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 <asm/unaligned.h>
  29 #include <net/tcp.h>
  30 #include <scsi/scsi_cmnd.h>
  31 #include <scsi/scsi_device.h>
  32 #include <scsi/scsi_eh.h>
  33 #include <scsi/scsi_tcq.h>
  34 #include <scsi/scsi_host.h>
  35 #include <scsi/scsi.h>
  36 #include <scsi/iscsi_proto.h>
  37 #include <scsi/scsi_transport.h>
  38 #include <scsi/scsi_transport_iscsi.h>
  39 #include <scsi/libiscsi.h>
  40
  41 struct iscsi_session *
  42 class_to_transport_session(struct iscsi_cls_session *cls_session)
  43 {
  44         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
  45         return iscsi_hostdata(shost->hostdata);
  46 }
  47 EXPORT_SYMBOL_GPL(class_to_transport_session);
  48
  49 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
  50 #define SNA32_CHECK 2147483648UL
  51
  52 static int iscsi_sna_lt(u32 n1, u32 n2)
  53 {
  54         return n1 != n2 && ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
  55                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
  56 }
  57
  58 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
  59 static int iscsi_sna_lte(u32 n1, u32 n2)
  60 {
  61         return n1 == n2 || ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
  62                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
  63 }
  64
  65 void
  66 iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
  67 {
  68         uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
  69         uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);
  70
  71         /*
  72          * standard specifies this check for when to update expected and
  73          * max sequence numbers
  74          */
  75         if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
  76                 return;
  77
  78         if (exp_cmdsn != session->exp_cmdsn &&
  79             !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
  80                 session->exp_cmdsn = exp_cmdsn;
  81
  82         if (max_cmdsn != session->max_cmdsn &&
  83             !iscsi_sna_lt(max_cmdsn, session->max_cmdsn)) {
  84                 session->max_cmdsn = max_cmdsn;
  85                 /*
  86                  * if the window closed with IO queued, then kick the
  87                  * xmit thread
  88                  */
  89                 if (!list_empty(&session->leadconn->xmitqueue) ||
  90                     !list_empty(&session->leadconn->mgmtqueue))
  91                         scsi_queue_work(session->host,
  92                                         &session->leadconn->xmitwork);
  93         }
  94 }
  95 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
  96
  97 void iscsi_prep_unsolicit_data_pdu(struct iscsi_cmd_task *ctask,
  98                                    struct iscsi_data *hdr)
  99 {
 100         struct iscsi_conn *conn = ctask->conn;
 101
 102         memset(hdr, 0, sizeof(struct iscsi_data));
 103         hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 104         hdr->datasn = cpu_to_be32(ctask->unsol_datasn);
 105         ctask->unsol_datasn++;
 106         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 107         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
 108
 109         hdr->itt = ctask->hdr->itt;
 110         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 111         hdr->offset = cpu_to_be32(ctask->unsol_offset);
 112
 113         if (ctask->unsol_count > conn->max_xmit_dlength) {
 114                 hton24(hdr->dlength, conn->max_xmit_dlength);
 115                 ctask->data_count = conn->max_xmit_dlength;
 116                 ctask->unsol_offset += ctask->data_count;
 117                 hdr->flags = 0;
 118         } else {
 119                 hton24(hdr->dlength, ctask->unsol_count);
 120                 ctask->data_count = ctask->unsol_count;
 121                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 122         }
 123 }
 124 EXPORT_SYMBOL_GPL(iscsi_prep_unsolicit_data_pdu);
 125
 126 static int iscsi_add_hdr(struct iscsi_cmd_task *ctask, unsigned len)
 127 {
 128         unsigned exp_len = ctask->hdr_len + len;
 129
 130         if (exp_len > ctask->hdr_max) {
 131                 WARN_ON(1);
 132                 return -EINVAL;
 133         }
 134
 135         WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 136         ctask->hdr_len = exp_len;
 137         return 0;
 138 }
 139
 140 /*
 141  * make an extended cdb AHS
 142  */
 143 static int iscsi_prep_ecdb_ahs(struct iscsi_cmd_task *ctask)
 144 {
 145         struct scsi_cmnd *cmd = ctask->sc;
 146         unsigned rlen, pad_len;
 147         unsigned short ahslength;
 148         struct iscsi_ecdb_ahdr *ecdb_ahdr;
 149         int rc;
 150
 151         ecdb_ahdr = iscsi_next_hdr(ctask);
 152         rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 153
 154         BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 155         ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 156
 157         pad_len = iscsi_padding(rlen);
 158
 159         rc = iscsi_add_hdr(ctask, sizeof(ecdb_ahdr->ahslength) +
 160                            sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 161         if (rc)
 162                 return rc;
 163
 164         if (pad_len)
 165                 memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 166
 167         ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 168         ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 169         ecdb_ahdr->reserved = 0;
 170         memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 171
 172         debug_scsi("iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 173                    "rlen %d pad_len %d ahs_length %d iscsi_headers_size %u\n",
 174                    cmd->cmd_len, rlen, pad_len, ahslength, ctask->hdr_len);
 175
 176         return 0;
 177 }
 178
 179 static int iscsi_prep_bidi_ahs(struct iscsi_cmd_task *ctask)
 180 {
 181         struct scsi_cmnd *sc = ctask->sc;
 182         struct iscsi_rlength_ahdr *rlen_ahdr;
 183         int rc;
 184
 185         rlen_ahdr = iscsi_next_hdr(ctask);
 186         rc = iscsi_add_hdr(ctask, sizeof(*rlen_ahdr));
 187         if (rc)
 188                 return rc;
 189
 190         rlen_ahdr->ahslength =
 191                 cpu_to_be16(sizeof(rlen_ahdr->read_length) +
 192                                                   sizeof(rlen_ahdr->reserved));
 193         rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
 194         rlen_ahdr->reserved = 0;
 195         rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
 196
 197         debug_scsi("bidi-in rlen_ahdr->read_length(%d) "
 198                    "rlen_ahdr->ahslength(%d)\n",
 199                    be32_to_cpu(rlen_ahdr->read_length),
 200                    be16_to_cpu(rlen_ahdr->ahslength));
 201         return 0;
 202 }
 203
 204 /**
 205  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 206  * @ctask: iscsi cmd task
 207  *
 208  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 209  * fields like dlength or final based on how much data it sends
 210  */
 211 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
 212 {
 213         struct iscsi_conn *conn = ctask->conn;
 214         struct iscsi_session *session = conn->session;
 215         struct iscsi_cmd *hdr = ctask->hdr;
 216         struct scsi_cmnd *sc = ctask->sc;
 217         unsigned hdrlength, cmd_len;
 218         int rc;
 219
 220         ctask->hdr_len = 0;
 221         rc = iscsi_add_hdr(ctask, sizeof(*hdr));
 222         if (rc)
 223                 return rc;
 224         hdr->opcode = ISCSI_OP_SCSI_CMD;
 225         hdr->flags = ISCSI_ATTR_SIMPLE;
 226         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
 227         hdr->itt = build_itt(ctask->itt, session->age);
 228         hdr->cmdsn = cpu_to_be32(session->cmdsn);
 229         session->cmdsn++;
 230         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 231         cmd_len = sc->cmd_len;
 232         if (cmd_len < ISCSI_CDB_SIZE)
 233                 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 234         else if (cmd_len > ISCSI_CDB_SIZE) {
 235                 rc = iscsi_prep_ecdb_ahs(ctask);
 236                 if (rc)
 237                         return rc;
 238                 cmd_len = ISCSI_CDB_SIZE;
 239         }
 240         memcpy(hdr->cdb, sc->cmnd, cmd_len);
 241
 242         ctask->imm_count = 0;
 243         if (scsi_bidi_cmnd(sc)) {
 244                 hdr->flags |= ISCSI_FLAG_CMD_READ;
 245                 rc = iscsi_prep_bidi_ahs(ctask);
 246                 if (rc)
 247                         return rc;
 248         }
 249         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 250                 unsigned out_len = scsi_out(sc)->length;
 251                 hdr->data_length = cpu_to_be32(out_len);
 252                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 253                 /*
 254                  * Write counters:
 255                  *
 256                  *      imm_count       bytes to be sent right after
 257                  *                      SCSI PDU Header
 258                  *
 259                  *      unsol_count     bytes(as Data-Out) to be sent
 260                  *                      without R2T ack right after
 261                  *                      immediate data
 262                  *
 263                  *      r2t_data_count  bytes to be sent via R2T ack's
 264                  *
 265                  *      pad_count       bytes to be sent as zero-padding
 266                  */
 267                 ctask->unsol_count = 0;
 268                 ctask->unsol_offset = 0;
 269                 ctask->unsol_datasn = 0;
 270
 271                 if (session->imm_data_en) {
 272                         if (out_len >= session->first_burst)
 273                                 ctask->imm_count = min(session->first_burst,
 274                                                         conn->max_xmit_dlength);
 275                         else
 276                                 ctask->imm_count = min(out_len,
 277                                                         conn->max_xmit_dlength);
 278                         hton24(hdr->dlength, ctask->imm_count);
 279                 } else
 280                         zero_data(hdr->dlength);
 281
 282                 if (!session->initial_r2t_en) {
 283                         ctask->unsol_count = min(session->first_burst, out_len)
 284                                                              - ctask->imm_count;
 285                         ctask->unsol_offset = ctask->imm_count;
 286                 }
 287
 288                 if (!ctask->unsol_count)
 289                         /* No unsolicit Data-Out's */
 290                         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 291         } else {
 292                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 293                 zero_data(hdr->dlength);
 294                 hdr->data_length = cpu_to_be32(scsi_in(sc)->length);
 295
 296                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
 297                         hdr->flags |= ISCSI_FLAG_CMD_READ;
 298         }
 299
 300         /* calculate size of additional header segments (AHSs) */
 301         hdrlength = ctask->hdr_len - sizeof(*hdr);
 302
 303         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 304         hdrlength /= ISCSI_PAD_LEN;
 305
 306         WARN_ON(hdrlength >= 256);
 307         hdr->hlength = hdrlength & 0xFF;
 308
 309         if (conn->session->tt->init_cmd_task(conn->ctask))
 310                 return EIO;
 311
 312         conn->scsicmd_pdus_cnt++;
 313         debug_scsi("iscsi prep [%s cid %d sc %p cdb 0x%x itt 0x%x "
 314                 "len %d bidi_len %d cmdsn %d win %d]\n",
 315                 scsi_bidi_cmnd(sc) ? "bidirectional" :
 316                      sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
 317                 conn->id, sc, sc->cmnd[0], ctask->itt,
 318                 scsi_bufflen(sc), scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
 319                 session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
 320         return 0;
 321 }
 322
 323 /**
 324  * iscsi_complete_command - return command back to scsi-ml
 325  * @ctask: iscsi cmd task
 326  *
 327  * Must be called with session lock.
 328  * This function returns the scsi command to scsi-ml and returns
 329  * the cmd task to the pool of available cmd tasks.
