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   1 /*
   2  * iSCSI lib functions
   3  *
   4  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   5  * Copyright (C) 2004 - 2006 Mike Christie
   6  * Copyright (C) 2004 - 2005 Dmitry Yusupov
   7  * Copyright (C) 2004 - 2005 Alex Aizman
   8  * maintained by open-iscsi@googlegroups.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  */
  24 #include <linux/types.h>
  25 #include <linux/kfifo.h>
  26 #include <linux/delay.h>
  27 #include <asm/unaligned.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 static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
  41                          int err);
  42
  43 struct iscsi_session *
  44 class_to_transport_session(struct iscsi_cls_session *cls_session)
  45 {
  46         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
  47         return iscsi_hostdata(shost->hostdata);
  48 }
  49 EXPORT_SYMBOL_GPL(class_to_transport_session);
  50
  51 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
  52 #define SNA32_CHECK 2147483648UL
  53
  54 static int iscsi_sna_lt(u32 n1, u32 n2)
  55 {
  56         return n1 != n2 && ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
  57                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
  58 }
  59
  60 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
  61 static int iscsi_sna_lte(u32 n1, u32 n2)
  62 {
  63         return n1 == n2 || ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
  64                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
  65 }
  66
  67 void
  68 iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
  69 {
  70         uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
  71         uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);
  72
  73         /*
  74          * standard specifies this check for when to update expected and
  75          * max sequence numbers
  76          */
  77         if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
  78                 return;
  79
  80         if (exp_cmdsn != session->exp_cmdsn &&
  81             !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
  82                 session->exp_cmdsn = exp_cmdsn;
  83
  84         if (max_cmdsn != session->max_cmdsn &&
  85             !iscsi_sna_lt(max_cmdsn, session->max_cmdsn)) {
  86                 session->max_cmdsn = max_cmdsn;
  87                 /*
  88                  * if the window closed with IO queued, then kick the
  89                  * xmit thread
  90                  */
  91                 if (!list_empty(&session->leadconn->xmitqueue) ||
  92                     !list_empty(&session->leadconn->mgmtqueue))
  93                         scsi_queue_work(session->host,
  94                                         &session->leadconn->xmitwork);
  95         }
  96 }
  97 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
  98
  99 void iscsi_prep_unsolicit_data_pdu(struct iscsi_cmd_task *ctask,
 100                                    struct iscsi_data *hdr)
 101 {
 102         struct iscsi_conn *conn = ctask->conn;
 103
 104         memset(hdr, 0, sizeof(struct iscsi_data));
 105         hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 106         hdr->datasn = cpu_to_be32(ctask->unsol_datasn);
 107         ctask->unsol_datasn++;
 108         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 109         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
 110
 111         hdr->itt = ctask->hdr->itt;
 112         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 113         hdr->offset = cpu_to_be32(ctask->unsol_offset);
 114
 115         if (ctask->unsol_count > conn->max_xmit_dlength) {
 116                 hton24(hdr->dlength, conn->max_xmit_dlength);
 117                 ctask->data_count = conn->max_xmit_dlength;
 118                 ctask->unsol_offset += ctask->data_count;
 119                 hdr->flags = 0;
 120         } else {
 121                 hton24(hdr->dlength, ctask->unsol_count);
 122                 ctask->data_count = ctask->unsol_count;
 123                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 124         }
 125 }
 126 EXPORT_SYMBOL_GPL(iscsi_prep_unsolicit_data_pdu);
 127
 128 static int iscsi_add_hdr(struct iscsi_cmd_task *ctask, unsigned len)
 129 {
 130         unsigned exp_len = ctask->hdr_len + len;
 131
 132         if (exp_len > ctask->hdr_max) {
 133                 WARN_ON(1);
 134                 return -EINVAL;
 135         }
 136
 137         WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 138         ctask->hdr_len = exp_len;
 139         return 0;
 140 }
 141
 142 /**
 143  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 144  * @ctask: iscsi cmd task
 145  *
 146  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 147  * fields like dlength or final based on how much data it sends
 148  */
 149 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
 150 {
 151         struct iscsi_conn *conn = ctask->conn;
 152         struct iscsi_session *session = conn->session;
 153         struct iscsi_cmd *hdr = ctask->hdr;
 154         struct scsi_cmnd *sc = ctask->sc;
 155         unsigned hdrlength;
 156         int rc;
 157
 158         ctask->hdr_len = 0;
 159         rc = iscsi_add_hdr(ctask, sizeof(*hdr));
 160         if (rc)
 161                 return rc;
 162         hdr->opcode = ISCSI_OP_SCSI_CMD;
 163         hdr->flags = ISCSI_ATTR_SIMPLE;
 164         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
 165         hdr->itt = build_itt(ctask->itt, conn->id, session->age);
 166         hdr->data_length = cpu_to_be32(scsi_bufflen(sc));
 167         hdr->cmdsn = cpu_to_be32(session->cmdsn);
 168         session->cmdsn++;
 169         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 170         memcpy(hdr->cdb, sc->cmnd, sc->cmd_len);
 171         if (sc->cmd_len < MAX_COMMAND_SIZE)
 172                 memset(&hdr->cdb[sc->cmd_len], 0,
 173                         MAX_COMMAND_SIZE - sc->cmd_len);
 174
 175         ctask->data_count = 0;
 176         ctask->imm_count = 0;
 177         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 178                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 179                 /*
 180                  * Write counters:
 181                  *
 182                  *      imm_count       bytes to be sent right after
 183                  *                      SCSI PDU Header
 184                  *
 185                  *      unsol_count     bytes(as Data-Out) to be sent
 186                  *                      without R2T ack right after
 187                  *                      immediate data
 188                  *
 189                  *      r2t_data_count  bytes to be sent via R2T ack's
 190                  *
 191                  *      pad_count       bytes to be sent as zero-padding
 192                  */
 193                 ctask->unsol_count = 0;
 194                 ctask->unsol_offset = 0;
 195                 ctask->unsol_datasn = 0;
 196
 197                 if (session->imm_data_en) {
 198                         if (scsi_bufflen(sc) >= session->first_burst)
 199                                 ctask->imm_count = min(session->first_burst,
 200                                                         conn->max_xmit_dlength);
 201                         else
 202                                 ctask->imm_count = min(scsi_bufflen(sc),
 203                                                         conn->max_xmit_dlength);
 204                         hton24(ctask->hdr->dlength, ctask->imm_count);
 205                 } else
 206                         zero_data(ctask->hdr->dlength);
 207
 208                 if (!session->initial_r2t_en) {
 209                         ctask->unsol_count = min((session->first_burst),
 210                                 (scsi_bufflen(sc))) - ctask->imm_count;
 211                         ctask->unsol_offset = ctask->imm_count;
 212                 }
 213
 214                 if (!ctask->unsol_count)
 215                         /* No unsolicit Data-Out's */
 216                         ctask->hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 217         } else {
 218                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 219                 zero_data(hdr->dlength);
 220
 221                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
 222                         hdr->flags |= ISCSI_FLAG_CMD_READ;
 223         }
 224
 225         /* calculate size of additional header segments (AHSs) */
 226         hdrlength = ctask->hdr_len - sizeof(*hdr);
 227
 228         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 229         hdrlength /= ISCSI_PAD_LEN;
 230
 231         WARN_ON(hdrlength >= 256);
 232         hdr->hlength = hdrlength & 0xFF;
 233
 234         conn->scsicmd_pdus_cnt++;
 235
 236         debug_scsi("iscsi prep [%s cid %d sc %p cdb 0x%x itt 0x%x len %d "
 237                 "cmdsn %d win %d]\n",
 238                 sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
 239                 conn->id, sc, sc->cmnd[0], ctask->itt, scsi_bufflen(sc),
 240                 session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
 241         return 0;
 242 }
 243
 244 /**
 245  * iscsi_complete_command - return command back to scsi-ml
 246  * @ctask: iscsi cmd task
 247  *
 248  * Must be called with session lock.
 249  * This function returns the scsi command to scsi-ml and returns
 250  * the cmd task to the pool of available cmd tasks.
 251  */
 252 static void iscsi_complete_command(struct iscsi_cmd_task *ctask)
 253 {
 254         struct iscsi_session *session = ctask->conn->session;
 255         struct scsi_cmnd *sc = ctask->sc;
 256
 257         ctask->state = ISCSI_TASK_COMPLETED;
 258         ctask->sc = NULL;
 259         /* SCSI eh reuses commands to verify us */
 260         sc->SCp.ptr = NULL;
 261         list_del_init(&ctask->running);
 262         __kfifo_put(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
 263         sc->scsi_done(sc);
 264 }
 265
 266 static void __iscsi_get_ctask(struct iscsi_cmd_task *ctask)
 267 {
 268         atomic_inc(&ctask->refcount);
 269 }
 270
 271 static void __iscsi_put_ctask(struct iscsi_cmd_task *ctask)
 272 {
 273         if (atomic_dec_and_test(&ctask->refcount))
 274                 iscsi_complete_command(ctask);
 275 }
 276
 277 /**
 278  * iscsi_cmd_rsp - SCSI Command Response processing
 279  * @conn: iscsi connection
 280  * @hdr: iscsi header
 281  * @ctask: scsi command task
 282  * @data: cmd data buffer
 283  * @datalen: len of buffer
 284  *
 285  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 286  * then completes the command and task.
