git.oblomov.eu Git - linux-2.6/blob - 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         if (atomic_dec_and_test(&ctask->refcount))
 217                 iscsi_complete_command(ctask);
 218 }
 219
 220 static void iscsi_put_ctask(struct iscsi_cmd_task *ctask)
 221 {
 222         spin_lock_bh(&ctask->conn->session->lock);
 223         __iscsi_put_ctask(ctask);
 224         spin_unlock_bh(&ctask->conn->session->lock);
 225 }
 226
 227 /**
 228  * iscsi_cmd_rsp - SCSI Command Response processing
 229  * @conn: iscsi connection
 230  * @hdr: iscsi header
 231  * @ctask: scsi command task
 232  * @data: cmd data buffer
 233  * @datalen: len of buffer
 234  *
 235  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 236  * then completes the command and task.
 237  **/
 238 static int iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 239                               struct iscsi_cmd_task *ctask, char *data,
 240                               int datalen)
 241 {
 242         int rc;
 243         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
 244         struct iscsi_session *session = conn->session;
 245         struct scsi_cmnd *sc = ctask->sc;
 246
 247         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 248         if (rc) {
 249                 sc->result = DID_ERROR << 16;
 250                 goto out;
 251         }
 252
 253         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 254
 255         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 256
 257         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 258                 sc->result = DID_ERROR << 16;
 259                 goto out;
 260         }
 261
 262         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 263                 int senselen;
 264
 265                 if (datalen < 2) {
 266 invalid_datalen:
 267                         printk(KERN_ERR "iscsi: Got CHECK_CONDITION but "
 268                                "invalid data buffer size of %d\n", datalen);
 269                         sc->result = DID_BAD_TARGET << 16;
 270                         goto out;
 271                 }
 272
 273                 senselen = (data[0] << 8) | data[1];
 274                 if (datalen < senselen)
 275                         goto invalid_datalen;
 276
 277                 memcpy(sc->sense_buffer, data + 2,
 278                        min(senselen, SCSI_SENSE_BUFFERSIZE));
 279                 debug_scsi("copied %d bytes of sense\n",
 280                            min(senselen, SCSI_SENSE_BUFFERSIZE));
 281         }
 282
 283         if (sc->sc_data_direction == DMA_TO_DEVICE)
 284                 goto out;
 285
 286         if (rhdr->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
 287                 int res_count = be32_to_cpu(rhdr->residual_count);
 288
 289                 if (res_count > 0 && res_count <= sc->request_bufflen)
 290                         sc->resid = res_count;
 291                 else
 292                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 293         } else if (rhdr->flags & ISCSI_FLAG_CMD_BIDI_UNDERFLOW)
 294                 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 295         else if (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW)
 296                 sc->resid = be32_to_cpu(rhdr->residual_count);
 297
 298 out:
 299         debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 300                    (long)sc, sc->result, ctask->itt);
 301         conn->scsirsp_pdus_cnt++;
 302
 303         __iscsi_put_ctask(ctask);
 304         return rc;
 305 }
 306
 307 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 308 {
 309         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 310
 311         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 312         conn->tmfrsp_pdus_cnt++;
 313
 314         if (conn->tmabort_state != TMABORT_INITIAL)
 315                 return;
 316
 317         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 318                 conn->tmabort_state = TMABORT_SUCCESS;
 319         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 320                 conn->tmabort_state = TMABORT_NOT_FOUND;
 321         else
 322                 conn->tmabort_state = TMABORT_FAILED;
 323         wake_up(&conn->ehwait);
 324 }
 325
 326 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 327                                char *data, int datalen)
 328 {
 329         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
 330         struct iscsi_hdr rejected_pdu;
 331         uint32_t itt;
 332
 333         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
 334
 335         if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
 336                 if (ntoh24(reject->dlength) > datalen)
 337                         return ISCSI_ERR_PROTO;
 338
 339                 if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
 340                         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
 341                         itt = rejected_pdu.itt & ISCSI_ITT_MASK;
 342                         printk(KERN_ERR "itt 0x%x had pdu (op 0x%x) rejected "
 343                                 "due to DataDigest error.\n", itt,
 344                                 rejected_pdu.opcode);
 345                 }
 346         }
 347         return 0;
 348 }
 349
 350 /**
 351  * __iscsi_complete_pdu - complete pdu
 352  * @conn: iscsi conn
 353  * @hdr: iscsi header
 354  * @data: data buffer
 355  * @datalen: len of data buffer
 356  *
 357  * Completes pdu processing by freeing any resources allocated at
 358  * queuecommand or send generic. session lock must be held and verify
 359  * itt must have been called.
 360  */
 361 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 362                          char *data, int datalen)
 363 {
 364         struct iscsi_session *session = conn->session;
 365         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
 366         struct iscsi_cmd_task *ctask;
 367         struct iscsi_mgmt_task *mtask;
 368         uint32_t itt;
 369
 370         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG))
 371                 itt = hdr->itt & ISCSI_ITT_MASK;
 372         else
 373                 itt = hdr->itt;
 374
 375         if (itt < session->cmds_max) {
 376                 ctask = session->cmds[itt];
 377
 378                 debug_scsi("cmdrsp [op 0x%x cid %d itt 0x%x len %d]\n",
 379                            opcode, conn->id, ctask->itt, datalen);
 380
 381                 switch(opcode) {
 382                 case ISCSI_OP_SCSI_CMD_RSP:
 383                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 384                         rc = iscsi_scsi_cmd_rsp(conn, hdr, ctask, data,
 385                                                 datalen);
 386                         break;
 387                 case ISCSI_OP_SCSI_DATA_IN:
 388                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 389                         if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
 390                                 conn->scsirsp_pdus_cnt++;
 391                                 __iscsi_put_ctask(ctask);
 392                         }
 393                         break;
 394                 case ISCSI_OP_R2T:
 395                         /* LLD handles this for now */
 396                         break;
 397                 default:
 398                         rc = ISCSI_ERR_BAD_OPCODE;
 399                         break;
 400                 }
 401         } else if (itt >= ISCSI_MGMT_ITT_OFFSET &&
 402                    itt < ISCSI_MGMT_ITT_OFFSET + session->mgmtpool_max) {
 403                 mtask = session->mgmt_cmds[itt - ISCSI_MGMT_ITT_OFFSET];
 404
 405                 debug_scsi("immrsp [op 0x%x cid %d itt 0x%x len %d]\n",
 406                            opcode, conn->id, mtask->itt, datalen);
 407
 408                 rc = iscsi_check_assign_cmdsn(session,
 409                                               (struct iscsi_nopin*)hdr);
 410                 if (rc)
 411                         goto done;
 412
 413                 switch(opcode) {
 414                 case ISCSI_OP_LOGOUT_RSP:
 415                         if (datalen) {
 416                                 rc = ISCSI_ERR_PROTO;
 417                                 break;
 418                         }
 419                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 420                         /* fall through */
 421                 case ISCSI_OP_LOGIN_RSP:
 422                 case ISCSI_OP_TEXT_RSP:
 423                         /*
 424                          * login related PDU's exp_statsn is handled in
 425                          * userspace
 426                          */
 427                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 428                                 rc = ISCSI_ERR_CONN_FAILED;
 429                         list_del(&mtask->running);
 430                         if (conn->login_mtask != mtask)
 431                                 __kfifo_put(session->mgmtpool.queue,
 432                                             (void*)&mtask, sizeof(void*));
 433                         break;
 434                 case ISCSI_OP_SCSI_TMFUNC_RSP:
 435                         if (datalen) {
 436                                 rc = ISCSI_ERR_PROTO;
 437                                 break;
 438                         }
 439
 440                         iscsi_tmf_rsp(conn, hdr);
 441                         break;
 442                 case ISCSI_OP_NOOP_IN:
 443                         if (hdr->ttt != ISCSI_RESERVED_TAG || datalen) {
 444                                 rc = ISCSI_ERR_PROTO;
 445                                 break;
 446                         }
 447                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 448
 449                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 450                                 rc = ISCSI_ERR_CONN_FAILED;
 451                         list_del(&mtask->running);
 452                         if (conn->login_mtask != mtask)
 453                                 __kfifo_put(session->mgmtpool.queue,
