         task->conn = conn;
 752         task->sc = NULL;
 753         INIT_LIST_HEAD(&task->running);
 754         task->state = ISCSI_TASK_PENDING;
 755
 756         if (data_size) {
 757                 memcpy(task->data, data, data_size);
 758                 task->data_count = data_size;
 759         } else
 760                 task->data_count = 0;
 761
 762         if (conn->session->tt->alloc_pdu) {
 763                 if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 764                         iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 765                                          "pdu for mgmt task.\n");
 766                         goto free_task;
 767                 }
 768         }
 769
 770         itt = task->hdr->itt;
 771         task->hdr_len = sizeof(struct iscsi_hdr);
 772         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 773
 774         if (hdr->itt != RESERVED_ITT) {
 775                 if (session->tt->parse_pdu_itt)
 776                         task->hdr->itt = itt;
 777                 else
 778                         task->hdr->itt = build_itt(task->itt,
 779                                                    task->conn->session->age);
 780         }
 781
 782         if (!ihost->workq) {
 783                 if (iscsi_prep_mgmt_task(conn, task))
 784                         goto free_task;
 785
 786                 if (session->tt->xmit_task(task))
 787                         goto free_task;
 788         } else {
 789                 list_add_tail(&task->running, &conn->mgmtqueue);
 790                 iscsi_conn_queue_work(conn);
 791         }
 792
 793         return task;
 794
 795 free_task:
 796         __iscsi_put_task(task);
 797         return NULL;
 798 }
 799
 800 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 801                         char *data, uint32_t data_size)
 802 {
 803         struct iscsi_conn *conn = cls_conn->dd_data;
 804         struct iscsi_session *session = conn->session;
 805         int err = 0;
 806
 807         spin_lock_bh(&session->lock);
 808         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 809                 err = -EPERM;
 810         spin_unlock_bh(&session->lock);
 811         return err;
 812 }
 813 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 814
 815 /**
 816  * iscsi_cmd_rsp - SCSI Command Response processing
 817  * @conn: iscsi connection
 818  * @hdr: iscsi header
 819  * @task: scsi command task
 820  * @data: cmd data buffer
 821  * @datalen: len of buffer
 822  *
 823  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 824  * then completes the command and task.
 825  **/
 826 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 827                                struct iscsi_task *task, char *data,
 828                                int datalen)
 829 {
 830         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
 831         struct iscsi_session *session = conn->session;
 832         struct scsi_cmnd *sc = task->sc;
 833
 834         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 835         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 836
 837         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 838
 839         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 840                 sc->result = DID_ERROR << 16;
 841                 goto out;
 842         }
 843
 844         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 845                 uint16_t senselen;
 846
 847                 if (datalen < 2) {
 848 invalid_datalen:
 849                         iscsi_conn_printk(KERN_ERR,  conn,
 850                                          "Got CHECK_CONDITION but invalid data "
 851                                          "buffer size of %d\n", datalen);
 852                         sc->result = DID_BAD_TARGET << 16;
 853                         goto out;
 854                 }
 855
 856                 senselen = get_unaligned_be16(data);
 857                 if (datalen < senselen)
 858                         goto invalid_datalen;
 859
 860                 memcpy(sc->sense_buffer, data + 2,
 861                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 862                 ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 863                                   min_t(uint16_t, senselen,
 864                                   SCSI_SENSE_BUFFERSIZE));
 865         }
 866
 867         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 868                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 869                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
 870
 871                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 872                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 873                                  res_count <= scsi_in(sc)->length))
 874                         scsi_in(sc)->resid = res_count;
 875                 else
 876                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 877         }
 878
 879         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 880                            ISCSI_FLAG_CMD_OVERFLOW)) {
 881                 int res_count = be32_to_cpu(rhdr->residual_count);
 882
 883                 if (res_count > 0 &&
 884                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 885                      res_count <= scsi_bufflen(sc)))
 886                         /* write side for bidi or uni-io set_resid */
 887                         scsi_set_resid(sc, res_count);
 888                 else
 889                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 890         }
 891 out:
 892         ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 893                           sc, sc->result, task->itt);
 894         conn->scsirsp_pdus_cnt++;
 895         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 896 }
 897
 898 /**
 899  * iscsi_data_in_rsp - SCSI Data-In Response processing
 900  * @conn: iscsi connection
 901  * @hdr:  iscsi pdu
 902  * @task: scsi command task
 903  **/
 904 static void
 905 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 906                   struct iscsi_task *task)
 907 {
 908         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 909         struct scsi_cmnd *sc = task->sc;
 910
 911         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 912                 return;
 913
 914         iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 915         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 916         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 917         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 918                            ISCSI_FLAG_DATA_OVERFLOW)) {
 919                 int res_count = be32_to_cpu(rhdr->residual_count);
 920
 921                 if (res_count > 0 &&
 922                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 923                      res_count <= scsi_in(sc)->length))
 924                         scsi_in(sc)->resid = res_count;
 925                 else
 926                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 927         }
 928
 929         ISCSI_DBG_SESSION(conn->session, "data in with status done "
 930                           "[sc %p res %d itt 0x%x]\n",
 931                           sc, sc->result, task->itt);
 932         conn->scsirsp_pdus_cnt++;
 933         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 934 }
 935
 936 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 937 {
 938         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 939
 940         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 941         conn->tmfrsp_pdus_cnt++;
 942
 943         if (conn->tmf_state != TMF_QUEUED)
 944                 return;
 945
 946         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 947                 conn->tmf_state = TMF_SUCCESS;
 948         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 949                 conn->tmf_state = TMF_NOT_FOUND;
 950         else
 951                 conn->tmf_state = TMF_FAILED;
 952         wake_up(&conn->ehwait);
 953 }
 954
 955 static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 956 {
 957         struct iscsi_nopout hdr;
 958         struct iscsi_task *task;
 959
 960         if (!rhdr && conn->ping_task)
 961                 return;
 962
 963         memset(&hdr, 0, sizeof(struct iscsi_nopout));
 964         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 965         hdr.flags = ISCSI_FLAG_CMD_FINAL;
 966
 967         if (rhdr) {
 968                 memcpy(hdr.lun, rhdr->lun, 8);
 969                 hdr.ttt = rhdr->ttt;
 970                 hdr.itt = RESERVED_ITT;
 971         } else
 972                 hdr.ttt = RESERVED_ITT;
 973
 974         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 975         if (!task)
 976                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 977         else if (!rhdr) {
 978                 /* only track our nops */
 979                 conn->ping_task = task;
 980                 conn->last_ping = jiffies;
 981         }
 982 }
 983
 984 static int iscsi_nop_out_rsp(struct iscsi_task *task,
 985                              struct iscsi_nopin *nop, char *data, int datalen)
 986 {
 987         struct iscsi_conn *conn = task->conn;
 988         int rc = 0;
 989
 990         if (conn->ping_task != task) {
 991                 /*
 992                  * If this is not in response to one of our
 993                  * nops then it must be from userspace.
 994                  */
 995                 if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
 996                                    data, datalen))
 997                         rc = ISCSI_ERR_CONN_FAILED;
 998         } else
 999                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1000         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1001         return rc;
1002 }
1003
1004 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1005                                char *data, int datalen)
1006 {
1007         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1008         struct iscsi_hdr rejected_pdu;
1009         int opcode, rc = 0;
1010
1011         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1012
1013         if (ntoh24(reject->dlength) > datalen ||
1014             ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1015                 iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1016                                   "pdu. Invalid data length (pdu dlength "
1017                                   "%u, datalen %d\n", ntoh24(reject->dlength),
1018                                   datalen);
1019                 return ISCSI_ERR_PROTO;
1020         }
1021         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1022         opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1023
1024         switch (reject->reason) {
1025         case ISCSI_REASON_DATA_DIGEST_ERROR:
1026                 iscsi_conn_printk(KERN_ERR, conn,
1027                                   "pdu (op 0x%x itt 0x%x) rejected "
1028                                   "due to DataDigest error.\n",
1029                                   rejected_pdu.itt, opcode);
1030                 break;
1031         case ISCSI_REASON_IMM_CMD_REJECT:
1032                 iscsi_conn_printk(KERN_ERR, conn,
1033                                   "pdu (op 0x%x itt 0x%x) rejected. Too many "
1034                                   "immediate commands.\n",
1035                                   rejected_pdu.itt, opcode);
1036                 /*
1037                  * We only send one TMF at a time so if the target could not
1038                  * handle it, then it should get fixed (RFC mandates that
1039                  * a target can handle one immediate TMF per conn).
1040                  *
1041                  * For nops-outs, we could have sent more than one if
1042                  * the target is sending us lots of nop-ins
1043                  */
1044                 if (opcode != ISCSI_OP_NOOP_OUT)
1045                         return 0;
1046
1047                  if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG))
1048                         /*
1049                          * nop-out in response to target's nop-out rejected.
1050                          * Just resend.
1051                          */
1052                         iscsi_send_nopout(conn,
1053                                           (struct iscsi_nopin*)&rejected_pdu);
1054                 else {
1055                         struct iscsi_task *task;
1056                         /*
1057                          * Our nop as ping got dropped. We know the target
1058                          * and transport are ok so just clean up
1059                          */
1060                         task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1061                         if (!task) {
1062                                 iscsi_conn_printk(KERN_ERR, conn,
1063                                                  "Invalid pdu reject. Could "
1064                                                  "not lookup rejected task.\n");
1065                                 rc = ISCSI_ERR_BAD_ITT;
1066                         } else
1067                                 rc = iscsi_nop_out_rsp(task,
1068                                         (struct iscsi_nopin*)&rejected_pdu,
1069                                         NULL, 0);
1070                 }
1071                 break;
1072         default:
1073                 iscsi_conn_printk(KERN_ERR, conn,
1074                                   "pdu (op 0x%x itt 0x%x) rejected. Reason "
1075                                   "code 0x%x\n", rejected_pdu.itt,
1076                                   rejected_pdu.opcode, reject->reason);
1077                 break;
1078         }
1079         return rc;
1080 }
1081
1082 /**
1083  * iscsi_itt_to_task - look up task by itt
1084  * @conn: iscsi connection
1085  * @itt: itt
1086  *
1087  * This should be used for mgmt tasks like login and nops, or if
1088  * the LDD's itt space does not include the session age.
1089  *
1090  * The session lock must be held.
1091  */
1092 struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1093 {
1094         struct iscsi_session *session = conn->session;
1095         int i;
1096
1097         if (itt == RESERVED_ITT)
1098                 return NULL;
1099
1100         if (session->tt->parse_pdu_itt)
1101                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1102         else
1103                 i = get_itt(itt);
1104         if (i >= session->cmds_max)
1105                 return NULL;
1106
1107         return session->cmds[i];
1108 }
1109 EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1110
1111 /**
1112  * __iscsi_complete_pdu - complete pdu
1113  * @conn: iscsi conn
1114  * @hdr: iscsi header
1115  * @data: data buffer
1116  * @datalen: len of data buffer
1117  *
1118  * Completes pdu processing by freeing any resources allocated at
1119  * queuecommand or send generic. session lock must be held and verify
1120  * itt must have been called.
