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/mutex.h>
  26 #include <linux/kfifo.h>
  27 #include <linux/delay.h>
  28 #include <net/tcp.h>
  29 #include <scsi/scsi_cmnd.h>
  30 #include <scsi/scsi_device.h>
  31 #include <scsi/scsi_eh.h>
  32 #include <scsi/scsi_tcq.h>
  33 #include <scsi/scsi_host.h>
  34 #include <scsi/scsi.h>
  35 #include <scsi/iscsi_proto.h>
  36 #include <scsi/scsi_transport.h>
  37 #include <scsi/scsi_transport_iscsi.h>
  38 #include <scsi/libiscsi.h>
  39
  40 struct iscsi_session *
  41 class_to_transport_session(struct iscsi_cls_session *cls_session)
  42 {
  43         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
  44         return iscsi_hostdata(shost->hostdata);
  45 }
  46 EXPORT_SYMBOL_GPL(class_to_transport_session);
  47
  48 #define INVALID_SN_DELTA        0xffff
  49
  50 int
  51 iscsi_check_assign_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
  52 {
  53         uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
  54         uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);
  55
  56         if (max_cmdsn < exp_cmdsn -1 &&
  57             max_cmdsn > exp_cmdsn - INVALID_SN_DELTA)
  58                 return ISCSI_ERR_MAX_CMDSN;
  59         if (max_cmdsn > session->max_cmdsn ||
  60             max_cmdsn < session->max_cmdsn - INVALID_SN_DELTA)
  61                 session->max_cmdsn = max_cmdsn;
  62         if (exp_cmdsn > session->exp_cmdsn ||
  63             exp_cmdsn < session->exp_cmdsn - INVALID_SN_DELTA)
  64                 session->exp_cmdsn = exp_cmdsn;
  65
  66         return 0;
  67 }
  68 EXPORT_SYMBOL_GPL(iscsi_check_assign_cmdsn);
  69
  70 void iscsi_prep_unsolicit_data_pdu(struct iscsi_cmd_task *ctask,
  71                                    struct iscsi_data *hdr)
  72 {
  73         struct iscsi_conn *conn = ctask->conn;
  74
  75         memset(hdr, 0, sizeof(struct iscsi_data));
  76         hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
  77         hdr->datasn = cpu_to_be32(ctask->unsol_datasn);
  78         ctask->unsol_datasn++;
  79         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
  80         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
  81
  82         hdr->itt = ctask->hdr->itt;
  83         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
  84         hdr->offset = cpu_to_be32(ctask->unsol_offset);
  85
  86         if (ctask->unsol_count > conn->max_xmit_dlength) {
  87                 hton24(hdr->dlength, conn->max_xmit_dlength);
  88                 ctask->data_count = conn->max_xmit_dlength;
  89                 ctask->unsol_offset += ctask->data_count;
  90                 hdr->flags = 0;
  91         } else {
  92                 hton24(hdr->dlength, ctask->unsol_count);
  93                 ctask->data_count = ctask->unsol_count;
  94                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
  95         }
  96 }
  97 EXPORT_SYMBOL_GPL(iscsi_prep_unsolicit_data_pdu);
  98
  99 /**
 100  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 101  * @ctask: iscsi cmd task
 102  *
 103  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 104  * fields like dlength or final based on how much data it sends
 105  */
 106 static void iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
 107 {
 108         struct iscsi_conn *conn = ctask->conn;
 109         struct iscsi_session *session = conn->session;
 110         struct iscsi_cmd *hdr = ctask->hdr;
 111         struct scsi_cmnd *sc = ctask->sc;
 112
 113         hdr->opcode = ISCSI_OP_SCSI_CMD;
 114         hdr->flags = ISCSI_ATTR_SIMPLE;
 115         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
 116         hdr->itt = ctask->itt | (conn->id << ISCSI_CID_SHIFT) |
 117                          (session->age << ISCSI_AGE_SHIFT);
 118         hdr->data_length = cpu_to_be32(sc->request_bufflen);
 119         hdr->cmdsn = cpu_to_be32(session->cmdsn);
 120         session->cmdsn++;
 121         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 122         memcpy(hdr->cdb, sc->cmnd, sc->cmd_len);
 123         memset(&hdr->cdb[sc->cmd_len], 0, MAX_COMMAND_SIZE - sc->cmd_len);
 124
 125         ctask->data_count = 0;
 126         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 127                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 128                 /*
 129                  * Write counters:
 130                  *
 131                  *      imm_count       bytes to be sent right after
 132                  *                      SCSI PDU Header
 133                  *
 134                  *      unsol_count     bytes(as Data-Out) to be sent
 135                  *                      without R2T ack right after
 136                  *                      immediate data
 137                  *
 138                  *      r2t_data_count  bytes to be sent via R2T ack's
 139                  *
 140                  *      pad_count       bytes to be sent as zero-padding
 141                  */
 142                 ctask->imm_count = 0;
 143                 ctask->unsol_count = 0;
 144                 ctask->unsol_offset = 0;
 145                 ctask->unsol_datasn = 0;
 146
 147                 if (session->imm_data_en) {
 148                         if (ctask->total_length >= session->first_burst)
 149                                 ctask->imm_count = min(session->first_burst,
 150                                                         conn->max_xmit_dlength);
 151                         else
 152                                 ctask->imm_count = min(ctask->total_length,
 153                                                         conn->max_xmit_dlength);
 154                         hton24(ctask->hdr->dlength, ctask->imm_count);
 155                 } else
 156                         zero_data(ctask->hdr->dlength);
 157
 158                 if (!session->initial_r2t_en) {
 159                         ctask->unsol_count = min(session->first_burst,
 160                                 ctask->total_length) - ctask->imm_count;
 161                         ctask->unsol_offset = ctask->imm_count;
 162                 }
 163
 164                 if (!ctask->unsol_count)
 165                         /* No unsolicit Data-Out's */
 166                         ctask->hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 167         } else {
 168                 ctask->datasn = 0;
 169                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 170                 zero_data(hdr->dlength);
 171
 172                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
 173                         hdr->flags |= ISCSI_FLAG_CMD_READ;
 174         }
 175
 176         conn->scsicmd_pdus_cnt++;
 177 }
 178 EXPORT_SYMBOL_GPL(iscsi_prep_scsi_cmd_pdu);
 179
 180 /**
 181  * iscsi_complete_command - return command back to scsi-ml
 182  * @ctask: iscsi cmd task
 183  *
 184  * Must be called with session lock.
 185  * This function returns the scsi command to scsi-ml and returns
 186  * the cmd task to the pool of available cmd tasks.
 187  */
 188 static void iscsi_complete_command(struct iscsi_cmd_task *ctask)
 189 {
 190         struct iscsi_session *session = ctask->conn->session;
 191         struct scsi_cmnd *sc = ctask->sc;
 192
 193         ctask->state = ISCSI_TASK_COMPLETED;
 194         ctask->sc = NULL;
 195         /* SCSI eh reuses commands to verify us */
 196         sc->SCp.ptr = NULL;
 197         list_del_init(&ctask->running);
 198         __kfifo_put(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
 199         sc->scsi_done(sc);
 200 }
 201
 202 static void __iscsi_get_ctask(struct iscsi_cmd_task *ctask)
 203 {
 204         atomic_inc(&ctask->refcount);
 205 }
 206
 207 static void iscsi_get_ctask(struct iscsi_cmd_task *ctask)
 208 {
 209         spin_lock_bh(&ctask->conn->session->lock);
 210         __iscsi_get_ctask(ctask);
 211         spin_unlock_bh(&ctask->conn->session->lock);
 212 }
 213
 214 static void __iscsi_put_ctask(struct iscsi_cmd_task *ctask)
 215 {
 216         struct iscsi_conn *conn = ctask->conn;
 217
 218         if (atomic_dec_and_test(&ctask->refcount)) {
 219                 conn->session->tt->cleanup_cmd_task(conn, ctask);
 220                 iscsi_complete_command(ctask);
 221         }
 222 }
 223
 224 static void iscsi_put_ctask(struct iscsi_cmd_task *ctask)
 225 {
 226         spin_lock_bh(&ctask->conn->session->lock);
 227         __iscsi_put_ctask(ctask);
 228         spin_unlock_bh(&ctask->conn->session->lock);
 229 }
 230
 231 /**
 232  * iscsi_cmd_rsp - SCSI Command Response processing
 233  * @conn: iscsi connection
 234  * @hdr: iscsi header
 235  * @ctask: scsi command task
 236  * @data: cmd data buffer
 237  * @datalen: len of buffer
 238  *
 239  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 240  * then completes the command and task.