 330  */
 331 static void iscsi_complete_command(struct iscsi_cmd_task *ctask)
 332 {
 333         struct iscsi_conn *conn = ctask->conn;
 334         struct iscsi_session *session = conn->session;
 335         struct scsi_cmnd *sc = ctask->sc;
 336
 337         ctask->state = ISCSI_TASK_COMPLETED;
 338         ctask->sc = NULL;
 339         /* SCSI eh reuses commands to verify us */
 340         sc->SCp.ptr = NULL;
 341         if (conn->ctask == ctask)
 342                 conn->ctask = NULL;
 343         list_del_init(&ctask->running);
 344         __kfifo_put(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
 345         sc->scsi_done(sc);
 346 }
 347
 348 static void __iscsi_get_ctask(struct iscsi_cmd_task *ctask)
 349 {
 350         atomic_inc(&ctask->refcount);
 351 }
 352
 353 static void __iscsi_put_ctask(struct iscsi_cmd_task *ctask)
 354 {
 355         if (atomic_dec_and_test(&ctask->refcount))
 356                 iscsi_complete_command(ctask);
 357 }
 358
 359 /*
 360  * session lock must be held
 361  */
 362 static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 363                          int err)
 364 {
 365         struct scsi_cmnd *sc;
 366
 367         sc = ctask->sc;
 368         if (!sc)
 369                 return;
 370
 371         if (ctask->state == ISCSI_TASK_PENDING)
 372                 /*
 373                  * cmd never made it to the xmit thread, so we should not count
 374                  * the cmd in the sequencing
 375                  */
 376                 conn->session->queued_cmdsn--;
 377         else
 378                 conn->session->tt->cleanup_cmd_task(conn, ctask);
 379
 380         sc->result = err;
 381         if (!scsi_bidi_cmnd(sc))
 382                 scsi_set_resid(sc, scsi_bufflen(sc));
 383         else {
 384                 scsi_out(sc)->resid = scsi_out(sc)->length;
 385                 scsi_in(sc)->resid = scsi_in(sc)->length;
 386         }
 387         if (conn->ctask == ctask)
 388                 conn->ctask = NULL;
 389         /* release ref from queuecommand */
 390         __iscsi_put_ctask(ctask);
 391 }
 392
 393 /**
 394  * iscsi_free_mgmt_task - return mgmt task back to pool
 395  * @conn: iscsi connection
 396  * @mtask: mtask
 397  *
 398  * Must be called with session lock.
 399  */
 400 void iscsi_free_mgmt_task(struct iscsi_conn *conn,
 401                           struct iscsi_mgmt_task *mtask)
 402 {
 403         list_del_init(&mtask->running);
 404         if (conn->login_mtask == mtask)
 405                 return;
 406
 407         if (conn->ping_mtask == mtask)
 408                 conn->ping_mtask = NULL;
 409         __kfifo_put(conn->session->mgmtpool.queue,
 410                     (void*)&mtask, sizeof(void*));
 411 }
 412 EXPORT_SYMBOL_GPL(iscsi_free_mgmt_task);
 413
 414 static struct iscsi_mgmt_task *
 415 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 416                       char *data, uint32_t data_size)
 417 {
 418         struct iscsi_session *session = conn->session;
 419         struct iscsi_mgmt_task *mtask;
 420
 421         if (session->state == ISCSI_STATE_TERMINATE)
 422                 return NULL;
 423
 424         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
 425             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 426                 /*
 427                  * Login and Text are sent serially, in
 428                  * request-followed-by-response sequence.
 429                  * Same mtask can be used. Same ITT must be used.
 430                  * Note that login_mtask is preallocated at conn_create().
 431                  */
 432                 mtask = conn->login_mtask;
 433         else {
 434                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 435                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 436
 437                 if (!__kfifo_get(session->mgmtpool.queue,
 438                                  (void*)&mtask, sizeof(void*)))
 439                         return NULL;
 440         }
 441
 442         if (data_size) {
 443                 memcpy(mtask->data, data, data_size);
 444                 mtask->data_count = data_size;
 445         } else
 446                 mtask->data_count = 0;
 447
 448         memcpy(mtask->hdr, hdr, sizeof(struct iscsi_hdr));
 449         INIT_LIST_HEAD(&mtask->running);
 450         list_add_tail(&mtask->running, &conn->mgmtqueue);
 451         return mtask;
 452 }
 453
 454 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 455                         char *data, uint32_t data_size)
 456 {
 457         struct iscsi_conn *conn = cls_conn->dd_data;
 458         struct iscsi_session *session = conn->session;
 459         int err = 0;
 460
 461         spin_lock_bh(&session->lock);
 462         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 463                 err = -EPERM;
 464         spin_unlock_bh(&session->lock);
 465         scsi_queue_work(session->host, &conn->xmitwork);
 466         return err;
 467 }
 468 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 469
 470 /**
 471  * iscsi_cmd_rsp - SCSI Command Response processing
 472  * @conn: iscsi connection
 473  * @hdr: iscsi header
 474  * @ctask: scsi command task
 475  * @data: cmd data buffer
 476  * @datalen: len of buffer
 477  *
 478  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 479  * then completes the command and task.
 480  **/
 481 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 482                                struct iscsi_cmd_task *ctask, char *data,
 483                                int datalen)
 484 {
 485         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
 486         struct iscsi_session *session = conn->session;
 487         struct scsi_cmnd *sc = ctask->sc;
 488
 489         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 490         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 491
 492         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 493
 494         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 495                 sc->result = DID_ERROR << 16;
 496                 goto out;
 497         }
 498
 499         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 500                 uint16_t senselen;
 501
 502                 if (datalen < 2) {
 503 invalid_datalen:
 504                         iscsi_conn_printk(KERN_ERR,  conn,
 505                                          "Got CHECK_CONDITION but invalid data "
 506                                          "buffer size of %d\n", datalen);
 507                         sc->result = DID_BAD_TARGET << 16;
 508                         goto out;
 509                 }
 510
 511                 senselen = be16_to_cpu(get_unaligned((__be16 *) data));
 512                 if (datalen < senselen)
 513                         goto invalid_datalen;
 514
 515                 memcpy(sc->sense_buffer, data + 2,
 516                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 517                 debug_scsi("copied %d bytes of sense\n",
 518                            min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 519         }
 520
 521         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 522                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 523                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
 524
 525                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 526                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 527                                  res_count <= scsi_in(sc)->length))
 528                         scsi_in(sc)->resid = res_count;
 529                 else
 530                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 531         }
 532
 533         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 534                            ISCSI_FLAG_CMD_OVERFLOW)) {
 535                 int res_count = be32_to_cpu(rhdr->residual_count);
 536
 537                 if (res_count > 0 &&
 538                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 539                      res_count <= scsi_bufflen(sc)))
 540                         /* write side for bidi or uni-io set_resid */
 541                         scsi_set_resid(sc, res_count);
 542                 else
 543                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 544         }
 545 out:
 546         debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 547                    (long)sc, sc->result, ctask->itt);
 548         conn->scsirsp_pdus_cnt++;
 549
 550         __iscsi_put_ctask(ctask);
 551 }
 552
 553 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 554 {
 555         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 556
 557         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 558         conn->tmfrsp_pdus_cnt++;
 559
 560         if (conn->tmf_state != TMF_QUEUED)
 561                 return;
 562
 563         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 564                 conn->tmf_state = TMF_SUCCESS;
 565         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 566                 conn->tmf_state = TMF_NOT_FOUND;
 567         else
 568                 conn->tmf_state = TMF_FAILED;
 569         wake_up(&conn->ehwait);
 570 }
 571
 572 static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 573 {
 574         struct iscsi_nopout hdr;
 575         struct iscsi_mgmt_task *mtask;
 576
 577         if (!rhdr && conn->ping_mtask)
 578                 return;
 579
 580         memset(&hdr, 0, sizeof(struct iscsi_nopout));
 581         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 582         hdr.flags = ISCSI_FLAG_CMD_FINAL;
 583
 584         if (rhdr) {
 585                 memcpy(hdr.lun, rhdr->lun, 8);
 586                 hdr.ttt = rhdr->ttt;
 587                 hdr.itt = RESERVED_ITT;
 588         } else
 589                 hdr.ttt = RESERVED_ITT;
 590
 591         mtask = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 592         if (!mtask) {
 593                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 594                 return;
 595         }
 596
 597         /* only track our nops */
 598         if (!rhdr) {
 599                 conn->ping_mtask = mtask;
 600                 conn->last_ping = jiffies;
 601         }
 602         scsi_queue_work(conn->session->host, &conn->xmitwork);
 603 }
 604
 605 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 606                                char *data, int datalen)
 607 {
 608         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
 609         struct iscsi_hdr rejected_pdu;
 610         uint32_t itt;
 611
 612         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
 613
 614         if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
 615                 if (ntoh24(reject->dlength) > datalen)
 616                         return ISCSI_ERR_PROTO;
 617
 618                 if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
 619                         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
 620                         itt = get_itt(rejected_pdu.itt);
 621                         iscsi_conn_printk(KERN_ERR, conn,
 622                                           "itt 0x%x had pdu (op 0x%x) rejected "
 623                                           "due to DataDigest error.\n", itt,
 624                                           rejected_pdu.opcode);
 625                 }
 626         }
 627         return 0;
 628 }
 629
 630 /**
 631  * __iscsi_complete_pdu - complete pdu
 632  * @conn: iscsi conn
 633  * @hdr: iscsi header
 634  * @data: data buffer
 635  * @datalen: len of data buffer
 636  *
 637  * Completes pdu processing by freeing any resources allocated at
 638  * queuecommand or send generic. session lock must be held and verify
 639  * itt must have been called.
 640  */
 641 static int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 642                                 char *data, int datalen)
 643 {
 644         struct iscsi_session *session = conn->session;
 645         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
 646         struct iscsi_cmd_task *ctask;
 647         struct iscsi_mgmt_task *mtask;
 648         uint32_t itt;
 649
 650         conn->last_recv = jiffies;
 651         if (hdr->itt != RESERVED_ITT)
 652                 itt = get_itt(hdr->itt);
 653         else
 654                 itt = ~0U;
 655
 656         if (itt < session->cmds_max) {
 657                 ctask = session->cmds[itt];
 658
 659                 debug_scsi("cmdrsp [op 0x%x cid %d itt 0x%x len %d]\n",
 660                            opcode, conn->id, ctask->itt, datalen);
 661
 662                 switch(opcode) {
 663                 case ISCSI_OP_SCSI_CMD_RSP:
 664                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 665                         iscsi_scsi_cmd_rsp(conn, hdr, ctask, data,
 666                                            datalen);
 667                         break;
 668                 case ISCSI_OP_SCSI_DATA_IN:
 669                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 670                         if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
 671                                 conn->scsirsp_pdus_cnt++;
 672                                 __iscsi_put_ctask(ctask);
 673                         }
 674                         break;
 675                 case ISCSI_OP_R2T:
 676                         /* LLD handles this for now */
 677                         break;
 678                 default:
 679                         rc = ISCSI_ERR_BAD_OPCODE;
 680                         break;
 681                 }
 682         } else if (itt >= ISCSI_MGMT_ITT_OFFSET &&
 683                    itt < ISCSI_MGMT_ITT_OFFSET + session->mgmtpool_max) {
 684                 mtask = session->mgmt_cmds[itt - ISCSI_MGMT_ITT_OFFSET];
 685
 686                 debug_scsi("immrsp [op 0x%x cid %d itt 0x%x len %d]\n",
 687                            opcode, conn->id, mtask->itt, datalen);
 688
 689                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 690                 switch(opcode) {
 691                 case ISCSI_OP_LOGOUT_RSP:
 692                         if (datalen) {
 693                                 rc = ISCSI_ERR_PROTO;
 694                                 break;
 695                         }
 696                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 697                         /* fall through */
 698                 case ISCSI_OP_LOGIN_RSP:
 699                 case ISCSI_OP_TEXT_RSP:
 700                         /*
 701                          * login related PDU's exp_statsn is handled in
 702                          * userspace
 703                          */
 704                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 705                                 rc = ISCSI_ERR_CONN_FAILED;
 706                         iscsi_free_mgmt_task(conn, mtask);
 707                         break;
 708                 case ISCSI_OP_SCSI_TMFUNC_RSP:
 709                         if (datalen) {
 710                                 rc = ISCSI_ERR_PROTO;
 711                                 break;
 712                         }
 713
 714                         iscsi_tmf_rsp(conn, hdr);
 715                         iscsi_free_mgmt_task(conn, mtask);
 716                         break;
 717                 case ISCSI_OP_NOOP_IN:
 718                         if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) ||
 719                             datalen) {
 720                                 rc = ISCSI_ERR_PROTO;
 721                                 break;
 722                         }
 723                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 724
 725                         if (conn->ping_mtask != mtask) {
 726                                 /*
 727                                  * If this is not in response to one of our
 728                                  * nops then it must be from userspace.