 454                                             (void*)&mtask, sizeof(void*));
 455                         break;
 456                 default:
 457                         rc = ISCSI_ERR_BAD_OPCODE;
 458                         break;
 459                 }
 460         } else if (itt == ISCSI_RESERVED_TAG) {
 461                 rc = iscsi_check_assign_cmdsn(session,
 462                                              (struct iscsi_nopin*)hdr);
 463                 if (rc)
 464                         goto done;
 465
 466                 switch(opcode) {
 467                 case ISCSI_OP_NOOP_IN:
 468                         if (datalen) {
 469                                 rc = ISCSI_ERR_PROTO;
 470                                 break;
 471                         }
 472
 473                         if (hdr->ttt == ISCSI_RESERVED_TAG)
 474                                 break;
 475
 476                         if (iscsi_recv_pdu(conn->cls_conn, hdr, NULL, 0))
 477                                 rc = ISCSI_ERR_CONN_FAILED;
 478                         break;
 479                 case ISCSI_OP_REJECT:
 480                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
 481                         break;
 482                 case ISCSI_OP_ASYNC_EVENT:
 483                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 484                         /* we need sth like iscsi_async_event_rsp() */
 485                         rc = ISCSI_ERR_BAD_OPCODE;
 486                         break;
 487                 default:
 488                         rc = ISCSI_ERR_BAD_OPCODE;
 489                         break;
 490                 }
 491         } else
 492                 rc = ISCSI_ERR_BAD_ITT;
 493
 494 done:
 495         return rc;
 496 }
 497 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
 498
 499 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 500                        char *data, int datalen)
 501 {
 502         int rc;
 503
 504         spin_lock(&conn->session->lock);
 505         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
 506         spin_unlock(&conn->session->lock);
 507         return rc;
 508 }
 509 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
 510
 511 /* verify itt (itt encoding: age+cid+itt) */
 512 int iscsi_verify_itt(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 513                      uint32_t *ret_itt)
 514 {
 515         struct iscsi_session *session = conn->session;
 516         struct iscsi_cmd_task *ctask;
 517         uint32_t itt;
 518
 519         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
 520                 if ((hdr->itt & ISCSI_AGE_MASK) !=
 521                     (session->age << ISCSI_AGE_SHIFT)) {
 522                         printk(KERN_ERR "iscsi: received itt %x expected "
 523                                 "session age (%x)\n", hdr->itt,
 524                                 session->age & ISCSI_AGE_MASK);
 525                         return ISCSI_ERR_BAD_ITT;
 526                 }
 527
 528                 if ((hdr->itt & ISCSI_CID_MASK) !=
 529                     (conn->id << ISCSI_CID_SHIFT)) {
 530                         printk(KERN_ERR "iscsi: received itt %x, expected "
 531                                 "CID (%x)\n", hdr->itt, conn->id);
 532                         return ISCSI_ERR_BAD_ITT;
 533                 }
 534                 itt = hdr->itt & ISCSI_ITT_MASK;
 535         } else
 536                 itt = hdr->itt;
 537
 538         if (itt < session->cmds_max) {
 539                 ctask = session->cmds[itt];
 540
 541                 if (!ctask->sc) {
 542                         printk(KERN_INFO "iscsi: dropping ctask with "
 543                                "itt 0x%x\n", ctask->itt);
 544                         /* force drop */
 545                         return ISCSI_ERR_NO_SCSI_CMD;
 546                 }
 547
 548                 if (ctask->sc->SCp.phase != session->age) {
 549                         printk(KERN_ERR "iscsi: ctask's session age %d, "
 550                                 "expected %d\n", ctask->sc->SCp.phase,
 551                                 session->age);
 552                         return ISCSI_ERR_SESSION_FAILED;
 553                 }
 554         }
 555
 556         *ret_itt = itt;
 557         return 0;
 558 }
 559 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
 560
 561 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
 562 {
 563         struct iscsi_session *session = conn->session;
 564         unsigned long flags;
 565
 566         spin_lock_irqsave(&session->lock, flags);
 567         if (session->state == ISCSI_STATE_FAILED) {
 568                 spin_unlock_irqrestore(&session->lock, flags);
 569                 return;
 570         }
 571
 572         if (conn->stop_stage == 0)
 573                 session->state = ISCSI_STATE_FAILED;
 574         spin_unlock_irqrestore(&session->lock, flags);
 575         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
 576         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
 577         iscsi_conn_error(conn->cls_conn, err);
 578 }
 579 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
 580
 581 /**
 582  * iscsi_data_xmit - xmit any command into the scheduled connection
 583  * @conn: iscsi connection
 584  *
 585  * Notes:
 586  *      The function can return -EAGAIN in which case the caller must
 587  *      re-schedule it again later or recover. '0' return code means
 588  *      successful xmit.
 589  **/
 590 static int iscsi_data_xmit(struct iscsi_conn *conn)
 591 {
 592         struct iscsi_transport *tt;
 593         int rc = 0;
 594
 595         if (unlikely(conn->suspend_tx)) {
 596                 debug_scsi("conn %d Tx suspended!\n", conn->id);
 597                 return -ENODATA;
 598         }
 599         tt = conn->session->tt;
 600
 601         /*
 602          * Transmit in the following order:
 603          *
 604          * 1) un-finished xmit (ctask or mtask)
 605          * 2) immediate control PDUs
 606          * 3) write data
 607          * 4) SCSI commands
 608          * 5) non-immediate control PDUs
 609          *
 610          * No need to lock around __kfifo_get as long as
 611          * there's one producer and one consumer.
 612          */
 613
 614         BUG_ON(conn->ctask && conn->mtask);
 615
 616         if (conn->ctask) {
 617                 iscsi_get_ctask(conn->ctask);
 618                 rc = tt->xmit_cmd_task(conn, conn->ctask);
 619                 iscsi_put_ctask(conn->ctask);
 620                 if (rc)
 621                         goto again;
 622                 /* done with this in-progress ctask */
 623                 conn->ctask = NULL;
 624         }
 625         if (conn->mtask) {
 626                 rc = tt->xmit_mgmt_task(conn, conn->mtask);
 627                 if (rc)
 628                         goto again;
 629                 /* done with this in-progress mtask */
 630                 conn->mtask = NULL;
 631         }
 632
 633         /* process immediate first */
 634         if (unlikely(__kfifo_len(conn->immqueue))) {
 635                 while (__kfifo_get(conn->immqueue, (void*)&conn->mtask,
 636                                    sizeof(void*))) {
 637                         spin_lock_bh(&conn->session->lock);
 638                         list_add_tail(&conn->mtask->running,
 639                                       &conn->mgmt_run_list);
 640                         spin_unlock_bh(&conn->session->lock);
 641                         rc = tt->xmit_mgmt_task(conn, conn->mtask);
 642                         if (rc)
 643                                 goto again;
 644                 }
 645                 /* done with this mtask */
 646                 conn->mtask = NULL;
 647         }
 648
 649         /* process command queue */
 650         spin_lock_bh(&conn->session->lock);
 651         while (!list_empty(&conn->xmitqueue)) {
 652                 /*
 653                  * iscsi tcp may readd the task to the xmitqueue to send
 654                  * write data
 655                  */
 656                 conn->ctask = list_entry(conn->xmitqueue.next,
 657                                          struct iscsi_cmd_task, running);
 658                 conn->ctask->state = ISCSI_TASK_RUNNING;
 659                 list_move_tail(conn->xmitqueue.next, &conn->run_list);
 660                 __iscsi_get_ctask(conn->ctask);
 661                 spin_unlock_bh(&conn->session->lock);
 662
 663                 rc = tt->xmit_cmd_task(conn, conn->ctask);
 664                 if (rc)
 665                         goto again;
 666
 667                 spin_lock_bh(&conn->session->lock);
 668                 __iscsi_put_ctask(conn->ctask);
 669                 if (rc) {
 670                         spin_unlock_bh(&conn->session->lock);
 671                         goto again;
 672                 }
 673         }
 674         spin_unlock_bh(&conn->session->lock);
 675         /* done with this ctask */
 676         conn->ctask = NULL;
 677
 678         /* process the rest control plane PDUs, if any */
 679         if (unlikely(__kfifo_len(conn->mgmtqueue))) {
 680                 while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask,
 681                                    sizeof(void*))) {
 682                         spin_lock_bh(&conn->session->lock);
 683                         list_add_tail(&conn->mtask->running,
 684                                       &conn->mgmt_run_list);
 685                         spin_unlock_bh(&conn->session->lock);
 686                         rc = tt->xmit_mgmt_task(conn, conn->mtask);
 687                         if (rc)
 688                                 goto again;
 689                 }
 690                 /* done with this mtask */
 691                 conn->mtask = NULL;
 692         }
 693
 694         return -ENODATA;
 695
 696 again:
 697         if (unlikely(conn->suspend_tx))
 698                 return -ENODATA;
 699
 700         return rc;
 701 }
 702
 703 static void iscsi_xmitworker(void *data)
 704 {
 705         struct iscsi_conn *conn = data;
 706         int rc;
 707         /*
 708          * serialize Xmit worker on a per-connection basis.