 241  **/
 242 static int iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 243                               struct iscsi_cmd_task *ctask, char *data,
 244                               int datalen)
 245 {
 246         int rc;
 247         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
 248         struct iscsi_session *session = conn->session;
 249         struct scsi_cmnd *sc = ctask->sc;
 250
 251         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 252         if (rc) {
 253                 sc->result = DID_ERROR << 16;
 254                 goto out;
 255         }
 256
 257         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 258
 259         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 260
 261         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 262                 sc->result = DID_ERROR << 16;
 263                 goto out;
 264         }
 265
 266         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 267                 int senselen;
 268
 269                 if (datalen < 2) {
 270 invalid_datalen:
 271                         printk(KERN_ERR "iscsi: Got CHECK_CONDITION but "
 272                                "invalid data buffer size of %d\n", datalen);
 273                         sc->result = DID_BAD_TARGET << 16;
 274                         goto out;
 275                 }
 276
 277                 senselen = (data[0] << 8) | data[1];
 278                 if (datalen < senselen)
 279                         goto invalid_datalen;
 280
 281                 memcpy(sc->sense_buffer, data + 2,
 282                        min(senselen, SCSI_SENSE_BUFFERSIZE));
 283                 debug_scsi("copied %d bytes of sense\n",
 284                            min(senselen, SCSI_SENSE_BUFFERSIZE));
 285         }
 286
 287         if (sc->sc_data_direction == DMA_TO_DEVICE)
 288                 goto out;
 289
 290         if (rhdr->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
 291                 int res_count = be32_to_cpu(rhdr->residual_count);
 292
 293                 if (res_count > 0 && res_count <= sc->request_bufflen)
 294                         sc->resid = res_count;
 295                 else
 296                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 297         } else if (rhdr->flags & ISCSI_FLAG_CMD_BIDI_UNDERFLOW)
 298                 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 299         else if (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW)
 300                 sc->resid = be32_to_cpu(rhdr->residual_count);
 301
 302 out:
 303         debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 304                    (long)sc, sc->result, ctask->itt);
 305         conn->scsirsp_pdus_cnt++;
 306
 307         __iscsi_put_ctask(ctask);
 308         return rc;
 309 }
 310
 311 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 312 {
 313         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 314
 315         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 316         conn->tmfrsp_pdus_cnt++;
 317
 318         if (conn->tmabort_state != TMABORT_INITIAL)
 319                 return;
 320
 321         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 322                 conn->tmabort_state = TMABORT_SUCCESS;
 323         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 324                 conn->tmabort_state = TMABORT_NOT_FOUND;
 325         else
 326                 conn->tmabort_state = TMABORT_FAILED;
 327         wake_up(&conn->ehwait);
 328 }
 329
 330 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 331                                char *data, int datalen)
 332 {
 333         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
 334         struct iscsi_hdr rejected_pdu;
 335         uint32_t itt;
 336
 337         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
 338
 339         if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
 340                 if (ntoh24(reject->dlength) > datalen)
 341                         return ISCSI_ERR_PROTO;
 342
 343                 if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
 344                         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
 345                         itt = rejected_pdu.itt & ISCSI_ITT_MASK;
 346                         printk(KERN_ERR "itt 0x%x had pdu (op 0x%x) rejected "
 347                                 "due to DataDigest error.\n", itt,
 348                                 rejected_pdu.opcode);
 349                 }
 350         }
 351         return 0;
 352 }
 353
 354 /**
 355  * __iscsi_complete_pdu - complete pdu
 356  * @conn: iscsi conn
 357  * @hdr: iscsi header
 358  * @data: data buffer
 359  * @datalen: len of data buffer
 360  *
 361  * Completes pdu processing by freeing any resources allocated at
 362  * queuecommand or send generic. session lock must be held and verify
 363  * itt must have been called.
 364  */
 365 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 366                          char *data, int datalen)
 367 {
 368         struct iscsi_session *session = conn->session;
 369         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
 370         struct iscsi_cmd_task *ctask;
 371         struct iscsi_mgmt_task *mtask;
 372         uint32_t itt;
 373
 374         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG))
 375                 itt = hdr->itt & ISCSI_ITT_MASK;
 376         else
 377                 itt = hdr->itt;
 378
 379         if (itt < session->cmds_max) {
 380                 ctask = session->cmds[itt];
 381
 382                 debug_scsi("cmdrsp [op 0x%x cid %d itt 0x%x len %d]\n",
 383                            opcode, conn->id, ctask->itt, datalen);
 384
 385                 switch(opcode) {
 386                 case ISCSI_OP_SCSI_CMD_RSP:
 387                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 388                         rc = iscsi_scsi_cmd_rsp(conn, hdr, ctask, data,
 389                                                 datalen);
 390                         break;
 391                 case ISCSI_OP_SCSI_DATA_IN:
 392                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 393                         if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
 394                                 conn->scsirsp_pdus_cnt++;
 395                                 __iscsi_put_ctask(ctask);
 396                         }
 397                         break;
 398                 case ISCSI_OP_R2T:
 399                         /* LLD handles this for now */
 400                         break;
 401                 default:
 402                         rc = ISCSI_ERR_BAD_OPCODE;
 403                         break;
 404                 }
 405         } else if (itt >= ISCSI_MGMT_ITT_OFFSET &&
 406                    itt < ISCSI_MGMT_ITT_OFFSET + session->mgmtpool_max) {
 407                 mtask = session->mgmt_cmds[itt - ISCSI_MGMT_ITT_OFFSET];
 408
 409                 debug_scsi("immrsp [op 0x%x cid %d itt 0x%x len %d]\n",
 410                            opcode, conn->id, mtask->itt, datalen);
 411
 412                 rc = iscsi_check_assign_cmdsn(session,
 413                                               (struct iscsi_nopin*)hdr);
 414                 if (rc)
 415                         goto done;
 416
 417                 switch(opcode) {
 418                 case ISCSI_OP_LOGOUT_RSP:
 419                         if (datalen) {
 420                                 rc = ISCSI_ERR_PROTO;
 421                                 break;
 422                         }
 423                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 424                         /* fall through */
 425                 case ISCSI_OP_LOGIN_RSP:
 426                 case ISCSI_OP_TEXT_RSP:
 427                         /*
 428                          * login related PDU's exp_statsn is handled in
 429                          * userspace
 430                          */
 431                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 432                                 rc = ISCSI_ERR_CONN_FAILED;
 433                         list_del(&mtask->running);
 434                         if (conn->login_mtask != mtask)
 435                                 __kfifo_put(session->mgmtpool.queue,
 436                                             (void*)&mtask, sizeof(void*));
 437                         break;
 438                 case ISCSI_OP_SCSI_TMFUNC_RSP:
 439                         if (datalen) {
 440                                 rc = ISCSI_ERR_PROTO;
 441                                 break;
 442                         }
 443
 444                         iscsi_tmf_rsp(conn, hdr);
 445                         break;
 446                 case ISCSI_OP_NOOP_IN:
 447                         if (hdr->ttt != ISCSI_RESERVED_TAG || datalen) {
 448                                 rc = ISCSI_ERR_PROTO;
 449                                 break;
 450                         }
 451                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 452
 453                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 454                                 rc = ISCSI_ERR_CONN_FAILED;
 455                         list_del(&mtask->running);
 456                         if (conn->login_mtask != mtask)
 457                                 __kfifo_put(session->mgmtpool.queue,
 458                                             (void*)&mtask, sizeof(void*));
 459                         break;
 460                 default:
 461                         rc = ISCSI_ERR_BAD_OPCODE;
 462                         break;
 463                 }
 464         } else if (itt == ISCSI_RESERVED_TAG) {
 465                 rc = iscsi_check_assign_cmdsn(session,
 466                                              (struct iscsi_nopin*)hdr);