 287  **/
 288 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 289                                struct iscsi_cmd_task *ctask, char *data,
 290                                int datalen)
 291 {
 292         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
 293         struct iscsi_session *session = conn->session;
 294         struct scsi_cmnd *sc = ctask->sc;
 295
 296         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 297         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 298
 299         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 300
 301         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 302                 sc->result = DID_ERROR << 16;
 303                 goto out;
 304         }
 305
 306         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 307                 uint16_t senselen;
 308
 309                 if (datalen < 2) {
 310 invalid_datalen:
 311                         printk(KERN_ERR "iscsi: Got CHECK_CONDITION but "
 312                                "invalid data buffer size of %d\n", datalen);
 313                         sc->result = DID_BAD_TARGET << 16;
 314                         goto out;
 315                 }
 316
 317                 senselen = be16_to_cpu(get_unaligned((__be16 *) data));
 318                 if (datalen < senselen)
 319                         goto invalid_datalen;
 320
 321                 memcpy(sc->sense_buffer, data + 2,
 322                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 323                 debug_scsi("copied %d bytes of sense\n",
 324                            min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 325         }
 326
 327         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 328                            ISCSI_FLAG_CMD_OVERFLOW)) {
 329                 int res_count = be32_to_cpu(rhdr->residual_count);
 330
 331                 if (res_count > 0 &&
 332                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 333                      res_count <= scsi_bufflen(sc)))
 334                         scsi_set_resid(sc, res_count);
 335                 else
 336                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 337         } else if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 338                                   ISCSI_FLAG_CMD_BIDI_OVERFLOW))
 339                 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 340
 341 out:
 342         debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 343                    (long)sc, sc->result, ctask->itt);
 344         conn->scsirsp_pdus_cnt++;
 345
 346         __iscsi_put_ctask(ctask);
 347 }
 348
 349 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 350 {
 351         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 352
 353         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 354         conn->tmfrsp_pdus_cnt++;
 355
 356         if (conn->tmf_state != TMF_QUEUED)
 357                 return;
 358
 359         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 360                 conn->tmf_state = TMF_SUCCESS;
 361         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 362                 conn->tmf_state = TMF_NOT_FOUND;
 363         else
 364                 conn->tmf_state = TMF_FAILED;
 365         wake_up(&conn->ehwait);
 366 }
 367
 368 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 369                                char *data, int datalen)
 370 {
 371         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
 372         struct iscsi_hdr rejected_pdu;
 373         uint32_t itt;
 374
 375         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
 376
 377         if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
 378                 if (ntoh24(reject->dlength) > datalen)
 379                         return ISCSI_ERR_PROTO;
 380
 381                 if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
 382                         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
 383                         itt = get_itt(rejected_pdu.itt);
 384                         printk(KERN_ERR "itt 0x%x had pdu (op 0x%x) rejected "
 385                                 "due to DataDigest error.\n", itt,
 386                                 rejected_pdu.opcode);
 387                 }
 388         }
 389         return 0;
 390 }
 391
 392 /**
 393  * __iscsi_complete_pdu - complete pdu
 394  * @conn: iscsi conn
 395  * @hdr: iscsi header
 396  * @data: data buffer
 397  * @datalen: len of data buffer
 398  *
 399  * Completes pdu processing by freeing any resources allocated at
 400  * queuecommand or send generic. session lock must be held and verify
 401  * itt must have been called.
 402  */
 403 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 404                          char *data, int datalen)
 405 {
 406         struct iscsi_session *session = conn->session;
 407         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
 408         struct iscsi_cmd_task *ctask;
 409         struct iscsi_mgmt_task *mtask;
 410         uint32_t itt;
 411
 412         if (hdr->itt != RESERVED_ITT)
 413                 itt = get_itt(hdr->itt);
 414         else
 415                 itt = ~0U;
 416
 417         if (itt < session->cmds_max) {
 418                 ctask = session->cmds[itt];
 419
 420                 debug_scsi("cmdrsp [op 0x%x cid %d itt 0x%x len %d]\n",
 421                            opcode, conn->id, ctask->itt, datalen);
 422
 423                 switch(opcode) {
 424                 case ISCSI_OP_SCSI_CMD_RSP:
 425                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 426                         iscsi_scsi_cmd_rsp(conn, hdr, ctask, data,
 427                                            datalen);
 428                         break;
 429                 case ISCSI_OP_SCSI_DATA_IN:
 430                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 431                         if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
 432                                 conn->scsirsp_pdus_cnt++;
 433                                 __iscsi_put_ctask(ctask);
 434                         }
 435                         break;
 436                 case ISCSI_OP_R2T:
 437                         /* LLD handles this for now */
 438                         break;
 439                 default:
 440                         rc = ISCSI_ERR_BAD_OPCODE;
 441                         break;
 442                 }
 443         } else if (itt >= ISCSI_MGMT_ITT_OFFSET &&
 444                    itt < ISCSI_MGMT_ITT_OFFSET + session->mgmtpool_max) {
 445                 mtask = session->mgmt_cmds[itt - ISCSI_MGMT_ITT_OFFSET];
 446
 447                 debug_scsi("immrsp [op 0x%x cid %d itt 0x%x len %d]\n",
 448                            opcode, conn->id, mtask->itt, datalen);
 449
 450                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 451                 switch(opcode) {
 452                 case ISCSI_OP_LOGOUT_RSP:
 453                         if (datalen) {
 454                                 rc = ISCSI_ERR_PROTO;
 455                                 break;
 456                         }
 457                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 458                         /* fall through */
 459                 case ISCSI_OP_LOGIN_RSP:
 460                 case ISCSI_OP_TEXT_RSP:
 461                         /*
 462                          * login related PDU's exp_statsn is handled in
 463                          * userspace
 464                          */
 465                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 466                                 rc = ISCSI_ERR_CONN_FAILED;
 467                         list_del_init(&mtask->running);
 468                         if (conn->login_mtask != mtask)
 469                                 __kfifo_put(session->mgmtpool.queue,
 470                                             (void*)&mtask, sizeof(void*));
 471                         break;
 472                 case ISCSI_OP_SCSI_TMFUNC_RSP:
 473                         if (datalen) {
 474                                 rc = ISCSI_ERR_PROTO;
 475                                 break;
 476                         }
 477
 478                         iscsi_tmf_rsp(conn, hdr);
 479                         break;
 480                 case ISCSI_OP_NOOP_IN:
 481                         if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
 482                                 rc = ISCSI_ERR_PROTO;
 483                                 break;
 484                         }
 485                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 486
 487                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 488                                 rc = ISCSI_ERR_CONN_FAILED;
 489                         list_del_init(&mtask->running);
 490                         __kfifo_put(session->mgmtpool.queue,
 491                                     (void*)&mtask, sizeof(void*));
 492                         break;
 493                 default:
 494                         rc = ISCSI_ERR_BAD_OPCODE;
 495                         break;
 496                 }
 497         } else if (itt == ~0U) {
 498                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 499
 500                 switch(opcode) {
 501                 case ISCSI_OP_NOOP_IN:
 502                         if (datalen) {
 503                                 rc = ISCSI_ERR_PROTO;
 504                                 break;
 505                         }
 506
 507                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
 508                                 break;
 509
 510                         if (iscsi_recv_pdu(conn->cls_conn, hdr, NULL, 0))
 511                                 rc = ISCSI_ERR_CONN_FAILED;
 512                         break;
 513                 case ISCSI_OP_REJECT:
 514                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
 515                         break;
 516                 case ISCSI_OP_ASYNC_EVENT:
 517                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 518                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 519                                 rc = ISCSI_ERR_CONN_FAILED;
 520                         break;
 521                 default:
 522                         rc = ISCSI_ERR_BAD_OPCODE;
 523                         break;
 524                 }
 525         } else
 526                 rc = ISCSI_ERR_BAD_ITT;
 527
 528         return rc;
 529 }
 530 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
 531
 532 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 533                        char *data, int datalen)
 534 {
 535         int rc;
 536
 537         spin_lock(&conn->session->lock);
 538         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
 539         spin_unlock(&conn->session->lock);
 540         return rc;
 541 }
 542 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
 543
 544 /* verify itt (itt encoding: age+cid+itt) */
 545 int iscsi_verify_itt(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 546                      uint32_t *ret_itt)
 547 {
 548         struct iscsi_session *session = conn->session;
 549         struct iscsi_cmd_task *ctask;
 550         uint32_t itt;
 551
 552         if (hdr->itt != RESERVED_ITT) {
 553                 if (((__force u32)hdr->itt & ISCSI_AGE_MASK) !=
 554                     (session->age << ISCSI_AGE_SHIFT)) {
 555                         printk(KERN_ERR "iscsi: received itt %x expected "
 556                                 "session age (%x)\n", (__force u32)hdr->itt,
 557                                 session->age & ISCSI_AGE_MASK);
 558                         return ISCSI_ERR_BAD_ITT;
 559                 }
 560
 561                 if (((__force u32)hdr->itt & ISCSI_CID_MASK) !=
 562                     (conn->id << ISCSI_CID_SHIFT)) {
 563                         printk(KERN_ERR "iscsi: received itt %x, expected "
 564                                 "CID (%x)\n", (__force u32)hdr->itt, conn->id);
 565                         return ISCSI_ERR_BAD_ITT;
 566                 }
 567                 itt = get_itt(hdr->itt);
 568         } else
 569                 itt = ~0U;
 570
 571         if (itt < session->cmds_max) {
 572                 ctask = session->cmds[itt];
 573
 574                 if (!ctask->sc) {
 575                         printk(KERN_INFO "iscsi: dropping ctask with "
 576                                "itt 0x%x\n", ctask->itt);
 577                         /* force drop */
 578                         return ISCSI_ERR_NO_SCSI_CMD;
 579                 }
 580
 581                 if (ctask->sc->SCp.phase != session->age) {
 582                         printk(KERN_ERR "iscsi: ctask's session age %d, "
 583                                 "expected %d\n", ctask->sc->SCp.phase,
 584                                 session->age);
 585                         return ISCSI_ERR_SESSION_FAILED;
 586                 }
 587         }
 588
 589         *ret_itt = itt;
 590         return 0;
 591 }
 592 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
 593
 594 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
 595 {
 596         struct iscsi_session *session = conn->session;
 597         unsigned long flags;
 598
 599         spin_lock_irqsave(&session->lock, flags);
 600         if (session->state == ISCSI_STATE_FAILED) {
 601                 spin_unlock_irqrestore(&session->lock, flags);
 602                 return;
 603         }
 604
 605         if (conn->stop_stage == 0)
 606                 session->state = ISCSI_STATE_FAILED;
 607         spin_unlock_irqrestore(&session->lock, flags);
 608         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
 609         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
 610         iscsi_conn_error(conn->cls_conn, err);
 611 }
 612 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
 613
 614 static void iscsi_prep_mtask(struct iscsi_conn *conn,
 615                              struct iscsi_mgmt_task *mtask)
 616 {
 617         struct iscsi_session *session = conn->session;
 618         struct iscsi_hdr *hdr = mtask->hdr;
 619         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 620
 621         if (hdr->opcode != (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) &&
 622             hdr->opcode != (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 623                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 624         /*
 625          * pre-format CmdSN for outgoing PDU.