1121  */
1122 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1123                          char *data, int datalen)
1124 {
1125         struct iscsi_session *session = conn->session;
1126         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1127         struct iscsi_task *task;
1128         uint32_t itt;
1129
1130         conn->last_recv = jiffies;
1131         rc = iscsi_verify_itt(conn, hdr->itt);
1132         if (rc)
1133                 return rc;
1134
1135         if (hdr->itt != RESERVED_ITT)
1136                 itt = get_itt(hdr->itt);
1137         else
1138                 itt = ~0U;
1139
1140         ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1141                           opcode, conn->id, itt, datalen);
1142
1143         if (itt == ~0U) {
1144                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1145
1146                 switch(opcode) {
1147                 case ISCSI_OP_NOOP_IN:
1148                         if (datalen) {
1149                                 rc = ISCSI_ERR_PROTO;
1150                                 break;
1151                         }
1152
1153                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1154                                 break;
1155
1156                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1157                         break;
1158                 case ISCSI_OP_REJECT:
1159                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
1160                         break;
1161                 case ISCSI_OP_ASYNC_EVENT:
1162                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1163                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1164                                 rc = ISCSI_ERR_CONN_FAILED;
1165                         break;
1166                 default:
1167                         rc = ISCSI_ERR_BAD_OPCODE;
1168                         break;
1169                 }
1170                 goto out;
1171         }
1172
1173         switch(opcode) {
1174         case ISCSI_OP_SCSI_CMD_RSP:
1175         case ISCSI_OP_SCSI_DATA_IN:
1176                 task = iscsi_itt_to_ctask(conn, hdr->itt);
1177                 if (!task)
1178                         return ISCSI_ERR_BAD_ITT;
1179                 task->last_xfer = jiffies;
1180                 break;
1181         case ISCSI_OP_R2T:
1182                 /*
1183                  * LLD handles R2Ts if they need to.
1184                  */
1185                 return 0;
1186         case ISCSI_OP_LOGOUT_RSP:
1187         case ISCSI_OP_LOGIN_RSP:
1188         case ISCSI_OP_TEXT_RSP:
1189         case ISCSI_OP_SCSI_TMFUNC_RSP:
1190         case ISCSI_OP_NOOP_IN:
1191                 task = iscsi_itt_to_task(conn, hdr->itt);
1192                 if (!task)
1193                         return ISCSI_ERR_BAD_ITT;
1194                 break;
1195         default:
1196                 return ISCSI_ERR_BAD_OPCODE;
1197         }
1198
1199         switch(opcode) {
1200         case ISCSI_OP_SCSI_CMD_RSP:
1201                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1202                 break;
1203         case ISCSI_OP_SCSI_DATA_IN:
1204                 iscsi_data_in_rsp(conn, hdr, task);
1205                 break;
1206         case ISCSI_OP_LOGOUT_RSP:
1207                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1208                 if (datalen) {
1209                         rc = ISCSI_ERR_PROTO;
1210                         break;
1211                 }
1212                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1213                 goto recv_pdu;
1214         case ISCSI_OP_LOGIN_RSP:
1215         case ISCSI_OP_TEXT_RSP:
1216                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1217                 /*
1218                  * login related PDU's exp_statsn is handled in
1219                  * userspace
1220                  */
1221                 goto recv_pdu;
1222         case ISCSI_OP_SCSI_TMFUNC_RSP:
1223                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1224                 if (datalen) {
1225                         rc = ISCSI_ERR_PROTO;
1226                         break;
1227                 }
1228
1229                 iscsi_tmf_rsp(conn, hdr);
1230                 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1231                 break;
1232         case ISCSI_OP_NOOP_IN:
1233                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1234                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1235                         rc = ISCSI_ERR_PROTO;
1236                         break;
1237                 }
1238                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1239
1240                 rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1241                                        data, datalen);
1242                 break;
1243         default:
1244                 rc = ISCSI_ERR_BAD_OPCODE;
1245                 break;
1246         }
1247
1248 out:
1249         return rc;
1250 recv_pdu:
1251         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1252                 rc = ISCSI_ERR_CONN_FAILED;
1253         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1254         return rc;
1255 }
1256 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1257
1258 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1259                        char *data, int datalen)
1260 {
1261         int rc;
1262
1263         spin_lock(&conn->session->lock);
1264         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1265         spin_unlock(&conn->session->lock);
1266         return rc;
1267 }
1268 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1269
1270 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1271 {
1272         struct iscsi_session *session = conn->session;
1273         int age = 0, i = 0;
1274
1275         if (itt == RESERVED_ITT)
1276                 return 0;
1277
1278         if (session->tt->parse_pdu_itt)
1279                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
1280         else {
1281                 i = get_itt(itt);
1282                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1283         }
1284
1285         if (age != session->age) {
1286                 iscsi_conn_printk(KERN_ERR, conn,
1287                                   "received itt %x expected session age (%x)\n",
1288                                   (__force u32)itt, session->age);
1289                 return ISCSI_ERR_BAD_ITT;
1290         }
1291
1292         if (i >= session->cmds_max) {
1293                 iscsi_conn_printk(KERN_ERR, conn,
1294                                   "received invalid itt index %u (max cmds "
1295                                    "%u.\n", i, session->cmds_max);
1296                 return ISCSI_ERR_BAD_ITT;
1297         }
1298         return 0;
1299 }
1300 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1301
1302 /**
1303  * iscsi_itt_to_ctask - look up ctask by itt
1304  * @conn: iscsi connection
1305  * @itt: itt
1306  *
1307  * This should be used for cmd tasks.
1308  *
1309  * The session lock must be held.
1310  */
1311 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1312 {
1313         struct iscsi_task *task;
1314
1315         if (iscsi_verify_itt(conn, itt))
1316                 return NULL;
1317
1318         task = iscsi_itt_to_task(conn, itt);
1319         if (!task || !task->sc)
1320                 return NULL;
1321
1322         if (task->sc->SCp.phase != conn->session->age) {
1323                 iscsi_session_printk(KERN_ERR, conn->session,
1324                                   "task's session age %d, expected %d\n",
1325                                   task->sc->SCp.phase, conn->session->age);
1326                 return NULL;
1327         }
1328
1329         return task;
1330 }
1331 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1332
1333 void iscsi_session_failure(struct iscsi_session *session,
1334                            enum iscsi_err err)
1335 {
1336         struct iscsi_conn *conn;
1337         struct device *dev;
1338         unsigned long flags;
1339
1340         spin_lock_irqsave(&session->lock, flags);
1341         conn = session->leadconn;
1342         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1343                 spin_unlock_irqrestore(&session->lock, flags);
1344                 return;
1345         }
1346
1347         dev = get_device(&conn->cls_conn->dev);
1348         spin_unlock_irqrestore(&session->lock, flags);
1349         if (!dev)
1350                 return;
1351         /*
1352          * if the host is being removed bypass the connection
1353          * recovery initialization because we are going to kill
1354          * the session.
1355          */
1356         if (err == ISCSI_ERR_INVALID_HOST)
1357                 iscsi_conn_error_event(conn->cls_conn, err);
1358         else
1359                 iscsi_conn_failure(conn, err);
1360         put_device(dev);
1361 }
1362 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1363
1364 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1365 {
1366         struct iscsi_session *session = conn->session;
1367         unsigned long flags;
1368
1369         spin_lock_irqsave(&session->lock, flags);
1370         if (session->state == ISCSI_STATE_FAILED) {
1371                 spin_unlock_irqrestore(&session->lock, flags);
1372                 return;
1373         }
1374
1375         if (conn->stop_stage == 0)
1376                 session->state = ISCSI_STATE_FAILED;
1377         spin_unlock_irqrestore(&session->lock, flags);
1378
1379         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1380         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1381         iscsi_conn_error_event(conn->cls_conn, err);
1382 }
1383 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1384
1385 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1386 {
1387         struct iscsi_session *session = conn->session;
1388
1389         /*
1390          * Check for iSCSI window and take care of CmdSN wrap-around
1391          */
1392         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1393                 ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1394                                   "%u MaxCmdSN %u CmdSN %u/%u\n",
1395                                   session->exp_cmdsn, session->max_cmdsn,
1396                                   session->cmdsn, session->queued_cmdsn);
1397                 return -ENOSPC;
1398         }
1399         return 0;
1400 }
1401
1402 static int iscsi_xmit_task(struct iscsi_conn *conn)
1403 {
1404         struct iscsi_task *task = conn->task;
1405         int rc;
1406
1407         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
1408                 return -ENODATA;
1409
1410         __iscsi_get_task(task);
1411         spin_unlock_bh(&conn->session->lock);
1412         rc = conn->session->tt->xmit_task(task);
1413         spin_lock_bh(&conn->session->lock);
1414         if (!rc) {
1415                 /* done with this task */
1416                 task->last_xfer = jiffies;
1417                 conn->task = NULL;
1418         }
1419         __iscsi_put_task(task);
1420         return rc;
1421 }
1422
1423 /**
1424  * iscsi_requeue_task - requeue task to run from session workqueue
1425  * @task: task to requeue
1426  *
1427  * LLDs that need to run a task from the session workqueue should call
1428  * this. The session lock must be held. This should only be called
1429  * by software drivers.
1430  */
1431 void iscsi_requeue_task(struct iscsi_task *task)
1432 {
1433         struct iscsi_conn *conn = task->conn;
1434
1435         /*
1436          * this may be on the requeue list already if the xmit_task callout
1437          * is handling the r2ts while we are adding new ones
1438          */
1439         if (list_empty(&task->running))
1440                 list_add_tail(&task->running, &conn->requeue);
1441         iscsi_conn_queue_work(conn);
1442 }
1443 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1444
1445 /**
1446  * iscsi_data_xmit - xmit any command into the scheduled connection
1447  * @conn: iscsi connection
1448  *
1449  * Notes:
1450  *      The function can return -EAGAIN in which case the caller must
1451  *      re-schedule it again later or recover. '0' return code means
1452  *      successful xmit.