 467                 if (rc)
 468                         goto done;
 469
 470                 switch(opcode) {
 471                 case ISCSI_OP_NOOP_IN:
 472                         if (datalen) {
 473                                 rc = ISCSI_ERR_PROTO;
 474                                 break;
 475                         }
 476
 477                         if (hdr->ttt == ISCSI_RESERVED_TAG)
 478                                 break;
 479
 480                         if (iscsi_recv_pdu(conn->cls_conn, hdr, NULL, 0))
 481                                 rc = ISCSI_ERR_CONN_FAILED;
 482                         break;
 483                 case ISCSI_OP_REJECT:
 484                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
 485                         break;
 486                 case ISCSI_OP_ASYNC_EVENT:
 487                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 488                         /* we need sth like iscsi_async_event_rsp() */
 489                         rc = ISCSI_ERR_BAD_OPCODE;
 490                         break;
 491                 default:
 492                         rc = ISCSI_ERR_BAD_OPCODE;
 493                         break;
 494                 }
 495         } else
 496                 rc = ISCSI_ERR_BAD_ITT;
 497
 498 done:
 499         return rc;
 500 }
 501 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
 502
 503 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 504                        char *data, int datalen)
 505 {
 506         int rc;
 507
 508         spin_lock(&conn->session->lock);
 509         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
 510         spin_unlock(&conn->session->lock);
 511         return rc;
 512 }
 513 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
 514
 515 /* verify itt (itt encoding: age+cid+itt) */
 516 int iscsi_verify_itt(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 517                      uint32_t *ret_itt)
 518 {
 519         struct iscsi_session *session = conn->session;
 520         struct iscsi_cmd_task *ctask;
 521         uint32_t itt;
 522
 523         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
 524                 if ((hdr->itt & ISCSI_AGE_MASK) !=
 525                     (session->age << ISCSI_AGE_SHIFT)) {
 526                         printk(KERN_ERR "iscsi: received itt %x expected "
 527                                 "session age (%x)\n", hdr->itt,
 528                                 session->age & ISCSI_AGE_MASK);
 529                         return ISCSI_ERR_BAD_ITT;
 530                 }
 531
 532                 if ((hdr->itt & ISCSI_CID_MASK) !=
 533                     (conn->id << ISCSI_CID_SHIFT)) {
 534                         printk(KERN_ERR "iscsi: received itt %x, expected "
 535                                 "CID (%x)\n", hdr->itt, conn->id);
 536                         return ISCSI_ERR_BAD_ITT;
 537                 }
 538                 itt = hdr->itt & ISCSI_ITT_MASK;
 539         } else
 540                 itt = hdr->itt;
 541
 542         if (itt < session->cmds_max) {
 543                 ctask = session->cmds[itt];
 544
 545                 if (!ctask->sc) {
 546                         printk(KERN_INFO "iscsi: dropping ctask with "
 547                                "itt 0x%x\n", ctask->itt);
 548                         /* force drop */
 549                         return ISCSI_ERR_NO_SCSI_CMD;
 550                 }
 551
 552                 if (ctask->sc->SCp.phase != session->age) {
 553                         printk(KERN_ERR "iscsi: ctask's session age %d, "
 554                                 "expected %d\n", ctask->sc->SCp.phase,
 555                                 session->age);
 556                         return ISCSI_ERR_SESSION_FAILED;
 557                 }
 558         }
 559
 560         *ret_itt = itt;
 561         return 0;
 562 }
 563 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
 564
 565 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
 566 {
 567         struct iscsi_session *session = conn->session;
 568         unsigned long flags;
 569
 570         spin_lock_irqsave(&session->lock, flags);
 571         if (session->state == ISCSI_STATE_FAILED) {
 572                 spin_unlock_irqrestore(&session->lock, flags);
 573                 return;
 574         }
 575
 576         if (conn->stop_stage == 0)
 577                 session->state = ISCSI_STATE_FAILED;
 578         spin_unlock_irqrestore(&session->lock, flags);
 579         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
 580         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
 581         iscsi_conn_error(conn->cls_conn, err);
 582 }
 583 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
 584
 585 /**
 586  * iscsi_data_xmit - xmit any command into the scheduled connection
 587  * @conn: iscsi connection
 588  *
 589  * Notes:
 590  *      The function can return -EAGAIN in which case the caller must
 591  *      re-schedule it again later or recover. '0' return code means
 592  *      successful xmit.
 593  **/
 594 static int iscsi_data_xmit(struct iscsi_conn *conn)
 595 {
 596         struct iscsi_transport *tt;
 597         int rc = 0;
 598
 599         if (unlikely(conn->suspend_tx)) {
 600                 debug_scsi("conn %d Tx suspended!\n", conn->id);
 601                 return -ENODATA;
 602         }
 603         tt = conn->session->tt;
 604
 605         /*
 606          * Transmit in the following order:
 607          *
 608          * 1) un-finished xmit (ctask or mtask)
 609          * 2) immediate control PDUs
 610          * 3) write data
 611          * 4) SCSI commands
 612          * 5) non-immediate control PDUs
 613          *
 614          * No need to lock around __kfifo_get as long as
 615          * there's one producer and one consumer.
 616          */
 617
 618         BUG_ON(conn->ctask && conn->mtask);
 619
 620         if (conn->ctask) {
 621                 iscsi_get_ctask(conn->ctask);
 622                 rc = tt->xmit_cmd_task(conn, conn->ctask);
 623                 iscsi_put_ctask(conn->ctask);
 624                 if (rc)
 625                         goto again;
 626                 /* done with this in-progress ctask */
 627                 conn->ctask = NULL;
 628         }
 629         if (conn->mtask) {
 630                 rc = tt->xmit_mgmt_task(conn, conn->mtask);
 631                 if (rc)
 632                         goto again;
 633                 /* done with this in-progress mtask */
 634                 conn->mtask = NULL;
 635         }
 636
 637         /* process immediate first */
 638         if (unlikely(__kfifo_len(conn->immqueue))) {
 639                 while (__kfifo_get(conn->immqueue, (void*)&conn->mtask,
 640                                    sizeof(void*))) {
 641                         spin_lock_bh(&conn->session->lock);
 642                         list_add_tail(&conn->mtask->running,
 643                                       &conn->mgmt_run_list);
 644                         spin_unlock_bh(&conn->session->lock);
 645                         rc = tt->xmit_mgmt_task(conn, conn->mtask);
 646                         if (rc)
 647                                 goto again;
 648                 }
 649                 /* done with this mtask */
 650                 conn->mtask = NULL;
 651         }
 652
 653         /* process command queue */
 654         spin_lock_bh(&conn->session->lock);
 655         while (!list_empty(&conn->xmitqueue)) {
 656                 /*
 657                  * iscsi tcp may readd the task to the xmitqueue to send
 658                  * write data
 659                  */
 660                 conn->ctask = list_entry(conn->xmitqueue.next,
 661                                          struct iscsi_cmd_task, running);
 662                 conn->ctask->state = ISCSI_TASK_RUNNING;
 663                 list_move_tail(conn->xmitqueue.next, &conn->run_list);
 664                 __iscsi_get_ctask(conn->ctask);
 665                 spin_unlock_bh(&conn->session->lock);
 666
 667                 rc = tt->xmit_cmd_task(conn, conn->ctask);
 668                 if (rc)
 669                         goto again;
 670
 671                 spin_lock_bh(&conn->session->lock);
 672                 __iscsi_put_ctask(conn->ctask);
 673                 if (rc) {
 674                         spin_unlock_bh(&conn->session->lock);
 675                         goto again;
 676                 }
 677         }
 678         spin_unlock_bh(&conn->session->lock);
 679         /* done with this ctask */
 680         conn->ctask = NULL;
 681
 682         /* process the rest control plane PDUs, if any */
 683         if (unlikely(__kfifo_len(conn->mgmtqueue))) {
 684                 while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask,
 685                                    sizeof(void*))) {
 686                         spin_lock_bh(&conn->session->lock);
 687                         list_add_tail(&conn->mtask->running,
 688                                       &conn->mgmt_run_list);
 689                         spin_unlock_bh(&conn->session->lock);
 690                         rc = tt->xmit_mgmt_task(conn, conn->mtask);
 691                         if (rc)
 692                                 goto again;
 693                 }
 694                 /* done with this mtask */
 695                 conn->mtask = NULL;
 696         }
 697
 698         return -ENODATA;
 699
 700 again:
 701         if (unlikely(conn->suspend_tx))
 702                 return -ENODATA;
 703
 704         return rc;
 705 }
 706
 707 static void iscsi_xmitworker(void *data)
 708 {
 709         struct iscsi_conn *conn = data;
 710         int rc;
 711         /*
 712          * serialize Xmit worker on a per-connection basis.