 626          */
 627         nop->cmdsn = cpu_to_be32(session->cmdsn);
 628         if (hdr->itt != RESERVED_ITT) {
 629                 hdr->itt = build_itt(mtask->itt, conn->id, session->age);
 630                 /*
 631                  * TODO: We always use immediate, so we never hit this.
 632                  * If we start to send tmfs or nops as non-immediate then
 633                  * we should start checking the cmdsn numbers for mgmt tasks.
 634                  */
 635                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 636                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 637                         session->queued_cmdsn++;
 638                         session->cmdsn++;
 639                 }
 640         }
 641
 642         if (session->tt->init_mgmt_task)
 643                 session->tt->init_mgmt_task(conn, mtask);
 644
 645         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
 646                    hdr->opcode & ISCSI_OPCODE_MASK, hdr->itt,
 647                    mtask->data_count);
 648 }
 649
 650 static int iscsi_xmit_mtask(struct iscsi_conn *conn)
 651 {
 652         struct iscsi_hdr *hdr = conn->mtask->hdr;
 653         int rc, was_logout = 0;
 654
 655         spin_unlock_bh(&conn->session->lock);
 656         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT) {
 657                 conn->session->state = ISCSI_STATE_IN_RECOVERY;
 658                 iscsi_block_session(session_to_cls(conn->session));
 659                 was_logout = 1;
 660         }
 661         rc = conn->session->tt->xmit_mgmt_task(conn, conn->mtask);
 662         spin_lock_bh(&conn->session->lock);
 663         if (rc)
 664                 return rc;
 665
 666         /* done with this in-progress mtask */
 667         conn->mtask = NULL;
 668
 669         if (was_logout) {
 670                 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
 671                 return -ENODATA;
 672         }
 673         return 0;
 674 }
 675
 676 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
 677 {
 678         struct iscsi_session *session = conn->session;
 679
 680         /*
 681          * Check for iSCSI window and take care of CmdSN wrap-around
 682          */
 683         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
 684                 debug_scsi("iSCSI CmdSN closed. ExpCmdSn %u MaxCmdSN %u "
 685                            "CmdSN %u/%u\n", session->exp_cmdsn,
 686                            session->max_cmdsn, session->cmdsn,
 687                            session->queued_cmdsn);
 688                 return -ENOSPC;
 689         }
 690         return 0;
 691 }
 692
 693 static int iscsi_xmit_ctask(struct iscsi_conn *conn)
 694 {
 695         struct iscsi_cmd_task *ctask = conn->ctask;
 696         int rc;
 697
 698         __iscsi_get_ctask(ctask);
 699         spin_unlock_bh(&conn->session->lock);
 700         rc = conn->session->tt->xmit_cmd_task(conn, ctask);
 701         spin_lock_bh(&conn->session->lock);
 702         __iscsi_put_ctask(ctask);
 703         if (!rc)
 704                 /* done with this ctask */
 705                 conn->ctask = NULL;
 706         return rc;
 707 }
 708
 709 /**
 710  * iscsi_requeue_ctask - requeue ctask to run from session workqueue
 711  * @ctask: ctask to requeue
 712  *
 713  * LLDs that need to run a ctask from the session workqueue should call
 714  * this. The session lock must be held.
 715  */
 716 void iscsi_requeue_ctask(struct iscsi_cmd_task *ctask)
 717 {
 718         struct iscsi_conn *conn = ctask->conn;
 719
 720         list_move_tail(&ctask->running, &conn->requeue);
 721         scsi_queue_work(conn->session->host, &conn->xmitwork);
 722 }
 723 EXPORT_SYMBOL_GPL(iscsi_requeue_ctask);
 724
 725 /**
 726  * iscsi_data_xmit - xmit any command into the scheduled connection
 727  * @conn: iscsi connection
 728  *
 729  * Notes:
 730  *      The function can return -EAGAIN in which case the caller must
 731  *      re-schedule it again later or recover. '0' return code means
 732  *      successful xmit.
 733  **/
 734 static int iscsi_data_xmit(struct iscsi_conn *conn)
 735 {
 736         int rc = 0;
 737
 738         spin_lock_bh(&conn->session->lock);
 739         if (unlikely(conn->suspend_tx)) {
 740                 debug_scsi("conn %d Tx suspended!\n", conn->id);
 741                 spin_unlock_bh(&conn->session->lock);
 742                 return -ENODATA;
 743         }
 744
 745         if (conn->ctask) {
 746                 rc = iscsi_xmit_ctask(conn);
 747                 if (rc)
 748                         goto again;
 749         }
 750
 751         if (conn->mtask) {
 752                 rc = iscsi_xmit_mtask(conn);
 753                 if (rc)
 754                         goto again;
 755         }
 756
 757         /*
 758          * process mgmt pdus like nops before commands since we should
 759          * only have one nop-out as a ping from us and targets should not
 760          * overflow us with nop-ins
 761          */
 762 check_mgmt:
 763         while (!list_empty(&conn->mgmtqueue)) {
 764                 conn->mtask = list_entry(conn->mgmtqueue.next,
 765                                          struct iscsi_mgmt_task, running);
 766                 iscsi_prep_mtask(conn, conn->mtask);
 767                 list_move_tail(conn->mgmtqueue.next, &conn->mgmt_run_list);
 768                 rc = iscsi_xmit_mtask(conn);
 769                 if (rc)
 770                         goto again;
 771         }
 772
 773         /* process pending command queue */
 774         while (!list_empty(&conn->xmitqueue)) {
 775                 if (conn->tmf_state == TMF_QUEUED)
 776                         break;
 777
 778                 conn->ctask = list_entry(conn->xmitqueue.next,
 779                                          struct iscsi_cmd_task, running);
 780                 if (iscsi_prep_scsi_cmd_pdu(conn->ctask)) {
 781                         fail_command(conn, conn->ctask, DID_ABORT << 16);
 782                         continue;
 783                 }
 784                 conn->session->tt->init_cmd_task(conn->ctask);
 785                 conn->ctask->state = ISCSI_TASK_RUNNING;
 786                 list_move_tail(conn->xmitqueue.next, &conn->run_list);
 787                 rc = iscsi_xmit_ctask(conn);
 788                 if (rc)
 789                         goto again;
 790                 /*
 791                  * we could continuously get new ctask requests so
 792                  * we need to check the mgmt queue for nops that need to
 793                  * be sent to aviod starvation
 794                  */
 795                 if (!list_empty(&conn->mgmtqueue))
 796                         goto check_mgmt;
 797         }
 798
 799         while (!list_empty(&conn->requeue)) {
 800                 if (conn->session->fast_abort && conn->tmf_state != TMF_INITIAL)
 801                         break;
 802
 803                 conn->ctask = list_entry(conn->requeue.next,
 804                                          struct iscsi_cmd_task, running);
 805                 conn->ctask->state = ISCSI_TASK_RUNNING;
 806                 list_move_tail(conn->requeue.next, &conn->run_list);
 807                 rc = iscsi_xmit_ctask(conn);
 808                 if (rc)
 809                         goto again;
 810                 if (!list_empty(&conn->mgmtqueue))
 811                         goto check_mgmt;
 812         }
 813         spin_unlock_bh(&conn->session->lock);
 814         return -ENODATA;
 815
 816 again:
 817         if (unlikely(conn->suspend_tx))
 818                 rc = -ENODATA;
 819         spin_unlock_bh(&conn->session->lock);
 820         return rc;
 821 }
 822
 823 static void iscsi_xmitworker(struct work_struct *work)
 824 {
 825         struct iscsi_conn *conn =
 826                 container_of(work, struct iscsi_conn, xmitwork);
 827         int rc;
 828         /*
 829          * serialize Xmit worker on a per-connection basis.