 709          */
 710         mutex_lock(&conn->xmitmutex);
 711         do {
 712                 rc = iscsi_data_xmit(conn);
 713         } while (rc >= 0 || rc == -EAGAIN);
 714         mutex_unlock(&conn->xmitmutex);
 715 }
 716
 717 enum {
 718         FAILURE_BAD_HOST = 1,
 719         FAILURE_SESSION_FAILED,
 720         FAILURE_SESSION_FREED,
 721         FAILURE_WINDOW_CLOSED,
 722         FAILURE_OOM,
 723         FAILURE_SESSION_TERMINATE,
 724         FAILURE_SESSION_IN_RECOVERY,
 725         FAILURE_SESSION_RECOVERY_TIMEOUT,
 726 };
 727
 728 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
 729 {
 730         struct Scsi_Host *host;
 731         int reason = 0;
 732         struct iscsi_session *session;
 733         struct iscsi_conn *conn;
 734         struct iscsi_cmd_task *ctask = NULL;
 735
 736         sc->scsi_done = done;
 737         sc->result = 0;
 738         sc->SCp.ptr = NULL;
 739
 740         host = sc->device->host;
 741         session = iscsi_hostdata(host->hostdata);
 742
 743         spin_lock(&session->lock);
 744
 745         /*
 746          * ISCSI_STATE_FAILED is a temp. state. The recovery
 747          * code will decide what is best to do with command queued
 748          * during this time
 749          */
 750         if (session->state != ISCSI_STATE_LOGGED_IN &&
 751             session->state != ISCSI_STATE_FAILED) {
 752                 /*
 753                  * to handle the race between when we set the recovery state
 754                  * and block the session we requeue here (commands could
 755                  * be entering our queuecommand while a block is starting
 756                  * up because the block code is not locked)
 757                  */
 758                 if (session->state == ISCSI_STATE_IN_RECOVERY) {
 759                         reason = FAILURE_SESSION_IN_RECOVERY;
 760                         goto reject;
 761                 }
 762
 763                 if (session->state == ISCSI_STATE_RECOVERY_FAILED)
 764                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
 765                 else if (session->state == ISCSI_STATE_TERMINATE)
 766                         reason = FAILURE_SESSION_TERMINATE;
 767                 else
 768                         reason = FAILURE_SESSION_FREED;
 769                 goto fault;
 770         }
 771
 772         /*
 773          * Check for iSCSI window and take care of CmdSN wrap-around
 774          */
 775         if ((int)(session->max_cmdsn - session->cmdsn) < 0) {
 776                 reason = FAILURE_WINDOW_CLOSED;
 777                 goto reject;
 778         }
 779
 780         conn = session->leadconn;
 781
 782         if (!__kfifo_get(session->cmdpool.queue, (void*)&ctask,
 783                          sizeof(void*))) {
 784                 reason = FAILURE_OOM;
 785                 goto reject;
 786         }
 787         sc->SCp.phase = session->age;
 788         sc->SCp.ptr = (char *)ctask;
 789
 790         atomic_set(&ctask->refcount, 1);
 791         ctask->state = ISCSI_TASK_PENDING;
 792         ctask->mtask = NULL;
 793         ctask->conn = conn;
 794         ctask->sc = sc;
 795         INIT_LIST_HEAD(&ctask->running);
 796         ctask->total_length = sc->request_bufflen;
 797         iscsi_prep_scsi_cmd_pdu(ctask);
 798
 799         session->tt->init_cmd_task(ctask);
 800
 801         list_add_tail(&ctask->running, &conn->xmitqueue);
 802         debug_scsi(
 803                "ctask enq [%s cid %d sc %p cdb 0x%x itt 0x%x len %d cmdsn %d "
 804                 "win %d]\n",
 805                 sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
 806                 conn->id, sc, sc->cmnd[0], ctask->itt, sc->request_bufflen,
 807                 session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
 808         spin_unlock(&session->lock);
 809
 810         scsi_queue_work(host, &conn->xmitwork);
 811         return 0;
 812
 813 reject:
 814         spin_unlock(&session->lock);
 815         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
 816         return SCSI_MLQUEUE_HOST_BUSY;
 817
 818 fault:
 819         spin_unlock(&session->lock);
 820         printk(KERN_ERR "iscsi: cmd 0x%x is not queued (%d)\n",
 821                sc->cmnd[0], reason);
 822         sc->result = (DID_NO_CONNECT << 16);
 823         sc->resid = sc->request_bufflen;
 824         sc->scsi_done(sc);
 825         return 0;
 826 }
 827 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
 828
 829 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
 830 {
 831         if (depth > ISCSI_MAX_CMD_PER_LUN)
 832                 depth = ISCSI_MAX_CMD_PER_LUN;
 833         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 834         return sdev->queue_depth;
 835 }
 836 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
 837
 838 static int
 839 iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 840                         char *data, uint32_t data_size)
 841 {
 842         struct iscsi_session *session = conn->session;
 843         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 844         struct iscsi_mgmt_task *mtask;
 845
 846         spin_lock_bh(&session->lock);
 847         if (session->state == ISCSI_STATE_TERMINATE) {
 848                 spin_unlock_bh(&session->lock);
 849                 return -EPERM;
 850         }
 851         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
 852             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 853                 /*
 854                  * Login and Text are sent serially, in
 855                  * request-followed-by-response sequence.
 856                  * Same mtask can be used. Same ITT must be used.
 857                  * Note that login_mtask is preallocated at conn_create().
 858                  */
 859                 mtask = conn->login_mtask;
 860         else {
 861                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 862                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 863
 864                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 865                 if (!__kfifo_get(session->mgmtpool.queue,
 866                                  (void*)&mtask, sizeof(void*))) {
 867                         spin_unlock_bh(&session->lock);
 868                         return -ENOSPC;
 869                 }
 870         }
 871
 872         /*
 873          * pre-format CmdSN for outgoing PDU.