 713          */
 714         mutex_lock(&conn->xmitmutex);
 715         do {
 716                 rc = iscsi_data_xmit(conn);
 717         } while (rc >= 0 || rc == -EAGAIN);
 718         mutex_unlock(&conn->xmitmutex);
 719 }
 720
 721 enum {
 722         FAILURE_BAD_HOST = 1,
 723         FAILURE_SESSION_FAILED,
 724         FAILURE_SESSION_FREED,
 725         FAILURE_WINDOW_CLOSED,
 726         FAILURE_OOM,
 727         FAILURE_SESSION_TERMINATE,
 728         FAILURE_SESSION_IN_RECOVERY,
 729         FAILURE_SESSION_RECOVERY_TIMEOUT,
 730 };
 731
 732 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
 733 {
 734         struct Scsi_Host *host;
 735         int reason = 0;
 736         struct iscsi_session *session;
 737         struct iscsi_conn *conn;
 738         struct iscsi_cmd_task *ctask = NULL;
 739
 740         sc->scsi_done = done;
 741         sc->result = 0;
 742         sc->SCp.ptr = NULL;
 743
 744         host = sc->device->host;
 745         session = iscsi_hostdata(host->hostdata);
 746
 747         spin_lock(&session->lock);
 748
 749         /*
 750          * ISCSI_STATE_FAILED is a temp. state. The recovery
 751          * code will decide what is best to do with command queued
 752          * during this time
 753          */
 754         if (session->state != ISCSI_STATE_LOGGED_IN &&
 755             session->state != ISCSI_STATE_FAILED) {
 756                 /*
 757                  * to handle the race between when we set the recovery state
 758                  * and block the session we requeue here (commands could
 759                  * be entering our queuecommand while a block is starting
 760                  * up because the block code is not locked)
 761                  */
 762                 if (session->state == ISCSI_STATE_IN_RECOVERY) {
 763                         reason = FAILURE_SESSION_IN_RECOVERY;
 764                         goto reject;
 765                 }
 766
 767                 if (session->state == ISCSI_STATE_RECOVERY_FAILED)
 768                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
 769                 else if (session->state == ISCSI_STATE_TERMINATE)
 770                         reason = FAILURE_SESSION_TERMINATE;
 771                 else
 772                         reason = FAILURE_SESSION_FREED;
 773                 goto fault;
 774         }
 775
 776         /*
 777          * Check for iSCSI window and take care of CmdSN wrap-around
 778          */
 779         if ((int)(session->max_cmdsn - session->cmdsn) < 0) {
 780                 reason = FAILURE_WINDOW_CLOSED;
 781                 goto reject;
 782         }
 783
 784         conn = session->leadconn;
 785
 786         if (!__kfifo_get(session->cmdpool.queue, (void*)&ctask,
 787                          sizeof(void*))) {
 788                 reason = FAILURE_OOM;
 789                 goto reject;
 790         }
 791         sc->SCp.phase = session->age;
 792         sc->SCp.ptr = (char *)ctask;
 793
 794         atomic_set(&ctask->refcount, 1);
 795         ctask->state = ISCSI_TASK_PENDING;
 796         ctask->mtask = NULL;
 797         ctask->conn = conn;
 798         ctask->sc = sc;
 799         INIT_LIST_HEAD(&ctask->running);
 800         ctask->total_length = sc->request_bufflen;
 801         iscsi_prep_scsi_cmd_pdu(ctask);
 802
 803         session->tt->init_cmd_task(ctask);
 804
 805         list_add_tail(&ctask->running, &conn->xmitqueue);
 806         debug_scsi(
 807                "ctask enq [%s cid %d sc %p cdb 0x%x itt 0x%x len %d cmdsn %d "
 808                 "win %d]\n",
 809                 sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
 810                 conn->id, sc, sc->cmnd[0], ctask->itt, sc->request_bufflen,
 811                 session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
 812         spin_unlock(&session->lock);
 813
 814         scsi_queue_work(host, &conn->xmitwork);
 815         return 0;
 816
 817 reject:
 818         spin_unlock(&session->lock);
 819         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
 820         return SCSI_MLQUEUE_HOST_BUSY;
 821
 822 fault:
 823         spin_unlock(&session->lock);
 824         printk(KERN_ERR "iscsi: cmd 0x%x is not queued (%d)\n",
 825                sc->cmnd[0], reason);
 826         sc->result = (DID_NO_CONNECT << 16);
 827         sc->resid = sc->request_bufflen;
 828         sc->scsi_done(sc);
 829         return 0;
 830 }
 831 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
 832
 833 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
 834 {
 835         if (depth > ISCSI_MAX_CMD_PER_LUN)
 836                 depth = ISCSI_MAX_CMD_PER_LUN;
 837         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 838         return sdev->queue_depth;
 839 }
 840 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
 841
 842 static int
 843 iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 844                         char *data, uint32_t data_size)
 845 {
 846         struct iscsi_session *session = conn->session;
 847         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 848         struct iscsi_mgmt_task *mtask;
 849
 850         spin_lock_bh(&session->lock);
 851         if (session->state == ISCSI_STATE_TERMINATE) {
 852                 spin_unlock_bh(&session->lock);
 853                 return -EPERM;
 854         }
 855         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
 856             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 857                 /*
 858                  * Login and Text are sent serially, in
 859                  * request-followed-by-response sequence.
 860                  * Same mtask can be used. Same ITT must be used.
 861                  * Note that login_mtask is preallocated at conn_create().
 862                  */
 863                 mtask = conn->login_mtask;
 864         else {
 865                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 866                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 867
 868                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 869                 if (!__kfifo_get(session->mgmtpool.queue,
 870                                  (void*)&mtask, sizeof(void*))) {
 871                         spin_unlock_bh(&session->lock);
 872                         return -ENOSPC;
 873                 }
 874         }
 875
 876         /*
 877          * pre-format CmdSN for outgoing PDU.
 878          */
 879         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
 880                 hdr->itt = mtask->itt | (conn->id << ISCSI_CID_SHIFT) |
 881                            (session->age << ISCSI_AGE_SHIFT);
 882                 nop->cmdsn = cpu_to_be32(session->cmdsn);
 883                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 884                     !(hdr->opcode & ISCSI_OP_IMMEDIATE))
 885                         session->cmdsn++;
 886         } else
 887                 /* do not advance CmdSN */
 888                 nop->cmdsn = cpu_to_be32(session->cmdsn);
 889
 890         if (data_size) {
 891                 memcpy(mtask->data, data, data_size);
 892                 mtask->data_count = data_size;
 893         } else
 894                 mtask->data_count = 0;
 895
 896         INIT_LIST_HEAD(&mtask->running);
 897         memcpy(mtask->hdr, hdr, sizeof(struct iscsi_hdr));
 898         if (session->tt->init_mgmt_task)
 899                 session->tt->init_mgmt_task(conn, mtask, data, data_size);
 900         spin_unlock_bh(&session->lock);
 901
 902         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
 903                    hdr->opcode, hdr->itt, data_size);
 904
 905         /*
 906          * since send_pdu() could be called at least from two contexts,
 907          * we need to serialize __kfifo_put, so we don't have to take
 908          * additional lock on fast data-path
 909          */
 910         if (hdr->opcode & ISCSI_OP_IMMEDIATE)
 911                 __kfifo_put(conn->immqueue, (void*)&mtask, sizeof(void*));
 912         else
 913                 __kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*));
 914
 915         scsi_queue_work(session->host, &conn->xmitwork);
 916         return 0;
 917 }
 918
 919 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 920                         char *data, uint32_t data_size)
 921 {
 922         struct iscsi_conn *conn = cls_conn->dd_data;
 923         int rc;
 924
 925         mutex_lock(&conn->xmitmutex);
 926         rc = iscsi_conn_send_generic(conn, hdr, data, data_size);
 927         mutex_unlock(&conn->xmitmutex);
 928
 929         return rc;
 930 }
 931 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 932
 933 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
 934 {
 935         struct iscsi_session *session = class_to_transport_session(cls_session);
 936         struct iscsi_conn *conn = session->leadconn;
 937
 938         spin_lock_bh(&session->lock);
 939         if (session->state != ISCSI_STATE_LOGGED_IN) {
 940                 session->state = ISCSI_STATE_RECOVERY_FAILED;
 941                 if (conn)
 942                         wake_up(&conn->ehwait);
 943         }
 944         spin_unlock_bh(&session->lock);
 945 }
 946 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
 947
 948 int iscsi_eh_host_reset(struct scsi_cmnd *sc)
 949 {
 950         struct Scsi_Host *host = sc->device->host;
 951         struct iscsi_session *session = iscsi_hostdata(host->hostdata);
 952         struct iscsi_conn *conn = session->leadconn;
 953         int fail_session = 0;
 954
 955         spin_lock_bh(&session->lock);
 956         if (session->state == ISCSI_STATE_TERMINATE) {
 957 failed:
 958                 debug_scsi("failing host reset: session terminated "
 959                            "[CID %d age %d]", conn->id, session->age);
 960                 spin_unlock_bh(&session->lock);
 961                 return FAILED;
 962         }
 963
 964         if (sc->SCp.phase == session->age) {
 965                 debug_scsi("failing connection CID %d due to SCSI host reset",
 966                            conn->id);
 967                 fail_session = 1;
 968         }
 969         spin_unlock_bh(&session->lock);
 970
 971         /*
 972          * we drop the lock here but the leadconn cannot be destoyed while
 973          * we are in the scsi eh
 974          */
 975         if (fail_session)
 976                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 977
 978         debug_scsi("iscsi_eh_host_reset wait for relogin\n");
 979         wait_event_interruptible(conn->ehwait,
 980                                  session->state == ISCSI_STATE_TERMINATE ||
 981                                  session->state == ISCSI_STATE_LOGGED_IN ||
 982                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
 983         if (signal_pending(current))
 984                 flush_signals(current);
 985
 986         spin_lock_bh(&session->lock);
 987         if (session->state == ISCSI_STATE_LOGGED_IN)
 988                 printk(KERN_INFO "iscsi: host reset succeeded\n");
 989         else
 990                 goto failed;
 991         spin_unlock_bh(&session->lock);
 992
 993         return SUCCESS;
 994 }
 995 EXPORT_SYMBOL_GPL(iscsi_eh_host_reset);
 996
 997 static void iscsi_tmabort_timedout(unsigned long data)
 998 {
 999         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)data;
1000         struct iscsi_conn *conn = ctask->conn;
1001         struct iscsi_session *session = conn->session;
1002
1003         spin_lock(&session->lock);
1004         if (conn->tmabort_state == TMABORT_INITIAL) {
1005                 conn->tmabort_state = TMABORT_TIMEDOUT;
1006                 debug_scsi("tmabort timedout [sc %p itt 0x%x]\n",
1007                         ctask->sc, ctask->itt);
1008                 /* unblock eh_abort() */
1009                 wake_up(&conn->ehwait);
1010         }
1011         spin_unlock(&session->lock);
1012 }
1013
1014 /* must be called with the mutex lock */
1015 static int iscsi_exec_abort_task(struct scsi_cmnd *sc,
1016                                  struct iscsi_cmd_task *ctask)
1017 {
1018         struct iscsi_conn *conn = ctask->conn;
1019         struct iscsi_session *session = conn->session;
1020         struct iscsi_tm *hdr = &conn->tmhdr;
1021         int rc;
1022
1023         /*
1024          * ctask timed out but session is OK requests must be serialized.