 830          */
 831         do {
 832                 rc = iscsi_data_xmit(conn);
 833         } while (rc >= 0 || rc == -EAGAIN);
 834 }
 835
 836 enum {
 837         FAILURE_BAD_HOST = 1,
 838         FAILURE_SESSION_FAILED,
 839         FAILURE_SESSION_FREED,
 840         FAILURE_WINDOW_CLOSED,
 841         FAILURE_OOM,
 842         FAILURE_SESSION_TERMINATE,
 843         FAILURE_SESSION_IN_RECOVERY,
 844         FAILURE_SESSION_RECOVERY_TIMEOUT,
 845 };
 846
 847 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
 848 {
 849         struct Scsi_Host *host;
 850         int reason = 0;
 851         struct iscsi_session *session;
 852         struct iscsi_conn *conn;
 853         struct iscsi_cmd_task *ctask = NULL;
 854
 855         sc->scsi_done = done;
 856         sc->result = 0;
 857         sc->SCp.ptr = NULL;
 858
 859         host = sc->device->host;
 860         session = iscsi_hostdata(host->hostdata);
 861
 862         spin_lock(&session->lock);
 863
 864         /*
 865          * ISCSI_STATE_FAILED is a temp. state. The recovery
 866          * code will decide what is best to do with command queued
 867          * during this time
 868          */
 869         if (session->state != ISCSI_STATE_LOGGED_IN &&
 870             session->state != ISCSI_STATE_FAILED) {
 871                 /*
 872                  * to handle the race between when we set the recovery state
 873                  * and block the session we requeue here (commands could
 874                  * be entering our queuecommand while a block is starting
 875                  * up because the block code is not locked)
 876                  */
 877                 if (session->state == ISCSI_STATE_IN_RECOVERY) {
 878                         reason = FAILURE_SESSION_IN_RECOVERY;
 879                         goto reject;
 880                 }
 881
 882                 if (session->state == ISCSI_STATE_RECOVERY_FAILED)
 883                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
 884                 else if (session->state == ISCSI_STATE_TERMINATE)
 885                         reason = FAILURE_SESSION_TERMINATE;
 886                 else
 887                         reason = FAILURE_SESSION_FREED;
 888                 goto fault;
 889         }
 890
 891         conn = session->leadconn;
 892         if (!conn) {
 893                 reason = FAILURE_SESSION_FREED;
 894                 goto fault;
 895         }
 896
 897         if (iscsi_check_cmdsn_window_closed(conn)) {
 898                 reason = FAILURE_WINDOW_CLOSED;
 899                 goto reject;
 900         }
 901
 902         if (!__kfifo_get(session->cmdpool.queue, (void*)&ctask,
 903                          sizeof(void*))) {
 904                 reason = FAILURE_OOM;
 905                 goto reject;
 906         }
 907         session->queued_cmdsn++;
 908
 909         sc->SCp.phase = session->age;
 910         sc->SCp.ptr = (char *)ctask;
 911
 912         atomic_set(&ctask->refcount, 1);
 913         ctask->state = ISCSI_TASK_PENDING;
 914         ctask->conn = conn;
 915         ctask->sc = sc;
 916         INIT_LIST_HEAD(&ctask->running);
 917
 918         list_add_tail(&ctask->running, &conn->xmitqueue);
 919         spin_unlock(&session->lock);
 920
 921         scsi_queue_work(host, &conn->xmitwork);
 922         return 0;
 923
 924 reject:
 925         spin_unlock(&session->lock);
 926         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
 927         return SCSI_MLQUEUE_HOST_BUSY;
 928
 929 fault:
 930         spin_unlock(&session->lock);
 931         printk(KERN_ERR "iscsi: cmd 0x%x is not queued (%d)\n",
 932                sc->cmnd[0], reason);
 933         sc->result = (DID_NO_CONNECT << 16);
 934         scsi_set_resid(sc, scsi_bufflen(sc));
 935         sc->scsi_done(sc);
 936         return 0;
 937 }
 938 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
 939
 940 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
 941 {
 942         if (depth > ISCSI_MAX_CMD_PER_LUN)
 943                 depth = ISCSI_MAX_CMD_PER_LUN;
 944         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 945         return sdev->queue_depth;
 946 }
 947 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
 948
 949 static struct iscsi_mgmt_task *
 950 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 951                       char *data, uint32_t data_size)
 952 {
 953         struct iscsi_session *session = conn->session;
 954         struct iscsi_mgmt_task *mtask;
 955
 956         if (session->state == ISCSI_STATE_TERMINATE)
 957                 return NULL;
 958
 959         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
 960             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 961                 /*
 962                  * Login and Text are sent serially, in
 963                  * request-followed-by-response sequence.
 964                  * Same mtask can be used. Same ITT must be used.
 965                  * Note that login_mtask is preallocated at conn_create().
 966                  */
 967                 mtask = conn->login_mtask;
 968         else {
 969                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 970                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 971
 972                 if (!__kfifo_get(session->mgmtpool.queue,
 973                                  (void*)&mtask, sizeof(void*)))
 974                         return NULL;
 975         }
 976
 977         if (data_size) {
 978                 memcpy(mtask->data, data, data_size);
 979                 mtask->data_count = data_size;
 980         } else
 981                 mtask->data_count = 0;
 982
 983         memcpy(mtask->hdr, hdr, sizeof(struct iscsi_hdr));
 984         INIT_LIST_HEAD(&mtask->running);
 985         list_add_tail(&mtask->running, &conn->mgmtqueue);
 986         return mtask;
 987 }
 988
 989 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 990                         char *data, uint32_t data_size)
 991 {
 992         struct iscsi_conn *conn = cls_conn->dd_data;
 993         struct iscsi_session *session = conn->session;
 994         int err = 0;
 995
 996         spin_lock_bh(&session->lock);
 997         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 998                 err = -EPERM;
 999         spin_unlock_bh(&session->lock);
1000         scsi_queue_work(session->host, &conn->xmitwork);
1001         return err;
1002 }
1003 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
1004
1005 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
1006 {
1007         struct iscsi_session *session = class_to_transport_session(cls_session);
1008
1009         spin_lock_bh(&session->lock);
1010         if (session->state != ISCSI_STATE_LOGGED_IN) {
1011                 session->state = ISCSI_STATE_RECOVERY_FAILED;
1012                 if (session->leadconn)
1013                         wake_up(&session->leadconn->ehwait);
1014         }
1015         spin_unlock_bh(&session->lock);
1016 }
1017 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
1018
1019 int iscsi_eh_host_reset(struct scsi_cmnd *sc)
1020 {
1021         struct Scsi_Host *host = sc->device->host;
1022         struct iscsi_session *session = iscsi_hostdata(host->hostdata);
1023         struct iscsi_conn *conn = session->leadconn;
1024
1025         spin_lock_bh(&session->lock);
1026         if (session->state == ISCSI_STATE_TERMINATE) {
1027 failed:
1028                 debug_scsi("failing host reset: session terminated "
1029                            "[CID %d age %d]\n", conn->id, session->age);
1030                 spin_unlock_bh(&session->lock);
1031                 return FAILED;
1032         }
1033
1034         spin_unlock_bh(&session->lock);
1035
1036         /*
1037          * we drop the lock here but the leadconn cannot be destoyed while
1038          * we are in the scsi eh
1039          */
1040         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1041
1042         debug_scsi("iscsi_eh_host_reset wait for relogin\n");
1043         wait_event_interruptible(conn->ehwait,
1044                                  session->state == ISCSI_STATE_TERMINATE ||
1045                                  session->state == ISCSI_STATE_LOGGED_IN ||
1046                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
1047         if (signal_pending(current))
1048                 flush_signals(current);
1049
1050         spin_lock_bh(&session->lock);
1051         if (session->state == ISCSI_STATE_LOGGED_IN)
1052                 printk(KERN_INFO "iscsi: host reset succeeded\n");
1053         else
1054                 goto failed;
1055         spin_unlock_bh(&session->lock);
1056
1057         return SUCCESS;
1058 }
1059 EXPORT_SYMBOL_GPL(iscsi_eh_host_reset);
1060
1061 static void iscsi_tmf_timedout(unsigned long data)
1062 {
1063         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1064         struct iscsi_session *session = conn->session;
1065
1066         spin_lock(&session->lock);
1067         if (conn->tmf_state == TMF_QUEUED) {
1068                 conn->tmf_state = TMF_TIMEDOUT;
1069                 debug_scsi("tmf timedout\n");
1070                 /* unblock eh_abort() */
1071                 wake_up(&conn->ehwait);
1072         }
1073         spin_unlock(&session->lock);
1074 }
1075
1076 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1077                                    struct iscsi_tm *hdr, int age)
1078 {
1079         struct iscsi_session *session = conn->session;
1080         struct iscsi_mgmt_task *mtask;
1081
1082         mtask = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1083                                       NULL, 0);
1084         if (!mtask) {
1085                 spin_unlock_bh(&session->lock);
1086                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1087                 spin_lock_bh(&session->lock);
1088                 debug_scsi("tmf exec failure\n");
1089                 return -EPERM;
1090         }
1091         conn->tmfcmd_pdus_cnt++;
1092         conn->tmf_timer.expires = 30 * HZ + jiffies;
1093         conn->tmf_timer.function = iscsi_tmf_timedout;
1094         conn->tmf_timer.data = (unsigned long)conn;
1095         add_timer(&conn->tmf_timer);
1096         debug_scsi("tmf set timeout\n");
1097
1098         spin_unlock_bh(&session->lock);
1099         mutex_unlock(&session->eh_mutex);
1100         scsi_queue_work(session->host, &conn->xmitwork);
1101
1102         /*
1103          * block eh thread until:
1104          *
1105          * 1) tmf response
1106          * 2) tmf timeout
1107          * 3) session is terminated or restarted or userspace has
1108          * given up on recovery
1109          */
1110         wait_event_interruptible(conn->ehwait, age != session->age ||
1111                                  session->state != ISCSI_STATE_LOGGED_IN ||
1112                                  conn->tmf_state != TMF_QUEUED);
1113         if (signal_pending(current))
1114                 flush_signals(current);
1115         del_timer_sync(&conn->tmf_timer);
1116
1117         mutex_lock(&session->eh_mutex);
1118         spin_lock_bh(&session->lock);
1119         /* if the session drops it will clean up the mtask */
1120         if (age != session->age ||