1453  **/
1454 static int iscsi_data_xmit(struct iscsi_conn *conn)
1455 {
1456         struct iscsi_task *task;
1457         int rc = 0;
1458
1459         spin_lock_bh(&conn->session->lock);
1460         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1461                 ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1462                 spin_unlock_bh(&conn->session->lock);
1463                 return -ENODATA;
1464         }
1465
1466         if (conn->task) {
1467                 rc = iscsi_xmit_task(conn);
1468                 if (rc)
1469                         goto done;
1470         }
1471
1472         /*
1473          * process mgmt pdus like nops before commands since we should
1474          * only have one nop-out as a ping from us and targets should not
1475          * overflow us with nop-ins
1476          */
1477 check_mgmt:
1478         while (!list_empty(&conn->mgmtqueue)) {
1479                 conn->task = list_entry(conn->mgmtqueue.next,
1480                                          struct iscsi_task, running);
1481                 list_del_init(&conn->task->running);
1482                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1483                         __iscsi_put_task(conn->task);
1484                         conn->task = NULL;
1485                         continue;
1486                 }
1487                 rc = iscsi_xmit_task(conn);
1488                 if (rc)
1489                         goto done;
1490         }
1491
1492         /* process pending command queue */
1493         while (!list_empty(&conn->cmdqueue)) {
1494                 conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1495                                         running);
1496                 list_del_init(&conn->task->running);
1497                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1498                         fail_scsi_task(conn->task, DID_IMM_RETRY);
1499                         continue;
1500                 }
1501                 rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1502                 if (rc) {
1503                         if (rc == -ENOMEM || rc == -EACCES) {
1504                                 list_add_tail(&conn->task->running,
1505                                               &conn->cmdqueue);
1506                                 conn->task = NULL;
1507                                 goto done;
1508                         } else
1509                                 fail_scsi_task(conn->task, DID_ABORT);
1510                         continue;
1511                 }
1512                 rc = iscsi_xmit_task(conn);
1513                 if (rc)
1514                         goto done;
1515                 /*
1516                  * we could continuously get new task requests so
1517                  * we need to check the mgmt queue for nops that need to
1518                  * be sent to aviod starvation
1519                  */
1520                 if (!list_empty(&conn->mgmtqueue))
1521                         goto check_mgmt;
1522         }
1523
1524         while (!list_empty(&conn->requeue)) {
1525                 /*
1526                  * we always do fastlogout - conn stop code will clean up.
1527                  */
1528                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1529                         break;
1530
1531                 task = list_entry(conn->requeue.next, struct iscsi_task,
1532                                   running);
1533                 if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1534                         break;
1535
1536                 conn->task = task;
1537                 list_del_init(&conn->task->running);
1538                 conn->task->state = ISCSI_TASK_RUNNING;
1539                 rc = iscsi_xmit_task(conn);
1540                 if (rc)
1541                         goto done;
1542                 if (!list_empty(&conn->mgmtqueue))
1543                         goto check_mgmt;
1544         }
1545         spin_unlock_bh(&conn->session->lock);
1546         return -ENODATA;
1547
1548 done:
1549         spin_unlock_bh(&conn->session->lock);
1550         return rc;
1551 }
1552
1553 static void iscsi_xmitworker(struct work_struct *work)
1554 {
1555         struct iscsi_conn *conn =
1556                 container_of(work, struct iscsi_conn, xmitwork);
1557         int rc;
1558         /*
1559          * serialize Xmit worker on a per-connection basis.
1560          */
1561         do {
1562                 rc = iscsi_data_xmit(conn);
1563         } while (rc >= 0 || rc == -EAGAIN);
1564 }
1565
1566 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1567                                                   struct scsi_cmnd *sc)
1568 {
1569         struct iscsi_task *task;
1570
1571         if (!kfifo_out(&conn->session->cmdpool.queue,
1572                          (void *) &task, sizeof(void *)))
1573                 return NULL;
1574
1575         sc->SCp.phase = conn->session->age;
1576         sc->SCp.ptr = (char *) task;
1577
1578         atomic_set(&task->refcount, 1);
1579         task->state = ISCSI_TASK_PENDING;
1580         task->conn = conn;
1581         task->sc = sc;
1582         task->have_checked_conn = false;
1583         task->last_timeout = jiffies;
1584         task->last_xfer = jiffies;
1585         INIT_LIST_HEAD(&task->running);
1586         return task;
1587 }
1588
1589 enum {
1590         FAILURE_BAD_HOST = 1,
1591         FAILURE_SESSION_FAILED,
1592         FAILURE_SESSION_FREED,
1593         FAILURE_WINDOW_CLOSED,
1594         FAILURE_OOM,
1595         FAILURE_SESSION_TERMINATE,
1596         FAILURE_SESSION_IN_RECOVERY,
1597         FAILURE_SESSION_RECOVERY_TIMEOUT,
1598         FAILURE_SESSION_LOGGING_OUT,
1599         FAILURE_SESSION_NOT_READY,
1600 };
1601
1602 static int iscsi_queuecommand_lck(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
1603 {
1604         struct iscsi_cls_session *cls_session;
1605         struct Scsi_Host *host;
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->scsi_done = done;
1613         sc->result = 0;
1614         sc->SCp.ptr = NULL;
1615
1616         host = sc->device->host;
1617         ihost = shost_priv(host);
1618         spin_unlock(host->host_lock);
1619
1620         cls_session = starget_to_session(scsi_target(sc->device));
1621         session = cls_session->dd_data;
1622         spin_lock(&session->lock);
1623
1624         reason = iscsi_session_chkready(cls_session);
1625         if (reason) {
1626                 sc->result = reason;
1627                 goto fault;
1628         }
1629
1630         if (session->state != ISCSI_STATE_LOGGED_IN) {
1631                 /*
1632                  * to handle the race between when we set the recovery state
1633                  * and block the session we requeue here (commands could
1634                  * be entering our queuecommand while a block is starting
1635                  * up because the block code is not locked)
1636                  */
1637                 switch (session->state) {
1638                 case ISCSI_STATE_FAILED:
1639                 case ISCSI_STATE_IN_RECOVERY:
1640                         reason = FAILURE_SESSION_IN_RECOVERY;
1641                         sc->result = DID_IMM_RETRY << 16;
1642                         break;
1643                 case ISCSI_STATE_LOGGING_OUT:
1644                         reason = FAILURE_SESSION_LOGGING_OUT;
1645                         sc->result = DID_IMM_RETRY << 16;
1646                         break;
1647                 case ISCSI_STATE_RECOVERY_FAILED:
1648                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1649                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1650                         break;
1651                 case ISCSI_STATE_TERMINATE:
1652                         reason = FAILURE_SESSION_TERMINATE;
1653                         sc->result = DID_NO_CONNECT << 16;
1654                         break;
1655                 default:
1656                         reason = FAILURE_SESSION_FREED;
1657                         sc->result = DID_NO_CONNECT << 16;
1658                 }
1659                 goto fault;
1660         }
1661
1662         conn = session->leadconn;
1663         if (!conn) {
1664                 reason = FAILURE_SESSION_FREED;
1665                 sc->result = DID_NO_CONNECT << 16;
1666                 goto fault;
1667         }
1668
1669         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1670                 reason = FAILURE_SESSION_IN_RECOVERY;
1671                 sc->result = DID_REQUEUE;
1672                 goto fault;
1673         }
1674
1675         if (iscsi_check_cmdsn_window_closed(conn)) {
1676                 reason = FAILURE_WINDOW_CLOSED;
1677                 goto reject;
1678         }
1679
1680         task = iscsi_alloc_task(conn, sc);
1681         if (!task) {
1682                 reason = FAILURE_OOM;
1683                 goto reject;
1684         }
1685
1686         if (!ihost->workq) {
1687                 reason = iscsi_prep_scsi_cmd_pdu(task);
1688                 if (reason) {
1689                         if (reason == -ENOMEM ||  reason == -EACCES) {
1690                                 reason = FAILURE_OOM;
1691                                 goto prepd_reject;
1692                         } else {
1693                                 sc->result = DID_ABORT << 16;
1694                                 goto prepd_fault;
1695                         }
1696                 }
1697                 if (session->tt->xmit_task(task)) {
1698                         session->cmdsn--;
1699                         reason = FAILURE_SESSION_NOT_READY;
1700                         goto prepd_reject;
1701                 }
1702         } else {
1703                 list_add_tail(&task->running, &conn->cmdqueue);
1704                 iscsi_conn_queue_work(conn);
1705         }
1706
1707         session->queued_cmdsn++;
1708         spin_unlock(&session->lock);
1709         spin_lock(host->host_lock);
1710         return 0;
1711
1712 prepd_reject:
1713         sc->scsi_done = NULL;
1714         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1715 reject:
1716         spin_unlock(&session->lock);
1717         ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1718                           sc->cmnd[0], reason);
1719         spin_lock(host->host_lock);
1720         return SCSI_MLQUEUE_TARGET_BUSY;
1721
1722 prepd_fault:
1723         sc->scsi_done = NULL;
1724         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1725 fault:
1726         spin_unlock(&session->lock);
1727         ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1728                           sc->cmnd[0], reason);
1729         if (!scsi_bidi_cmnd(sc))
1730                 scsi_set_resid(sc, scsi_bufflen(sc));
1731         else {
1732                 scsi_out(sc)->resid = scsi_out(sc)->length;
1733                 scsi_in(sc)->resid = scsi_in(sc)->length;
1734         }
1735         done(sc);
1736         spin_lock(host->host_lock);
1737         return 0;
1738 }
1739
1740 DEF_SCSI_QCMD(iscsi_queuecommand)
1741 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1742
1743 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth, int reason)
1744 {
1745         switch (reason) {
1746         case SCSI_QDEPTH_DEFAULT:
1747                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1748                 break;
1749         case SCSI_QDEPTH_QFULL:
1750                 scsi_track_queue_full(sdev, depth);
1751                 break;
1752         case SCSI_QDEPTH_RAMP_UP:
1753                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1754                 break;
1755         default:
1756                 return -EOPNOTSUPP;
1757         }
1758         return sdev->queue_depth;
1759 }
1760 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1761
1762 int iscsi_target_alloc(struct scsi_target *starget)
1763 {
1764         struct iscsi_cls_session *cls_session = starget_to_session(starget);
1765         struct iscsi_session *session = cls_session->dd_data;
1766
1767         starget->can_queue = session->scsi_cmds_max;
1768         return 0;
1769 }
1770 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1771
1772 static void iscsi_tmf_timedout(unsigned long data)
1773 {
1774         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1775         struct iscsi_session *session = conn->session;
1776
1777         spin_lock(&session->lock);
1778         if (conn->tmf_state == TMF_QUEUED) {
1779                 conn->tmf_state = TMF_TIMEDOUT;
1780                 ISCSI_DBG_EH(session, "tmf timedout\n");
1781                 /* unblock eh_abort() */
1782                 wake_up(&conn->ehwait);
1783         }
1784         spin_unlock(&session->lock);
1785 }
1786
1787 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1788                                    struct iscsi_tm *hdr, int age,
1789                                    int timeout)
1790 {
1791         struct iscsi_session *session = conn->session;
1792         struct iscsi_task *task;
1793
1794         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1795                                       NULL, 0);
1796         if (!task) {
1797                 spin_unlock_bh(&session->lock);
1798                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1799                 spin_lock_bh(&session->lock);
1800                 ISCSI_DBG_EH(session, "tmf exec failure\n");
1801                 return -EPERM;
1802         }
1803         conn->tmfcmd_pdus_cnt++;
1804         conn->tmf_timer.expires = timeout * HZ + jiffies;
1805         conn->tmf_timer.function = iscsi_tmf_timedout;
1806         conn->tmf_timer.data = (unsigned long)conn;
1807         add_timer(&conn->tmf_timer);
1808         ISCSI_DBG_EH(session, "tmf set timeout\n");
1809
1810         spin_unlock_bh(&session->lock);
1811         mutex_unlock(&session->eh_mutex);
1812
1813         /*
1814          * block eh thread until:
1815          *
1816          * 1) tmf response
1817          * 2) tmf timeout
1818          * 3) session is terminated or restarted or userspace has
1819          * given up on recovery
1820          */
1821         wait_event_interruptible(conn->ehwait, age != session->age ||
1822                                  session->state != ISCSI_STATE_LOGGED_IN ||
1823                                  conn->tmf_state != TMF_QUEUED);
1824         if (signal_pending(current))
1825                 flush_signals(current);
1826         del_timer_sync(&conn->tmf_timer);
1827
1828         mutex_lock(&session->eh_mutex);
1829         spin_lock_bh(&session->lock);
1830         /* if the session drops it will clean up the task */
1831         if (age != session->age ||
1832             session->state != ISCSI_STATE_LOGGED_IN)
1833                 return -ENOTCONN;
1834         return 0;
1835 }
1836
1837 /*
1838  * Fail commands. session lock held and recv side suspended and xmit
1839  * thread flushed
1840  */
1841 static void fail_scsi_tasks(struct iscsi_conn *conn, unsigned lun,
1842                             int error)
1843 {
1844         struct iscsi_task *task;
1845         int i;
1846
1847         for (i = 0; i < conn->session->cmds_max; i++) {
1848                 task = conn->session->cmds[i];
1849                 if (!task->sc || task->state == ISCSI_TASK_FREE)
1850                         continue;
1851
1852                 if (lun != -1 && lun != task->sc->device->lun)
1853                         continue;
1854
1855                 ISCSI_DBG_SESSION(conn->session,
1856                                   "failing sc %p itt 0x%x state %d\n",
1857                                   task->sc, task->itt, task->state);
1858                 fail_scsi_task(task, error);
1859         }
1860 }
1861
1862 /**
1863  * iscsi_suspend_queue - suspend iscsi_queuecommand
1864  * @conn: iscsi conn to stop queueing IO on
1865  *
1866  * This grabs the session lock to make sure no one is in
1867  * xmit_task/queuecommand, and then sets suspend to prevent
1868  * new commands from being queued. This only needs to be called
1869  * by offload drivers that need to sync a path like ep disconnect
1870  * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1871  * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1872  */
1873 void iscsi_suspend_queue(struct iscsi_conn *conn)
1874 {
1875         spin_lock_bh(&conn->session->lock);
1876         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1877         spin_unlock_bh(&conn->session->lock);
1878 }
1879 EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1880
1881 /**
1882  * iscsi_suspend_tx - suspend iscsi_data_xmit
1883  * @conn: iscsi conn tp stop processing IO on.