1025          */
1026         memset(hdr, 0, sizeof(struct iscsi_tm));
1027         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1028         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK;
1029         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1030         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1031         hdr->rtt = ctask->hdr->itt;
1032         hdr->refcmdsn = ctask->hdr->cmdsn;
1033
1034         rc = iscsi_conn_send_generic(conn, (struct iscsi_hdr *)hdr,
1035                                      NULL, 0);
1036         if (rc) {
1037                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1038                 debug_scsi("abort sent failure [itt 0x%x] %d", ctask->itt, rc);
1039                 return rc;
1040         }
1041
1042         debug_scsi("abort sent [itt 0x%x]\n", ctask->itt);
1043
1044         spin_lock_bh(&session->lock);
1045         ctask->mtask = (struct iscsi_mgmt_task *)
1046                         session->mgmt_cmds[(hdr->itt & ISCSI_ITT_MASK) -
1047                                         ISCSI_MGMT_ITT_OFFSET];
1048
1049         if (conn->tmabort_state == TMABORT_INITIAL) {
1050                 conn->tmfcmd_pdus_cnt++;
1051                 conn->tmabort_timer.expires = 10*HZ + jiffies;
1052                 conn->tmabort_timer.function = iscsi_tmabort_timedout;
1053                 conn->tmabort_timer.data = (unsigned long)ctask;
1054                 add_timer(&conn->tmabort_timer);
1055                 debug_scsi("abort set timeout [itt 0x%x]", ctask->itt);
1056         }
1057         spin_unlock_bh(&session->lock);
1058         mutex_unlock(&conn->xmitmutex);
1059
1060         /*
1061          * block eh thread until:
1062          *
1063          * 1) abort response
1064          * 2) abort timeout
1065          * 3) session is terminated or restarted or userspace has
1066          * given up on recovery
1067          */
1068         wait_event_interruptible(conn->ehwait,
1069                                  sc->SCp.phase != session->age ||
1070                                  session->state != ISCSI_STATE_LOGGED_IN ||
1071                                  conn->tmabort_state != TMABORT_INITIAL);
1072         if (signal_pending(current))
1073                 flush_signals(current);
1074         del_timer_sync(&conn->tmabort_timer);
1075
1076         mutex_lock(&conn->xmitmutex);
1077         return 0;
1078 }
1079
1080 /*
1081  * xmit mutex and session lock must be held
1082  */
1083 static struct iscsi_mgmt_task *
1084 iscsi_remove_mgmt_task(struct kfifo *fifo, uint32_t itt)
1085 {
1086         int i, nr_tasks = __kfifo_len(fifo) / sizeof(void*);
1087         struct iscsi_mgmt_task *task;
1088
1089         debug_scsi("searching %d tasks\n", nr_tasks);
1090
1091         for (i = 0; i < nr_tasks; i++) {
1092                 __kfifo_get(fifo, (void*)&task, sizeof(void*));
1093                 debug_scsi("check task %u\n", task->itt);
1094
1095                 if (task->itt == itt) {
1096                         debug_scsi("matched task\n");
1097                         return task;
1098                 }
1099
1100                 __kfifo_put(fifo, (void*)&task, sizeof(void*));
1101         }
1102         return NULL;
1103 }
1104
1105 static int iscsi_ctask_mtask_cleanup(struct iscsi_cmd_task *ctask)
1106 {
1107         struct iscsi_conn *conn = ctask->conn;
1108         struct iscsi_session *session = conn->session;
1109
1110         if (!ctask->mtask)
1111                 return -EINVAL;
1112
1113         if (!iscsi_remove_mgmt_task(conn->immqueue, ctask->mtask->itt))
1114                 list_del(&ctask->mtask->running);
1115         __kfifo_put(session->mgmtpool.queue, (void*)&ctask->mtask,
1116                     sizeof(void*));
1117         ctask->mtask = NULL;
1118         return 0;
1119 }
1120
1121 /*
1122  * session lock and xmitmutex must be held
1123  */
1124 static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1125                          int err)
1126 {
1127         struct scsi_cmnd *sc;
1128
1129         sc = ctask->sc;
1130         if (!sc)
1131                 return;
1132         iscsi_ctask_mtask_cleanup(ctask);
1133
1134         sc->result = err;
1135         sc->resid = sc->request_bufflen;
1136         __iscsi_put_ctask(ctask);
1137 }
1138
1139 int iscsi_eh_abort(struct scsi_cmnd *sc)
1140 {
1141         struct iscsi_cmd_task *ctask;
1142         struct iscsi_conn *conn;
1143         struct iscsi_session *session;
1144         int rc;
1145
1146         /*
1147          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1148          * got the command.
1149          */
1150         if (!sc->SCp.ptr) {
1151                 debug_scsi("sc never reached iscsi layer or it completed.\n");
1152                 return SUCCESS;
1153         }
1154
1155         ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
1156         conn = ctask->conn;
1157         session = conn->session;
1158
1159         conn->eh_abort_cnt++;
1160         debug_scsi("aborting [sc %p itt 0x%x]\n", sc, ctask->itt);
1161
1162         mutex_lock(&conn->xmitmutex);
1163         spin_lock_bh(&session->lock);
1164
1165         /*
1166          * If we are not logged in or we have started a new session
1167          * then let the host reset code handle this
1168          */
1169         if (session->state != ISCSI_STATE_LOGGED_IN ||
1170             sc->SCp.phase != session->age)
1171                 goto failed;
1172
1173         /* ctask completed before time out */
1174         if (!ctask->sc) {
1175                 spin_unlock_bh(&session->lock);
1176                 debug_scsi("sc completed while abort in progress\n");
1177                 goto success_rel_mutex;
1178         }
1179
1180         /* what should we do here ? */
1181         if (conn->ctask == ctask) {
1182                 printk(KERN_INFO "iscsi: sc %p itt 0x%x partially sent. "
1183                        "Failing abort\n", sc, ctask->itt);
1184                 goto failed;
1185         }
1186
1187         if (ctask->state == ISCSI_TASK_PENDING)
1188                 goto success_cleanup;
1189
1190         conn->tmabort_state = TMABORT_INITIAL;
1191
1192         spin_unlock_bh(&session->lock);
1193         rc = iscsi_exec_abort_task(sc, ctask);
1194         spin_lock_bh(&session->lock);
1195
1196         if (rc || sc->SCp.phase != session->age ||
1197             session->state != ISCSI_STATE_LOGGED_IN)
1198                 goto failed;
1199         iscsi_ctask_mtask_cleanup(ctask);
1200
1201         switch (conn->tmabort_state) {
1202         case TMABORT_SUCCESS:
1203                 goto success_cleanup;
1204         case TMABORT_NOT_FOUND:
1205                 if (!ctask->sc) {
1206                         /* ctask completed before tmf abort response */
1207                         spin_unlock_bh(&session->lock);
1208                         debug_scsi("sc completed while abort in progress\n");
1209                         goto success_rel_mutex;
1210                 }
1211                 /* fall through */
1212         default:
1213                 /* timedout or failed */
1214                 spin_unlock_bh(&session->lock);
1215                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1216                 spin_lock_bh(&session->lock);
1217                 goto failed;
1218         }
1219
1220 success_cleanup:
1221         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1222         spin_unlock_bh(&session->lock);
1223
1224         /*
1225          * clean up task if aborted. we have the xmitmutex so grab
1226          * the recv lock as a writer
1227          */
1228         write_lock_bh(conn->recv_lock);
1229         spin_lock(&session->lock);
1230         fail_command(conn, ctask, DID_ABORT << 16);
1231         spin_unlock(&session->lock);
1232         write_unlock_bh(conn->recv_lock);
1233
1234 success_rel_mutex:
1235         mutex_unlock(&conn->xmitmutex);
1236         return SUCCESS;
1237
1238 failed:
1239         spin_unlock_bh(&session->lock);
1240         mutex_unlock(&conn->xmitmutex);
1241
1242         debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1243         return FAILED;
1244 }
1245 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1246
1247 int
1248 iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
1249 {
1250         int i;
1251
1252         *items = kmalloc(max * sizeof(void*), GFP_KERNEL);
1253         if (*items == NULL)
1254                 return -ENOMEM;
1255
1256         q->max = max;
1257         q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL);
1258         if (q->pool == NULL) {
1259                 kfree(*items);
1260                 return -ENOMEM;
1261         }
1262
1263         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1264                               GFP_KERNEL, NULL);
1265         if (q->queue == ERR_PTR(-ENOMEM)) {
1266                 kfree(q->pool);
1267                 kfree(*items);
1268                 return -ENOMEM;
1269         }
1270
1271         for (i = 0; i < max; i++) {
1272                 q->pool[i] = kmalloc(item_size, GFP_KERNEL);
1273                 if (q->pool[i] == NULL) {
1274                         int j;
1275
1276                         for (j = 0; j < i; j++)
1277                                 kfree(q->pool[j]);
1278
1279                         kfifo_free(q->queue);
1280                         kfree(q->pool);
1281                         kfree(*items);
1282                         return -ENOMEM;
1283                 }
1284                 memset(q->pool[i], 0, item_size);
1285                 (*items)[i] = q->pool[i];
1286                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1287         }
1288         return 0;
1289 }
1290 EXPORT_SYMBOL_GPL(iscsi_pool_init);
1291
1292 void iscsi_pool_free(struct iscsi_queue *q, void **items)
1293 {
1294         int i;
1295
1296         for (i = 0; i < q->max; i++)
1297                 kfree(items[i]);
1298         kfree(q->pool);
1299         kfree(items);
1300 }
1301 EXPORT_SYMBOL_GPL(iscsi_pool_free);
1302
1303 /*
1304  * iSCSI Session's hostdata organization:
1305  *
1306  *    *------------------* <== hostdata_session(host->hostdata)
1307  *    | ptr to class sess|
1308  *    |------------------| <== iscsi_hostdata(host->hostdata)
1309  *    | iscsi_session    |
1310  *    *------------------*
1311  */
1312
1313 #define hostdata_privsize(_sz)  (sizeof(unsigned long) + _sz + \
1314                                  _sz % sizeof(unsigned long))
1315
1316 #define hostdata_session(_hostdata) (iscsi_ptr(*(unsigned long *)_hostdata))
1317
1318 /**
1319  * iscsi_session_setup - create iscsi cls session and host and session
1320  * @scsit: scsi transport template
1321  * @iscsit: iscsi transport template
1322  * @initial_cmdsn: initial CmdSN
1323  * @hostno: host no allocated
1324  *
1325  * This can be used by software iscsi_transports that allocate
1326  * a session per scsi host.