1121             session->state != ISCSI_STATE_LOGGED_IN)
1122                 return -ENOTCONN;
1123
1124         if (!list_empty(&mtask->running)) {
1125                 list_del_init(&mtask->running);
1126                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1127                             sizeof(void*));
1128         }
1129         return 0;
1130 }
1131
1132 /*
1133  * session lock must be held
1134  */
1135 static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1136                          int err)
1137 {
1138         struct scsi_cmnd *sc;
1139
1140         sc = ctask->sc;
1141         if (!sc)
1142                 return;
1143
1144         if (ctask->state == ISCSI_TASK_PENDING)
1145                 /*
1146                  * cmd never made it to the xmit thread, so we should not count
1147                  * the cmd in the sequencing
1148                  */
1149                 conn->session->queued_cmdsn--;
1150         else
1151                 conn->session->tt->cleanup_cmd_task(conn, ctask);
1152
1153         sc->result = err;
1154         scsi_set_resid(sc, scsi_bufflen(sc));
1155         if (conn->ctask == ctask)
1156                 conn->ctask = NULL;
1157         /* release ref from queuecommand */
1158         __iscsi_put_ctask(ctask);
1159 }
1160
1161 /*
1162  * Fail commands. session lock held and recv side suspended and xmit
1163  * thread flushed
1164  */
1165 static void fail_all_commands(struct iscsi_conn *conn, unsigned lun)
1166 {
1167         struct iscsi_cmd_task *ctask, *tmp;
1168
1169         if (conn->ctask && (conn->ctask->sc->device->lun == lun || lun == -1))
1170                 conn->ctask = NULL;
1171
1172         /* flush pending */
1173         list_for_each_entry_safe(ctask, tmp, &conn->xmitqueue, running) {
1174                 if (lun == ctask->sc->device->lun || lun == -1) {
1175                         debug_scsi("failing pending sc %p itt 0x%x\n",
1176                                    ctask->sc, ctask->itt);
1177                         fail_command(conn, ctask, DID_BUS_BUSY << 16);
1178                 }
1179         }
1180
1181         list_for_each_entry_safe(ctask, tmp, &conn->requeue, running) {
1182                 if (lun == ctask->sc->device->lun || lun == -1) {
1183                         debug_scsi("failing requeued sc %p itt 0x%x\n",
1184                                    ctask->sc, ctask->itt);
1185                         fail_command(conn, ctask, DID_BUS_BUSY << 16);
1186                 }
1187         }
1188
1189         /* fail all other running */
1190         list_for_each_entry_safe(ctask, tmp, &conn->run_list, running) {
1191                 if (lun == ctask->sc->device->lun || lun == -1) {
1192                         debug_scsi("failing in progress sc %p itt 0x%x\n",
1193                                    ctask->sc, ctask->itt);
1194                         fail_command(conn, ctask, DID_BUS_BUSY << 16);
1195                 }
1196         }
1197 }
1198
1199 static void iscsi_suspend_tx(struct iscsi_conn *conn)
1200 {
1201         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1202         scsi_flush_work(conn->session->host);
1203 }
1204
1205 static void iscsi_start_tx(struct iscsi_conn *conn)
1206 {
1207         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1208         scsi_queue_work(conn->session->host, &conn->xmitwork);
1209 }
1210
1211 static void iscsi_prep_abort_task_pdu(struct iscsi_cmd_task *ctask,
1212                                       struct iscsi_tm *hdr)
1213 {
1214         memset(hdr, 0, sizeof(*hdr));
1215         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1216         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
1217         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1218         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1219         hdr->rtt = ctask->hdr->itt;
1220         hdr->refcmdsn = ctask->hdr->cmdsn;
1221 }
1222
1223 int iscsi_eh_abort(struct scsi_cmnd *sc)
1224 {
1225         struct Scsi_Host *host = sc->device->host;
1226         struct iscsi_session *session = iscsi_hostdata(host->hostdata);
1227         struct iscsi_conn *conn;
1228         struct iscsi_cmd_task *ctask;
1229         struct iscsi_tm *hdr;
1230         int rc, age;
1231
1232         mutex_lock(&session->eh_mutex);
1233         spin_lock_bh(&session->lock);
1234         /*
1235          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1236          * got the command.
1237          */
1238         if (!sc->SCp.ptr) {
1239                 debug_scsi("sc never reached iscsi layer or it completed.\n");
1240                 spin_unlock_bh(&session->lock);
1241                 mutex_unlock(&session->eh_mutex);
1242                 return SUCCESS;
1243         }
1244
1245         /*
1246          * If we are not logged in or we have started a new session
1247          * then let the host reset code handle this
1248          */
1249         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
1250             sc->SCp.phase != session->age) {
1251                 spin_unlock_bh(&session->lock);
1252                 mutex_unlock(&session->eh_mutex);
1253                 return FAILED;
1254         }
1255
1256         conn = session->leadconn;
1257         conn->eh_abort_cnt++;
1258         age = session->age;
1259
1260         ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
1261         debug_scsi("aborting [sc %p itt 0x%x]\n", sc, ctask->itt);
1262
1263         /* ctask completed before time out */
1264         if (!ctask->sc) {
1265                 debug_scsi("sc completed while abort in progress\n");
1266                 goto success;
1267         }
1268
1269         if (ctask->state == ISCSI_TASK_PENDING) {
1270                 fail_command(conn, ctask, DID_ABORT << 16);
1271                 goto success;
1272         }
1273
1274         /* only have one tmf outstanding at a time */
1275         if (conn->tmf_state != TMF_INITIAL)
1276                 goto failed;
1277         conn->tmf_state = TMF_QUEUED;
1278
1279         hdr = &conn->tmhdr;
1280         iscsi_prep_abort_task_pdu(ctask, hdr);
1281
1282         if (iscsi_exec_task_mgmt_fn(conn, hdr, age)) {
1283                 rc = FAILED;
1284                 goto failed;
1285         }
1286
1287         switch (conn->tmf_state) {
1288         case TMF_SUCCESS:
1289                 spin_unlock_bh(&session->lock);
1290                 iscsi_suspend_tx(conn);
1291                 /*
1292                  * clean up task if aborted. grab the recv lock as a writer
1293                  */
1294                 write_lock_bh(conn->recv_lock);
1295                 spin_lock(&session->lock);
1296                 fail_command(conn, ctask, DID_ABORT << 16);
1297                 conn->tmf_state = TMF_INITIAL;
1298                 spin_unlock(&session->lock);
1299                 write_unlock_bh(conn->recv_lock);
1300                 iscsi_start_tx(conn);
1301                 goto success_unlocked;
1302         case TMF_TIMEDOUT:
1303                 spin_unlock_bh(&session->lock);
1304                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1305                 goto failed_unlocked;
1306         case TMF_NOT_FOUND:
1307                 if (!sc->SCp.ptr) {
1308                         conn->tmf_state = TMF_INITIAL;
1309                         /* ctask completed before tmf abort response */
1310                         debug_scsi("sc completed while abort in progress\n");
1311                         goto success;
1312                 }
1313                 /* fall through */
1314         default:
1315                 conn->tmf_state = TMF_INITIAL;
1316                 goto failed;
1317         }
1318
1319 success:
1320         spin_unlock_bh(&session->lock);
1321 success_unlocked:
1322         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1323         mutex_unlock(&session->eh_mutex);
1324         return SUCCESS;
1325
1326 failed:
1327         spin_unlock_bh(&session->lock);
1328 failed_unlocked:
1329         debug_scsi("abort failed [sc %p itt 0x%x]\n", sc,
1330                     ctask ? ctask->itt : 0);
1331         mutex_unlock(&session->eh_mutex);
1332         return FAILED;
1333 }
1334 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1335
1336 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
1337 {
1338         memset(hdr, 0, sizeof(*hdr));
1339         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1340         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
1341         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1342         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
1343         hdr->rtt = ISCSI_RESERVED_TAG;
1344 }
1345
1346 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
1347 {
1348         struct Scsi_Host *host = sc->device->host;
1349         struct iscsi_session *session = iscsi_hostdata(host->hostdata);
1350         struct iscsi_conn *conn;
1351         struct iscsi_tm *hdr;
1352         int rc = FAILED;
1353
1354         debug_scsi("LU Reset [sc %p lun %u]\n", sc, sc->device->lun);
1355
1356         mutex_lock(&session->eh_mutex);
1357         spin_lock_bh(&session->lock);
1358         /*
1359          * Just check if we are not logged in. We cannot check for
1360          * the phase because the reset could come from a ioctl.
1361          */
1362         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
1363                 goto unlock;
1364         conn = session->leadconn;
1365
1366         /* only have one tmf outstanding at a time */
1367         if (conn->tmf_state != TMF_INITIAL)
1368                 goto unlock;
1369         conn->tmf_state = TMF_QUEUED;
1370
1371         hdr = &conn->tmhdr;
1372         iscsi_prep_lun_reset_pdu(sc, hdr);
1373
1374         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age)) {
1375                 rc = FAILED;
1376                 goto unlock;
1377         }
1378
1379         switch (conn->tmf_state) {
1380         case TMF_SUCCESS:
1381                 break;
1382         case TMF_TIMEDOUT:
1383                 spin_unlock_bh(&session->lock);
1384                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1385                 goto done;
1386         default:
1387                 conn->tmf_state = TMF_INITIAL;
1388                 goto unlock;
1389         }
1390
1391         rc = SUCCESS;
1392         spin_unlock_bh(&session->lock);
1393
1394         iscsi_suspend_tx(conn);
1395         /* need to grab the recv lock then session lock */
1396         write_lock_bh(conn->recv_lock);
1397         spin_lock(&session->lock);
1398         fail_all_commands(conn, sc->device->lun);
1399         conn->tmf_state = TMF_INITIAL;
1400         spin_unlock(&session->lock);
1401         write_unlock_bh(conn->recv_lock);
1402
1403         iscsi_start_tx(conn);
1404         goto done;
1405
1406 unlock:
1407         spin_unlock_bh(&session->lock);
1408 done:
1409         debug_scsi("iscsi_eh_device_reset %s\n",
1410                   rc == SUCCESS ? "SUCCESS" : "FAILED");
1411         mutex_unlock(&session->eh_mutex);
1412         return rc;
1413 }
1414 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
1415
1416 /*
1417  * Pre-allocate a pool of @max items of @item_size. By default, the pool
1418  * should be accessed via kfifo_{get,put} on q->queue.