1884  *
1885  * This function sets the suspend bit to prevent iscsi_data_xmit
1886  * from sending new IO, and if work is queued on the xmit thread
1887  * it will wait for it to be completed.
1888  */
1889 void iscsi_suspend_tx(struct iscsi_conn *conn)
1890 {
1891         struct Scsi_Host *shost = conn->session->host;
1892         struct iscsi_host *ihost = shost_priv(shost);
1893
1894         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1895         if (ihost->workq)
1896                 flush_workqueue(ihost->workq);
1897 }
1898 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1899
1900 static void iscsi_start_tx(struct iscsi_conn *conn)
1901 {
1902         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1903         iscsi_conn_queue_work(conn);
1904 }
1905
1906 /*
1907  * We want to make sure a ping is in flight. It has timed out.
1908  * And we are not busy processing a pdu that is making
1909  * progress but got started before the ping and is taking a while
1910  * to complete so the ping is just stuck behind it in a queue.
1911  */
1912 static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1913 {
1914         if (conn->ping_task &&
1915             time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1916                            (conn->ping_timeout * HZ), jiffies))
1917                 return 1;
1918         else
1919                 return 0;
1920 }
1921
1922 static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1923 {
1924         enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1925         struct iscsi_task *task = NULL, *running_task;
1926         struct iscsi_cls_session *cls_session;
1927         struct iscsi_session *session;
1928         struct iscsi_conn *conn;
1929         int i;
1930
1931         cls_session = starget_to_session(scsi_target(sc->device));
1932         session = cls_session->dd_data;
1933
1934         ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1935
1936         spin_lock(&session->lock);
1937         if (session->state != ISCSI_STATE_LOGGED_IN) {
1938                 /*
1939                  * We are probably in the middle of iscsi recovery so let
1940                  * that complete and handle the error.
1941                  */
1942                 rc = BLK_EH_RESET_TIMER;
1943                 goto done;
1944         }
1945
1946         conn = session->leadconn;
1947         if (!conn) {
1948                 /* In the middle of shuting down */
1949                 rc = BLK_EH_RESET_TIMER;
1950                 goto done;
1951         }
1952
1953         task = (struct iscsi_task *)sc->SCp.ptr;
1954         if (!task) {
1955                 /*
1956                  * Raced with completion. Just reset timer, and let it
1957                  * complete normally
1958                  */
1959                 rc = BLK_EH_RESET_TIMER;
1960                 goto done;
1961         }
1962
1963         /*
1964          * If we have sent (at least queued to the network layer) a pdu or
1965          * recvd one for the task since the last timeout ask for
1966          * more time. If on the next timeout we have not made progress
1967          * we can check if it is the task or connection when we send the
1968          * nop as a ping.
1969          */
1970         if (time_after(task->last_xfer, task->last_timeout)) {
1971                 ISCSI_DBG_EH(session, "Command making progress. Asking "
1972                              "scsi-ml for more time to complete. "
1973                              "Last data xfer at %lu. Last timeout was at "
1974                              "%lu\n.", task->last_xfer, task->last_timeout);
1975                 task->have_checked_conn = false;
1976                 rc = BLK_EH_RESET_TIMER;
1977                 goto done;
1978         }
1979
1980         if (!conn->recv_timeout && !conn->ping_timeout)
1981                 goto done;
1982         /*
1983          * if the ping timedout then we are in the middle of cleaning up
1984          * and can let the iscsi eh handle it
1985          */
1986         if (iscsi_has_ping_timed_out(conn)) {
1987                 rc = BLK_EH_RESET_TIMER;
1988                 goto done;
1989         }
1990
1991         for (i = 0; i < conn->session->cmds_max; i++) {
1992                 running_task = conn->session->cmds[i];
1993                 if (!running_task->sc || running_task == task ||
1994                      running_task->state != ISCSI_TASK_RUNNING)
1995                         continue;
1996
1997                 /*
1998                  * Only check if cmds started before this one have made
1999                  * progress, or this could never fail
2000                  */
2001                 if (time_after(running_task->sc->jiffies_at_alloc,
2002                                task->sc->jiffies_at_alloc))
2003                         continue;
2004
2005                 if (time_after(running_task->last_xfer, task->last_timeout)) {
2006                         /*
2007                          * This task has not made progress, but a task
2008                          * started before us has transferred data since
2009                          * we started/last-checked. We could be queueing
2010                          * too many tasks or the LU is bad.
2011                          *
2012                          * If the device is bad the cmds ahead of us on
2013                          * other devs will complete, and this loop will
2014                          * eventually fail starting the scsi eh.
2015                          */
2016                         ISCSI_DBG_EH(session, "Command has not made progress "
2017                                      "but commands ahead of it have. "
2018                                      "Asking scsi-ml for more time to "
2019                                      "complete. Our last xfer vs running task "
2020                                      "last xfer %lu/%lu. Last check %lu.\n",
2021                                      task->last_xfer, running_task->last_xfer,
2022                                      task->last_timeout);
2023                         rc = BLK_EH_RESET_TIMER;
2024                         goto done;
2025                 }
2026         }
2027
2028         /* Assumes nop timeout is shorter than scsi cmd timeout */
2029         if (task->have_checked_conn)
2030                 goto done;
2031
2032         /*
2033          * Checking the transport already or nop from a cmd timeout still
2034          * running
2035          */
2036         if (conn->ping_task) {
2037                 task->have_checked_conn = true;
2038                 rc = BLK_EH_RESET_TIMER;
2039                 goto done;
2040         }
2041
2042         /* Make sure there is a transport check done */
2043         iscsi_send_nopout(conn, NULL);
2044         task->have_checked_conn = true;
2045         rc = BLK_EH_RESET_TIMER;
2046
2047 done:
2048         if (task)
2049                 task->last_timeout = jiffies;
2050         spin_unlock(&session->lock);
2051         ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2052                      "timer reset" : "nh");
2053         return rc;
2054 }
2055
2056 static void iscsi_check_transport_timeouts(unsigned long data)
2057 {
2058         struct iscsi_conn *conn = (struct iscsi_conn *)data;
2059         struct iscsi_session *session = conn->session;
2060         unsigned long recv_timeout, next_timeout = 0, last_recv;
2061
2062         spin_lock(&session->lock);
2063         if (session->state != ISCSI_STATE_LOGGED_IN)
2064                 goto done;
2065
2066         recv_timeout = conn->recv_timeout;
2067         if (!recv_timeout)
2068                 goto done;
2069
2070         recv_timeout *= HZ;
2071         last_recv = conn->last_recv;
2072
2073         if (iscsi_has_ping_timed_out(conn)) {
2074                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2075                                   "expired, recv timeout %d, last rx %lu, "
2076                                   "last ping %lu, now %lu\n",
2077                                   conn->ping_timeout, conn->recv_timeout,
2078                                   last_recv, conn->last_ping, jiffies);
2079                 spin_unlock(&session->lock);
2080                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
2081                 return;
2082         }
2083
2084         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2085                 /* send a ping to try to provoke some traffic */
2086                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2087                 iscsi_send_nopout(conn, NULL);
2088                 next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2089         } else
2090                 next_timeout = last_recv + recv_timeout;
2091
2092         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2093         mod_timer(&conn->transport_timer, next_timeout);
2094 done:
2095         spin_unlock(&session->lock);
2096 }
2097
2098 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2099                                       struct iscsi_tm *hdr)
2100 {
2101         memset(hdr, 0, sizeof(*hdr));
2102         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2103         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2104         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2105         memcpy(hdr->lun, task->lun, sizeof(hdr->lun));
2106         hdr->rtt = task->hdr_itt;
2107         hdr->refcmdsn = task->cmdsn;
2108 }
2109
2110 int iscsi_eh_abort(struct scsi_cmnd *sc)
2111 {
2112         struct iscsi_cls_session *cls_session;
2113         struct iscsi_session *session;
2114         struct iscsi_conn *conn;
2115         struct iscsi_task *task;
2116         struct iscsi_tm *hdr;
2117         int rc, age;
2118
2119         cls_session = starget_to_session(scsi_target(sc->device));
2120         session = cls_session->dd_data;
2121
2122         ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2123
2124         mutex_lock(&session->eh_mutex);
2125         spin_lock_bh(&session->lock);
2126         /*
2127          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2128          * got the command.