1327  **/
1328 struct iscsi_cls_session *
1329 iscsi_session_setup(struct iscsi_transport *iscsit,
1330                     struct scsi_transport_template *scsit,
1331                     int cmd_task_size, int mgmt_task_size,
1332                     uint32_t initial_cmdsn, uint32_t *hostno)
1333 {
1334         struct Scsi_Host *shost;
1335         struct iscsi_session *session;
1336         struct iscsi_cls_session *cls_session;
1337         int cmd_i;
1338
1339         shost = scsi_host_alloc(iscsit->host_template,
1340                                 hostdata_privsize(sizeof(*session)));
1341         if (!shost)
1342                 return NULL;
1343
1344         shost->max_id = 1;
1345         shost->max_channel = 0;
1346         shost->max_lun = iscsit->max_lun;
1347         shost->max_cmd_len = iscsit->max_cmd_len;
1348         shost->transportt = scsit;
1349         shost->transportt->create_work_queue = 1;
1350         *hostno = shost->host_no;
1351
1352         session = iscsi_hostdata(shost->hostdata);
1353         memset(session, 0, sizeof(struct iscsi_session));
1354         session->host = shost;
1355         session->state = ISCSI_STATE_FREE;
1356         session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
1357         session->cmds_max = ISCSI_XMIT_CMDS_MAX;
1358         session->cmdsn = initial_cmdsn;
1359         session->exp_cmdsn = initial_cmdsn + 1;
1360         session->max_cmdsn = initial_cmdsn + 1;
1361         session->max_r2t = 1;
1362         session->tt = iscsit;
1363
1364         /* initialize SCSI PDU commands pool */
1365         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
1366                             (void***)&session->cmds,
1367                             cmd_task_size + sizeof(struct iscsi_cmd_task)))
1368                 goto cmdpool_alloc_fail;
1369
1370         /* pre-format cmds pool with ITT */
1371         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1372                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1373
1374                 if (cmd_task_size)
1375                         ctask->dd_data = &ctask[1];
1376                 ctask->itt = cmd_i;
1377                 INIT_LIST_HEAD(&ctask->running);
1378         }
1379
1380         spin_lock_init(&session->lock);
1381         INIT_LIST_HEAD(&session->connections);
1382
1383         /* initialize immediate command pool */
1384         if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max,
1385                            (void***)&session->mgmt_cmds,
1386                            mgmt_task_size + sizeof(struct iscsi_mgmt_task)))
1387                 goto mgmtpool_alloc_fail;
1388
1389
1390         /* pre-format immediate cmds pool with ITT */
1391         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
1392                 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
1393
1394                 if (mgmt_task_size)
1395                         mtask->dd_data = &mtask[1];
1396                 mtask->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i;
1397                 INIT_LIST_HEAD(&mtask->running);
1398         }
1399
1400         if (scsi_add_host(shost, NULL))
1401                 goto add_host_fail;
1402
1403         if (!try_module_get(iscsit->owner))
1404                 goto cls_session_fail;
1405
1406         cls_session = iscsi_create_session(shost, iscsit, 0);
1407         if (!cls_session)
1408                 goto module_put;
1409         *(unsigned long*)shost->hostdata = (unsigned long)cls_session;
1410
1411         return cls_session;
1412
1413 module_put:
1414         module_put(iscsit->owner);
1415 cls_session_fail:
1416         scsi_remove_host(shost);
1417 add_host_fail:
1418         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1419 mgmtpool_alloc_fail:
1420         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1421 cmdpool_alloc_fail:
1422         scsi_host_put(shost);
1423         return NULL;
1424 }
1425 EXPORT_SYMBOL_GPL(iscsi_session_setup);
1426
1427 /**
1428  * iscsi_session_teardown - destroy session, host, and cls_session
1429  * shost: scsi host
1430  *
1431  * This can be used by software iscsi_transports that allocate
1432  * a session per scsi host.
1433  **/
1434 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
1435 {
1436         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1437         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1438         struct module *owner = cls_session->transport->owner;
1439
1440         scsi_remove_host(shost);
1441
1442         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1443         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1444
1445         kfree(session->targetname);
1446
1447         iscsi_destroy_session(cls_session);
1448         scsi_host_put(shost);
1449         module_put(owner);
1450 }
1451 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
1452
1453 /**
1454  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
1455  * @cls_session: iscsi_cls_session
1456  * @conn_idx: cid
1457  **/
1458 struct iscsi_cls_conn *
1459 iscsi_conn_setup(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1460 {
1461         struct iscsi_session *session = class_to_transport_session(cls_session);
1462         struct iscsi_conn *conn;
1463         struct iscsi_cls_conn *cls_conn;
1464         char *data;
1465
1466         cls_conn = iscsi_create_conn(cls_session, conn_idx);
1467         if (!cls_conn)
1468                 return NULL;
1469         conn = cls_conn->dd_data;
1470         memset(conn, 0, sizeof(*conn));
1471
1472         conn->session = session;
1473         conn->cls_conn = cls_conn;
1474         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
1475         conn->id = conn_idx;
1476         conn->exp_statsn = 0;
1477         conn->tmabort_state = TMABORT_INITIAL;
1478         INIT_LIST_HEAD(&conn->run_list);
1479         INIT_LIST_HEAD(&conn->mgmt_run_list);
1480         INIT_LIST_HEAD(&conn->xmitqueue);
1481
1482         /* initialize general immediate & non-immediate PDU commands queue */
1483         conn->immqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
1484                                         GFP_KERNEL, NULL);
1485         if (conn->immqueue == ERR_PTR(-ENOMEM))
1486                 goto immqueue_alloc_fail;
1487
1488         conn->mgmtqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
1489                                         GFP_KERNEL, NULL);
1490         if (conn->mgmtqueue == ERR_PTR(-ENOMEM))
1491                 goto mgmtqueue_alloc_fail;
1492
1493         INIT_WORK(&conn->xmitwork, iscsi_xmitworker, conn);
1494
1495         /* allocate login_mtask used for the login/text sequences */
1496         spin_lock_bh(&session->lock);
1497         if (!__kfifo_get(session->mgmtpool.queue,
1498                          (void*)&conn->login_mtask,
1499                          sizeof(void*))) {
1500                 spin_unlock_bh(&session->lock);
1501                 goto login_mtask_alloc_fail;
1502         }
1503         spin_unlock_bh(&session->lock);
1504
1505         data = kmalloc(DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH, GFP_KERNEL);
1506         if (!data)
1507                 goto login_mtask_data_alloc_fail;
1508         conn->login_mtask->data = conn->data = data;
1509
1510         init_timer(&conn->tmabort_timer);
1511         mutex_init(&conn->xmitmutex);
1512         init_waitqueue_head(&conn->ehwait);
1513
1514         return cls_conn;
1515
1516 login_mtask_data_alloc_fail:
1517         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1518                     sizeof(void*));
1519 login_mtask_alloc_fail:
1520         kfifo_free(conn->mgmtqueue);
1521 mgmtqueue_alloc_fail:
1522         kfifo_free(conn->immqueue);
1523 immqueue_alloc_fail:
1524         iscsi_destroy_conn(cls_conn);
1525         return NULL;
1526 }
1527 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
1528
1529 /**
1530  * iscsi_conn_teardown - teardown iscsi connection
1531  * cls_conn: iscsi class connection
1532  *
1533  * TODO: we may need to make this into a two step process
1534  * like scsi-mls remove + put host
1535  */
1536 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
1537 {
1538         struct iscsi_conn *conn = cls_conn->dd_data;
1539         struct iscsi_session *session = conn->session;
1540         unsigned long flags;
1541
1542         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1543         mutex_lock(&conn->xmitmutex);
1544
1545         spin_lock_bh(&session->lock);
1546         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
1547         if (session->leadconn == conn) {
1548                 /*
1549                  * leading connection? then give up on recovery.