 729                                  */
 730                                 if (iscsi_recv_pdu(conn->cls_conn, hdr, data,
 731                                                    datalen))
 732                                         rc = ISCSI_ERR_CONN_FAILED;
 733                         } else
 734                                 mod_timer(&conn->transport_timer,
 735                                           jiffies + conn->recv_timeout);
 736                         iscsi_free_mgmt_task(conn, mtask);
 737                         break;
 738                 default:
 739                         rc = ISCSI_ERR_BAD_OPCODE;
 740                         break;
 741                 }
 742         } else if (itt == ~0U) {
 743                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 744
 745                 switch(opcode) {
 746                 case ISCSI_OP_NOOP_IN:
 747                         if (datalen) {
 748                                 rc = ISCSI_ERR_PROTO;
 749                                 break;
 750                         }
 751
 752                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
 753                                 break;
 754
 755                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
 756                         break;
 757                 case ISCSI_OP_REJECT:
 758                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
 759                         break;
 760                 case ISCSI_OP_ASYNC_EVENT:
 761                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 762                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 763                                 rc = ISCSI_ERR_CONN_FAILED;
 764                         break;
 765                 default:
 766                         rc = ISCSI_ERR_BAD_OPCODE;
 767                         break;
 768                 }
 769         } else
 770                 rc = ISCSI_ERR_BAD_ITT;
 771
 772         return rc;
 773 }
 774
 775 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 776                        char *data, int datalen)
 777 {
 778         int rc;
 779
 780         spin_lock(&conn->session->lock);
 781         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
 782         spin_unlock(&conn->session->lock);
 783         return rc;
 784 }
 785 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
 786
 787 /* verify itt (itt encoding: age+cid+itt) */
 788 int iscsi_verify_itt(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 789                      uint32_t *ret_itt)
 790 {
 791         struct iscsi_session *session = conn->session;
 792         struct iscsi_cmd_task *ctask;
 793         uint32_t itt;
 794
 795         if (hdr->itt != RESERVED_ITT) {
 796                 if (((__force u32)hdr->itt & ISCSI_AGE_MASK) !=
 797                     (session->age << ISCSI_AGE_SHIFT)) {
 798                         iscsi_conn_printk(KERN_ERR, conn,
 799                                           "received itt %x expected session "
 800                                           "age (%x)\n", (__force u32)hdr->itt,
 801                                           session->age & ISCSI_AGE_MASK);
 802                         return ISCSI_ERR_BAD_ITT;
 803                 }
 804
 805                 itt = get_itt(hdr->itt);
 806         } else
 807                 itt = ~0U;
 808
 809         if (itt < session->cmds_max) {
 810                 ctask = session->cmds[itt];
 811
 812                 if (!ctask->sc) {
 813                         iscsi_conn_printk(KERN_INFO, conn, "dropping ctask "
 814                                           "with itt 0x%x\n", ctask->itt);
 815                         /* force drop */
 816                         return ISCSI_ERR_NO_SCSI_CMD;
 817                 }
 818
 819                 if (ctask->sc->SCp.phase != session->age) {
 820                         iscsi_conn_printk(KERN_ERR, conn,
 821                                           "iscsi: ctask's session age %d, "
 822                                           "expected %d\n", ctask->sc->SCp.phase,
 823                                           session->age);
 824                         return ISCSI_ERR_SESSION_FAILED;
 825                 }
 826         }
 827
 828         *ret_itt = itt;
 829         return 0;
 830 }
 831 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
 832
 833 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
 834 {
 835         struct iscsi_session *session = conn->session;
 836         unsigned long flags;
 837
 838         spin_lock_irqsave(&session->lock, flags);
 839         if (session->state == ISCSI_STATE_FAILED) {
 840                 spin_unlock_irqrestore(&session->lock, flags);
 841                 return;
 842         }
 843
 844         if (conn->stop_stage == 0)
 845                 session->state = ISCSI_STATE_FAILED;
 846         spin_unlock_irqrestore(&session->lock, flags);
 847         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
 848         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
 849         iscsi_conn_error(conn->cls_conn, err);
 850 }
 851 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
 852
 853 static void iscsi_prep_mtask(struct iscsi_conn *conn,
 854                              struct iscsi_mgmt_task *mtask)
 855 {
 856         struct iscsi_session *session = conn->session;
 857         struct iscsi_hdr *hdr = mtask->hdr;
 858         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 859
 860         if (hdr->opcode != (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) &&
 861             hdr->opcode != (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 862                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 863         /*
 864          * pre-format CmdSN for outgoing PDU.
 865          */
 866         nop->cmdsn = cpu_to_be32(session->cmdsn);
 867         if (hdr->itt != RESERVED_ITT) {
 868                 hdr->itt = build_itt(mtask->itt, session->age);
 869                 /*
 870                  * TODO: We always use immediate, so we never hit this.
 871                  * If we start to send tmfs or nops as non-immediate then
 872                  * we should start checking the cmdsn numbers for mgmt tasks.
 873                  */
 874                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 875                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 876                         session->queued_cmdsn++;
 877                         session->cmdsn++;
 878                 }
 879         }
 880
 881         if (session->tt->init_mgmt_task)
 882                 session->tt->init_mgmt_task(conn, mtask);
 883
 884         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
 885                    hdr->opcode & ISCSI_OPCODE_MASK, hdr->itt,
 886                    mtask->data_count);
 887 }
 888
 889 static int iscsi_xmit_mtask(struct iscsi_conn *conn)
 890 {
 891         struct iscsi_hdr *hdr = conn->mtask->hdr;
 892         int rc;
 893
 894         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 895                 conn->session->state = ISCSI_STATE_LOGGING_OUT;
 896         spin_unlock_bh(&conn->session->lock);
 897
 898         rc = conn->session->tt->xmit_mgmt_task(conn, conn->mtask);
 899         spin_lock_bh(&conn->session->lock);
 900         if (rc)
 901                 return rc;
 902
 903         /* done with this in-progress mtask */
 904         conn->mtask = NULL;
 905         return 0;
 906 }
 907
 908 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
 909 {
 910         struct iscsi_session *session = conn->session;
 911
 912         /*
 913          * Check for iSCSI window and take care of CmdSN wrap-around
 914          */
 915         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
 916                 debug_scsi("iSCSI CmdSN closed. ExpCmdSn %u MaxCmdSN %u "
 917                            "CmdSN %u/%u\n", session->exp_cmdsn,
 918                            session->max_cmdsn, session->cmdsn,
 919                            session->queued_cmdsn);
 920                 return -ENOSPC;
 921         }
 922         return 0;
 923 }
 924
 925 static int iscsi_xmit_ctask(struct iscsi_conn *conn)
 926 {
 927         struct iscsi_cmd_task *ctask = conn->ctask;
 928         int rc;
 929
 930         __iscsi_get_ctask(ctask);
 931         spin_unlock_bh(&conn->session->lock);
 932         rc = conn->session->tt->xmit_cmd_task(conn, ctask);
 933         spin_lock_bh(&conn->session->lock);
 934         __iscsi_put_ctask(ctask);
 935         if (!rc)
 936                 /* done with this ctask */
 937                 conn->ctask = NULL;
 938         return rc;
 939 }
 940
 941 /**
 942  * iscsi_requeue_ctask - requeue ctask to run from session workqueue
 943  * @ctask: ctask to requeue
 944  *
 945  * LLDs that need to run a ctask from the session workqueue should call
 946  * this. The session lock must be held.
 947  */
 948 void iscsi_requeue_ctask(struct iscsi_cmd_task *ctask)
 949 {
 950         struct iscsi_conn *conn = ctask->conn;
 951
 952         list_move_tail(&ctask->running, &conn->requeue);
 953         scsi_queue_work(conn->session->host, &conn->xmitwork);
 954 }
 955 EXPORT_SYMBOL_GPL(iscsi_requeue_ctask);
 956
 957 /**
 958  * iscsi_data_xmit - xmit any command into the scheduled connection
 959  * @conn: iscsi connection
 960  *
 961  * Notes:
 962  *      The function can return -EAGAIN in which case the caller must
 963  *      re-schedule it again later or recover. '0' return code means
 964  *      successful xmit.
 965  **/
 966 static int iscsi_data_xmit(struct iscsi_conn *conn)
 967 {
 968         int rc = 0;
 969
 970         spin_lock_bh(&conn->session->lock);
 971         if (unlikely(conn->suspend_tx)) {
 972                 debug_scsi("conn %d Tx suspended!\n", conn->id);
 973                 spin_unlock_bh(&conn->session->lock);
 974                 return -ENODATA;
 975         }
 976
 977         if (conn->ctask) {
 978                 rc = iscsi_xmit_ctask(conn);
 979                 if (rc)
 980                         goto again;
 981         }
 982
 983         if (conn->mtask) {
 984                 rc = iscsi_xmit_mtask(conn);
 985                 if (rc)
 986                         goto again;
 987         }
 988
 989         /*
 990          * process mgmt pdus like nops before commands since we should
 991          * only have one nop-out as a ping from us and targets should not
 992          * overflow us with nop-ins
 993          */
 994 check_mgmt:
 995         while (!list_empty(&conn->mgmtqueue)) {
 996                 conn->mtask = list_entry(conn->mgmtqueue.next,
 997                                          struct iscsi_mgmt_task, running);
 998                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
 999                         iscsi_free_mgmt_task(conn, conn->mtask);
1000                         conn->mtask = NULL;
1001                         continue;
1002                 }
1003
1004                 iscsi_prep_mtask(conn, conn->mtask);
1005                 list_move_tail(conn->mgmtqueue.next, &conn->mgmt_run_list);
1006                 rc = iscsi_xmit_mtask(conn);
1007                 if (rc)
1008                         goto again;
1009         }
1010
1011         /* process pending command queue */
1012         while (!list_empty(&conn->xmitqueue)) {
1013                 if (conn->tmf_state == TMF_QUEUED)
1014                         break;
1015
1016                 conn->ctask = list_entry(conn->xmitqueue.next,
1017                                          struct iscsi_cmd_task, running);
1018                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1019                         fail_command(conn, conn->ctask, DID_IMM_RETRY << 16);
1020                         continue;
1021                 }
1022                 if (iscsi_prep_scsi_cmd_pdu(conn->ctask)) {
1023                         fail_command(conn, conn->ctask, DID_ABORT << 16);
1024                         continue;
1025                 }
1026
1027                 conn->ctask->state = ISCSI_TASK_RUNNING;
1028                 list_move_tail(conn->xmitqueue.next, &conn->run_list);
1029                 rc = iscsi_xmit_ctask(conn);
1030                 if (rc)
1031                         goto again;
1032                 /*
1033                  * we could continuously get new ctask requests so
1034                  * we need to check the mgmt queue for nops that need to
1035                  * be sent to aviod starvation
1036                  */
1037                 if (!list_empty(&conn->mgmtqueue))
1038                         goto check_mgmt;
1039         }
1040
1041         while (!list_empty(&conn->requeue)) {
1042                 if (conn->session->fast_abort && conn->tmf_state != TMF_INITIAL)
1043                         break;
1044
1045                 /*
1046                  * we always do fastlogout - conn stop code will clean up.