 874          */
 875         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
 876                 hdr->itt = mtask->itt | (conn->id << ISCSI_CID_SHIFT) |
 877                            (session->age << ISCSI_AGE_SHIFT);
 878                 nop->cmdsn = cpu_to_be32(session->cmdsn);
 879                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 880                     !(hdr->opcode & ISCSI_OP_IMMEDIATE))
 881                         session->cmdsn++;
 882         } else
 883                 /* do not advance CmdSN */
 884                 nop->cmdsn = cpu_to_be32(session->cmdsn);
 885
 886         if (data_size) {
 887                 memcpy(mtask->data, data, data_size);
 888                 mtask->data_count = data_size;
 889         } else
 890                 mtask->data_count = 0;
 891
 892         INIT_LIST_HEAD(&mtask->running);
 893         memcpy(mtask->hdr, hdr, sizeof(struct iscsi_hdr));
 894         if (session->tt->init_mgmt_task)
 895                 session->tt->init_mgmt_task(conn, mtask, data, data_size);
 896         spin_unlock_bh(&session->lock);
 897
 898         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
 899                    hdr->opcode, hdr->itt, data_size);
 900
 901         /*
 902          * since send_pdu() could be called at least from two contexts,
 903          * we need to serialize __kfifo_put, so we don't have to take
 904          * additional lock on fast data-path
 905          */
 906         if (hdr->opcode & ISCSI_OP_IMMEDIATE)
 907                 __kfifo_put(conn->immqueue, (void*)&mtask, sizeof(void*));
 908         else
 909                 __kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*));
 910
 911         scsi_queue_work(session->host, &conn->xmitwork);
 912         return 0;
 913 }
 914
 915 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 916                         char *data, uint32_t data_size)
 917 {
 918         struct iscsi_conn *conn = cls_conn->dd_data;
 919         int rc;
 920
 921         mutex_lock(&conn->xmitmutex);
 922         rc = iscsi_conn_send_generic(conn, hdr, data, data_size);
 923         mutex_unlock(&conn->xmitmutex);
 924
 925         return rc;
 926 }
 927 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 928
 929 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
 930 {
 931         struct iscsi_session *session = class_to_transport_session(cls_session);
 932         struct iscsi_conn *conn = session->leadconn;
 933
 934         spin_lock_bh(&session->lock);
 935         if (session->state != ISCSI_STATE_LOGGED_IN) {
 936                 session->state = ISCSI_STATE_RECOVERY_FAILED;
 937                 if (conn)
 938                         wake_up(&conn->ehwait);
 939         }
 940         spin_unlock_bh(&session->lock);
 941 }
 942 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
 943
 944 int iscsi_eh_host_reset(struct scsi_cmnd *sc)
 945 {
 946         struct Scsi_Host *host = sc->device->host;
 947         struct iscsi_session *session = iscsi_hostdata(host->hostdata);
 948         struct iscsi_conn *conn = session->leadconn;
 949         int fail_session = 0;
 950
 951         spin_lock_bh(&session->lock);
 952         if (session->state == ISCSI_STATE_TERMINATE) {
 953 failed:
 954                 debug_scsi("failing host reset: session terminated "
 955                            "[CID %d age %d]", conn->id, session->age);
 956                 spin_unlock_bh(&session->lock);
 957                 return FAILED;
 958         }
 959
 960         if (sc->SCp.phase == session->age) {
 961                 debug_scsi("failing connection CID %d due to SCSI host reset",
 962                            conn->id);
 963                 fail_session = 1;
 964         }
 965         spin_unlock_bh(&session->lock);
 966
 967         /*
 968          * we drop the lock here but the leadconn cannot be destoyed while
 969          * we are in the scsi eh
 970          */
 971         if (fail_session)
 972                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 973
 974         debug_scsi("iscsi_eh_host_reset wait for relogin\n");
 975         wait_event_interruptible(conn->ehwait,
 976                                  session->state == ISCSI_STATE_TERMINATE ||
 977                                  session->state == ISCSI_STATE_LOGGED_IN ||
 978                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
 979         if (signal_pending(current))
 980                 flush_signals(current);
 981
 982         spin_lock_bh(&session->lock);
 983         if (session->state == ISCSI_STATE_LOGGED_IN)
 984                 printk(KERN_INFO "iscsi: host reset succeeded\n");
 985         else
 986                 goto failed;
 987         spin_unlock_bh(&session->lock);
 988
 989         return SUCCESS;
 990 }
 991 EXPORT_SYMBOL_GPL(iscsi_eh_host_reset);
 992
 993 static void iscsi_tmabort_timedout(unsigned long data)
 994 {
 995         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)data;
 996         struct iscsi_conn *conn = ctask->conn;
 997         struct iscsi_session *session = conn->session;
 998
 999         spin_lock(&session->lock);
1000         if (conn->tmabort_state == TMABORT_INITIAL) {
1001                 conn->tmabort_state = TMABORT_TIMEDOUT;
1002                 debug_scsi("tmabort timedout [sc %p itt 0x%x]\n",
1003                         ctask->sc, ctask->itt);
1004                 /* unblock eh_abort() */
1005                 wake_up(&conn->ehwait);
1006         }
1007         spin_unlock(&session->lock);
1008 }
1009
1010 /* must be called with the mutex lock */
1011 static int iscsi_exec_abort_task(struct scsi_cmnd *sc,
1012                                  struct iscsi_cmd_task *ctask)
1013 {
1014         struct iscsi_conn *conn = ctask->conn;
1015         struct iscsi_session *session = conn->session;
1016         struct iscsi_tm *hdr = &conn->tmhdr;
1017         int rc;
1018
1019         /*
1020          * ctask timed out but session is OK requests must be serialized.
1021          */
1022         memset(hdr, 0, sizeof(struct iscsi_tm));
1023         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1024         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK;
1025         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1026         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1027         hdr->rtt = ctask->hdr->itt;
1028         hdr->refcmdsn = ctask->hdr->cmdsn;
1029
1030         rc = iscsi_conn_send_generic(conn, (struct iscsi_hdr *)hdr,
1031                                      NULL, 0);
1032         if (rc) {
1033                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1034                 debug_scsi("abort sent failure [itt 0x%x] %d", ctask->itt, rc);
1035                 return rc;
1036         }
1037
1038         debug_scsi("abort sent [itt 0x%x]\n", ctask->itt);
1039
1040         spin_lock_bh(&session->lock);
1041         ctask->mtask = (struct iscsi_mgmt_task *)
1042                         session->mgmt_cmds[(hdr->itt & ISCSI_ITT_MASK) -
1043                                         ISCSI_MGMT_ITT_OFFSET];
1044
1045         if (conn->tmabort_state == TMABORT_INITIAL) {
1046                 conn->tmfcmd_pdus_cnt++;
1047                 conn->tmabort_timer.expires = 10*HZ + jiffies;
1048                 conn->tmabort_timer.function = iscsi_tmabort_timedout;
1049                 conn->tmabort_timer.data = (unsigned long)ctask;
1050                 add_timer(&conn->tmabort_timer);
1051                 debug_scsi("abort set timeout [itt 0x%x]", ctask->itt);
1052         }
1053         spin_unlock_bh(&session->lock);
1054         mutex_unlock(&conn->xmitmutex);
1055
1056         /*
1057          * block eh thread until:
1058          *
1059          * 1) abort response
1060          * 2) abort timeout
1061          * 3) session is terminated or restarted or userspace has
1062          * given up on recovery
1063          */
1064         wait_event_interruptible(conn->ehwait,
1065                                  sc->SCp.phase != session->age ||
1066                                  session->state != ISCSI_STATE_LOGGED_IN ||
1067                                  conn->tmabort_state != TMABORT_INITIAL);
1068         if (signal_pending(current))
1069                 flush_signals(current);
1070         del_timer_sync(&conn->tmabort_timer);
1071
1072         mutex_lock(&conn->xmitmutex);
1073         return 0;
1074 }
1075
1076 /*
1077  * xmit mutex and session lock must be held
1078  */
1079 static struct iscsi_mgmt_task *
1080 iscsi_remove_mgmt_task(struct kfifo *fifo, uint32_t itt)
1081 {
1082         int i, nr_tasks = __kfifo_len(fifo) / sizeof(void*);
1083         struct iscsi_mgmt_task *task;
1084
1085         debug_scsi("searching %d tasks\n", nr_tasks);
1086
1087         for (i = 0; i < nr_tasks; i++) {
1088                 __kfifo_get(fifo, (void*)&task, sizeof(void*));
1089                 debug_scsi("check task %u\n", task->itt);
1090
1091                 if (task->itt == itt) {
1092                         debug_scsi("matched task\n");
1093                         return task;
1094                 }
1095
1096                 __kfifo_put(fifo, (void*)&task, sizeof(void*));
1097         }
1098         return NULL;
1099 }
1100
1101 static int iscsi_ctask_mtask_cleanup(struct iscsi_cmd_task *ctask)
1102 {
1103         struct iscsi_conn *conn = ctask->conn;
1104         struct iscsi_session *session = conn->session;
1105
1106         if (!ctask->mtask)
1107                 return -EINVAL;
1108
1109         if (!iscsi_remove_mgmt_task(conn->immqueue, ctask->mtask->itt))
1110                 list_del(&ctask->mtask->running);
1111         __kfifo_put(session->mgmtpool.queue, (void*)&ctask->mtask,
1112                     sizeof(void*));
1113         ctask->mtask = NULL;
1114         return 0;
1115 }
1116
1117 /*
1118  * session lock and xmitmutex must be held
1119  */
1120 static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1121                          int err)
1122 {
1123         struct scsi_cmnd *sc;
1124
1125         sc = ctask->sc;
1126         if (!sc)
1127                 return;
1128
1129         conn->session->tt->cleanup_cmd_task(conn, ctask);
1130         iscsi_ctask_mtask_cleanup(ctask);
1131
1132         sc->result = err;
1133         sc->resid = sc->request_bufflen;
1134         /* release ref from queuecommand */
1135         __iscsi_put_ctask(ctask);
1136 }
1137
1138 int iscsi_eh_abort(struct scsi_cmnd *sc)
1139 {
1140         struct iscsi_cmd_task *ctask;
1141         struct iscsi_conn *conn;
1142         struct iscsi_session *session;
1143         int rc;
1144
1145         /*
1146          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1147          * got the command.