1550                  */
1551                 session->state = ISCSI_STATE_TERMINATE;
1552                 wake_up(&conn->ehwait);
1553         }
1554         spin_unlock_bh(&session->lock);
1555
1556         mutex_unlock(&conn->xmitmutex);
1557
1558         /*
1559          * Block until all in-progress commands for this connection
1560          * time out or fail.
1561          */
1562         for (;;) {
1563                 spin_lock_irqsave(session->host->host_lock, flags);
1564                 if (!session->host->host_busy) { /* OK for ERL == 0 */
1565                         spin_unlock_irqrestore(session->host->host_lock, flags);
1566                         break;
1567                 }
1568                 spin_unlock_irqrestore(session->host->host_lock, flags);
1569                 msleep_interruptible(500);
1570                 printk(KERN_INFO "iscsi: scsi conn_destroy(): host_busy %d "
1571                        "host_failed %d\n", session->host->host_busy,
1572                        session->host->host_failed);
1573                 /*
1574                  * force eh_abort() to unblock
1575                  */
1576                 wake_up(&conn->ehwait);
1577         }
1578
1579         spin_lock_bh(&session->lock);
1580         kfree(conn->data);
1581         kfree(conn->persistent_address);
1582         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1583                     sizeof(void*));
1584         list_del(&conn->item);
1585         if (list_empty(&session->connections))
1586                 session->leadconn = NULL;
1587         if (session->leadconn && session->leadconn == conn)
1588                 session->leadconn = container_of(session->connections.next,
1589                         struct iscsi_conn, item);
1590
1591         if (session->leadconn == NULL)
1592                 /* no connections exits.. reset sequencing */
1593                 session->cmdsn = session->max_cmdsn = session->exp_cmdsn = 1;
1594         spin_unlock_bh(&session->lock);
1595
1596         kfifo_free(conn->immqueue);
1597         kfifo_free(conn->mgmtqueue);
1598
1599         iscsi_destroy_conn(cls_conn);
1600 }
1601 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
1602
1603 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
1604 {
1605         struct iscsi_conn *conn = cls_conn->dd_data;
1606         struct iscsi_session *session = conn->session;
1607
1608         if (!session) {
1609                 printk(KERN_ERR "iscsi: can't start unbound connection\n");
1610                 return -EPERM;
1611         }
1612
1613         if ((session->imm_data_en || !session->initial_r2t_en) &&
1614              session->first_burst > session->max_burst) {
1615                 printk("iscsi: invalid burst lengths: "
1616                        "first_burst %d max_burst %d\n",
1617                        session->first_burst, session->max_burst);
1618                 return -EINVAL;
1619         }
1620
1621         spin_lock_bh(&session->lock);
1622         conn->c_stage = ISCSI_CONN_STARTED;
1623         session->state = ISCSI_STATE_LOGGED_IN;
1624
1625         switch(conn->stop_stage) {
1626         case STOP_CONN_RECOVER:
1627                 /*
1628                  * unblock eh_abort() if it is blocked. re-try all
1629                  * commands after successful recovery
1630                  */
1631                 conn->stop_stage = 0;
1632                 conn->tmabort_state = TMABORT_INITIAL;
1633                 session->age++;
1634                 spin_unlock_bh(&session->lock);
1635
1636                 iscsi_unblock_session(session_to_cls(session));
1637                 wake_up(&conn->ehwait);
1638                 return 0;
1639         case STOP_CONN_TERM:
1640                 conn->stop_stage = 0;
1641                 break;
1642         default:
1643                 break;
1644         }
1645         spin_unlock_bh(&session->lock);
1646
1647         return 0;
1648 }
1649 EXPORT_SYMBOL_GPL(iscsi_conn_start);
1650
1651 static void
1652 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
1653 {
1654         struct iscsi_mgmt_task *mtask, *tmp;
1655
1656         /* handle pending */
1657         while (__kfifo_get(conn->immqueue, (void*)&mtask, sizeof(void*)) ||
1658                __kfifo_get(conn->mgmtqueue, (void*)&mtask, sizeof(void*))) {
1659                 if (mtask == conn->login_mtask)
1660                         continue;
1661                 debug_scsi("flushing pending mgmt task itt 0x%x\n", mtask->itt);
1662                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1663                             sizeof(void*));
1664         }
1665
1666         /* handle running */
1667         list_for_each_entry_safe(mtask, tmp, &conn->mgmt_run_list, running) {
1668                 debug_scsi("flushing running mgmt task itt 0x%x\n", mtask->itt);
1669                 list_del(&mtask->running);
1670
1671                 if (mtask == conn->login_mtask)
1672                         continue;
1673                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1674                            sizeof(void*));
1675         }
1676
1677         conn->mtask = NULL;
1678 }
1679
1680 /* Fail commands. Mutex and session lock held and recv side suspended */
1681 static void fail_all_commands(struct iscsi_conn *conn)
1682 {
1683         struct iscsi_cmd_task *ctask, *tmp;
1684
1685         /* flush pending */
1686         list_for_each_entry_safe(ctask, tmp, &conn->xmitqueue, running) {
1687                 debug_scsi("failing pending sc %p itt 0x%x\n", ctask->sc,
1688                            ctask->itt);
1689                 fail_command(conn, ctask, DID_BUS_BUSY << 16);
1690         }
1691
1692         /* fail all other running */
1693         list_for_each_entry_safe(ctask, tmp, &conn->run_list, running) {
1694                 debug_scsi("failing in progress sc %p itt 0x%x\n",
1695                            ctask->sc, ctask->itt);
1696                 fail_command(conn, ctask, DID_BUS_BUSY << 16);
1697         }
1698
1699         conn->ctask = NULL;
1700 }
1701
1702 static void iscsi_start_session_recovery(struct iscsi_session *session,
1703                                          struct iscsi_conn *conn, int flag)
1704 {
1705         int old_stop_stage;
1706
1707         spin_lock_bh(&session->lock);
1708         if (conn->stop_stage == STOP_CONN_TERM) {
1709                 spin_unlock_bh(&session->lock);
1710                 return;
1711         }
1712
1713         /*
1714          * When this is called for the in_login state, we only want to clean
1715          * up the login task and connection. We do not need to block and set
1716          * the recovery state again
1717          */
1718         if (flag == STOP_CONN_TERM)
1719                 session->state = ISCSI_STATE_TERMINATE;
1720         else if (conn->stop_stage != STOP_CONN_RECOVER)
1721                 session->state = ISCSI_STATE_IN_RECOVERY;
1722
1723         old_stop_stage = conn->stop_stage;
1724         conn->stop_stage = flag;
1725         conn->c_stage = ISCSI_CONN_STOPPED;
1726         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1727         spin_unlock_bh(&session->lock);
1728
1729         write_lock_bh(conn->recv_lock);
1730         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1731         write_unlock_bh(conn->recv_lock);
1732
1733         mutex_lock(&conn->xmitmutex);
1734         /*
1735          * for connection level recovery we should not calculate
1736          * header digest. conn->hdr_size used for optimization
1737          * in hdr_extract() and will be re-negotiated at
1738          * set_param() time.
1739          */
1740         if (flag == STOP_CONN_RECOVER) {
1741                 conn->hdrdgst_en = 0;
1742                 conn->datadgst_en = 0;
1743                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
1744                     old_stop_stage != STOP_CONN_RECOVER) {
1745                         debug_scsi("blocking session\n");
1746                         iscsi_block_session(session_to_cls(session));
1747                 }
1748         }
1749
1750         /*
1751          * flush queues.