1047                  */
1048                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1049                         break;
1050
1051                 conn->ctask = list_entry(conn->requeue.next,
1052                                          struct iscsi_cmd_task, running);
1053                 conn->ctask->state = ISCSI_TASK_RUNNING;
1054                 list_move_tail(conn->requeue.next, &conn->run_list);
1055                 rc = iscsi_xmit_ctask(conn);
1056                 if (rc)
1057                         goto again;
1058                 if (!list_empty(&conn->mgmtqueue))
1059                         goto check_mgmt;
1060         }
1061         spin_unlock_bh(&conn->session->lock);
1062         return -ENODATA;
1063
1064 again:
1065         if (unlikely(conn->suspend_tx))
1066                 rc = -ENODATA;
1067         spin_unlock_bh(&conn->session->lock);
1068         return rc;
1069 }
1070
1071 static void iscsi_xmitworker(struct work_struct *work)
1072 {
1073         struct iscsi_conn *conn =
1074                 container_of(work, struct iscsi_conn, xmitwork);
1075         int rc;
1076         /*
1077          * serialize Xmit worker on a per-connection basis.
1078          */
1079         do {
1080                 rc = iscsi_data_xmit(conn);
1081         } while (rc >= 0 || rc == -EAGAIN);
1082 }
1083
1084 enum {
1085         FAILURE_BAD_HOST = 1,
1086         FAILURE_SESSION_FAILED,
1087         FAILURE_SESSION_FREED,
1088         FAILURE_WINDOW_CLOSED,
1089         FAILURE_OOM,
1090         FAILURE_SESSION_TERMINATE,
1091         FAILURE_SESSION_IN_RECOVERY,
1092         FAILURE_SESSION_RECOVERY_TIMEOUT,
1093         FAILURE_SESSION_LOGGING_OUT,
1094         FAILURE_SESSION_NOT_READY,
1095 };
1096
1097 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
1098 {
1099         struct Scsi_Host *host;
1100         int reason = 0;
1101         struct iscsi_session *session;
1102         struct iscsi_conn *conn;
1103         struct iscsi_cmd_task *ctask = NULL;
1104
1105         sc->scsi_done = done;
1106         sc->result = 0;
1107         sc->SCp.ptr = NULL;
1108
1109         host = sc->device->host;
1110         spin_unlock(host->host_lock);
1111
1112         session = iscsi_hostdata(host->hostdata);
1113         spin_lock(&session->lock);
1114
1115         reason = iscsi_session_chkready(session_to_cls(session));
1116         if (reason) {
1117                 sc->result = reason;
1118                 goto fault;
1119         }
1120
1121         /*
1122          * ISCSI_STATE_FAILED is a temp. state. The recovery
1123          * code will decide what is best to do with command queued
1124          * during this time
1125          */
1126         if (session->state != ISCSI_STATE_LOGGED_IN &&
1127             session->state != ISCSI_STATE_FAILED) {
1128                 /*
1129                  * to handle the race between when we set the recovery state
1130                  * and block the session we requeue here (commands could
1131                  * be entering our queuecommand while a block is starting
1132                  * up because the block code is not locked)
1133                  */
1134                 switch (session->state) {
1135                 case ISCSI_STATE_IN_RECOVERY:
1136                         reason = FAILURE_SESSION_IN_RECOVERY;
1137                         sc->result = DID_IMM_RETRY << 16;
1138                         break;
1139                 case ISCSI_STATE_LOGGING_OUT:
1140                         reason = FAILURE_SESSION_LOGGING_OUT;
1141                         sc->result = DID_IMM_RETRY << 16;
1142                         break;
1143                 case ISCSI_STATE_RECOVERY_FAILED:
1144                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1145                         sc->result = DID_NO_CONNECT << 16;
1146                         break;
1147                 case ISCSI_STATE_TERMINATE:
1148                         reason = FAILURE_SESSION_TERMINATE;
1149                         sc->result = DID_NO_CONNECT << 16;
1150                         break;
1151                 default:
1152                         reason = FAILURE_SESSION_FREED;
1153                         sc->result = DID_NO_CONNECT << 16;
1154                 }
1155                 goto fault;
1156         }
1157
1158         conn = session->leadconn;
1159         if (!conn) {
1160                 reason = FAILURE_SESSION_FREED;
1161                 sc->result = DID_NO_CONNECT << 16;
1162                 goto fault;
1163         }
1164
1165         if (iscsi_check_cmdsn_window_closed(conn)) {
1166                 reason = FAILURE_WINDOW_CLOSED;
1167                 goto reject;
1168         }
1169
1170         if (!__kfifo_get(session->cmdpool.queue, (void*)&ctask,
1171                          sizeof(void*))) {
1172                 reason = FAILURE_OOM;
1173                 goto reject;
1174         }
1175         session->queued_cmdsn++;
1176
1177         sc->SCp.phase = session->age;
1178         sc->SCp.ptr = (char *)ctask;
1179
1180         atomic_set(&ctask->refcount, 1);
1181         ctask->state = ISCSI_TASK_PENDING;
1182         ctask->conn = conn;
1183         ctask->sc = sc;
1184         INIT_LIST_HEAD(&ctask->running);
1185
1186         list_add_tail(&ctask->running, &conn->xmitqueue);
1187         spin_unlock(&session->lock);
1188
1189         scsi_queue_work(host, &conn->xmitwork);
1190         spin_lock(host->host_lock);
1191         return 0;
1192
1193 reject:
1194         spin_unlock(&session->lock);
1195         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
1196         spin_lock(host->host_lock);
1197         return SCSI_MLQUEUE_HOST_BUSY;
1198
1199 fault:
1200         spin_unlock(&session->lock);
1201         debug_scsi("iscsi: cmd 0x%x is not queued (%d)\n", sc->cmnd[0], reason);
1202         if (!scsi_bidi_cmnd(sc))
1203                 scsi_set_resid(sc, scsi_bufflen(sc));
1204         else {
1205                 scsi_out(sc)->resid = scsi_out(sc)->length;
1206                 scsi_in(sc)->resid = scsi_in(sc)->length;
1207         }
1208         sc->scsi_done(sc);
1209         spin_lock(host->host_lock);
1210         return 0;
1211 }
1212 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1213
1214 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
1215 {
1216         if (depth > ISCSI_MAX_CMD_PER_LUN)
1217                 depth = ISCSI_MAX_CMD_PER_LUN;
1218         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1219         return sdev->queue_depth;
1220 }
1221 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1222
1223 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
1224 {
1225         struct iscsi_session *session = class_to_transport_session(cls_session);
1226
1227         spin_lock_bh(&session->lock);
1228         if (session->state != ISCSI_STATE_LOGGED_IN) {
1229                 session->state = ISCSI_STATE_RECOVERY_FAILED;
1230                 if (session->leadconn)
1231                         wake_up(&session->leadconn->ehwait);
1232         }
1233         spin_unlock_bh(&session->lock);
1234 }
1235 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
1236
1237 int iscsi_eh_host_reset(struct scsi_cmnd *sc)
1238 {
1239         struct Scsi_Host *host = sc->device->host;
1240         struct iscsi_session *session = iscsi_hostdata(host->hostdata);
1241         struct iscsi_conn *conn = session->leadconn;
1242
1243         mutex_lock(&session->eh_mutex);
1244         spin_lock_bh(&session->lock);
1245         if (session->state == ISCSI_STATE_TERMINATE) {
1246 failed:
1247                 debug_scsi("failing host reset: session terminated "
1248                            "[CID %d age %d]\n", conn->id, session->age);
1249                 spin_unlock_bh(&session->lock);
1250                 mutex_unlock(&session->eh_mutex);
1251                 return FAILED;
1252         }
1253
1254         spin_unlock_bh(&session->lock);
1255         mutex_unlock(&session->eh_mutex);
1256         /*
1257          * we drop the lock here but the leadconn cannot be destoyed while
1258          * we are in the scsi eh
1259          */
1260         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1261
1262         debug_scsi("iscsi_eh_host_reset wait for relogin\n");
1263         wait_event_interruptible(conn->ehwait,
1264                                  session->state == ISCSI_STATE_TERMINATE ||
1265                                  session->state == ISCSI_STATE_LOGGED_IN ||
1266                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
1267         if (signal_pending(current))
1268                 flush_signals(current);
1269
1270         mutex_lock(&session->eh_mutex);
1271         spin_lock_bh(&session->lock);
1272         if (session->state == ISCSI_STATE_LOGGED_IN)
1273                 iscsi_session_printk(KERN_INFO, session,
1274                                      "host reset succeeded\n");
1275         else
1276                 goto failed;
1277         spin_unlock_bh(&session->lock);
1278         mutex_unlock(&session->eh_mutex);
1279         return SUCCESS;
1280 }
1281 EXPORT_SYMBOL_GPL(iscsi_eh_host_reset);
1282
1283 static void iscsi_tmf_timedout(unsigned long data)
1284 {
1285         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1286         struct iscsi_session *session = conn->session;
1287
1288         spin_lock(&session->lock);
1289         if (conn->tmf_state == TMF_QUEUED) {
1290                 conn->tmf_state = TMF_TIMEDOUT;
1291                 debug_scsi("tmf timedout\n");
1292                 /* unblock eh_abort() */
1293                 wake_up(&conn->ehwait);
1294         }
1295         spin_unlock(&session->lock);
1296 }
1297
1298 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1299                                    struct iscsi_tm *hdr, int age,
1300                                    int timeout)
1301 {
1302         struct iscsi_session *session = conn->session;
1303         struct iscsi_mgmt_task *mtask;
1304
1305         mtask = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1306                                       NULL, 0);
1307         if (!mtask) {
1308                 spin_unlock_bh(&session->lock);
1309                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1310                 spin_lock_bh(&session->lock);
1311                 debug_scsi("tmf exec failure\n");
1312                 return -EPERM;
1313         }
1314         conn->tmfcmd_pdus_cnt++;
1315         conn->tmf_timer.expires = timeout * HZ + jiffies;
1316         conn->tmf_timer.function = iscsi_tmf_timedout;
1317         conn->tmf_timer.data = (unsigned long)conn;
1318         add_timer(&conn->tmf_timer);
1319         debug_scsi("tmf set timeout\n");
1320
1321         spin_unlock_bh(&session->lock);
1322         mutex_unlock(&session->eh_mutex);
1323         scsi_queue_work(session->host, &conn->xmitwork);
1324
1325         /*
1326          * block eh thread until:
1327          *
1328          * 1) tmf response
1329          * 2) tmf timeout
1330          * 3) session is terminated or restarted or userspace has
1331          * given up on recovery
1332          */
1333         wait_event_interruptible(conn->ehwait, age != session->age ||
1334                                  session->state != ISCSI_STATE_LOGGED_IN ||
1335                                  conn->tmf_state != TMF_QUEUED);
1336         if (signal_pending(current))
1337                 flush_signals(current);
1338         del_timer_sync(&conn->tmf_timer);
1339
1340         mutex_lock(&session->eh_mutex);
1341         spin_lock_bh(&session->lock);
1342         /* if the session drops it will clean up the mtask */
1343         if (age != session->age ||
1344             session->state != ISCSI_STATE_LOGGED_IN)
1345                 return -ENOTCONN;
1346         return 0;
1347 }
1348
1349 /*
1350  * Fail commands. session lock held and recv side suspended and xmit
1351  * thread flushed