1148          */
1149         if (!sc->SCp.ptr) {
1150                 debug_scsi("sc never reached iscsi layer or it completed.\n");
1151                 return SUCCESS;
1152         }
1153
1154         ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
1155         conn = ctask->conn;
1156         session = conn->session;
1157
1158         conn->eh_abort_cnt++;
1159         debug_scsi("aborting [sc %p itt 0x%x]\n", sc, ctask->itt);
1160
1161         mutex_lock(&conn->xmitmutex);
1162         spin_lock_bh(&session->lock);
1163
1164         /*
1165          * If we are not logged in or we have started a new session
1166          * then let the host reset code handle this
1167          */
1168         if (session->state != ISCSI_STATE_LOGGED_IN ||
1169             sc->SCp.phase != session->age)
1170                 goto failed;
1171
1172         /* ctask completed before time out */
1173         if (!ctask->sc) {
1174                 spin_unlock_bh(&session->lock);
1175                 debug_scsi("sc completed while abort in progress\n");
1176                 goto success_rel_mutex;
1177         }
1178
1179         /* what should we do here ? */
1180         if (conn->ctask == ctask) {
1181                 printk(KERN_INFO "iscsi: sc %p itt 0x%x partially sent. "
1182                        "Failing abort\n", sc, ctask->itt);
1183                 goto failed;
1184         }
1185
1186         if (ctask->state == ISCSI_TASK_PENDING)
1187                 goto success_cleanup;
1188
1189         conn->tmabort_state = TMABORT_INITIAL;
1190
1191         spin_unlock_bh(&session->lock);
1192         rc = iscsi_exec_abort_task(sc, ctask);
1193         spin_lock_bh(&session->lock);
1194
1195         if (rc || sc->SCp.phase != session->age ||
1196             session->state != ISCSI_STATE_LOGGED_IN)
1197                 goto failed;
1198         iscsi_ctask_mtask_cleanup(ctask);
1199
1200         switch (conn->tmabort_state) {
1201         case TMABORT_SUCCESS:
1202                 goto success_cleanup;
1203         case TMABORT_NOT_FOUND:
1204                 if (!ctask->sc) {
1205                         /* ctask completed before tmf abort response */
1206                         spin_unlock_bh(&session->lock);
1207                         debug_scsi("sc completed while abort in progress\n");
1208                         goto success_rel_mutex;
1209                 }
1210                 /* fall through */
1211         default:
1212                 /* timedout or failed */
1213                 spin_unlock_bh(&session->lock);
1214                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1215                 spin_lock_bh(&session->lock);
1216                 goto failed;
1217         }
1218
1219 success_cleanup:
1220         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1221         spin_unlock_bh(&session->lock);
1222
1223         /*
1224          * clean up task if aborted. we have the xmitmutex so grab
1225          * the recv lock as a writer
1226          */
1227         write_lock_bh(conn->recv_lock);
1228         spin_lock(&session->lock);
1229         fail_command(conn, ctask, DID_ABORT << 16);
1230         spin_unlock(&session->lock);
1231         write_unlock_bh(conn->recv_lock);
1232
1233 success_rel_mutex:
1234         mutex_unlock(&conn->xmitmutex);
1235         return SUCCESS;
1236
1237 failed:
1238         spin_unlock_bh(&session->lock);
1239         mutex_unlock(&conn->xmitmutex);
1240
1241         debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1242         return FAILED;
1243 }
1244 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1245
1246 int
1247 iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
1248 {
1249         int i;
1250
1251         *items = kmalloc(max * sizeof(void*), GFP_KERNEL);
1252         if (*items == NULL)
1253                 return -ENOMEM;
1254
1255         q->max = max;
1256         q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL);
1257         if (q->pool == NULL) {
1258                 kfree(*items);
1259                 return -ENOMEM;
1260         }
1261
1262         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1263                               GFP_KERNEL, NULL);
1264         if (q->queue == ERR_PTR(-ENOMEM)) {
1265                 kfree(q->pool);
1266                 kfree(*items);
1267                 return -ENOMEM;
1268         }
1269
1270         for (i = 0; i < max; i++) {
1271                 q->pool[i] = kmalloc(item_size, GFP_KERNEL);
1272                 if (q->pool[i] == NULL) {
1273                         int j;
1274
1275                         for (j = 0; j < i; j++)
1276                                 kfree(q->pool[j]);
1277
1278                         kfifo_free(q->queue);
1279                         kfree(q->pool);
1280                         kfree(*items);
1281                         return -ENOMEM;
1282                 }
1283                 memset(q->pool[i], 0, item_size);
1284                 (*items)[i] = q->pool[i];
1285                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1286         }
1287         return 0;
1288 }
1289 EXPORT_SYMBOL_GPL(iscsi_pool_init);
1290
1291 void iscsi_pool_free(struct iscsi_queue *q, void **items)
1292 {
1293         int i;
1294
1295         for (i = 0; i < q->max; i++)
1296                 kfree(items[i]);
1297         kfree(q->pool);
1298         kfree(items);
1299 }
1300 EXPORT_SYMBOL_GPL(iscsi_pool_free);
1301
1302 /*
1303  * iSCSI Session's hostdata organization:
1304  *
1305  *    *------------------* <== hostdata_session(host->hostdata)
1306  *    | ptr to class sess|
1307  *    |------------------| <== iscsi_hostdata(host->hostdata)
1308  *    | iscsi_session    |
1309  *    *------------------*
1310  */
1311
1312 #define hostdata_privsize(_sz)  (sizeof(unsigned long) + _sz + \
1313                                  _sz % sizeof(unsigned long))
1314
1315 #define hostdata_session(_hostdata) (iscsi_ptr(*(unsigned long *)_hostdata))
1316
1317 /**
1318  * iscsi_session_setup - create iscsi cls session and host and session
1319  * @scsit: scsi transport template
1320  * @iscsit: iscsi transport template
1321  * @initial_cmdsn: initial CmdSN
1322  * @hostno: host no allocated
1323  *
1324  * This can be used by software iscsi_transports that allocate
1325  * a session per scsi host.