1419  * Optionally, the caller can obtain the array of object pointers
1420  * by passing in a non-NULL @items pointer
1421  */
1422 int
1423 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
1424 {
1425         int i, num_arrays = 1;
1426
1427         memset(q, 0, sizeof(*q));
1428
1429         q->max = max;
1430
1431         /* If the user passed an items pointer, he wants a copy of
1432          * the array. */
1433         if (items)
1434                 num_arrays++;
1435         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
1436         if (q->pool == NULL)
1437                 goto enomem;
1438
1439         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1440                               GFP_KERNEL, NULL);
1441         if (q->queue == ERR_PTR(-ENOMEM))
1442                 goto enomem;
1443
1444         for (i = 0; i < max; i++) {
1445                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
1446                 if (q->pool[i] == NULL) {
1447                         q->max = i;
1448                         goto enomem;
1449                 }
1450                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1451         }
1452
1453         if (items) {
1454                 *items = q->pool + max;
1455                 memcpy(*items, q->pool, max * sizeof(void *));
1456         }
1457
1458         return 0;
1459
1460 enomem:
1461         iscsi_pool_free(q);
1462         return -ENOMEM;
1463 }
1464 EXPORT_SYMBOL_GPL(iscsi_pool_init);
1465
1466 void iscsi_pool_free(struct iscsi_pool *q)
1467 {
1468         int i;
1469
1470         for (i = 0; i < q->max; i++)
1471                 kfree(q->pool[i]);
1472         if (q->pool)
1473                 kfree(q->pool);
1474 }
1475 EXPORT_SYMBOL_GPL(iscsi_pool_free);
1476
1477 /*
1478  * iSCSI Session's hostdata organization:
1479  *
1480  *    *------------------* <== hostdata_session(host->hostdata)
1481  *    | ptr to class sess|
1482  *    |------------------| <== iscsi_hostdata(host->hostdata)
1483  *    | iscsi_session    |
1484  *    *------------------*
1485  */
1486
1487 #define hostdata_privsize(_sz)  (sizeof(unsigned long) + _sz + \
1488                                  _sz % sizeof(unsigned long))
1489
1490 #define hostdata_session(_hostdata) (iscsi_ptr(*(unsigned long *)_hostdata))
1491
1492 /**
1493  * iscsi_session_setup - create iscsi cls session and host and session
1494  * @scsit: scsi transport template
1495  * @iscsit: iscsi transport template
1496  * @cmds_max: scsi host can queue
1497  * @qdepth: scsi host cmds per lun
1498  * @cmd_task_size: LLD ctask private data size
1499  * @mgmt_task_size: LLD mtask private data size
1500  * @initial_cmdsn: initial CmdSN
1501  * @hostno: host no allocated
1502  *
1503  * This can be used by software iscsi_transports that allocate
1504  * a session per scsi host.
1505  **/
1506 struct iscsi_cls_session *
1507 iscsi_session_setup(struct iscsi_transport *iscsit,
1508                     struct scsi_transport_template *scsit,
1509                     uint16_t cmds_max, uint16_t qdepth,
1510                     int cmd_task_size, int mgmt_task_size,
1511                     uint32_t initial_cmdsn, uint32_t *hostno)
1512 {
1513         struct Scsi_Host *shost;
1514         struct iscsi_session *session;
1515         struct iscsi_cls_session *cls_session;
1516         int cmd_i;
1517
1518         if (qdepth > ISCSI_MAX_CMD_PER_LUN || qdepth < 1) {
1519                 if (qdepth != 0)
1520                         printk(KERN_ERR "iscsi: invalid queue depth of %d. "
1521                               "Queue depth must be between 1 and %d.\n",
1522                               qdepth, ISCSI_MAX_CMD_PER_LUN);
1523                 qdepth = ISCSI_DEF_CMD_PER_LUN;
1524         }
1525
1526         if (cmds_max < 2 || (cmds_max & (cmds_max - 1)) ||
1527             cmds_max >= ISCSI_MGMT_ITT_OFFSET) {
1528                 if (cmds_max != 0)
1529                         printk(KERN_ERR "iscsi: invalid can_queue of %d. "
1530                                "can_queue must be a power of 2 and between "
1531                                "2 and %d - setting to %d.\n", cmds_max,
1532                                ISCSI_MGMT_ITT_OFFSET, ISCSI_DEF_XMIT_CMDS_MAX);
1533                 cmds_max = ISCSI_DEF_XMIT_CMDS_MAX;
1534         }
1535
1536         shost = scsi_host_alloc(iscsit->host_template,
1537                                 hostdata_privsize(sizeof(*session)));
1538         if (!shost)
1539                 return NULL;
1540
1541         /* the iscsi layer takes one task for reserve */
1542         shost->can_queue = cmds_max - 1;
1543         shost->cmd_per_lun = qdepth;
1544         shost->max_id = 1;
1545         shost->max_channel = 0;
1546         shost->max_lun = iscsit->max_lun;
1547         shost->max_cmd_len = iscsit->max_cmd_len;
1548         shost->transportt = scsit;
1549         shost->transportt->create_work_queue = 1;
1550         *hostno = shost->host_no;
1551
1552         session = iscsi_hostdata(shost->hostdata);
1553         memset(session, 0, sizeof(struct iscsi_session));
1554         session->host = shost;
1555         session->state = ISCSI_STATE_FREE;
1556         session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
1557         session->cmds_max = cmds_max;
1558         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
1559         session->exp_cmdsn = initial_cmdsn + 1;
1560         session->max_cmdsn = initial_cmdsn + 1;
1561         session->max_r2t = 1;
1562         session->tt = iscsit;
1563         mutex_init(&session->eh_mutex);
1564
1565         /* initialize SCSI PDU commands pool */
1566         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
1567                             (void***)&session->cmds,
1568                             cmd_task_size + sizeof(struct iscsi_cmd_task)))
1569                 goto cmdpool_alloc_fail;
1570
1571         /* pre-format cmds pool with ITT */
1572         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1573                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1574
1575                 if (cmd_task_size)
1576                         ctask->dd_data = &ctask[1];
1577                 ctask->itt = cmd_i;
1578                 INIT_LIST_HEAD(&ctask->running);
1579         }
1580
1581         spin_lock_init(&session->lock);
1582
1583         /* initialize immediate command pool */
1584         if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max,
1585                            (void***)&session->mgmt_cmds,
1586                            mgmt_task_size + sizeof(struct iscsi_mgmt_task)))
1587                 goto mgmtpool_alloc_fail;
1588
1589
1590         /* pre-format immediate cmds pool with ITT */
1591         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
1592                 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
1593
1594                 if (mgmt_task_size)
1595                         mtask->dd_data = &mtask[1];
1596                 mtask->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i;
1597                 INIT_LIST_HEAD(&mtask->running);
1598         }
1599
1600         if (scsi_add_host(shost, NULL))
1601                 goto add_host_fail;
1602
1603         if (!try_module_get(iscsit->owner))
1604                 goto cls_session_fail;
1605
1606         cls_session = iscsi_create_session(shost, iscsit, 0);
1607         if (!cls_session)
1608                 goto module_put;
1609         *(unsigned long*)shost->hostdata = (unsigned long)cls_session;
1610
1611         return cls_session;
1612
1613 module_put:
1614         module_put(iscsit->owner);
1615 cls_session_fail:
1616         scsi_remove_host(shost);
1617 add_host_fail:
1618         iscsi_pool_free(&session->mgmtpool);
1619 mgmtpool_alloc_fail:
1620         iscsi_pool_free(&session->cmdpool);
1621 cmdpool_alloc_fail:
1622         scsi_host_put(shost);
1623         return NULL;
1624 }
1625 EXPORT_SYMBOL_GPL(iscsi_session_setup);
1626
1627 /**
1628  * iscsi_session_teardown - destroy session, host, and cls_session
1629  * shost: scsi host
1630  *
1631  * This can be used by software iscsi_transports that allocate
1632  * a session per scsi host.
1633  **/
1634 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
1635 {
1636         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1637         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1638         struct module *owner = cls_session->transport->owner;
1639
1640         iscsi_unblock_session(cls_session);
1641         scsi_remove_host(shost);
1642
1643         iscsi_pool_free(&session->mgmtpool);
1644         iscsi_pool_free(&session->cmdpool);
1645
1646         kfree(session->password);
1647         kfree(session->password_in);
1648         kfree(session->username);
1649         kfree(session->username_in);
1650         kfree(session->targetname);
1651         kfree(session->netdev);
1652         kfree(session->hwaddress);
1653         kfree(session->initiatorname);
1654
1655         iscsi_destroy_session(cls_session);
1656         scsi_host_put(shost);
1657         module_put(owner);
1658 }
1659 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
1660
1661 /**
1662  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
1663  * @cls_session: iscsi_cls_session
1664  * @conn_idx: cid
1665  **/
1666 struct iscsi_cls_conn *
1667 iscsi_conn_setup(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1668 {
1669         struct iscsi_session *session = class_to_transport_session(cls_session);
1670         struct iscsi_conn *conn;
1671         struct iscsi_cls_conn *cls_conn;
1672         char *data;
1673
1674         cls_conn = iscsi_create_conn(cls_session, conn_idx);
1675         if (!cls_conn)
1676                 return NULL;
1677         conn = cls_conn->dd_data;
1678         memset(conn, 0, sizeof(*conn));
1679
1680         conn->session = session;
1681         conn->cls_conn = cls_conn;
1682         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
1683         conn->id = conn_idx;
1684         conn->exp_statsn = 0;
1685         conn->tmf_state = TMF_INITIAL;
1686         INIT_LIST_HEAD(&conn->run_list);
1687         INIT_LIST_HEAD(&conn->mgmt_run_list);
1688         INIT_LIST_HEAD(&conn->mgmtqueue);
1689         INIT_LIST_HEAD(&conn->xmitqueue);
1690         INIT_LIST_HEAD(&conn->requeue);
1691         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
1692
1693         /* allocate login_mtask used for the login/text sequences */
1694         spin_lock_bh(&session->lock);
1695         if (!__kfifo_get(session->mgmtpool.queue,
1696                          (void*)&conn->login_mtask,
1697                          sizeof(void*))) {
1698                 spin_unlock_bh(&session->lock);
1699                 goto login_mtask_alloc_fail;
1700         }
1701         spin_unlock_bh(&session->lock);
1702
1703         data = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN, GFP_KERNEL);
1704         if (!data)
1705                 goto login_mtask_data_alloc_fail;
1706         conn->login_mtask->data = conn->data = data;
1707
1708         init_timer(&conn->tmf_timer);
1709         init_waitqueue_head(&conn->ehwait);
1710
1711         return cls_conn;
1712
1713 login_mtask_data_alloc_fail:
1714         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1715                     sizeof(void*));
1716 login_mtask_alloc_fail:
1717         iscsi_destroy_conn(cls_conn);
1718         return NULL;
1719 }
1720 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
1721
1722 /**
1723  * iscsi_conn_teardown - teardown iscsi connection
1724  * cls_conn: iscsi class connection
1725  *
1726  * TODO: we may need to make this into a two step process
1727  * like scsi-mls remove + put host
1728  */
1729 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
1730 {
1731         struct iscsi_conn *conn = cls_conn->dd_data;
1732         struct iscsi_session *session = conn->session;
1733         unsigned long flags;
1734
1735         spin_lock_bh(&session->lock);
1736         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
1737         if (session->leadconn == conn) {
1738                 /*
1739                  * leading connection? then give up on recovery.