1352  */
1353 static void fail_all_commands(struct iscsi_conn *conn, unsigned lun,
1354                               int error)
1355 {
1356         struct iscsi_cmd_task *ctask, *tmp;
1357
1358         if (conn->ctask && (conn->ctask->sc->device->lun == lun || lun == -1))
1359                 conn->ctask = NULL;
1360
1361         /* flush pending */
1362         list_for_each_entry_safe(ctask, tmp, &conn->xmitqueue, running) {
1363                 if (lun == ctask->sc->device->lun || lun == -1) {
1364                         debug_scsi("failing pending sc %p itt 0x%x\n",
1365                                    ctask->sc, ctask->itt);
1366                         fail_command(conn, ctask, error << 16);
1367                 }
1368         }
1369
1370         list_for_each_entry_safe(ctask, tmp, &conn->requeue, running) {
1371                 if (lun == ctask->sc->device->lun || lun == -1) {
1372                         debug_scsi("failing requeued sc %p itt 0x%x\n",
1373                                    ctask->sc, ctask->itt);
1374                         fail_command(conn, ctask, error << 16);
1375                 }
1376         }
1377
1378         /* fail all other running */
1379         list_for_each_entry_safe(ctask, tmp, &conn->run_list, running) {
1380                 if (lun == ctask->sc->device->lun || lun == -1) {
1381                         debug_scsi("failing in progress sc %p itt 0x%x\n",
1382                                    ctask->sc, ctask->itt);
1383                         fail_command(conn, ctask, DID_BUS_BUSY << 16);
1384                 }
1385         }
1386 }
1387
1388 static void iscsi_suspend_tx(struct iscsi_conn *conn)
1389 {
1390         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1391         scsi_flush_work(conn->session->host);
1392 }
1393
1394 static void iscsi_start_tx(struct iscsi_conn *conn)
1395 {
1396         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1397         scsi_queue_work(conn->session->host, &conn->xmitwork);
1398 }
1399
1400 static enum scsi_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *scmd)
1401 {
1402         struct iscsi_cls_session *cls_session;
1403         struct iscsi_session *session;
1404         struct iscsi_conn *conn;
1405         enum scsi_eh_timer_return rc = EH_NOT_HANDLED;
1406
1407         cls_session = starget_to_session(scsi_target(scmd->device));
1408         session = class_to_transport_session(cls_session);
1409
1410         debug_scsi("scsi cmd %p timedout\n", scmd);
1411
1412         spin_lock(&session->lock);
1413         if (session->state != ISCSI_STATE_LOGGED_IN) {
1414                 /*
1415                  * We are probably in the middle of iscsi recovery so let
1416                  * that complete and handle the error.
1417                  */
1418                 rc = EH_RESET_TIMER;
1419                 goto done;
1420         }
1421
1422         conn = session->leadconn;
1423         if (!conn) {
1424                 /* In the middle of shuting down */
1425                 rc = EH_RESET_TIMER;
1426                 goto done;
1427         }
1428
1429         if (!conn->recv_timeout && !conn->ping_timeout)
1430                 goto done;
1431         /*
1432          * if the ping timedout then we are in the middle of cleaning up
1433          * and can let the iscsi eh handle it
1434          */
1435         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1436                             (conn->ping_timeout * HZ), jiffies))
1437                 rc = EH_RESET_TIMER;
1438         /*
1439          * if we are about to check the transport then give the command
1440          * more time
1441          */
1442         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ),
1443                            jiffies))
1444                 rc = EH_RESET_TIMER;
1445         /* if in the middle of checking the transport then give us more time */
1446         if (conn->ping_mtask)
1447                 rc = EH_RESET_TIMER;
1448 done:
1449         spin_unlock(&session->lock);
1450         debug_scsi("return %s\n", rc == EH_RESET_TIMER ? "timer reset" : "nh");
1451         return rc;
1452 }
1453
1454 static void iscsi_check_transport_timeouts(unsigned long data)
1455 {
1456         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1457         struct iscsi_session *session = conn->session;
1458         unsigned long recv_timeout, next_timeout = 0, last_recv;
1459
1460         spin_lock(&session->lock);
1461         if (session->state != ISCSI_STATE_LOGGED_IN)
1462                 goto done;
1463
1464         recv_timeout = conn->recv_timeout;
1465         if (!recv_timeout)
1466                 goto done;
1467
1468         recv_timeout *= HZ;
1469         last_recv = conn->last_recv;
1470         if (conn->ping_mtask &&
1471             time_before_eq(conn->last_ping + (conn->ping_timeout * HZ),
1472                            jiffies)) {
1473                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
1474                                   "expired, last rx %lu, last ping %lu, "
1475                                   "now %lu\n", conn->ping_timeout, last_recv,
1476                                   conn->last_ping, jiffies);
1477                 spin_unlock(&session->lock);
1478                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1479                 return;
1480         }
1481
1482         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
1483                 /* send a ping to try to provoke some traffic */
1484                 debug_scsi("Sending nopout as ping on conn %p\n", conn);
1485                 iscsi_send_nopout(conn, NULL);
1486                 next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
1487         } else
1488                 next_timeout = last_recv + recv_timeout;
1489
1490         debug_scsi("Setting next tmo %lu\n", next_timeout);
1491         mod_timer(&conn->transport_timer, next_timeout);
1492 done:
1493         spin_unlock(&session->lock);
1494 }
1495
1496 static void iscsi_prep_abort_task_pdu(struct iscsi_cmd_task *ctask,
1497                                       struct iscsi_tm *hdr)
1498 {
1499         memset(hdr, 0, sizeof(*hdr));
1500         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1501         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
1502         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1503         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1504         hdr->rtt = ctask->hdr->itt;
1505         hdr->refcmdsn = ctask->hdr->cmdsn;
1506 }
1507
1508 int iscsi_eh_abort(struct scsi_cmnd *sc)
1509 {
1510         struct Scsi_Host *host = sc->device->host;
1511         struct iscsi_session *session = iscsi_hostdata(host->hostdata);
1512         struct iscsi_conn *conn;
1513         struct iscsi_cmd_task *ctask;
1514         struct iscsi_tm *hdr;
1515         int rc, age;
1516
1517         mutex_lock(&session->eh_mutex);
1518         spin_lock_bh(&session->lock);
1519         /*
1520          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1521          * got the command.
1522          */
1523         if (!sc->SCp.ptr) {
1524                 debug_scsi("sc never reached iscsi layer or it completed.\n");
1525                 spin_unlock_bh(&session->lock);
1526                 mutex_unlock(&session->eh_mutex);
1527                 return SUCCESS;
1528         }
1529
1530         /*
1531          * If we are not logged in or we have started a new session
1532          * then let the host reset code handle this
1533          */
1534         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
1535             sc->SCp.phase != session->age) {
1536                 spin_unlock_bh(&session->lock);
1537                 mutex_unlock(&session->eh_mutex);
1538                 return FAILED;
1539         }
1540
1541         conn = session->leadconn;
1542         conn->eh_abort_cnt++;
1543         age = session->age;
1544
1545         ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
1546         debug_scsi("aborting [sc %p itt 0x%x]\n", sc, ctask->itt);
1547
1548         /* ctask completed before time out */
1549         if (!ctask->sc) {
1550                 debug_scsi("sc completed while abort in progress\n");
1551                 goto success;
1552         }
1553
1554         if (ctask->state == ISCSI_TASK_PENDING) {
1555                 fail_command(conn, ctask, DID_ABORT << 16);
1556                 goto success;
1557         }
1558
1559         /* only have one tmf outstanding at a time */
1560         if (conn->tmf_state != TMF_INITIAL)
1561                 goto failed;
1562         conn->tmf_state = TMF_QUEUED;
1563
1564         hdr = &conn->tmhdr;
1565         iscsi_prep_abort_task_pdu(ctask, hdr);
1566
1567         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
1568                 rc = FAILED;
1569                 goto failed;
1570         }
1571
1572         switch (conn->tmf_state) {
1573         case TMF_SUCCESS:
1574                 spin_unlock_bh(&session->lock);
1575                 iscsi_suspend_tx(conn);
1576                 /*
1577                  * clean up task if aborted. grab the recv lock as a writer
1578                  */
1579                 write_lock_bh(conn->recv_lock);
1580                 spin_lock(&session->lock);
1581                 fail_command(conn, ctask, DID_ABORT << 16);
1582                 conn->tmf_state = TMF_INITIAL;
1583                 spin_unlock(&session->lock);
1584                 write_unlock_bh(conn->recv_lock);
1585                 iscsi_start_tx(conn);
1586                 goto success_unlocked;
1587         case TMF_TIMEDOUT:
1588                 spin_unlock_bh(&session->lock);
1589                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1590                 goto failed_unlocked;
1591         case TMF_NOT_FOUND:
1592                 if (!sc->SCp.ptr) {
1593                         conn->tmf_state = TMF_INITIAL;
1594                         /* ctask completed before tmf abort response */
1595                         debug_scsi("sc completed while abort in progress\n");
1596                         goto success;
1597                 }
1598                 /* fall through */
1599         default:
1600                 conn->tmf_state = TMF_INITIAL;
1601                 goto failed;
1602         }
1603
1604 success:
1605         spin_unlock_bh(&session->lock);
1606 success_unlocked:
1607         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1608         mutex_unlock(&session->eh_mutex);
1609         return SUCCESS;
1610
1611 failed:
1612         spin_unlock_bh(&session->lock);
1613 failed_unlocked:
1614         debug_scsi("abort failed [sc %p itt 0x%x]\n", sc,
1615                     ctask ? ctask->itt : 0);
1616         mutex_unlock(&session->eh_mutex);
1617         return FAILED;
1618 }
1619 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1620
1621 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
1622 {
1623         memset(hdr, 0, sizeof(*hdr));
1624         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1625         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
1626         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1627         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
1628         hdr->rtt = RESERVED_ITT;
1629 }
1630
1631 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
1632 {
1633         struct Scsi_Host *host = sc->device->host;
1634         struct iscsi_session *session = iscsi_hostdata(host->hostdata);
1635         struct iscsi_conn *conn;
1636         struct iscsi_tm *hdr;
1637         int rc = FAILED;
1638
1639         debug_scsi("LU Reset [sc %p lun %u]\n", sc, sc->device->lun);
1640
1641         mutex_lock(&session->eh_mutex);
1642         spin_lock_bh(&session->lock);
1643         /*
1644          * Just check if we are not logged in. We cannot check for
1645          * the phase because the reset could come from a ioctl.