1326  **/
1327 struct iscsi_cls_session *
1328 iscsi_session_setup(struct iscsi_transport *iscsit,
1329                     struct scsi_transport_template *scsit,
1330                     int cmd_task_size, int mgmt_task_size,
1331                     uint32_t initial_cmdsn, uint32_t *hostno)
1332 {
1333         struct Scsi_Host *shost;
1334         struct iscsi_session *session;
1335         struct iscsi_cls_session *cls_session;
1336         int cmd_i;
1337
1338         shost = scsi_host_alloc(iscsit->host_template,
1339                                 hostdata_privsize(sizeof(*session)));
1340         if (!shost)
1341                 return NULL;
1342
1343         shost->max_id = 1;
1344         shost->max_channel = 0;
1345         shost->max_lun = iscsit->max_lun;
1346         shost->max_cmd_len = iscsit->max_cmd_len;
1347         shost->transportt = scsit;
1348         shost->transportt->create_work_queue = 1;
1349         *hostno = shost->host_no;
1350
1351         session = iscsi_hostdata(shost->hostdata);
1352         memset(session, 0, sizeof(struct iscsi_session));
1353         session->host = shost;
1354         session->state = ISCSI_STATE_FREE;
1355         session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
1356         session->cmds_max = ISCSI_XMIT_CMDS_MAX;
1357         session->cmdsn = initial_cmdsn;
1358         session->exp_cmdsn = initial_cmdsn + 1;
1359         session->max_cmdsn = initial_cmdsn + 1;
1360         session->max_r2t = 1;
1361         session->tt = iscsit;
1362
1363         /* initialize SCSI PDU commands pool */
1364         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
1365                             (void***)&session->cmds,
1366                             cmd_task_size + sizeof(struct iscsi_cmd_task)))
1367                 goto cmdpool_alloc_fail;
1368
1369         /* pre-format cmds pool with ITT */
1370         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1371                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1372
1373                 if (cmd_task_size)
1374                         ctask->dd_data = &ctask[1];
1375                 ctask->itt = cmd_i;
1376                 INIT_LIST_HEAD(&ctask->running);
1377         }
1378
1379         spin_lock_init(&session->lock);
1380         INIT_LIST_HEAD(&session->connections);
1381
1382         /* initialize immediate command pool */
1383         if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max,
1384                            (void***)&session->mgmt_cmds,
1385                            mgmt_task_size + sizeof(struct iscsi_mgmt_task)))
1386                 goto mgmtpool_alloc_fail;
1387
1388
1389         /* pre-format immediate cmds pool with ITT */
1390         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
1391                 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
1392
1393                 if (mgmt_task_size)
1394                         mtask->dd_data = &mtask[1];
1395                 mtask->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i;
1396                 INIT_LIST_HEAD(&mtask->running);
1397         }
1398
1399         if (scsi_add_host(shost, NULL))
1400                 goto add_host_fail;
1401
1402         if (!try_module_get(iscsit->owner))
1403                 goto cls_session_fail;
1404
1405         cls_session = iscsi_create_session(shost, iscsit, 0);
1406         if (!cls_session)
1407                 goto module_put;
1408         *(unsigned long*)shost->hostdata = (unsigned long)cls_session;
1409
1410         return cls_session;
1411
1412 module_put:
1413         module_put(iscsit->owner);
1414 cls_session_fail:
1415         scsi_remove_host(shost);
1416 add_host_fail:
1417         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1418 mgmtpool_alloc_fail:
1419         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1420 cmdpool_alloc_fail:
1421         scsi_host_put(shost);
1422         return NULL;
1423 }
1424 EXPORT_SYMBOL_GPL(iscsi_session_setup);
1425
1426 /**
1427  * iscsi_session_teardown - destroy session, host, and cls_session
1428  * shost: scsi host
1429  *
1430  * This can be used by software iscsi_transports that allocate
1431  * a session per scsi host.
1432  **/
1433 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
1434 {
1435         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1436         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1437         struct module *owner = cls_session->transport->owner;
1438
1439         scsi_remove_host(shost);
1440
1441         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1442         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1443
1444         kfree(session->targetname);
1445
1446         iscsi_destroy_session(cls_session);
1447         scsi_host_put(shost);
1448         module_put(owner);
1449 }
1450 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
1451
1452 /**
1453  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
1454  * @cls_session: iscsi_cls_session
1455  * @conn_idx: cid
1456  **/
1457 struct iscsi_cls_conn *
1458 iscsi_conn_setup(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1459 {
1460         struct iscsi_session *session = class_to_transport_session(cls_session);
1461         struct iscsi_conn *conn;
1462         struct iscsi_cls_conn *cls_conn;
1463         char *data;
1464
1465         cls_conn = iscsi_create_conn(cls_session, conn_idx);
1466         if (!cls_conn)
1467                 return NULL;
1468         conn = cls_conn->dd_data;
1469         memset(conn, 0, sizeof(*conn));
1470
1471         conn->session = session;
1472         conn->cls_conn = cls_conn;
1473         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
1474         conn->id = conn_idx;
1475         conn->exp_statsn = 0;
1476         conn->tmabort_state = TMABORT_INITIAL;
1477         INIT_LIST_HEAD(&conn->run_list);
1478         INIT_LIST_HEAD(&conn->mgmt_run_list);
1479         INIT_LIST_HEAD(&conn->xmitqueue);
1480
1481         /* initialize general immediate & non-immediate PDU commands queue */
1482         conn->immqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
1483                                         GFP_KERNEL, NULL);
1484         if (conn->immqueue == ERR_PTR(-ENOMEM))
1485                 goto immqueue_alloc_fail;
1486
1487         conn->mgmtqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
1488                                         GFP_KERNEL, NULL);
1489         if (conn->mgmtqueue == ERR_PTR(-ENOMEM))
1490                 goto mgmtqueue_alloc_fail;
1491
1492         INIT_WORK(&conn->xmitwork, iscsi_xmitworker, conn);
1493
1494         /* allocate login_mtask used for the login/text sequences */
1495         spin_lock_bh(&session->lock);
1496         if (!__kfifo_get(session->mgmtpool.queue,
1497                          (void*)&conn->login_mtask,
1498                          sizeof(void*))) {
1499                 spin_unlock_bh(&session->lock);
1500                 goto login_mtask_alloc_fail;
1501         }
1502         spin_unlock_bh(&session->lock);
1503
1504         data = kmalloc(DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH, GFP_KERNEL);
1505         if (!data)
1506                 goto login_mtask_data_alloc_fail;
1507         conn->login_mtask->data = conn->data = data;
1508
1509         init_timer(&conn->tmabort_timer);
1510         mutex_init(&conn->xmitmutex);
1511         init_waitqueue_head(&conn->ehwait);
1512
1513         return cls_conn;
1514
1515 login_mtask_data_alloc_fail:
1516         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1517                     sizeof(void*));
1518 login_mtask_alloc_fail:
1519         kfifo_free(conn->mgmtqueue);
1520 mgmtqueue_alloc_fail:
1521         kfifo_free(conn->immqueue);
1522 immqueue_alloc_fail:
1523         iscsi_destroy_conn(cls_conn);
1524         return NULL;
1525 }
1526 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
1527
1528 /**
1529  * iscsi_conn_teardown - teardown iscsi connection
1530  * cls_conn: iscsi class connection
1531  *
1532  * TODO: we may need to make this into a two step process
1533  * like scsi-mls remove + put host
1534  */
1535 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
1536 {
1537         struct iscsi_conn *conn = cls_conn->dd_data;
1538         struct iscsi_session *session = conn->session;
1539         unsigned long flags;
1540
1541         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1542         mutex_lock(&conn->xmitmutex);
1543
1544         spin_lock_bh(&session->lock);
1545         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
1546         if (session->leadconn == conn) {
1547                 /*
1548                  * leading connection? then give up on recovery.
1549                  */
1550                 session->state = ISCSI_STATE_TERMINATE;
1551                 wake_up(&conn->ehwait);
1552         }
1553         spin_unlock_bh(&session->lock);
1554
1555         mutex_unlock(&conn->xmitmutex);
1556
1557         /*
1558          * Block until all in-progress commands for this connection
1559          * time out or fail.