1740                  */
1741                 session->state = ISCSI_STATE_TERMINATE;
1742                 wake_up(&conn->ehwait);
1743         }
1744         spin_unlock_bh(&session->lock);
1745
1746         /*
1747          * Block until all in-progress commands for this connection
1748          * time out or fail.
1749          */
1750         for (;;) {
1751                 spin_lock_irqsave(session->host->host_lock, flags);
1752                 if (!session->host->host_busy) { /* OK for ERL == 0 */
1753                         spin_unlock_irqrestore(session->host->host_lock, flags);
1754                         break;
1755                 }
1756                 spin_unlock_irqrestore(session->host->host_lock, flags);
1757                 msleep_interruptible(500);
1758                 printk(KERN_INFO "iscsi: scsi conn_destroy(): host_busy %d "
1759                        "host_failed %d\n", session->host->host_busy,
1760                        session->host->host_failed);
1761                 /*
1762                  * force eh_abort() to unblock
1763                  */
1764                 wake_up(&conn->ehwait);
1765         }
1766
1767         /* flush queued up work because we free the connection below */
1768         iscsi_suspend_tx(conn);
1769
1770         spin_lock_bh(&session->lock);
1771         kfree(conn->data);
1772         kfree(conn->persistent_address);
1773         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1774                     sizeof(void*));
1775         if (session->leadconn == conn)
1776                 session->leadconn = NULL;
1777         spin_unlock_bh(&session->lock);
1778
1779         iscsi_destroy_conn(cls_conn);
1780 }
1781 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
1782
1783 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
1784 {
1785         struct iscsi_conn *conn = cls_conn->dd_data;
1786         struct iscsi_session *session = conn->session;
1787
1788         if (!session) {
1789                 printk(KERN_ERR "iscsi: can't start unbound connection\n");
1790                 return -EPERM;
1791         }
1792
1793         if ((session->imm_data_en || !session->initial_r2t_en) &&
1794              session->first_burst > session->max_burst) {
1795                 printk("iscsi: invalid burst lengths: "
1796                        "first_burst %d max_burst %d\n",
1797                        session->first_burst, session->max_burst);
1798                 return -EINVAL;
1799         }
1800
1801         spin_lock_bh(&session->lock);
1802         conn->c_stage = ISCSI_CONN_STARTED;
1803         session->state = ISCSI_STATE_LOGGED_IN;
1804         session->queued_cmdsn = session->cmdsn;
1805
1806         switch(conn->stop_stage) {
1807         case STOP_CONN_RECOVER:
1808                 /*
1809                  * unblock eh_abort() if it is blocked. re-try all
1810                  * commands after successful recovery
1811                  */
1812                 conn->stop_stage = 0;
1813                 conn->tmf_state = TMF_INITIAL;
1814                 session->age++;
1815                 spin_unlock_bh(&session->lock);
1816
1817                 iscsi_unblock_session(session_to_cls(session));
1818                 wake_up(&conn->ehwait);
1819                 return 0;
1820         case STOP_CONN_TERM:
1821                 conn->stop_stage = 0;
1822                 break;
1823         default:
1824                 break;
1825         }
1826         spin_unlock_bh(&session->lock);
1827
1828         return 0;
1829 }
1830 EXPORT_SYMBOL_GPL(iscsi_conn_start);
1831
1832 static void
1833 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
1834 {
1835         struct iscsi_mgmt_task *mtask, *tmp;
1836
1837         /* handle pending */
1838         list_for_each_entry_safe(mtask, tmp, &conn->mgmtqueue, running) {
1839                 debug_scsi("flushing pending mgmt task itt 0x%x\n", mtask->itt);
1840                 list_del_init(&mtask->running);
1841                 if (mtask == conn->login_mtask)
1842                         continue;
1843                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1844                             sizeof(void*));
1845         }
1846
1847         /* handle running */
1848         list_for_each_entry_safe(mtask, tmp, &conn->mgmt_run_list, running) {
1849                 debug_scsi("flushing running mgmt task itt 0x%x\n", mtask->itt);
1850                 list_del_init(&mtask->running);
1851
1852                 if (mtask == conn->login_mtask)
1853                         continue;
1854                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1855                            sizeof(void*));
1856         }
1857
1858         conn->mtask = NULL;
1859 }
1860
1861 static void iscsi_start_session_recovery(struct iscsi_session *session,
1862                                          struct iscsi_conn *conn, int flag)
1863 {
1864         int old_stop_stage;
1865
1866         mutex_lock(&session->eh_mutex);
1867         spin_lock_bh(&session->lock);
1868         if (conn->stop_stage == STOP_CONN_TERM) {
1869                 spin_unlock_bh(&session->lock);
1870                 mutex_unlock(&session->eh_mutex);
1871                 return;
1872         }
1873
1874         /*
1875          * The LLD either freed/unset the lock on us, or userspace called
1876          * stop but did not create a proper connection (connection was never
1877          * bound or it was unbound then stop was called).
1878          */
1879         if (!conn->recv_lock) {
1880                 spin_unlock_bh(&session->lock);
1881                 mutex_unlock(&session->eh_mutex);
1882                 return;
1883         }
1884
1885         /*
1886          * When this is called for the in_login state, we only want to clean
1887          * up the login task and connection. We do not need to block and set
1888          * the recovery state again
1889          */
1890         if (flag == STOP_CONN_TERM)
1891                 session->state = ISCSI_STATE_TERMINATE;
1892         else if (conn->stop_stage != STOP_CONN_RECOVER)
1893                 session->state = ISCSI_STATE_IN_RECOVERY;
1894
1895         old_stop_stage = conn->stop_stage;
1896         conn->stop_stage = flag;
1897         conn->c_stage = ISCSI_CONN_STOPPED;
1898         spin_unlock_bh(&session->lock);
1899
1900         iscsi_suspend_tx(conn);
1901
1902         write_lock_bh(conn->recv_lock);
1903         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1904         write_unlock_bh(conn->recv_lock);
1905
1906         /*
1907          * for connection level recovery we should not calculate
1908          * header digest. conn->hdr_size used for optimization
1909          * in hdr_extract() and will be re-negotiated at
1910          * set_param() time.
1911          */
1912         if (flag == STOP_CONN_RECOVER) {
1913                 conn->hdrdgst_en = 0;
1914                 conn->datadgst_en = 0;
1915                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
1916                     old_stop_stage != STOP_CONN_RECOVER) {
1917                         debug_scsi("blocking session\n");
1918                         iscsi_block_session(session_to_cls(session));
1919                 }
1920         }
1921
1922         /*
1923          * flush queues.
1924          */
1925         spin_lock_bh(&session->lock);
1926         fail_all_commands(conn, -1);
1927         flush_control_queues(session, conn);
1928         spin_unlock_bh(&session->lock);
1929         mutex_unlock(&session->eh_mutex);
1930 }
1931
1932 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1933 {
1934         struct iscsi_conn *conn = cls_conn->dd_data;
1935         struct iscsi_session *session = conn->session;
1936
1937         switch (flag) {
1938         case STOP_CONN_RECOVER:
1939         case STOP_CONN_TERM:
1940                 iscsi_start_session_recovery(session, conn, flag);
1941                 break;
1942         default:
1943                 printk(KERN_ERR "iscsi: invalid stop flag %d\n", flag);
1944         }
1945 }
1946 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
1947
1948 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
1949                     struct iscsi_cls_conn *cls_conn, int is_leading)
1950 {
1951         struct iscsi_session *session = class_to_transport_session(cls_session);
1952         struct iscsi_conn *conn = cls_conn->dd_data;
1953
1954         spin_lock_bh(&session->lock);
1955         if (is_leading)
1956                 session->leadconn = conn;
1957         spin_unlock_bh(&session->lock);
1958
1959         /*
1960          * Unblock xmitworker(), Login Phase will pass through.