2129          */
2130         if (!sc->SCp.ptr) {
2131                 ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2132                                       "it completed.\n");
2133                 spin_unlock_bh(&session->lock);
2134                 mutex_unlock(&session->eh_mutex);
2135                 return SUCCESS;
2136         }
2137
2138         /*
2139          * If we are not logged in or we have started a new session
2140          * then let the host reset code handle this
2141          */
2142         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2143             sc->SCp.phase != session->age) {
2144                 spin_unlock_bh(&session->lock);
2145                 mutex_unlock(&session->eh_mutex);
2146                 ISCSI_DBG_EH(session, "failing abort due to dropped "
2147                                   "session.\n");
2148                 return FAILED;
2149         }
2150
2151         conn = session->leadconn;
2152         conn->eh_abort_cnt++;
2153         age = session->age;
2154
2155         task = (struct iscsi_task *)sc->SCp.ptr;
2156         ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2157                      sc, task->itt);
2158
2159         /* task completed before time out */
2160         if (!task->sc) {
2161                 ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2162                 goto success;
2163         }
2164
2165         if (task->state == ISCSI_TASK_PENDING) {
2166                 fail_scsi_task(task, DID_ABORT);
2167                 goto success;
2168         }
2169
2170         /* only have one tmf outstanding at a time */
2171         if (conn->tmf_state != TMF_INITIAL)
2172                 goto failed;
2173         conn->tmf_state = TMF_QUEUED;
2174
2175         hdr = &conn->tmhdr;
2176         iscsi_prep_abort_task_pdu(task, hdr);
2177
2178         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
2179                 rc = FAILED;
2180                 goto failed;
2181         }
2182
2183         switch (conn->tmf_state) {
2184         case TMF_SUCCESS:
2185                 spin_unlock_bh(&session->lock);
2186                 /*
2187                  * stop tx side incase the target had sent a abort rsp but
2188                  * the initiator was still writing out data.
2189                  */
2190                 iscsi_suspend_tx(conn);
2191                 /*
2192                  * we do not stop the recv side because targets have been
2193                  * good and have never sent us a successful tmf response
2194                  * then sent more data for the cmd.
2195                  */
2196                 spin_lock_bh(&session->lock);
2197                 fail_scsi_task(task, DID_ABORT);
2198                 conn->tmf_state = TMF_INITIAL;
2199                 memset(hdr, 0, sizeof(*hdr));
2200                 spin_unlock_bh(&session->lock);
2201                 iscsi_start_tx(conn);
2202                 goto success_unlocked;
2203         case TMF_TIMEDOUT:
2204                 spin_unlock_bh(&session->lock);
2205                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
2206                 goto failed_unlocked;
2207         case TMF_NOT_FOUND:
2208                 if (!sc->SCp.ptr) {
2209                         conn->tmf_state = TMF_INITIAL;
2210                         memset(hdr, 0, sizeof(*hdr));
2211                         /* task completed before tmf abort response */
2212                         ISCSI_DBG_EH(session, "sc completed while abort in "
2213                                               "progress\n");
2214                         goto success;
2215                 }
2216                 /* fall through */
2217         default:
2218                 conn->tmf_state = TMF_INITIAL;
2219                 goto failed;
2220         }
2221
2222 success:
2223         spin_unlock_bh(&session->lock);
2224 success_unlocked:
2225         ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2226                      sc, task->itt);
2227         mutex_unlock(&session->eh_mutex);
2228         return SUCCESS;
2229
2230 failed:
2231         spin_unlock_bh(&session->lock);
2232 failed_unlocked:
2233         ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2234                      task ? task->itt : 0);
2235         mutex_unlock(&session->eh_mutex);
2236         return FAILED;
2237 }
2238 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2239
2240 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2241 {
2242         memset(hdr, 0, sizeof(*hdr));
2243         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2244         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2245         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2246         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
2247         hdr->rtt = RESERVED_ITT;
2248 }
2249
2250 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2251 {
2252         struct iscsi_cls_session *cls_session;
2253         struct iscsi_session *session;
2254         struct iscsi_conn *conn;
2255         struct iscsi_tm *hdr;
2256         int rc = FAILED;
2257
2258         cls_session = starget_to_session(scsi_target(sc->device));
2259         session = cls_session->dd_data;
2260
2261         ISCSI_DBG_EH(session, "LU Reset [sc %p lun %u]\n", sc, sc->device->lun);
2262
2263         mutex_lock(&session->eh_mutex);
2264         spin_lock_bh(&session->lock);
2265         /*
2266          * Just check if we are not logged in. We cannot check for
2267          * the phase because the reset could come from a ioctl.
2268          */
2269         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2270                 goto unlock;
2271         conn = session->leadconn;
2272
2273         /* only have one tmf outstanding at a time */
2274         if (conn->tmf_state != TMF_INITIAL)
2275                 goto unlock;
2276         conn->tmf_state = TMF_QUEUED;
2277
2278         hdr = &conn->tmhdr;
2279         iscsi_prep_lun_reset_pdu(sc, hdr);
2280
2281         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2282                                     session->lu_reset_timeout)) {
2283                 rc = FAILED;
2284                 goto unlock;
2285         }
2286
2287         switch (conn->tmf_state) {
2288         case TMF_SUCCESS:
2289                 break;
2290         case TMF_TIMEDOUT:
2291                 spin_unlock_bh(&session->lock);
2292                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
2293                 goto done;
2294         default:
2295                 conn->tmf_state = TMF_INITIAL;
2296                 goto unlock;
2297         }
2298
2299         rc = SUCCESS;
2300         spin_unlock_bh(&session->lock);
2301
2302         iscsi_suspend_tx(conn);
2303
2304         spin_lock_bh(&session->lock);
2305         memset(hdr, 0, sizeof(*hdr));
2306         fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2307         conn->tmf_state = TMF_INITIAL;
2308         spin_unlock_bh(&session->lock);
2309
2310         iscsi_start_tx(conn);
2311         goto done;
2312
2313 unlock:
2314         spin_unlock_bh(&session->lock);
2315 done:
2316         ISCSI_DBG_EH(session, "dev reset result = %s\n",
2317                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2318         mutex_unlock(&session->eh_mutex);
2319         return rc;
2320 }
2321 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2322
2323 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2324 {
2325         struct iscsi_session *session = cls_session->dd_data;
2326
2327         spin_lock_bh(&session->lock);
2328         if (session->state != ISCSI_STATE_LOGGED_IN) {
2329                 session->state = ISCSI_STATE_RECOVERY_FAILED;
2330                 if (session->leadconn)
2331                         wake_up(&session->leadconn->ehwait);
2332         }
2333         spin_unlock_bh(&session->lock);
2334 }
2335 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2336
2337 /**
2338  * iscsi_eh_session_reset - drop session and attempt relogin
2339  * @sc: scsi command
2340  *
2341  * This function will wait for a relogin, session termination from
2342  * userspace, or a recovery/replacement timeout.
2343  */
2344 int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2345 {
2346         struct iscsi_cls_session *cls_session;
2347         struct iscsi_session *session;
2348         struct iscsi_conn *conn;
2349
2350         cls_session = starget_to_session(scsi_target(sc->device));
2351         session = cls_session->dd_data;
2352         conn = session->leadconn;
2353
2354         mutex_lock(&session->eh_mutex);
2355         spin_lock_bh(&session->lock);
2356         if (session->state == ISCSI_STATE_TERMINATE) {
2357 failed:
2358                 ISCSI_DBG_EH(session,
2359                              "failing session reset: Could not log back into "
2360                              "%s, %s [age %d]\n", session->targetname,
2361                              conn->persistent_address, session->age);
2362                 spin_unlock_bh(&session->lock);
2363                 mutex_unlock(&session->eh_mutex);
2364                 return FAILED;
2365         }
2366
2367         spin_unlock_bh(&session->lock);
2368         mutex_unlock(&session->eh_mutex);
2369         /*
2370          * we drop the lock here but the leadconn cannot be destoyed while
2371          * we are in the scsi eh
2372          */
2373         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
2374
2375         ISCSI_DBG_EH(session, "wait for relogin\n");
2376         wait_event_interruptible(conn->ehwait,
2377                                  session->state == ISCSI_STATE_TERMINATE ||
2378                                  session->state == ISCSI_STATE_LOGGED_IN ||
2379                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
2380         if (signal_pending(current))
2381                 flush_signals(current);
2382
2383         mutex_lock(&session->eh_mutex);
2384         spin_lock_bh(&session->lock);
2385         if (session->state == ISCSI_STATE_LOGGED_IN) {
2386                 ISCSI_DBG_EH(session,
2387                              "session reset succeeded for %s,%s\n",
2388                              session->targetname, conn->persistent_address);
2389         } else
2390                 goto failed;
2391         spin_unlock_bh(&session->lock);
2392         mutex_unlock(&session->eh_mutex);
2393         return SUCCESS;
2394 }
2395 EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2396
2397 static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2398 {
2399         memset(hdr, 0, sizeof(*hdr));
2400         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2401         hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2402         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2403         hdr->rtt = RESERVED_ITT;
2404 }
2405
2406 /**
2407  * iscsi_eh_target_reset - reset target
2408  * @sc: scsi command
2409  *
2410  * This will attempt to send a warm target reset.
2411  */
2412 int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2413 {
2414         struct iscsi_cls_session *cls_session;
2415         struct iscsi_session *session;
2416         struct iscsi_conn *conn;
2417         struct iscsi_tm *hdr;
2418         int rc = FAILED;
2419
2420         cls_session = starget_to_session(scsi_target(sc->device));
2421         session = cls_session->dd_data;
2422
2423         ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2424                      session->targetname);
2425
2426         mutex_lock(&session->eh_mutex);
2427         spin_lock_bh(&session->lock);
2428         /*
2429          * Just check if we are not logged in. We cannot check for
2430          * the phase because the reset could come from a ioctl.
2431          */
2432         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2433                 goto unlock;
2434         conn = session->leadconn;
2435
2436         /* only have one tmf outstanding at a time */
2437         if (conn->tmf_state != TMF_INITIAL)
2438                 goto unlock;
2439         conn->tmf_state = TMF_QUEUED;
2440
2441         hdr = &conn->tmhdr;
2442         iscsi_prep_tgt_reset_pdu(sc, hdr);
2443
2444         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2445                                     session->tgt_reset_timeout)) {
2446                 rc = FAILED;
2447                 goto unlock;
2448         }
2449
2450         switch (conn->tmf_state) {
2451         case TMF_SUCCESS:
2452                 break;
2453         case TMF_TIMEDOUT:
2454                 spin_unlock_bh(&session->lock);
2455                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
2456                 goto done;
2457         default:
2458                 conn->tmf_state = TMF_INITIAL;
2459                 goto unlock;
2460         }
2461
2462         rc = SUCCESS;
2463         spin_unlock_bh(&session->lock);
2464
2465         iscsi_suspend_tx(conn);
2466
2467         spin_lock_bh(&session->lock);
2468         memset(hdr, 0, sizeof(*hdr));
2469         fail_scsi_tasks(conn, -1, DID_ERROR);
2470         conn->tmf_state = TMF_INITIAL;
2471         spin_unlock_bh(&session->lock);
2472
2473         iscsi_start_tx(conn);
2474         goto done;
2475
2476 unlock:
2477         spin_unlock_bh(&session->lock);
2478 done:
2479         ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2480                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2481         mutex_unlock(&session->eh_mutex);
2482         return rc;
2483 }
2484 EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
2485
2486 /**
2487  * iscsi_eh_recover_target - reset target and possibly the session
2488  * @sc: scsi command
2489  *
2490  * This will attempt to send a warm target reset. If that fails,
2491  * we will escalate to ERL0 session recovery.