1752          */
1753         spin_lock_bh(&session->lock);
1754         fail_all_commands(conn);
1755         flush_control_queues(session, conn);
1756         spin_unlock_bh(&session->lock);
1757
1758         mutex_unlock(&conn->xmitmutex);
1759 }
1760
1761 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1762 {
1763         struct iscsi_conn *conn = cls_conn->dd_data;
1764         struct iscsi_session *session = conn->session;
1765
1766         switch (flag) {
1767         case STOP_CONN_RECOVER:
1768         case STOP_CONN_TERM:
1769                 iscsi_start_session_recovery(session, conn, flag);
1770                 break;
1771         default:
1772                 printk(KERN_ERR "iscsi: invalid stop flag %d\n", flag);
1773         }
1774 }
1775 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
1776
1777 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
1778                     struct iscsi_cls_conn *cls_conn, int is_leading)
1779 {
1780         struct iscsi_session *session = class_to_transport_session(cls_session);
1781         struct iscsi_conn *tmp = ERR_PTR(-EEXIST), *conn = cls_conn->dd_data;
1782
1783         /* lookup for existing connection */
1784         spin_lock_bh(&session->lock);
1785         list_for_each_entry(tmp, &session->connections, item) {
1786                 if (tmp == conn) {
1787                         if (conn->c_stage != ISCSI_CONN_STOPPED ||
1788                             conn->stop_stage == STOP_CONN_TERM) {
1789                                 printk(KERN_ERR "iscsi: can't bind "
1790                                        "non-stopped connection (%d:%d)\n",
1791                                        conn->c_stage, conn->stop_stage);
1792                                 spin_unlock_bh(&session->lock);
1793                                 return -EIO;
1794                         }
1795                         break;
1796                 }
1797         }
1798         if (tmp != conn) {
1799                 /* bind new iSCSI connection to session */
1800                 conn->session = session;
1801                 list_add(&conn->item, &session->connections);
1802         }
1803         spin_unlock_bh(&session->lock);
1804
1805         if (is_leading)
1806                 session->leadconn = conn;
1807
1808         /*
1809          * Unblock xmitworker(), Login Phase will pass through.
1810          */
1811         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1812         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1813         return 0;
1814 }
1815 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
1816
1817
1818 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
1819                     enum iscsi_param param, char *buf, int buflen)
1820 {
1821         struct iscsi_conn *conn = cls_conn->dd_data;
1822         struct iscsi_session *session = conn->session;
1823         uint32_t value;
1824
1825         switch(param) {
1826         case ISCSI_PARAM_MAX_RECV_DLENGTH:
1827                 sscanf(buf, "%d", &conn->max_recv_dlength);
1828                 break;
1829         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
1830                 sscanf(buf, "%d", &conn->max_xmit_dlength);
1831                 break;
1832         case ISCSI_PARAM_HDRDGST_EN:
1833                 sscanf(buf, "%d", &conn->hdrdgst_en);
1834                 break;
1835         case ISCSI_PARAM_DATADGST_EN:
1836                 sscanf(buf, "%d", &conn->datadgst_en);
1837                 break;
1838         case ISCSI_PARAM_INITIAL_R2T_EN:
1839                 sscanf(buf, "%d", &session->initial_r2t_en);
1840                 break;
1841         case ISCSI_PARAM_MAX_R2T:
1842                 sscanf(buf, "%d", &session->max_r2t);
1843                 break;
1844         case ISCSI_PARAM_IMM_DATA_EN:
1845                 sscanf(buf, "%d", &session->imm_data_en);
1846                 break;
1847         case ISCSI_PARAM_FIRST_BURST:
1848                 sscanf(buf, "%d", &session->first_burst);
1849                 break;
1850         case ISCSI_PARAM_MAX_BURST:
1851                 sscanf(buf, "%d", &session->max_burst);
1852                 break;
1853         case ISCSI_PARAM_PDU_INORDER_EN:
1854                 sscanf(buf, "%d", &session->pdu_inorder_en);
1855                 break;
1856         case ISCSI_PARAM_DATASEQ_INORDER_EN:
1857                 sscanf(buf, "%d", &session->dataseq_inorder_en);
1858                 break;
1859         case ISCSI_PARAM_ERL:
1860                 sscanf(buf, "%d", &session->erl);
1861                 break;
1862         case ISCSI_PARAM_IFMARKER_EN:
1863                 sscanf(buf, "%d", &value);
1864                 BUG_ON(value);
1865                 break;
1866         case ISCSI_PARAM_OFMARKER_EN:
1867                 sscanf(buf, "%d", &value);
1868                 BUG_ON(value);
1869                 break;
1870         case ISCSI_PARAM_EXP_STATSN:
1871                 sscanf(buf, "%u", &conn->exp_statsn);
1872                 break;
1873         case ISCSI_PARAM_TARGET_NAME:
1874                 /* this should not change between logins */
1875                 if (session->targetname)
1876                         break;
1877
1878                 session->targetname = kstrdup(buf, GFP_KERNEL);
1879                 if (!session->targetname)
1880                         return -ENOMEM;
1881                 break;
1882         case ISCSI_PARAM_TPGT:
1883                 sscanf(buf, "%d", &session->tpgt);
1884                 break;
1885         case ISCSI_PARAM_PERSISTENT_PORT:
1886                 sscanf(buf, "%d", &conn->persistent_port);
1887                 break;
1888         case ISCSI_PARAM_PERSISTENT_ADDRESS:
1889                 /*
1890                  * this is the address returned in discovery so it should
1891                  * not change between logins.
1892                  */
1893                 if (conn->persistent_address)
1894                         break;
1895
1896                 conn->persistent_address = kstrdup(buf, GFP_KERNEL);
1897                 if (!conn->persistent_address)
1898                         return -ENOMEM;
1899                 break;
1900         default:
1901                 return -ENOSYS;
1902         }
1903
1904         return 0;
1905 }
1906 EXPORT_SYMBOL_GPL(iscsi_set_param);
1907
1908 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
1909                             enum iscsi_param param, char *buf)
1910 {
1911         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1912         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1913         int len;
1914
1915         switch(param) {
1916         case ISCSI_PARAM_INITIAL_R2T_EN:
1917                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
1918                 break;
1919         case ISCSI_PARAM_MAX_R2T:
1920                 len = sprintf(buf, "%hu\n", session->max_r2t);
1921                 break;
1922         case ISCSI_PARAM_IMM_DATA_EN:
1923                 len = sprintf(buf, "%d\n", session->imm_data_en);
1924                 break;
1925         case ISCSI_PARAM_FIRST_BURST:
1926                 len = sprintf(buf, "%u\n", session->first_burst);
1927                 break;
1928         case ISCSI_PARAM_MAX_BURST:
1929                 len = sprintf(buf, "%u\n", session->max_burst);
1930                 break;
1931         case ISCSI_PARAM_PDU_INORDER_EN:
1932                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
1933                 break;
1934         case ISCSI_PARAM_DATASEQ_INORDER_EN:
1935                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
1936                 break;
1937         case ISCSI_PARAM_ERL:
1938                 len = sprintf(buf, "%d\n", session->erl);
1939                 break;
1940         case ISCSI_PARAM_TARGET_NAME:
1941                 len = sprintf(buf, "%s\n", session->targetname);
1942                 break;
1943         case ISCSI_PARAM_TPGT:
1944                 len = sprintf(buf, "%d\n", session->tpgt);
1945                 break;
1946         default:
1947                 return -ENOSYS;
1948         }
1949
1950         return len;
1951 }
1952 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
1953
1954 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
1955                          enum iscsi_param param, char *buf)
1956 {
1957         struct iscsi_conn *conn = cls_conn->dd_data;
1958         int len;
1959
1960         switch(param) {
1961         case ISCSI_PARAM_MAX_RECV_DLENGTH:
1962                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
1963                 break;
1964         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
1965                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
1966                 break;
1967         case ISCSI_PARAM_HDRDGST_EN:
1968                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
1969                 break;
1970         case ISCSI_PARAM_DATADGST_EN:
1971                 len = sprintf(buf, "%d\n", conn->datadgst_en);
1972                 break;
1973         case ISCSI_PARAM_IFMARKER_EN:
1974                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
1975                 break;
1976         case ISCSI_PARAM_OFMARKER_EN:
1977                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
1978                 break;
1979         case ISCSI_PARAM_EXP_STATSN:
1980                 len = sprintf(buf, "%u\n", conn->exp_statsn);
1981                 break;
1982         case ISCSI_PARAM_PERSISTENT_PORT:
1983                 len = sprintf(buf, "%d\n", conn->persistent_port);
1984                 break;
1985         case ISCSI_PARAM_PERSISTENT_ADDRESS:
1986                 len = sprintf(buf, "%s\n", conn->persistent_address);
1987                 break;
1988         default:
1989                 return -ENOSYS;
1990         }
1991
1992         return len;
1993 }
1994 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
1995
1996 MODULE_AUTHOR("Mike Christie");
1997 MODULE_DESCRIPTION("iSCSI library functions");
1998 MODULE_LICENSE("GPL");