1646          */
1647         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
1648                 goto unlock;
1649         conn = session->leadconn;
1650
1651         /* only have one tmf outstanding at a time */
1652         if (conn->tmf_state != TMF_INITIAL)
1653                 goto unlock;
1654         conn->tmf_state = TMF_QUEUED;
1655
1656         hdr = &conn->tmhdr;
1657         iscsi_prep_lun_reset_pdu(sc, hdr);
1658
1659         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
1660                                     session->lu_reset_timeout)) {
1661                 rc = FAILED;
1662                 goto unlock;
1663         }
1664
1665         switch (conn->tmf_state) {
1666         case TMF_SUCCESS:
1667                 break;
1668         case TMF_TIMEDOUT:
1669                 spin_unlock_bh(&session->lock);
1670                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1671                 goto done;
1672         default:
1673                 conn->tmf_state = TMF_INITIAL;
1674                 goto unlock;
1675         }
1676
1677         rc = SUCCESS;
1678         spin_unlock_bh(&session->lock);
1679
1680         iscsi_suspend_tx(conn);
1681         /* need to grab the recv lock then session lock */
1682         write_lock_bh(conn->recv_lock);
1683         spin_lock(&session->lock);
1684         fail_all_commands(conn, sc->device->lun, DID_ERROR);
1685         conn->tmf_state = TMF_INITIAL;
1686         spin_unlock(&session->lock);
1687         write_unlock_bh(conn->recv_lock);
1688
1689         iscsi_start_tx(conn);
1690         goto done;
1691
1692 unlock:
1693         spin_unlock_bh(&session->lock);
1694 done:
1695         debug_scsi("iscsi_eh_device_reset %s\n",
1696                   rc == SUCCESS ? "SUCCESS" : "FAILED");
1697         mutex_unlock(&session->eh_mutex);
1698         return rc;
1699 }
1700 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
1701
1702 /*
1703  * Pre-allocate a pool of @max items of @item_size. By default, the pool
1704  * should be accessed via kfifo_{get,put} on q->queue.
1705  * Optionally, the caller can obtain the array of object pointers
1706  * by passing in a non-NULL @items pointer
1707  */
1708 int
1709 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
1710 {
1711         int i, num_arrays = 1;
1712
1713         memset(q, 0, sizeof(*q));
1714
1715         q->max = max;
1716
1717         /* If the user passed an items pointer, he wants a copy of
1718          * the array. */
1719         if (items)
1720                 num_arrays++;
1721         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
1722         if (q->pool == NULL)
1723                 goto enomem;
1724
1725         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1726                               GFP_KERNEL, NULL);
1727         if (q->queue == ERR_PTR(-ENOMEM))
1728                 goto enomem;
1729
1730         for (i = 0; i < max; i++) {
1731                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
1732                 if (q->pool[i] == NULL) {
1733                         q->max = i;
1734                         goto enomem;
1735                 }
1736                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1737         }
1738
1739         if (items) {
1740                 *items = q->pool + max;
1741                 memcpy(*items, q->pool, max * sizeof(void *));
1742         }
1743
1744         return 0;
1745
1746 enomem:
1747         iscsi_pool_free(q);
1748         return -ENOMEM;
1749 }
1750 EXPORT_SYMBOL_GPL(iscsi_pool_init);
1751
1752 void iscsi_pool_free(struct iscsi_pool *q)
1753 {
1754         int i;
1755
1756         for (i = 0; i < q->max; i++)
1757                 kfree(q->pool[i]);
1758         if (q->pool)
1759                 kfree(q->pool);
1760 }
1761 EXPORT_SYMBOL_GPL(iscsi_pool_free);
1762
1763 /*
1764  * iSCSI Session's hostdata organization:
1765  *
1766  *    *------------------* <== hostdata_session(host->hostdata)
1767  *    | ptr to class sess|
1768  *    |------------------| <== iscsi_hostdata(host->hostdata)
1769  *    | iscsi_session    |
1770  *    *------------------*
1771  */
1772
1773 #define hostdata_privsize(_sz)  (sizeof(unsigned long) + _sz + \
1774                                  _sz % sizeof(unsigned long))
1775
1776 #define hostdata_session(_hostdata) (iscsi_ptr(*(unsigned long *)_hostdata))
1777
1778 /**
1779  * iscsi_session_setup - create iscsi cls session and host and session
1780  * @scsit: scsi transport template
1781  * @iscsit: iscsi transport template
1782  * @cmds_max: scsi host can queue
1783  * @qdepth: scsi host cmds per lun
1784  * @cmd_task_size: LLD ctask private data size
1785  * @mgmt_task_size: LLD mtask private data size
1786  * @initial_cmdsn: initial CmdSN
1787  * @hostno: host no allocated
1788  *
1789  * This can be used by software iscsi_transports that allocate
1790  * a session per scsi host.
1791  **/
1792 struct iscsi_cls_session *
1793 iscsi_session_setup(struct iscsi_transport *iscsit,
1794                     struct scsi_transport_template *scsit,
1795                     uint16_t cmds_max, uint16_t qdepth,
1796                     int cmd_task_size, int mgmt_task_size,
1797                     uint32_t initial_cmdsn, uint32_t *hostno)
1798 {
1799         struct Scsi_Host *shost;
1800         struct iscsi_session *session;
1801         struct iscsi_cls_session *cls_session;
1802         int cmd_i;
1803
1804         if (qdepth > ISCSI_MAX_CMD_PER_LUN || qdepth < 1) {
1805                 if (qdepth != 0)
1806                         printk(KERN_ERR "iscsi: invalid queue depth of %d. "
1807                               "Queue depth must be between 1 and %d.\n",
1808                               qdepth, ISCSI_MAX_CMD_PER_LUN);
1809                 qdepth = ISCSI_DEF_CMD_PER_LUN;
1810         }
1811
1812         if (!is_power_of_2(cmds_max) || cmds_max >= ISCSI_MGMT_ITT_OFFSET ||
1813             cmds_max < 2) {
1814                 if (cmds_max != 0)
1815                         printk(KERN_ERR "iscsi: invalid can_queue of %d. "
1816                                "can_queue must be a power of 2 and between "
1817                                "2 and %d - setting to %d.\n", cmds_max,
1818                                ISCSI_MGMT_ITT_OFFSET, ISCSI_DEF_XMIT_CMDS_MAX);
1819                 cmds_max = ISCSI_DEF_XMIT_CMDS_MAX;
1820         }
1821
1822         shost = scsi_host_alloc(iscsit->host_template,
1823                                 hostdata_privsize(sizeof(*session)));
1824         if (!shost)
1825                 return NULL;
1826
1827         /* the iscsi layer takes one task for reserve */
1828         shost->can_queue = cmds_max - 1;
1829         shost->cmd_per_lun = qdepth;
1830         shost->max_id = 1;
1831         shost->max_channel = 0;
1832         shost->max_lun = iscsit->max_lun;
1833         shost->max_cmd_len = iscsit->max_cmd_len;
1834         shost->transportt = scsit;
1835         shost->transportt->create_work_queue = 1;
1836         shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
1837         *hostno = shost->host_no;
1838
1839         session = iscsi_hostdata(shost->hostdata);
1840         memset(session, 0, sizeof(struct iscsi_session));
1841         session->host = shost;
1842         session->state = ISCSI_STATE_FREE;
1843         session->fast_abort = 1;
1844         session->lu_reset_timeout = 15;
1845         session->abort_timeout = 10;
1846         session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
1847         session->cmds_max = cmds_max;
1848         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
1849         session->exp_cmdsn = initial_cmdsn + 1;
1850         session->max_cmdsn = initial_cmdsn + 1;
1851         session->max_r2t = 1;
1852         session->tt = iscsit;
1853         mutex_init(&session->eh_mutex);
1854
1855         /* initialize SCSI PDU commands pool */
1856         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
1857                             (void***)&session->cmds,
1858                             cmd_task_size + sizeof(struct iscsi_cmd_task)))
1859                 goto cmdpool_alloc_fail;
1860
1861         /* pre-format cmds pool with ITT */
1862         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1863                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1864
1865                 if (cmd_task_size)
1866                         ctask->dd_data = &ctask[1];
1867                 ctask->itt = cmd_i;
1868                 INIT_LIST_HEAD(&ctask->running);
1869         }
1870
1871         spin_lock_init(&session->lock);
1872
1873         /* initialize immediate command pool */
1874         if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max,
1875                            (void***)&session->mgmt_cmds,
1876                            mgmt_task_size + sizeof(struct iscsi_mgmt_task)))
1877                 goto mgmtpool_alloc_fail;
1878
1879
1880         /* pre-format immediate cmds pool with ITT */
1881         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
1882                 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
1883
1884                 if (mgmt_task_size)
1885                         mtask->dd_data = &mtask[1];
1886                 mtask->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i;
1887                 INIT_LIST_HEAD(&mtask->running);
1888         }
1889
1890         if (scsi_add_host(shost, NULL))
1891                 goto add_host_fail;
1892
1893         if (!try_module_get(iscsit->owner))
1894                 goto cls_session_fail;
1895
1896         cls_session = iscsi_create_session(shost, iscsit, 0);
1897         if (!cls_session)
1898                 goto module_put;
1899         *(unsigned long*)shost->hostdata = (unsigned long)cls_session;
1900
1901         return cls_session;
1902
1903 module_put:
1904         module_put(iscsit->owner);
1905 cls_session_fail:
1906         scsi_remove_host(shost);
1907 add_host_fail:
1908         iscsi_pool_free(&session->mgmtpool);
1909 mgmtpool_alloc_fail:
1910         iscsi_pool_free(&session->cmdpool);
1911 cmdpool_alloc_fail:
1912         scsi_host_put(shost);
1913         return NULL;
1914 }
1915 EXPORT_SYMBOL_GPL(iscsi_session_setup);
1916
1917 /**
1918  * iscsi_session_teardown - destroy session, host, and cls_session
1919  * shost: scsi host
1920  *
1921  * This can be used by software iscsi_transports that allocate
1922  * a session per scsi host.