2492  */
2493 int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2494 {
2495         int rc;
2496
2497         rc = iscsi_eh_target_reset(sc);
2498         if (rc == FAILED)
2499                 rc = iscsi_eh_session_reset(sc);
2500         return rc;
2501 }
2502 EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2503
2504 /*
2505  * Pre-allocate a pool of @max items of @item_size. By default, the pool
2506  * should be accessed via kfifo_{get,put} on q->queue.
2507  * Optionally, the caller can obtain the array of object pointers
2508  * by passing in a non-NULL @items pointer
2509  */
2510 int
2511 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2512 {
2513         int i, num_arrays = 1;
2514
2515         memset(q, 0, sizeof(*q));
2516
2517         q->max = max;
2518
2519         /* If the user passed an items pointer, he wants a copy of
2520          * the array. */
2521         if (items)
2522                 num_arrays++;
2523         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
2524         if (q->pool == NULL)
2525                 return -ENOMEM;
2526
2527         kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2528
2529         for (i = 0; i < max; i++) {
2530                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2531                 if (q->pool[i] == NULL) {
2532                         q->max = i;
2533                         goto enomem;
2534                 }
2535                 kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2536         }
2537
2538         if (items) {
2539                 *items = q->pool + max;
2540                 memcpy(*items, q->pool, max * sizeof(void *));
2541         }
2542
2543         return 0;
2544
2545 enomem:
2546         iscsi_pool_free(q);
2547         return -ENOMEM;
2548 }
2549 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2550
2551 void iscsi_pool_free(struct iscsi_pool *q)
2552 {
2553         int i;
2554
2555         for (i = 0; i < q->max; i++)
2556                 kfree(q->pool[i]);
2557         kfree(q->pool);
2558 }
2559 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2560
2561 /**
2562  * iscsi_host_add - add host to system
2563  * @shost: scsi host
2564  * @pdev: parent device
2565  *
2566  * This should be called by partial offload and software iscsi drivers
2567  * to add a host to the system.
2568  */
2569 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2570 {
2571         if (!shost->can_queue)
2572                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2573
2574         if (!shost->cmd_per_lun)
2575                 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2576
2577         if (!shost->transportt->eh_timed_out)
2578                 shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
2579         return scsi_add_host(shost, pdev);
2580 }
2581 EXPORT_SYMBOL_GPL(iscsi_host_add);
2582
2583 /**
2584  * iscsi_host_alloc - allocate a host and driver data
2585  * @sht: scsi host template
2586  * @dd_data_size: driver host data size
2587  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2588  *
2589  * This should be called by partial offload and software iscsi drivers.
2590  * To access the driver specific memory use the iscsi_host_priv() macro.
2591  */
2592 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2593                                    int dd_data_size, bool xmit_can_sleep)
2594 {
2595         struct Scsi_Host *shost;
2596         struct iscsi_host *ihost;
2597
2598         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2599         if (!shost)
2600                 return NULL;
2601         ihost = shost_priv(shost);
2602
2603         if (xmit_can_sleep) {
2604                 snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2605                         "iscsi_q_%d", shost->host_no);
2606                 ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2607                 if (!ihost->workq)
2608                         goto free_host;
2609         }
2610
2611         spin_lock_init(&ihost->lock);
2612         ihost->state = ISCSI_HOST_SETUP;
2613         ihost->num_sessions = 0;
2614         init_waitqueue_head(&ihost->session_removal_wq);
2615         return shost;
2616
2617 free_host:
2618         scsi_host_put(shost);
2619         return NULL;
2620 }
2621 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2622
2623 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2624 {
2625         iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2626 }
2627
2628 /**
2629  * iscsi_host_remove - remove host and sessions
2630  * @shost: scsi host
2631  *
2632  * If there are any sessions left, this will initiate the removal and wait
2633  * for the completion.
2634  */
2635 void iscsi_host_remove(struct Scsi_Host *shost)
2636 {
2637         struct iscsi_host *ihost = shost_priv(shost);
2638         unsigned long flags;
2639
2640         spin_lock_irqsave(&ihost->lock, flags);
2641         ihost->state = ISCSI_HOST_REMOVED;
2642         spin_unlock_irqrestore(&ihost->lock, flags);
2643
2644         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2645         wait_event_interruptible(ihost->session_removal_wq,
2646                                  ihost->num_sessions == 0);
2647         if (signal_pending(current))
2648                 flush_signals(current);
2649
2650         scsi_remove_host(shost);
2651         if (ihost->workq)
2652                 destroy_workqueue(ihost->workq);
2653 }
2654 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2655
2656 void iscsi_host_free(struct Scsi_Host *shost)
2657 {
2658         struct iscsi_host *ihost = shost_priv(shost);
2659
2660         kfree(ihost->netdev);
2661         kfree(ihost->hwaddress);
2662         kfree(ihost->initiatorname);
2663         scsi_host_put(shost);
2664 }
2665 EXPORT_SYMBOL_GPL(iscsi_host_free);
2666
2667 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2668 {
2669         struct iscsi_host *ihost = shost_priv(shost);
2670         unsigned long flags;
2671
2672         shost = scsi_host_get(shost);
2673         if (!shost) {
2674                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2675                       "of session teardown event because host already "
2676                       "removed.\n");
2677                 return;
2678         }
2679
2680         spin_lock_irqsave(&ihost->lock, flags);
2681         ihost->num_sessions--;
2682         if (ihost->num_sessions == 0)
2683                 wake_up(&ihost->session_removal_wq);
2684         spin_unlock_irqrestore(&ihost->lock, flags);
2685         scsi_host_put(shost);
2686 }
2687
2688 /**
2689  * iscsi_session_setup - create iscsi cls session and host and session
2690  * @iscsit: iscsi transport template
2691  * @shost: scsi host
2692  * @cmds_max: session can queue
2693  * @cmd_task_size: LLD task private data size
2694  * @initial_cmdsn: initial CmdSN
2695  *
2696  * This can be used by software iscsi_transports that allocate
2697  * a session per scsi host.
2698  *
2699  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2700  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2701  * for nop handling and login/logout requests.
2702  */
2703 struct iscsi_cls_session *
2704 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2705                     uint16_t cmds_max, int dd_size, int cmd_task_size,
2706                     uint32_t initial_cmdsn, unsigned int id)
2707 {
2708         struct iscsi_host *ihost = shost_priv(shost);
2709         struct iscsi_session *session;
2710         struct iscsi_cls_session *cls_session;
2711         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2712         unsigned long flags;
2713
2714         spin_lock_irqsave(&ihost->lock, flags);
2715         if (ihost->state == ISCSI_HOST_REMOVED) {
2716                 spin_unlock_irqrestore(&ihost->lock, flags);
2717                 return NULL;
2718         }
2719         ihost->num_sessions++;
2720         spin_unlock_irqrestore(&ihost->lock, flags);
2721
2722         if (!total_cmds)
2723                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2724         /*
2725          * The iscsi layer needs some tasks for nop handling and tmfs,
2726          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2727          * + 1 command for scsi IO.
2728          */
2729         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2730                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2731                        "must be a power of two that is at least %d.\n",
2732                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2733                 goto dec_session_count;
2734         }
2735
2736         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2737                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2738                        "must be a power of 2 less than or equal to %d.\n",
2739                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2740                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2741         }
2742
2743         if (!is_power_of_2(total_cmds)) {
2744                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2745                        "must be a power of 2.\n", total_cmds);
2746                 total_cmds = rounddown_pow_of_two(total_cmds);
2747                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2748                         return NULL;
2749                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2750                        total_cmds);
2751         }
2752         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2753
2754         cls_session = iscsi_alloc_session(shost, iscsit,
2755                                           sizeof(struct iscsi_session) +
2756                                           dd_size);
2757         if (!cls_session)
2758                 goto dec_session_count;
2759         session = cls_session->dd_data;
2760         session->cls_session = cls_session;
2761         session->host = shost;
2762         session->state = ISCSI_STATE_FREE;
2763         session->fast_abort = 1;
2764         session->tgt_reset_timeout = 30;
2765         session->lu_reset_timeout = 15;
2766         session->abort_timeout = 10;
2767         session->scsi_cmds_max = scsi_cmds;
2768         session->cmds_max = total_cmds;
2769         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2770         session->exp_cmdsn = initial_cmdsn + 1;
2771         session->max_cmdsn = initial_cmdsn + 1;
2772         session->max_r2t = 1;
2773         session->tt = iscsit;
2774         session->dd_data = cls_session->dd_data + sizeof(*session);
2775         mutex_init(&session->eh_mutex);
2776         spin_lock_init(&session->lock);
2777
2778         /* initialize SCSI PDU commands pool */
2779         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2780                             (void***)&session->cmds,
2781                             cmd_task_size + sizeof(struct iscsi_task)))
2782                 goto cmdpool_alloc_fail;
2783
2784         /* pre-format cmds pool with ITT */
2785         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2786                 struct iscsi_task *task = session->cmds[cmd_i];
2787
2788                 if (cmd_task_size)
2789                         task->dd_data = &task[1];
2790                 task->itt = cmd_i;
2791                 task->state = ISCSI_TASK_FREE;
2792                 INIT_LIST_HEAD(&task->running);
2793         }
2794
2795         if (!try_module_get(iscsit->owner))
2796                 goto module_get_fail;
2797
2798         if (iscsi_add_session(cls_session, id))
2799                 goto cls_session_fail;
2800
2801         return cls_session;
2802
2803 cls_session_fail:
2804         module_put(iscsit->owner);
2805 module_get_fail:
2806         iscsi_pool_free(&session->cmdpool);
2807 cmdpool_alloc_fail:
2808         iscsi_free_session(cls_session);
2809 dec_session_count:
2810         iscsi_host_dec_session_cnt(shost);
2811         return NULL;
2812 }
2813 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2814
2815 /**
2816  * iscsi_session_teardown - destroy session, host, and cls_session
2817  * @cls_session: iscsi session
2818  *
2819  * The driver must have called iscsi_remove_session before
2820  * calling this.