1560          */
1561         for (;;) {
1562                 spin_lock_irqsave(session->host->host_lock, flags);
1563                 if (!session->host->host_busy) { /* OK for ERL == 0 */
1564                         spin_unlock_irqrestore(session->host->host_lock, flags);
1565                         break;
1566                 }
1567                 spin_unlock_irqrestore(session->host->host_lock, flags);
1568                 msleep_interruptible(500);
1569                 printk(KERN_INFO "iscsi: scsi conn_destroy(): host_busy %d "
1570                        "host_failed %d\n", session->host->host_busy,
1571                        session->host->host_failed);
1572                 /*
1573                  * force eh_abort() to unblock
1574                  */
1575                 wake_up(&conn->ehwait);
1576         }
1577
1578         spin_lock_bh(&session->lock);
1579         kfree(conn->data);
1580         kfree(conn->persistent_address);
1581         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1582                     sizeof(void*));
1583         list_del(&conn->item);
1584         if (list_empty(&session->connections))
1585                 session->leadconn = NULL;
1586         if (session->leadconn && session->leadconn == conn)
1587                 session->leadconn = container_of(session->connections.next,
1588                         struct iscsi_conn, item);
1589
1590         if (session->leadconn == NULL)
1591                 /* no connections exits.. reset sequencing */
1592                 session->cmdsn = session->max_cmdsn = session->exp_cmdsn = 1;
1593         spin_unlock_bh(&session->lock);
1594
1595         kfifo_free(conn->immqueue);
1596         kfifo_free(conn->mgmtqueue);
1597
1598         iscsi_destroy_conn(cls_conn);
1599 }
1600 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
1601
1602 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
1603 {
1604         struct iscsi_conn *conn = cls_conn->dd_data;
1605         struct iscsi_session *session = conn->session;
1606
1607         if (!session) {
1608                 printk(KERN_ERR "iscsi: can't start unbound connection\n");
1609                 return -EPERM;
1610         }
1611
1612         if ((session->imm_data_en || !session->initial_r2t_en) &&
1613              session->first_burst > session->max_burst) {
1614                 printk("iscsi: invalid burst lengths: "
1615                        "first_burst %d max_burst %d\n",
1616                        session->first_burst, session->max_burst);
1617                 return -EINVAL;
1618         }
1619
1620         spin_lock_bh(&session->lock);
1621         conn->c_stage = ISCSI_CONN_STARTED;
1622         session->state = ISCSI_STATE_LOGGED_IN;
1623
1624         switch(conn->stop_stage) {
1625         case STOP_CONN_RECOVER:
1626                 /*
1627                  * unblock eh_abort() if it is blocked. re-try all
1628                  * commands after successful recovery
1629                  */
1630                 conn->stop_stage = 0;
1631                 conn->tmabort_state = TMABORT_INITIAL;
1632                 session->age++;
1633                 spin_unlock_bh(&session->lock);
1634
1635                 iscsi_unblock_session(session_to_cls(session));
1636                 wake_up(&conn->ehwait);
1637                 return 0;
1638         case STOP_CONN_TERM:
1639                 conn->stop_stage = 0;
1640                 break;
1641         default:
1642                 break;
1643         }
1644         spin_unlock_bh(&session->lock);
1645
1646         return 0;
1647 }
1648 EXPORT_SYMBOL_GPL(iscsi_conn_start);
1649
1650 static void
1651 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
1652 {
1653         struct iscsi_mgmt_task *mtask, *tmp;
1654
1655         /* handle pending */
1656         while (__kfifo_get(conn->immqueue, (void*)&mtask, sizeof(void*)) ||
1657                __kfifo_get(conn->mgmtqueue, (void*)&mtask, sizeof(void*))) {
1658                 if (mtask == conn->login_mtask)
1659                         continue;
1660                 debug_scsi("flushing pending mgmt task itt 0x%x\n", mtask->itt);
1661                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1662                             sizeof(void*));
1663         }
1664
1665         /* handle running */
1666         list_for_each_entry_safe(mtask, tmp, &conn->mgmt_run_list, running) {
1667                 debug_scsi("flushing running mgmt task itt 0x%x\n", mtask->itt);
1668                 list_del(&mtask->running);
1669
1670                 if (mtask == conn->login_mtask)
1671                         continue;
1672                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1673                            sizeof(void*));
1674         }
1675
1676         conn->mtask = NULL;
1677 }
1678
1679 /* Fail commands. Mutex and session lock held and recv side suspended */
1680 static void fail_all_commands(struct iscsi_conn *conn)
1681 {
1682         struct iscsi_cmd_task *ctask, *tmp;
1683
1684         /* flush pending */
1685         list_for_each_entry_safe(ctask, tmp, &conn->xmitqueue, running) {
1686                 debug_scsi("failing pending sc %p itt 0x%x\n", ctask->sc,
1687                            ctask->itt);
1688                 fail_command(conn, ctask, DID_BUS_BUSY << 16);
1689         }
1690
1691         /* fail all other running */
1692         list_for_each_entry_safe(ctask, tmp, &conn->run_list, running) {
1693                 debug_scsi("failing in progress sc %p itt 0x%x\n",
1694                            ctask->sc, ctask->itt);
1695                 fail_command(conn, ctask, DID_BUS_BUSY << 16);
1696         }
1697
1698         conn->ctask = NULL;
1699 }
1700
1701 static void iscsi_start_session_recovery(struct iscsi_session *session,
1702                                          struct iscsi_conn *conn, int flag)
1703 {
1704         int old_stop_stage;
1705
1706         spin_lock_bh(&session->lock);
1707         if (conn->stop_stage == STOP_CONN_TERM) {
1708                 spin_unlock_bh(&session->lock);
1709                 return;
1710         }
1711
1712         /*
1713          * When this is called for the in_login state, we only want to clean
1714          * up the login task and connection. We do not need to block and set
1715          * the recovery state again
1716          */
1717         if (flag == STOP_CONN_TERM)
1718                 session->state = ISCSI_STATE_TERMINATE;
1719         else if (conn->stop_stage != STOP_CONN_RECOVER)
1720                 session->state = ISCSI_STATE_IN_RECOVERY;
1721
1722         old_stop_stage = conn->stop_stage;
1723         conn->stop_stage = flag;
1724         conn->c_stage = ISCSI_CONN_STOPPED;
1725         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1726         spin_unlock_bh(&session->lock);
1727
1728         write_lock_bh(conn->recv_lock);
1729         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1730         write_unlock_bh(conn->recv_lock);
1731
1732         mutex_lock(&conn->xmitmutex);
1733         /*
1734          * for connection level recovery we should not calculate
1735          * header digest. conn->hdr_size used for optimization
1736          * in hdr_extract() and will be re-negotiated at
1737          * set_param() time.
1738          */
1739         if (flag == STOP_CONN_RECOVER) {
1740                 conn->hdrdgst_en = 0;
1741                 conn->datadgst_en = 0;
1742                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
1743                     old_stop_stage != STOP_CONN_RECOVER) {
1744                         debug_scsi("blocking session\n");
1745                         iscsi_block_session(session_to_cls(session));
1746                 }
1747         }
1748
1749         /*
1750          * flush queues.
1751          */
1752         spin_lock_bh(&session->lock);
1753         fail_all_commands(conn);
1754         flush_control_queues(session, conn);
1755         spin_unlock_bh(&session->lock);
1756
1757         mutex_unlock(&conn->xmitmutex);
1758 }
1759
1760 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1761 {
1762         struct iscsi_conn *conn = cls_conn->dd_data;
1763         struct iscsi_session *session = conn->session;
1764
1765         switch (flag) {
1766         case STOP_CONN_RECOVER:
1767         case STOP_CONN_TERM:
1768                 iscsi_start_session_recovery(session, conn, flag);
1769                 break;
1770         default:
1771                 printk(KERN_ERR "iscsi: invalid stop flag %d\n", flag);
1772         }
1773 }
1774 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
1775
1776 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
1777                     struct iscsi_cls_conn *cls_conn, int is_leading)
1778 {
1779         struct iscsi_session *session = class_to_transport_session(cls_session);
1780         struct iscsi_conn *tmp = ERR_PTR(-EEXIST), *conn = cls_conn->dd_data;
1781
1782         /* lookup for existing connection */
1783         spin_lock_bh(&session->lock);
1784         list_for_each_entry(tmp, &session->connections, item) {
1785                 if (tmp == conn) {
1786                         if (conn->c_stage != ISCSI_CONN_STOPPED ||
1787                             conn->stop_stage == STOP_CONN_TERM) {
1788                                 printk(KERN_ERR "iscsi: can't bind "
1789                                        "non-stopped connection (%d:%d)\n",
1790                                        conn->c_stage, conn->stop_stage);
1791                                 spin_unlock_bh(&session->lock);
1792                                 return -EIO;
1793                         }
1794                         break;
1795                 }
1796         }
1797         if (tmp != conn) {
1798                 /* bind new iSCSI connection to session */
1799                 conn->session = session;
1800                 list_add(&conn->item, &session->connections);
1801         }
1802         spin_unlock_bh(&session->lock);
1803
1804         if (is_leading)
1805                 session->leadconn = conn;
1806
1807         /*
1808          * Unblock xmitworker(), Login Phase will pass through.