1961          */
1962         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1963         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1964         return 0;
1965 }
1966 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
1967
1968
1969 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
1970                     enum iscsi_param param, char *buf, int buflen)
1971 {
1972         struct iscsi_conn *conn = cls_conn->dd_data;
1973         struct iscsi_session *session = conn->session;
1974         uint32_t value;
1975
1976         switch(param) {
1977         case ISCSI_PARAM_FAST_ABORT:
1978                 sscanf(buf, "%d", &session->fast_abort);
1979                 break;
1980         case ISCSI_PARAM_MAX_RECV_DLENGTH:
1981                 sscanf(buf, "%d", &conn->max_recv_dlength);
1982                 break;
1983         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
1984                 sscanf(buf, "%d", &conn->max_xmit_dlength);
1985                 break;
1986         case ISCSI_PARAM_HDRDGST_EN:
1987                 sscanf(buf, "%d", &conn->hdrdgst_en);
1988                 break;
1989         case ISCSI_PARAM_DATADGST_EN:
1990                 sscanf(buf, "%d", &conn->datadgst_en);
1991                 break;
1992         case ISCSI_PARAM_INITIAL_R2T_EN:
1993                 sscanf(buf, "%d", &session->initial_r2t_en);
1994                 break;
1995         case ISCSI_PARAM_MAX_R2T:
1996                 sscanf(buf, "%d", &session->max_r2t);
1997                 break;
1998         case ISCSI_PARAM_IMM_DATA_EN:
1999                 sscanf(buf, "%d", &session->imm_data_en);
2000                 break;
2001         case ISCSI_PARAM_FIRST_BURST:
2002                 sscanf(buf, "%d", &session->first_burst);
2003                 break;
2004         case ISCSI_PARAM_MAX_BURST:
2005                 sscanf(buf, "%d", &session->max_burst);
2006                 break;
2007         case ISCSI_PARAM_PDU_INORDER_EN:
2008                 sscanf(buf, "%d", &session->pdu_inorder_en);
2009                 break;
2010         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2011                 sscanf(buf, "%d", &session->dataseq_inorder_en);
2012                 break;
2013         case ISCSI_PARAM_ERL:
2014                 sscanf(buf, "%d", &session->erl);
2015                 break;
2016         case ISCSI_PARAM_IFMARKER_EN:
2017                 sscanf(buf, "%d", &value);
2018                 BUG_ON(value);
2019                 break;
2020         case ISCSI_PARAM_OFMARKER_EN:
2021                 sscanf(buf, "%d", &value);
2022                 BUG_ON(value);
2023                 break;
2024         case ISCSI_PARAM_EXP_STATSN:
2025                 sscanf(buf, "%u", &conn->exp_statsn);
2026                 break;
2027         case ISCSI_PARAM_USERNAME:
2028                 kfree(session->username);
2029                 session->username = kstrdup(buf, GFP_KERNEL);
2030                 if (!session->username)
2031                         return -ENOMEM;
2032                 break;
2033         case ISCSI_PARAM_USERNAME_IN:
2034                 kfree(session->username_in);
2035                 session->username_in = kstrdup(buf, GFP_KERNEL);
2036                 if (!session->username_in)
2037                         return -ENOMEM;
2038                 break;
2039         case ISCSI_PARAM_PASSWORD:
2040                 kfree(session->password);
2041                 session->password = kstrdup(buf, GFP_KERNEL);
2042                 if (!session->password)
2043                         return -ENOMEM;
2044                 break;
2045         case ISCSI_PARAM_PASSWORD_IN:
2046                 kfree(session->password_in);
2047                 session->password_in = kstrdup(buf, GFP_KERNEL);
2048                 if (!session->password_in)
2049                         return -ENOMEM;
2050                 break;
2051         case ISCSI_PARAM_TARGET_NAME:
2052                 /* this should not change between logins */
2053                 if (session->targetname)
2054                         break;
2055
2056                 session->targetname = kstrdup(buf, GFP_KERNEL);
2057                 if (!session->targetname)
2058                         return -ENOMEM;
2059                 break;
2060         case ISCSI_PARAM_TPGT:
2061                 sscanf(buf, "%d", &session->tpgt);
2062                 break;
2063         case ISCSI_PARAM_PERSISTENT_PORT:
2064                 sscanf(buf, "%d", &conn->persistent_port);
2065                 break;
2066         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2067                 /*
2068                  * this is the address returned in discovery so it should
2069                  * not change between logins.
2070                  */
2071                 if (conn->persistent_address)
2072                         break;
2073
2074                 conn->persistent_address = kstrdup(buf, GFP_KERNEL);
2075                 if (!conn->persistent_address)
2076                         return -ENOMEM;
2077                 break;
2078         default:
2079                 return -ENOSYS;
2080         }
2081
2082         return 0;
2083 }
2084 EXPORT_SYMBOL_GPL(iscsi_set_param);
2085
2086 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
2087                             enum iscsi_param param, char *buf)
2088 {
2089         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
2090         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2091         int len;
2092
2093         switch(param) {
2094         case ISCSI_PARAM_FAST_ABORT:
2095                 len = sprintf(buf, "%d\n", session->fast_abort);
2096                 break;
2097         case ISCSI_PARAM_INITIAL_R2T_EN:
2098                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
2099                 break;
2100         case ISCSI_PARAM_MAX_R2T:
2101                 len = sprintf(buf, "%hu\n", session->max_r2t);
2102                 break;
2103         case ISCSI_PARAM_IMM_DATA_EN:
2104                 len = sprintf(buf, "%d\n", session->imm_data_en);
2105                 break;
2106         case ISCSI_PARAM_FIRST_BURST:
2107                 len = sprintf(buf, "%u\n", session->first_burst);
2108                 break;
2109         case ISCSI_PARAM_MAX_BURST:
2110                 len = sprintf(buf, "%u\n", session->max_burst);
2111                 break;
2112         case ISCSI_PARAM_PDU_INORDER_EN:
2113                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
2114                 break;
2115         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2116                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
2117                 break;
2118         case ISCSI_PARAM_ERL:
2119                 len = sprintf(buf, "%d\n", session->erl);
2120                 break;
2121         case ISCSI_PARAM_TARGET_NAME:
2122                 len = sprintf(buf, "%s\n", session->targetname);
2123                 break;
2124         case ISCSI_PARAM_TPGT:
2125                 len = sprintf(buf, "%d\n", session->tpgt);
2126                 break;
2127         case ISCSI_PARAM_USERNAME:
2128                 len = sprintf(buf, "%s\n", session->username);
2129                 break;
2130         case ISCSI_PARAM_USERNAME_IN:
2131                 len = sprintf(buf, "%s\n", session->username_in);
2132                 break;
2133         case ISCSI_PARAM_PASSWORD:
2134                 len = sprintf(buf, "%s\n", session->password);
2135                 break;
2136         case ISCSI_PARAM_PASSWORD_IN:
2137                 len = sprintf(buf, "%s\n", session->password_in);
2138                 break;
2139         default:
2140                 return -ENOSYS;
2141         }
2142
2143         return len;
2144 }
2145 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
2146
2147 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2148                          enum iscsi_param param, char *buf)
2149 {
2150         struct iscsi_conn *conn = cls_conn->dd_data;
2151         int len;
2152
2153         switch(param) {
2154         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2155                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
2156                 break;
2157         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2158                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
2159                 break;
2160         case ISCSI_PARAM_HDRDGST_EN:
2161                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
2162                 break;
2163         case ISCSI_PARAM_DATADGST_EN:
2164                 len = sprintf(buf, "%d\n", conn->datadgst_en);
2165                 break;
2166         case ISCSI_PARAM_IFMARKER_EN:
2167                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
2168                 break;
2169         case ISCSI_PARAM_OFMARKER_EN:
2170                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
2171                 break;
2172         case ISCSI_PARAM_EXP_STATSN:
2173                 len = sprintf(buf, "%u\n", conn->exp_statsn);
2174                 break;
2175         case ISCSI_PARAM_PERSISTENT_PORT:
2176                 len = sprintf(buf, "%d\n", conn->persistent_port);
2177                 break;
2178         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2179                 len = sprintf(buf, "%s\n", conn->persistent_address);
2180                 break;
2181         default:
2182                 return -ENOSYS;
2183         }
2184
2185         return len;
2186 }
2187 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
2188
2189 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2190                          char *buf)
2191 {
2192         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2193         int len;
2194
2195         switch (param) {
2196         case ISCSI_HOST_PARAM_NETDEV_NAME:
2197                 if (!session->netdev)
2198                         len = sprintf(buf, "%s\n", "default");
2199                 else
2200                         len = sprintf(buf, "%s\n", session->netdev);
2201                 break;
2202         case ISCSI_HOST_PARAM_HWADDRESS:
2203                 if (!session->hwaddress)
2204                         len = sprintf(buf, "%s\n", "default");
2205                 else
2206                         len = sprintf(buf, "%s\n", session->hwaddress);
2207                 break;
2208         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2209                 if (!session->initiatorname)
2210                         len = sprintf(buf, "%s\n", "unknown");
2211                 else
2212                         len = sprintf(buf, "%s\n", session->initiatorname);
2213                 break;
2214
2215         default:
2216                 return -ENOSYS;
2217         }
2218
2219         return len;
2220 }
2221 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
2222
2223 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2224                          char *buf, int buflen)
2225 {
2226         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2227
2228         switch (param) {
2229         case ISCSI_HOST_PARAM_NETDEV_NAME:
2230                 if (!session->netdev)
2231                         session->netdev = kstrdup(buf, GFP_KERNEL);
2232                 break;
2233         case ISCSI_HOST_PARAM_HWADDRESS:
2234                 if (!session->hwaddress)
2235                         session->hwaddress = kstrdup(buf, GFP_KERNEL);
2236                 break;
2237         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2238                 if (!session->initiatorname)
2239                         session->initiatorname = kstrdup(buf, GFP_KERNEL);
2240                 break;
2241         default:
2242                 return -ENOSYS;
2243         }
2244
2245         return 0;
2246 }
2247 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
2248
2249 MODULE_AUTHOR("Mike Christie");
2250 MODULE_DESCRIPTION("iSCSI library functions");
2251 MODULE_LICENSE("GPL");