2821  */
2822 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2823 {
2824         struct iscsi_session *session = cls_session->dd_data;
2825         struct module *owner = cls_session->transport->owner;
2826         struct Scsi_Host *shost = session->host;
2827
2828         iscsi_pool_free(&session->cmdpool);
2829
2830         kfree(session->password);
2831         kfree(session->password_in);
2832         kfree(session->username);
2833         kfree(session->username_in);
2834         kfree(session->targetname);
2835         kfree(session->initiatorname);
2836         kfree(session->ifacename);
2837
2838         iscsi_destroy_session(cls_session);
2839         iscsi_host_dec_session_cnt(shost);
2840         module_put(owner);
2841 }
2842 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2843
2844 /**
2845  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2846  * @cls_session: iscsi_cls_session
2847  * @dd_size: private driver data size
2848  * @conn_idx: cid
2849  */
2850 struct iscsi_cls_conn *
2851 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2852                  uint32_t conn_idx)
2853 {
2854         struct iscsi_session *session = cls_session->dd_data;
2855         struct iscsi_conn *conn;
2856         struct iscsi_cls_conn *cls_conn;
2857         char *data;
2858
2859         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2860                                      conn_idx);
2861         if (!cls_conn)
2862                 return NULL;
2863         conn = cls_conn->dd_data;
2864         memset(conn, 0, sizeof(*conn) + dd_size);
2865
2866         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2867         conn->session = session;
2868         conn->cls_conn = cls_conn;
2869         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2870         conn->id = conn_idx;
2871         conn->exp_statsn = 0;
2872         conn->tmf_state = TMF_INITIAL;
2873
2874         init_timer(&conn->transport_timer);
2875         conn->transport_timer.data = (unsigned long)conn;
2876         conn->transport_timer.function = iscsi_check_transport_timeouts;
2877
2878         INIT_LIST_HEAD(&conn->mgmtqueue);
2879         INIT_LIST_HEAD(&conn->cmdqueue);
2880         INIT_LIST_HEAD(&conn->requeue);
2881         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2882
2883         /* allocate login_task used for the login/text sequences */
2884         spin_lock_bh(&session->lock);
2885         if (!kfifo_out(&session->cmdpool.queue,
2886                          (void*)&conn->login_task,
2887                          sizeof(void*))) {
2888                 spin_unlock_bh(&session->lock);
2889                 goto login_task_alloc_fail;
2890         }
2891         spin_unlock_bh(&session->lock);
2892
2893         data = (char *) __get_free_pages(GFP_KERNEL,
2894                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2895         if (!data)
2896                 goto login_task_data_alloc_fail;
2897         conn->login_task->data = conn->data = data;
2898
2899         init_timer(&conn->tmf_timer);
2900         init_waitqueue_head(&conn->ehwait);
2901
2902         return cls_conn;
2903
2904 login_task_data_alloc_fail:
2905         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2906                     sizeof(void*));
2907 login_task_alloc_fail:
2908         iscsi_destroy_conn(cls_conn);
2909         return NULL;
2910 }
2911 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2912
2913 /**
2914  * iscsi_conn_teardown - teardown iscsi connection
2915  * cls_conn: iscsi class connection
2916  *
2917  * TODO: we may need to make this into a two step process
2918  * like scsi-mls remove + put host
2919  */
2920 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2921 {
2922         struct iscsi_conn *conn = cls_conn->dd_data;
2923         struct iscsi_session *session = conn->session;
2924         unsigned long flags;
2925
2926         del_timer_sync(&conn->transport_timer);
2927
2928         spin_lock_bh(&session->lock);
2929         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2930         if (session->leadconn == conn) {
2931                 /*
2932                  * leading connection? then give up on recovery.
2933                  */
2934                 session->state = ISCSI_STATE_TERMINATE;
2935                 wake_up(&conn->ehwait);
2936         }
2937         spin_unlock_bh(&session->lock);
2938
2939         /*
2940          * Block until all in-progress commands for this connection
2941          * time out or fail.
2942          */
2943         for (;;) {
2944                 spin_lock_irqsave(session->host->host_lock, flags);
2945                 if (!session->host->host_busy) { /* OK for ERL == 0 */
2946                         spin_unlock_irqrestore(session->host->host_lock, flags);
2947                         break;
2948                 }
2949                 spin_unlock_irqrestore(session->host->host_lock, flags);
2950                 msleep_interruptible(500);
2951                 iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2952                                   "host_busy %d host_failed %d\n",
2953                                   session->host->host_busy,
2954                                   session->host->host_failed);
2955                 /*
2956                  * force eh_abort() to unblock
2957                  */
2958                 wake_up(&conn->ehwait);
2959         }
2960
2961         /* flush queued up work because we free the connection below */
2962         iscsi_suspend_tx(conn);
2963
2964         spin_lock_bh(&session->lock);
2965         free_pages((unsigned long) conn->data,
2966                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2967         kfree(conn->persistent_address);
2968         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2969                     sizeof(void*));
2970         if (session->leadconn == conn)
2971                 session->leadconn = NULL;
2972         spin_unlock_bh(&session->lock);
2973
2974         iscsi_destroy_conn(cls_conn);
2975 }
2976 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2977
2978 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2979 {
2980         struct iscsi_conn *conn = cls_conn->dd_data;
2981         struct iscsi_session *session = conn->session;
2982
2983         if (!session) {
2984                 iscsi_conn_printk(KERN_ERR, conn,
2985                                   "can't start unbound connection\n");
2986                 return -EPERM;
2987         }
2988
2989         if ((session->imm_data_en || !session->initial_r2t_en) &&
2990              session->first_burst > session->max_burst) {
2991                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2992                                   "first_burst %d max_burst %d\n",
2993                                   session->first_burst, session->max_burst);
2994                 return -EINVAL;
2995         }
2996
2997         if (conn->ping_timeout && !conn->recv_timeout) {
2998                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
2999                                   "zero. Using 5 seconds\n.");
3000                 conn->recv_timeout = 5;
3001         }
3002
3003         if (conn->recv_timeout && !conn->ping_timeout) {
3004                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3005                                   "zero. Using 5 seconds.\n");
3006                 conn->ping_timeout = 5;
3007         }
3008
3009         spin_lock_bh(&session->lock);
3010         conn->c_stage = ISCSI_CONN_STARTED;
3011         session->state = ISCSI_STATE_LOGGED_IN;
3012         session->queued_cmdsn = session->cmdsn;
3013
3014         conn->last_recv = jiffies;
3015         conn->last_ping = jiffies;
3016         if (conn->recv_timeout && conn->ping_timeout)
3017                 mod_timer(&conn->transport_timer,
3018                           jiffies + (conn->recv_timeout * HZ));
3019
3020         switch(conn->stop_stage) {
3021         case STOP_CONN_RECOVER:
3022                 /*
3023                  * unblock eh_abort() if it is blocked. re-try all
3024                  * commands after successful recovery
3025                  */
3026                 conn->stop_stage = 0;
3027                 conn->tmf_state = TMF_INITIAL;
3028                 session->age++;
3029                 if (session->age == 16)
3030                         session->age = 0;
3031                 break;
3032         case STOP_CONN_TERM:
3033                 conn->stop_stage = 0;
3034                 break;
3035         default:
3036                 break;
3037         }
3038         spin_unlock_bh(&session->lock);
3039
3040         iscsi_unblock_session(session->cls_session);
3041         wake_up(&conn->ehwait);
3042         return 0;
3043 }
3044 EXPORT_SYMBOL_GPL(iscsi_conn_start);
3045
3046 static void
3047 fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3048 {
3049         struct iscsi_task *task;
3050         int i, state;
3051
3052         for (i = 0; i < conn->session->cmds_max; i++) {
3053                 task = conn->session->cmds[i];
3054                 if (task->sc)
3055                         continue;
3056
3057                 if (task->state == ISCSI_TASK_FREE)
3058                         continue;
3059
3060                 ISCSI_DBG_SESSION(conn->session,
3061                                   "failing mgmt itt 0x%x state %d\n",
3062                                   task->itt, task->state);
3063                 state = ISCSI_TASK_ABRT_SESS_RECOV;
3064                 if (task->state == ISCSI_TASK_PENDING)
3065                         state = ISCSI_TASK_COMPLETED;
3066                 iscsi_complete_task(task, state);
3067
3068         }
3069 }
3070
3071 static void iscsi_start_session_recovery(struct iscsi_session *session,
3072                                          struct iscsi_conn *conn, int flag)
3073 {
3074         int old_stop_stage;
3075
3076         mutex_lock(&session->eh_mutex);
3077         spin_lock_bh(&session->lock);
3078         if (conn->stop_stage == STOP_CONN_TERM) {
3079                 spin_unlock_bh(&session->lock);
3080                 mutex_unlock(&session->eh_mutex);
3081                 return;
3082         }
3083
3084         /*
3085          * When this is called for the in_login state, we only want to clean
3086          * up the login task and connection. We do not need to block and set
3087          * the recovery state again
3088          */
3089         if (flag == STOP_CONN_TERM)
3090                 session->state = ISCSI_STATE_TERMINATE;
3091         else if (conn->stop_stage != STOP_CONN_RECOVER)
3092                 session->state = ISCSI_STATE_IN_RECOVERY;
3093
3094         old_stop_stage = conn->stop_stage;
3095         conn->stop_stage = flag;
3096         spin_unlock_bh(&session->lock);
3097
3098         del_timer_sync(&conn->transport_timer);
3099         iscsi_suspend_tx(conn);
3100
3101         spin_lock_bh(&session->lock);
3102         conn->c_stage = ISCSI_CONN_STOPPED;
3103         spin_unlock_bh(&session->lock);
3104
3105         /*
3106          * for connection level recovery we should not calculate
3107          * header digest. conn->hdr_size used for optimization
3108          * in hdr_extract() and will be re-negotiated at
3109          * set_param() time.
3110          */
3111         if (flag == STOP_CONN_RECOVER) {
3112                 conn->hdrdgst_en = 0;
3113                 conn->datadgst_en = 0;
3114                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
3115                     old_stop_stage != STOP_CONN_RECOVER) {
3116                         ISCSI_DBG_SESSION(session, "blocking session\n");
3117                         iscsi_block_session(session->cls_session);
3118                 }
3119         }
3120
3121         /*
3122          * flush queues.
3123          */
3124         spin_lock_bh(&session->lock);
3125         fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3126         fail_mgmt_tasks(session, conn);
3127         memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3128         spin_unlock_bh(&session->lock);
3129         mutex_unlock(&session->eh_mutex);
3130 }
3131
3132 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3133 {
3134         struct iscsi_conn *conn = cls_conn->dd_data;
3135         struct iscsi_session *session = conn->session;
3136
3137         switch (flag) {
3138         case STOP_CONN_RECOVER:
3139         case STOP_CONN_TERM:
3140                 iscsi_start_session_recovery(session, conn, flag);
3141                 break;
3142         default:
3143                 iscsi_conn_printk(KERN_ERR, conn,
3144                                   "invalid stop flag %d\n", flag);
3145         }
3146 }
3147 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3148
3149 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3150                     struct iscsi_cls_conn *cls_conn, int is_leading)
3151 {
3152         struct iscsi_session *session = cls_session->dd_data;
3153         struct iscsi_conn *conn = cls_conn->dd_data;
3154
3155         spin_lock_bh(&session->lock);
3156         if (is_leading)
3157                 session->leadconn = conn;
3158         spin_unlock_bh(&session->lock);
3159
3160         /*
3161          * Unblock xmitworker(), Login Phase will pass through.