1809          */
1810         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1811         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1812         return 0;
1813 }
1814 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
1815
1816
1817 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
1818                     enum iscsi_param param, char *buf, int buflen)
1819 {
1820         struct iscsi_conn *conn = cls_conn->dd_data;
1821         struct iscsi_session *session = conn->session;
1822         uint32_t value;
1823
1824         switch(param) {
1825         case ISCSI_PARAM_MAX_RECV_DLENGTH:
1826                 sscanf(buf, "%d", &conn->max_recv_dlength);
1827                 break;
1828         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
1829                 sscanf(buf, "%d", &conn->max_xmit_dlength);
1830                 break;
1831         case ISCSI_PARAM_HDRDGST_EN:
1832                 sscanf(buf, "%d", &conn->hdrdgst_en);
1833                 break;
1834         case ISCSI_PARAM_DATADGST_EN:
1835                 sscanf(buf, "%d", &conn->datadgst_en);
1836                 break;
1837         case ISCSI_PARAM_INITIAL_R2T_EN:
1838                 sscanf(buf, "%d", &session->initial_r2t_en);
1839                 break;
1840         case ISCSI_PARAM_MAX_R2T:
1841                 sscanf(buf, "%d", &session->max_r2t);
1842                 break;
1843         case ISCSI_PARAM_IMM_DATA_EN:
1844                 sscanf(buf, "%d", &session->imm_data_en);
1845                 break;
1846         case ISCSI_PARAM_FIRST_BURST:
1847                 sscanf(buf, "%d", &session->first_burst);
1848                 break;
1849         case ISCSI_PARAM_MAX_BURST:
1850                 sscanf(buf, "%d", &session->max_burst);
1851                 break;
1852         case ISCSI_PARAM_PDU_INORDER_EN:
1853                 sscanf(buf, "%d", &session->pdu_inorder_en);
1854                 break;
1855         case ISCSI_PARAM_DATASEQ_INORDER_EN:
1856                 sscanf(buf, "%d", &session->dataseq_inorder_en);
1857                 break;
1858         case ISCSI_PARAM_ERL:
1859                 sscanf(buf, "%d", &session->erl);
1860                 break;
1861         case ISCSI_PARAM_IFMARKER_EN:
1862                 sscanf(buf, "%d", &value);
1863                 BUG_ON(value);
1864                 break;
1865         case ISCSI_PARAM_OFMARKER_EN:
1866                 sscanf(buf, "%d", &value);
1867                 BUG_ON(value);
1868                 break;
1869         case ISCSI_PARAM_EXP_STATSN:
1870                 sscanf(buf, "%u", &conn->exp_statsn);
1871                 break;
1872         case ISCSI_PARAM_TARGET_NAME:
1873                 /* this should not change between logins */
1874                 if (session->targetname)
1875                         break;
1876
1877                 session->targetname = kstrdup(buf, GFP_KERNEL);
1878                 if (!session->targetname)
1879                         return -ENOMEM;
1880                 break;
1881         case ISCSI_PARAM_TPGT:
1882                 sscanf(buf, "%d", &session->tpgt);
1883                 break;
1884         case ISCSI_PARAM_PERSISTENT_PORT:
1885                 sscanf(buf, "%d", &conn->persistent_port);
1886                 break;
1887         case ISCSI_PARAM_PERSISTENT_ADDRESS:
1888                 /*
1889                  * this is the address returned in discovery so it should
1890                  * not change between logins.
1891                  */
1892                 if (conn->persistent_address)
1893                         break;
1894
1895                 conn->persistent_address = kstrdup(buf, GFP_KERNEL);
1896                 if (!conn->persistent_address)
1897                         return -ENOMEM;
1898                 break;
1899         default:
1900                 return -ENOSYS;
1901         }
1902
1903         return 0;
1904 }
1905 EXPORT_SYMBOL_GPL(iscsi_set_param);
1906
1907 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
1908                             enum iscsi_param param, char *buf)
1909 {
1910         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1911         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1912         int len;
1913
1914         switch(param) {
1915         case ISCSI_PARAM_INITIAL_R2T_EN:
1916                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
1917                 break;
1918         case ISCSI_PARAM_MAX_R2T:
1919                 len = sprintf(buf, "%hu\n", session->max_r2t);
1920                 break;
1921         case ISCSI_PARAM_IMM_DATA_EN:
1922                 len = sprintf(buf, "%d\n", session->imm_data_en);
1923                 break;
1924         case ISCSI_PARAM_FIRST_BURST:
1925                 len = sprintf(buf, "%u\n", session->first_burst);
1926                 break;
1927         case ISCSI_PARAM_MAX_BURST:
1928                 len = sprintf(buf, "%u\n", session->max_burst);
1929                 break;
1930         case ISCSI_PARAM_PDU_INORDER_EN:
1931                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
1932                 break;
1933         case ISCSI_PARAM_DATASEQ_INORDER_EN:
1934                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
1935                 break;
1936         case ISCSI_PARAM_ERL:
1937                 len = sprintf(buf, "%d\n", session->erl);
1938                 break;
1939         case ISCSI_PARAM_TARGET_NAME:
1940                 len = sprintf(buf, "%s\n", session->targetname);
1941                 break;
1942         case ISCSI_PARAM_TPGT:
1943                 len = sprintf(buf, "%d\n", session->tpgt);
1944                 break;
1945         default:
1946                 return -ENOSYS;
1947         }
1948
1949         return len;
1950 }
1951 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
1952
1953 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
1954                          enum iscsi_param param, char *buf)
1955 {
1956         struct iscsi_conn *conn = cls_conn->dd_data;
1957         int len;
1958
1959         switch(param) {
1960         case ISCSI_PARAM_MAX_RECV_DLENGTH:
1961                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
1962                 break;
1963         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
1964                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
1965                 break;
1966         case ISCSI_PARAM_HDRDGST_EN:
1967                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
1968                 break;
1969         case ISCSI_PARAM_DATADGST_EN:
1970                 len = sprintf(buf, "%d\n", conn->datadgst_en);
1971                 break;
1972         case ISCSI_PARAM_IFMARKER_EN:
1973                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
1974                 break;
1975         case ISCSI_PARAM_OFMARKER_EN:
1976                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
1977                 break;
1978         case ISCSI_PARAM_EXP_STATSN:
1979                 len = sprintf(buf, "%u\n", conn->exp_statsn);
1980                 break;
1981         case ISCSI_PARAM_PERSISTENT_PORT:
1982                 len = sprintf(buf, "%d\n", conn->persistent_port);
1983                 break;
1984         case ISCSI_PARAM_PERSISTENT_ADDRESS:
1985                 len = sprintf(buf, "%s\n", conn->persistent_address);
1986                 break;
1987         default:
1988                 return -ENOSYS;
1989         }
1990
1991         return len;
1992 }
1993 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
1994
1995 MODULE_AUTHOR("Mike Christie");
1996 MODULE_DESCRIPTION("iSCSI library functions");
1997 MODULE_LICENSE("GPL");