1923  **/
1924 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
1925 {
1926         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1927         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1928         struct module *owner = cls_session->transport->owner;
1929
1930         iscsi_remove_session(cls_session);
1931         scsi_remove_host(shost);
1932
1933         iscsi_pool_free(&session->mgmtpool);
1934         iscsi_pool_free(&session->cmdpool);
1935
1936         kfree(session->password);
1937         kfree(session->password_in);
1938         kfree(session->username);
1939         kfree(session->username_in);
1940         kfree(session->targetname);
1941         kfree(session->netdev);
1942         kfree(session->hwaddress);
1943         kfree(session->initiatorname);
1944
1945         iscsi_free_session(cls_session);
1946         scsi_host_put(shost);
1947         module_put(owner);
1948 }
1949 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
1950
1951 /**
1952  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
1953  * @cls_session: iscsi_cls_session
1954  * @conn_idx: cid
1955  **/
1956 struct iscsi_cls_conn *
1957 iscsi_conn_setup(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1958 {
1959         struct iscsi_session *session = class_to_transport_session(cls_session);
1960         struct iscsi_conn *conn;
1961         struct iscsi_cls_conn *cls_conn;
1962         char *data;
1963
1964         cls_conn = iscsi_create_conn(cls_session, conn_idx);
1965         if (!cls_conn)
1966                 return NULL;
1967         conn = cls_conn->dd_data;
1968         memset(conn, 0, sizeof(*conn));
1969
1970         conn->session = session;
1971         conn->cls_conn = cls_conn;
1972         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
1973         conn->id = conn_idx;
1974         conn->exp_statsn = 0;
1975         conn->tmf_state = TMF_INITIAL;
1976
1977         init_timer(&conn->transport_timer);
1978         conn->transport_timer.data = (unsigned long)conn;
1979         conn->transport_timer.function = iscsi_check_transport_timeouts;
1980
1981         INIT_LIST_HEAD(&conn->run_list);
1982         INIT_LIST_HEAD(&conn->mgmt_run_list);
1983         INIT_LIST_HEAD(&conn->mgmtqueue);
1984         INIT_LIST_HEAD(&conn->xmitqueue);
1985         INIT_LIST_HEAD(&conn->requeue);
1986         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
1987
1988         /* allocate login_mtask used for the login/text sequences */
1989         spin_lock_bh(&session->lock);
1990         if (!__kfifo_get(session->mgmtpool.queue,
1991                          (void*)&conn->login_mtask,
1992                          sizeof(void*))) {
1993                 spin_unlock_bh(&session->lock);
1994                 goto login_mtask_alloc_fail;
1995         }
1996         spin_unlock_bh(&session->lock);
1997
1998         data = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN, GFP_KERNEL);
1999         if (!data)
2000                 goto login_mtask_data_alloc_fail;
2001         conn->login_mtask->data = conn->data = data;
2002
2003         init_timer(&conn->tmf_timer);
2004         init_waitqueue_head(&conn->ehwait);
2005
2006         return cls_conn;
2007
2008 login_mtask_data_alloc_fail:
2009         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
2010                     sizeof(void*));
2011 login_mtask_alloc_fail:
2012         iscsi_destroy_conn(cls_conn);
2013         return NULL;
2014 }
2015 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2016
2017 /**
2018  * iscsi_conn_teardown - teardown iscsi connection
2019  * cls_conn: iscsi class connection
2020  *
2021  * TODO: we may need to make this into a two step process
2022  * like scsi-mls remove + put host
2023  */
2024 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2025 {
2026         struct iscsi_conn *conn = cls_conn->dd_data;
2027         struct iscsi_session *session = conn->session;
2028         unsigned long flags;
2029
2030         del_timer_sync(&conn->transport_timer);
2031
2032         spin_lock_bh(&session->lock);
2033         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2034         if (session->leadconn == conn) {
2035                 /*
2036                  * leading connection? then give up on recovery.
2037                  */
2038                 session->state = ISCSI_STATE_TERMINATE;
2039                 wake_up(&conn->ehwait);
2040         }
2041         spin_unlock_bh(&session->lock);
2042
2043         /*
2044          * Block until all in-progress commands for this connection
2045          * time out or fail.
2046          */
2047         for (;;) {
2048                 spin_lock_irqsave(session->host->host_lock, flags);
2049                 if (!session->host->host_busy) { /* OK for ERL == 0 */
2050                         spin_unlock_irqrestore(session->host->host_lock, flags);
2051                         break;
2052                 }
2053                 spin_unlock_irqrestore(session->host->host_lock, flags);
2054                 msleep_interruptible(500);
2055                 iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2056                                   "host_busy %d host_failed %d\n",
2057                                   session->host->host_busy,
2058                                   session->host->host_failed);
2059                 /*
2060                  * force eh_abort() to unblock
2061                  */
2062                 wake_up(&conn->ehwait);
2063         }
2064
2065         /* flush queued up work because we free the connection below */
2066         iscsi_suspend_tx(conn);
2067
2068         spin_lock_bh(&session->lock);
2069         kfree(conn->data);
2070         kfree(conn->persistent_address);
2071         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
2072                     sizeof(void*));
2073         if (session->leadconn == conn)
2074                 session->leadconn = NULL;
2075         spin_unlock_bh(&session->lock);
2076
2077         iscsi_destroy_conn(cls_conn);
2078 }
2079 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2080
2081 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2082 {
2083         struct iscsi_conn *conn = cls_conn->dd_data;
2084         struct iscsi_session *session = conn->session;
2085
2086         if (!session) {
2087                 iscsi_conn_printk(KERN_ERR, conn,
2088                                   "can't start unbound connection\n");
2089                 return -EPERM;
2090         }
2091
2092         if ((session->imm_data_en || !session->initial_r2t_en) &&
2093              session->first_burst > session->max_burst) {
2094                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2095                                   "first_burst %d max_burst %d\n",
2096                                   session->first_burst, session->max_burst);
2097                 return -EINVAL;
2098         }
2099
2100         if (conn->ping_timeout && !conn->recv_timeout) {
2101                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
2102                                   "zero. Using 5 seconds\n.");
2103                 conn->recv_timeout = 5;
2104         }
2105
2106         if (conn->recv_timeout && !conn->ping_timeout) {
2107                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
2108                                   "zero. Using 5 seconds.\n");
2109                 conn->ping_timeout = 5;
2110         }
2111
2112         spin_lock_bh(&session->lock);
2113         conn->c_stage = ISCSI_CONN_STARTED;
2114         session->state = ISCSI_STATE_LOGGED_IN;
2115         session->queued_cmdsn = session->cmdsn;
2116
2117         conn->last_recv = jiffies;
2118         conn->last_ping = jiffies;
2119         if (conn->recv_timeout && conn->ping_timeout)
2120                 mod_timer(&conn->transport_timer,
2121                           jiffies + (conn->recv_timeout * HZ));
2122
2123         switch(conn->stop_stage) {
2124         case STOP_CONN_RECOVER:
2125                 /*
2126                  * unblock eh_abort() if it is blocked. re-try all
2127                  * commands after successful recovery
2128                  */
2129                 conn->stop_stage = 0;
2130                 conn->tmf_state = TMF_INITIAL;
2131                 session->age++;
2132                 if (session->age == 16)
2133                         session->age = 0;
2134                 break;
2135         case STOP_CONN_TERM:
2136                 conn->stop_stage = 0;
2137                 break;
2138         default:
2139                 break;
2140         }
2141         spin_unlock_bh(&session->lock);
2142
2143         iscsi_unblock_session(session_to_cls(session));
2144         wake_up(&conn->ehwait);
2145         return 0;
2146 }
2147 EXPORT_SYMBOL_GPL(iscsi_conn_start);
2148
2149 static void
2150 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
2151 {
2152         struct iscsi_mgmt_task *mtask, *tmp;
2153
2154         /* handle pending */
2155         list_for_each_entry_safe(mtask, tmp, &conn->mgmtqueue, running) {
2156                 debug_scsi("flushing pending mgmt task itt 0x%x\n", mtask->itt);
2157                 iscsi_free_mgmt_task(conn, mtask);
2158         }
2159
2160         /* handle running */
2161         list_for_each_entry_safe(mtask, tmp, &conn->mgmt_run_list, running) {
2162                 debug_scsi("flushing running mgmt task itt 0x%x\n", mtask->itt);
2163                 iscsi_free_mgmt_task(conn, mtask);
2164         }
2165
2166         conn->mtask = NULL;
2167 }
2168
2169 static void iscsi_start_session_recovery(struct iscsi_session *session,
2170                                          struct iscsi_conn *conn, int flag)
2171 {
2172         int old_stop_stage;
2173
2174         del_timer_sync(&conn->transport_timer);
2175
2176         mutex_lock(&session->eh_mutex);
2177         spin_lock_bh(&session->lock);
2178         if (conn->stop_stage == STOP_CONN_TERM) {
2179                 spin_unlock_bh(&session->lock);
2180                 mutex_unlock(&session->eh_mutex);
2181                 return;
2182         }
2183
2184         /*
2185          * The LLD either freed/unset the lock on us, or userspace called
2186          * stop but did not create a proper connection (connection was never
2187          * bound or it was unbound then stop was called).
2188          */
2189         if (!conn->recv_lock) {
2190                 spin_unlock_bh(&session->lock);
2191                 mutex_unlock(&session->eh_mutex);
2192                 return;
2193         }
2194
2195         /*
2196          * When this is called for the in_login state, we only want to clean
2197          * up the login task and connection. We do not need to block and set
2198          * the recovery state again
2199          */
2200         if (flag == STOP_CONN_TERM)
2201                 session->state = ISCSI_STATE_TERMINATE;
2202         else if (conn->stop_stage != STOP_CONN_RECOVER)
2203                 session->state = ISCSI_STATE_IN_RECOVERY;
2204
2205         old_stop_stage = conn->stop_stage;
2206         conn->stop_stage = flag;
2207         conn->c_stage = ISCSI_CONN_STOPPED;
2208         spin_unlock_bh(&session->lock);
2209
2210         iscsi_suspend_tx(conn);
2211
2212         write_lock_bh(conn->recv_lock);
2213         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
2214         write_unlock_bh(conn->recv_lock);
2215
2216         /*
2217          * for connection level recovery we should not calculate
2218          * header digest. conn->hdr_size used for optimization
2219          * in hdr_extract() and will be re-negotiated at
2220          * set_param() time.
2221          */
2222         if (flag == STOP_CONN_RECOVER) {
2223                 conn->hdrdgst_en = 0;
2224                 conn->datadgst_en = 0;
2225                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
2226                     old_stop_stage != STOP_CONN_RECOVER) {
2227                         debug_scsi("blocking session\n");
2228                         iscsi_block_session(session_to_cls(session));
2229                 }
2230         }
2231
2232         /*
2233          * flush queues.
2234          */
2235         spin_lock_bh(&session->lock);
2236         fail_all_commands(conn, -1,
2237                         STOP_CONN_RECOVER ? DID_BUS_BUSY : DID_ERROR);
2238         flush_control_queues(session, conn);
2239         spin_unlock_bh(&session->lock);
2240         mutex_unlock(&session->eh_mutex);
2241 }
2242
2243 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
2244 {
2245         struct iscsi_conn *conn = cls_conn->dd_data;
2246         struct iscsi_session *session = conn->session;
2247
2248         switch (flag) {
2249         case STOP_CONN_RECOVER:
2250         case STOP_CONN_TERM:
2251                 iscsi_start_session_recovery(session, conn, flag);
2252                 break;
2253         default:
2254                 iscsi_conn_printk(KERN_ERR, conn,
2255                                   "invalid stop flag %d\n", flag);
2256         }
2257 }
2258 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
2259
2260 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
2261                     struct iscsi_cls_conn *cls_conn, int is_leading)
2262 {
2263         struct iscsi_session *session = class_to_transport_session(cls_session);
2264         struct iscsi_conn *conn = cls_conn->dd_data;
2265
2266         spin_lock_bh(&session->lock);
2267         if (is_leading)
2268                 session->leadconn = conn;
2269         spin_unlock_bh(&session->lock);
2270
2271         /*
2272          * Unblock xmitworker(), Login Phase will pass through.