3162          */
3163         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3164         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3165         return 0;
3166 }
3167 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3168
3169 static int iscsi_switch_str_param(char **param, char *new_val_buf)
3170 {
3171         char *new_val;
3172
3173         if (*param) {
3174                 if (!strcmp(*param, new_val_buf))
3175                         return 0;
3176         }
3177
3178         new_val = kstrdup(new_val_buf, GFP_NOIO);
3179         if (!new_val)
3180                 return -ENOMEM;
3181
3182         kfree(*param);
3183         *param = new_val;
3184         return 0;
3185 }
3186
3187 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3188                     enum iscsi_param param, char *buf, int buflen)
3189 {
3190         struct iscsi_conn *conn = cls_conn->dd_data;
3191         struct iscsi_session *session = conn->session;
3192         uint32_t value;
3193
3194         switch(param) {
3195         case ISCSI_PARAM_FAST_ABORT:
3196                 sscanf(buf, "%d", &session->fast_abort);
3197                 break;
3198         case ISCSI_PARAM_ABORT_TMO:
3199                 sscanf(buf, "%d", &session->abort_timeout);
3200                 break;
3201         case ISCSI_PARAM_LU_RESET_TMO:
3202                 sscanf(buf, "%d", &session->lu_reset_timeout);
3203                 break;
3204         case ISCSI_PARAM_TGT_RESET_TMO:
3205                 sscanf(buf, "%d", &session->tgt_reset_timeout);
3206                 break;
3207         case ISCSI_PARAM_PING_TMO:
3208                 sscanf(buf, "%d", &conn->ping_timeout);
3209                 break;
3210         case ISCSI_PARAM_RECV_TMO:
3211                 sscanf(buf, "%d", &conn->recv_timeout);
3212                 break;
3213         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3214                 sscanf(buf, "%d", &conn->max_recv_dlength);
3215                 break;
3216         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3217                 sscanf(buf, "%d", &conn->max_xmit_dlength);
3218                 break;
3219         case ISCSI_PARAM_HDRDGST_EN:
3220                 sscanf(buf, "%d", &conn->hdrdgst_en);
3221                 break;
3222         case ISCSI_PARAM_DATADGST_EN:
3223                 sscanf(buf, "%d", &conn->datadgst_en);
3224                 break;
3225         case ISCSI_PARAM_INITIAL_R2T_EN:
3226                 sscanf(buf, "%d", &session->initial_r2t_en);
3227                 break;
3228         case ISCSI_PARAM_MAX_R2T:
3229                 sscanf(buf, "%d", &session->max_r2t);
3230                 break;
3231         case ISCSI_PARAM_IMM_DATA_EN:
3232                 sscanf(buf, "%d", &session->imm_data_en);
3233                 break;
3234         case ISCSI_PARAM_FIRST_BURST:
3235                 sscanf(buf, "%d", &session->first_burst);
3236                 break;
3237         case ISCSI_PARAM_MAX_BURST:
3238                 sscanf(buf, "%d", &session->max_burst);
3239                 break;
3240         case ISCSI_PARAM_PDU_INORDER_EN:
3241                 sscanf(buf, "%d", &session->pdu_inorder_en);
3242                 break;
3243         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3244                 sscanf(buf, "%d", &session->dataseq_inorder_en);
3245                 break;
3246         case ISCSI_PARAM_ERL:
3247                 sscanf(buf, "%d", &session->erl);
3248                 break;
3249         case ISCSI_PARAM_IFMARKER_EN:
3250                 sscanf(buf, "%d", &value);
3251                 BUG_ON(value);
3252                 break;
3253         case ISCSI_PARAM_OFMARKER_EN:
3254                 sscanf(buf, "%d", &value);
3255                 BUG_ON(value);
3256                 break;
3257         case ISCSI_PARAM_EXP_STATSN:
3258                 sscanf(buf, "%u", &conn->exp_statsn);
3259                 break;
3260         case ISCSI_PARAM_USERNAME:
3261                 return iscsi_switch_str_param(&session->username, buf);
3262         case ISCSI_PARAM_USERNAME_IN:
3263                 return iscsi_switch_str_param(&session->username_in, buf);
3264         case ISCSI_PARAM_PASSWORD:
3265                 return iscsi_switch_str_param(&session->password, buf);
3266         case ISCSI_PARAM_PASSWORD_IN:
3267                 return iscsi_switch_str_param(&session->password_in, buf);
3268         case ISCSI_PARAM_TARGET_NAME:
3269                 return iscsi_switch_str_param(&session->targetname, buf);
3270         case ISCSI_PARAM_TPGT:
3271                 sscanf(buf, "%d", &session->tpgt);
3272                 break;
3273         case ISCSI_PARAM_PERSISTENT_PORT:
3274                 sscanf(buf, "%d", &conn->persistent_port);
3275                 break;
3276         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3277                 return iscsi_switch_str_param(&conn->persistent_address, buf);
3278         case ISCSI_PARAM_IFACE_NAME:
3279                 return iscsi_switch_str_param(&session->ifacename, buf);
3280         case ISCSI_PARAM_INITIATOR_NAME:
3281                 return iscsi_switch_str_param(&session->initiatorname, buf);
3282         default:
3283                 return -ENOSYS;
3284         }
3285
3286         return 0;
3287 }
3288 EXPORT_SYMBOL_GPL(iscsi_set_param);
3289
3290 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3291                             enum iscsi_param param, char *buf)
3292 {
3293         struct iscsi_session *session = cls_session->dd_data;
3294         int len;
3295
3296         switch(param) {
3297         case ISCSI_PARAM_FAST_ABORT:
3298                 len = sprintf(buf, "%d\n", session->fast_abort);
3299                 break;
3300         case ISCSI_PARAM_ABORT_TMO:
3301                 len = sprintf(buf, "%d\n", session->abort_timeout);
3302                 break;
3303         case ISCSI_PARAM_LU_RESET_TMO:
3304                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
3305                 break;
3306         case ISCSI_PARAM_TGT_RESET_TMO:
3307                 len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
3308                 break;
3309         case ISCSI_PARAM_INITIAL_R2T_EN:
3310                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
3311                 break;
3312         case ISCSI_PARAM_MAX_R2T:
3313                 len = sprintf(buf, "%hu\n", session->max_r2t);
3314                 break;
3315         case ISCSI_PARAM_IMM_DATA_EN:
3316                 len = sprintf(buf, "%d\n", session->imm_data_en);
3317                 break;
3318         case ISCSI_PARAM_FIRST_BURST:
3319                 len = sprintf(buf, "%u\n", session->first_burst);
3320                 break;
3321         case ISCSI_PARAM_MAX_BURST:
3322                 len = sprintf(buf, "%u\n", session->max_burst);
3323                 break;
3324         case ISCSI_PARAM_PDU_INORDER_EN:
3325                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
3326                 break;
3327         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3328                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
3329                 break;
3330         case ISCSI_PARAM_ERL:
3331                 len = sprintf(buf, "%d\n", session->erl);
3332                 break;
3333         case ISCSI_PARAM_TARGET_NAME:
3334                 len = sprintf(buf, "%s\n", session->targetname);
3335                 break;
3336         case ISCSI_PARAM_TPGT:
3337                 len = sprintf(buf, "%d\n", session->tpgt);
3338                 break;
3339         case ISCSI_PARAM_USERNAME:
3340                 len = sprintf(buf, "%s\n", session->username);
3341                 break;
3342         case ISCSI_PARAM_USERNAME_IN:
3343                 len = sprintf(buf, "%s\n", session->username_in);
3344                 break;
3345         case ISCSI_PARAM_PASSWORD:
3346                 len = sprintf(buf, "%s\n", session->password);
3347                 break;
3348         case ISCSI_PARAM_PASSWORD_IN:
3349                 len = sprintf(buf, "%s\n", session->password_in);
3350                 break;
3351         case ISCSI_PARAM_IFACE_NAME:
3352                 len = sprintf(buf, "%s\n", session->ifacename);
3353                 break;
3354         case ISCSI_PARAM_INITIATOR_NAME:
3355                 len = sprintf(buf, "%s\n", session->initiatorname);
3356                 break;
3357         default:
3358                 return -ENOSYS;
3359         }
3360
3361         return len;
3362 }
3363 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3364
3365 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3366                          enum iscsi_param param, char *buf)
3367 {
3368         struct iscsi_conn *conn = cls_conn->dd_data;
3369         int len;
3370
3371         switch(param) {
3372         case ISCSI_PARAM_PING_TMO:
3373                 len = sprintf(buf, "%u\n", conn->ping_timeout);
3374                 break;
3375         case ISCSI_PARAM_RECV_TMO:
3376                 len = sprintf(buf, "%u\n", conn->recv_timeout);
3377                 break;
3378         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3379                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
3380                 break;
3381         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3382                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
3383                 break;
3384         case ISCSI_PARAM_HDRDGST_EN:
3385                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
3386                 break;
3387         case ISCSI_PARAM_DATADGST_EN:
3388                 len = sprintf(buf, "%d\n", conn->datadgst_en);
3389                 break;
3390         case ISCSI_PARAM_IFMARKER_EN:
3391                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
3392                 break;
3393         case ISCSI_PARAM_OFMARKER_EN:
3394                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
3395                 break;
3396         case ISCSI_PARAM_EXP_STATSN:
3397                 len = sprintf(buf, "%u\n", conn->exp_statsn);
3398                 break;
3399         case ISCSI_PARAM_PERSISTENT_PORT:
3400                 len = sprintf(buf, "%d\n", conn->persistent_port);
3401                 break;
3402         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3403                 len = sprintf(buf, "%s\n", conn->persistent_address);
3404                 break;
3405         default:
3406                 return -ENOSYS;
3407         }
3408
3409         return len;
3410 }
3411 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3412
3413 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3414                          char *buf)
3415 {
3416         struct iscsi_host *ihost = shost_priv(shost);
3417         int len;
3418
3419         switch (param) {
3420         case ISCSI_HOST_PARAM_NETDEV_NAME:
3421                 len = sprintf(buf, "%s\n", ihost->netdev);
3422                 break;
3423         case ISCSI_HOST_PARAM_HWADDRESS:
3424                 len = sprintf(buf, "%s\n", ihost->hwaddress);
3425                 break;
3426         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3427                 len = sprintf(buf, "%s\n", ihost->initiatorname);
3428                 break;
3429         case ISCSI_HOST_PARAM_IPADDRESS:
3430                 len = sprintf(buf, "%s\n", ihost->local_address);
3431                 break;
3432         default:
3433                 return -ENOSYS;
3434         }
3435
3436         return len;
3437 }
3438 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3439
3440 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3441                          char *buf, int buflen)
3442 {
3443         struct iscsi_host *ihost = shost_priv(shost);
3444
3445         switch (param) {
3446         case ISCSI_HOST_PARAM_NETDEV_NAME:
3447                 return iscsi_switch_str_param(&ihost->netdev, buf);
3448         case ISCSI_HOST_PARAM_HWADDRESS:
3449                 return iscsi_switch_str_param(&ihost->hwaddress, buf);
3450         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3451                 return iscsi_switch_str_param(&ihost->initiatorname, buf);
3452         default:
3453                 return -ENOSYS;
3454         }
3455
3456         return 0;
3457 }
3458 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3459
3460 MODULE_AUTHOR("Mike Christie");
3461 MODULE_DESCRIPTION("iSCSI library functions");
3462 MODULE_LICENSE("GPL");