2273          */
2274         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
2275         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
2276         return 0;
2277 }
2278 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
2279
2280
2281 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
2282                     enum iscsi_param param, char *buf, int buflen)
2283 {
2284         struct iscsi_conn *conn = cls_conn->dd_data;
2285         struct iscsi_session *session = conn->session;
2286         uint32_t value;
2287
2288         switch(param) {
2289         case ISCSI_PARAM_FAST_ABORT:
2290                 sscanf(buf, "%d", &session->fast_abort);
2291                 break;
2292         case ISCSI_PARAM_ABORT_TMO:
2293                 sscanf(buf, "%d", &session->abort_timeout);
2294                 break;
2295         case ISCSI_PARAM_LU_RESET_TMO:
2296                 sscanf(buf, "%d", &session->lu_reset_timeout);
2297                 break;
2298         case ISCSI_PARAM_PING_TMO:
2299                 sscanf(buf, "%d", &conn->ping_timeout);
2300                 break;
2301         case ISCSI_PARAM_RECV_TMO:
2302                 sscanf(buf, "%d", &conn->recv_timeout);
2303                 break;
2304         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2305                 sscanf(buf, "%d", &conn->max_recv_dlength);
2306                 break;
2307         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2308                 sscanf(buf, "%d", &conn->max_xmit_dlength);
2309                 break;
2310         case ISCSI_PARAM_HDRDGST_EN:
2311                 sscanf(buf, "%d", &conn->hdrdgst_en);
2312                 break;
2313         case ISCSI_PARAM_DATADGST_EN:
2314                 sscanf(buf, "%d", &conn->datadgst_en);
2315                 break;
2316         case ISCSI_PARAM_INITIAL_R2T_EN:
2317                 sscanf(buf, "%d", &session->initial_r2t_en);
2318                 break;
2319         case ISCSI_PARAM_MAX_R2T:
2320                 sscanf(buf, "%d", &session->max_r2t);
2321                 break;
2322         case ISCSI_PARAM_IMM_DATA_EN:
2323                 sscanf(buf, "%d", &session->imm_data_en);
2324                 break;
2325         case ISCSI_PARAM_FIRST_BURST:
2326                 sscanf(buf, "%d", &session->first_burst);
2327                 break;
2328         case ISCSI_PARAM_MAX_BURST:
2329                 sscanf(buf, "%d", &session->max_burst);
2330                 break;
2331         case ISCSI_PARAM_PDU_INORDER_EN:
2332                 sscanf(buf, "%d", &session->pdu_inorder_en);
2333                 break;
2334         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2335                 sscanf(buf, "%d", &session->dataseq_inorder_en);
2336                 break;
2337         case ISCSI_PARAM_ERL:
2338                 sscanf(buf, "%d", &session->erl);
2339                 break;
2340         case ISCSI_PARAM_IFMARKER_EN:
2341                 sscanf(buf, "%d", &value);
2342                 BUG_ON(value);
2343                 break;
2344         case ISCSI_PARAM_OFMARKER_EN:
2345                 sscanf(buf, "%d", &value);
2346                 BUG_ON(value);
2347                 break;
2348         case ISCSI_PARAM_EXP_STATSN:
2349                 sscanf(buf, "%u", &conn->exp_statsn);
2350                 break;
2351         case ISCSI_PARAM_USERNAME:
2352                 kfree(session->username);
2353                 session->username = kstrdup(buf, GFP_KERNEL);
2354                 if (!session->username)
2355                         return -ENOMEM;
2356                 break;
2357         case ISCSI_PARAM_USERNAME_IN:
2358                 kfree(session->username_in);
2359                 session->username_in = kstrdup(buf, GFP_KERNEL);
2360                 if (!session->username_in)
2361                         return -ENOMEM;
2362                 break;
2363         case ISCSI_PARAM_PASSWORD:
2364                 kfree(session->password);
2365                 session->password = kstrdup(buf, GFP_KERNEL);
2366                 if (!session->password)
2367                         return -ENOMEM;
2368                 break;
2369         case ISCSI_PARAM_PASSWORD_IN:
2370                 kfree(session->password_in);
2371                 session->password_in = kstrdup(buf, GFP_KERNEL);
2372                 if (!session->password_in)
2373                         return -ENOMEM;
2374                 break;
2375         case ISCSI_PARAM_TARGET_NAME:
2376                 /* this should not change between logins */
2377                 if (session->targetname)
2378                         break;
2379
2380                 session->targetname = kstrdup(buf, GFP_KERNEL);
2381                 if (!session->targetname)
2382                         return -ENOMEM;
2383                 break;
2384         case ISCSI_PARAM_TPGT:
2385                 sscanf(buf, "%d", &session->tpgt);
2386                 break;
2387         case ISCSI_PARAM_PERSISTENT_PORT:
2388                 sscanf(buf, "%d", &conn->persistent_port);
2389                 break;
2390         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2391                 /*
2392                  * this is the address returned in discovery so it should
2393                  * not change between logins.
2394                  */
2395                 if (conn->persistent_address)
2396                         break;
2397
2398                 conn->persistent_address = kstrdup(buf, GFP_KERNEL);
2399                 if (!conn->persistent_address)
2400                         return -ENOMEM;
2401                 break;
2402         default:
2403                 return -ENOSYS;
2404         }
2405
2406         return 0;
2407 }
2408 EXPORT_SYMBOL_GPL(iscsi_set_param);
2409
2410 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
2411                             enum iscsi_param param, char *buf)
2412 {
2413         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
2414         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2415         int len;
2416
2417         switch(param) {
2418         case ISCSI_PARAM_FAST_ABORT:
2419                 len = sprintf(buf, "%d\n", session->fast_abort);
2420                 break;
2421         case ISCSI_PARAM_ABORT_TMO:
2422                 len = sprintf(buf, "%d\n", session->abort_timeout);
2423                 break;
2424         case ISCSI_PARAM_LU_RESET_TMO:
2425                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
2426                 break;
2427         case ISCSI_PARAM_INITIAL_R2T_EN:
2428                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
2429                 break;
2430         case ISCSI_PARAM_MAX_R2T:
2431                 len = sprintf(buf, "%hu\n", session->max_r2t);
2432                 break;
2433         case ISCSI_PARAM_IMM_DATA_EN:
2434                 len = sprintf(buf, "%d\n", session->imm_data_en);
2435                 break;
2436         case ISCSI_PARAM_FIRST_BURST:
2437                 len = sprintf(buf, "%u\n", session->first_burst);
2438                 break;
2439         case ISCSI_PARAM_MAX_BURST:
2440                 len = sprintf(buf, "%u\n", session->max_burst);
2441                 break;
2442         case ISCSI_PARAM_PDU_INORDER_EN:
2443                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
2444                 break;
2445         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2446                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
2447                 break;
2448         case ISCSI_PARAM_ERL:
2449                 len = sprintf(buf, "%d\n", session->erl);
2450                 break;
2451         case ISCSI_PARAM_TARGET_NAME:
2452                 len = sprintf(buf, "%s\n", session->targetname);
2453                 break;
2454         case ISCSI_PARAM_TPGT:
2455                 len = sprintf(buf, "%d\n", session->tpgt);
2456                 break;
2457         case ISCSI_PARAM_USERNAME:
2458                 len = sprintf(buf, "%s\n", session->username);
2459                 break;
2460         case ISCSI_PARAM_USERNAME_IN:
2461                 len = sprintf(buf, "%s\n", session->username_in);
2462                 break;
2463         case ISCSI_PARAM_PASSWORD:
2464                 len = sprintf(buf, "%s\n", session->password);
2465                 break;
2466         case ISCSI_PARAM_PASSWORD_IN:
2467                 len = sprintf(buf, "%s\n", session->password_in);
2468                 break;
2469         default:
2470                 return -ENOSYS;
2471         }
2472
2473         return len;
2474 }
2475 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
2476
2477 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2478                          enum iscsi_param param, char *buf)
2479 {
2480         struct iscsi_conn *conn = cls_conn->dd_data;
2481         int len;
2482
2483         switch(param) {
2484         case ISCSI_PARAM_PING_TMO:
2485                 len = sprintf(buf, "%u\n", conn->ping_timeout);
2486                 break;
2487         case ISCSI_PARAM_RECV_TMO:
2488                 len = sprintf(buf, "%u\n", conn->recv_timeout);
2489                 break;
2490         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2491                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
2492                 break;
2493         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2494                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
2495                 break;
2496         case ISCSI_PARAM_HDRDGST_EN:
2497                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
2498                 break;
2499         case ISCSI_PARAM_DATADGST_EN:
2500                 len = sprintf(buf, "%d\n", conn->datadgst_en);
2501                 break;
2502         case ISCSI_PARAM_IFMARKER_EN:
2503                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
2504                 break;
2505         case ISCSI_PARAM_OFMARKER_EN:
2506                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
2507                 break;
2508         case ISCSI_PARAM_EXP_STATSN:
2509                 len = sprintf(buf, "%u\n", conn->exp_statsn);
2510                 break;
2511         case ISCSI_PARAM_PERSISTENT_PORT:
2512                 len = sprintf(buf, "%d\n", conn->persistent_port);
2513                 break;
2514         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2515                 len = sprintf(buf, "%s\n", conn->persistent_address);
2516                 break;
2517         default:
2518                 return -ENOSYS;
2519         }
2520
2521         return len;
2522 }
2523 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
2524
2525 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2526                          char *buf)
2527 {
2528         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2529         int len;
2530
2531         switch (param) {
2532         case ISCSI_HOST_PARAM_NETDEV_NAME:
2533                 if (!session->netdev)
2534                         len = sprintf(buf, "%s\n", "default");
2535                 else
2536                         len = sprintf(buf, "%s\n", session->netdev);
2537                 break;
2538         case ISCSI_HOST_PARAM_HWADDRESS:
2539                 if (!session->hwaddress)
2540                         len = sprintf(buf, "%s\n", "default");
2541                 else
2542                         len = sprintf(buf, "%s\n", session->hwaddress);
2543                 break;
2544         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2545                 if (!session->initiatorname)
2546                         len = sprintf(buf, "%s\n", "unknown");
2547                 else
2548                         len = sprintf(buf, "%s\n", session->initiatorname);
2549                 break;
2550
2551         default:
2552                 return -ENOSYS;
2553         }
2554
2555         return len;
2556 }
2557 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
2558
2559 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2560                          char *buf, int buflen)
2561 {
2562         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2563
2564         switch (param) {
2565         case ISCSI_HOST_PARAM_NETDEV_NAME:
2566                 if (!session->netdev)
2567                         session->netdev = kstrdup(buf, GFP_KERNEL);
2568                 break;
2569         case ISCSI_HOST_PARAM_HWADDRESS:
2570                 if (!session->hwaddress)
2571                         session->hwaddress = kstrdup(buf, GFP_KERNEL);
2572                 break;
2573         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2574                 if (!session->initiatorname)
2575                         session->initiatorname = kstrdup(buf, GFP_KERNEL);
2576                 break;
2577         default:
2578                 return -ENOSYS;
2579         }
2580
2581         return 0;
2582 }
2583 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
2584
2585 MODULE_AUTHOR("Mike Christie");
2586 MODULE_DESCRIPTION("iSCSI library functions");
2587 MODULE_LICENSE("GPL");