drivers/scsi/libiscsi.c

   1 /*
   2  * iSCSI lib functions
   3  *
   4  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   5  * Copyright (C) 2004 - 2006 Mike Christie
   6  * Copyright (C) 2004 - 2005 Dmitry Yusupov
   7  * Copyright (C) 2004 - 2005 Alex Aizman
   8  * maintained by open-iscsi@googlegroups.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  */
  24 #include <linux/types.h>
  25 #include <linux/kfifo.h>
  26 #include <linux/delay.h>
  27 #include <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 int
1417 iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
1418 {
1419         int i;
1420
1421         *items = kmalloc(max * sizeof(void*), GFP_KERNEL);
1422         if (*items == NULL)
1423                 return -ENOMEM;
1424
1425         q->max = max;
1426         q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL);
1427         if (q->pool == NULL) {
1428                 kfree(*items);
1429                 return -ENOMEM;
1430         }
1431
1432         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1433                               GFP_KERNEL, NULL);
1434         if (q->queue == ERR_PTR(-ENOMEM)) {
1435                 kfree(q->pool);
1436                 kfree(*items);
1437                 return -ENOMEM;
1438         }
1439
1440         for (i = 0; i < max; i++) {
1441                 q->pool[i] = kmalloc(item_size, GFP_KERNEL);
1442                 if (q->pool[i] == NULL) {
1443                         int j;
1444
1445                         for (j = 0; j < i; j++)
1446                                 kfree(q->pool[j]);
1447
1448                         kfifo_free(q->queue);
1449                         kfree(q->pool);
1450                         kfree(*items);
1451                         return -ENOMEM;
1452                 }
1453                 memset(q->pool[i], 0, item_size);
1454                 (*items)[i] = q->pool[i];
1455                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1456         }
1457         return 0;
1458 }
1459 EXPORT_SYMBOL_GPL(iscsi_pool_init);
1460
1461 void iscsi_pool_free(struct iscsi_queue *q, void **items)
1462 {
1463         int i;
1464
1465         for (i = 0; i < q->max; i++)
1466                 kfree(items[i]);
1467         kfree(q->pool);
1468         kfree(items);
1469 }
1470 EXPORT_SYMBOL_GPL(iscsi_pool_free);
1471
1472 /*
1473  * iSCSI Session's hostdata organization:
1474  *
1475  *    *------------------* <== hostdata_session(host->hostdata)
1476  *    | ptr to class sess|
1477  *    |------------------| <== iscsi_hostdata(host->hostdata)
1478  *    | iscsi_session    |
1479  *    *------------------*
1480  */
1481
1482 #define hostdata_privsize(_sz)  (sizeof(unsigned long) + _sz + \
1483                                  _sz % sizeof(unsigned long))
1484
1485 #define hostdata_session(_hostdata) (iscsi_ptr(*(unsigned long *)_hostdata))
1486
1487 /**
1488  * iscsi_session_setup - create iscsi cls session and host and session
1489  * @scsit: scsi transport template
1490  * @iscsit: iscsi transport template
1491  * @cmds_max: scsi host can queue
1492  * @qdepth: scsi host cmds per lun
1493  * @cmd_task_size: LLD ctask private data size
1494  * @mgmt_task_size: LLD mtask private data size
1495  * @initial_cmdsn: initial CmdSN
1496  * @hostno: host no allocated
1497  *
1498  * This can be used by software iscsi_transports that allocate
1499  * a session per scsi host.
1500  **/
1501 struct iscsi_cls_session *
1502 iscsi_session_setup(struct iscsi_transport *iscsit,
1503                     struct scsi_transport_template *scsit,
1504                     uint16_t cmds_max, uint16_t qdepth,
1505                     int cmd_task_size, int mgmt_task_size,
1506                     uint32_t initial_cmdsn, uint32_t *hostno)
1507 {
1508         struct Scsi_Host *shost;
1509         struct iscsi_session *session;
1510         struct iscsi_cls_session *cls_session;
1511         int cmd_i;
1512
1513         if (qdepth > ISCSI_MAX_CMD_PER_LUN || qdepth < 1) {
1514                 if (qdepth != 0)
1515                         printk(KERN_ERR "iscsi: invalid queue depth of %d. "
1516                               "Queue depth must be between 1 and %d.\n",
1517                               qdepth, ISCSI_MAX_CMD_PER_LUN);
1518                 qdepth = ISCSI_DEF_CMD_PER_LUN;
1519         }
1520
1521         if (cmds_max < 2 || (cmds_max & (cmds_max - 1)) ||
1522             cmds_max >= ISCSI_MGMT_ITT_OFFSET) {
1523                 if (cmds_max != 0)
1524                         printk(KERN_ERR "iscsi: invalid can_queue of %d. "
1525                                "can_queue must be a power of 2 and between "
1526                                "2 and %d - setting to %d.\n", cmds_max,
1527                                ISCSI_MGMT_ITT_OFFSET, ISCSI_DEF_XMIT_CMDS_MAX);
1528                 cmds_max = ISCSI_DEF_XMIT_CMDS_MAX;
1529         }
1530
1531         shost = scsi_host_alloc(iscsit->host_template,
1532                                 hostdata_privsize(sizeof(*session)));
1533         if (!shost)
1534                 return NULL;
1535
1536         /* the iscsi layer takes one task for reserve */
1537         shost->can_queue = cmds_max - 1;
1538         shost->cmd_per_lun = qdepth;
1539         shost->max_id = 1;
1540         shost->max_channel = 0;
1541         shost->max_lun = iscsit->max_lun;
1542         shost->max_cmd_len = iscsit->max_cmd_len;
1543         shost->transportt = scsit;
1544         shost->transportt->create_work_queue = 1;
1545         *hostno = shost->host_no;
1546
1547         session = iscsi_hostdata(shost->hostdata);
1548         memset(session, 0, sizeof(struct iscsi_session));
1549         session->host = shost;
1550         session->state = ISCSI_STATE_FREE;
1551         session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
1552         session->cmds_max = cmds_max;
1553         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
1554         session->exp_cmdsn = initial_cmdsn + 1;
1555         session->max_cmdsn = initial_cmdsn + 1;
1556         session->max_r2t = 1;
1557         session->tt = iscsit;
1558         mutex_init(&session->eh_mutex);
1559
1560         /* initialize SCSI PDU commands pool */
1561         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
1562                             (void***)&session->cmds,
1563                             cmd_task_size + sizeof(struct iscsi_cmd_task)))
1564                 goto cmdpool_alloc_fail;
1565
1566         /* pre-format cmds pool with ITT */
1567         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1568                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1569
1570                 if (cmd_task_size)
1571                         ctask->dd_data = &ctask[1];
1572                 ctask->itt = cmd_i;
1573                 ctask->hdr_max = sizeof(struct iscsi_cmd);
1574                 INIT_LIST_HEAD(&ctask->running);
1575         }
1576
1577         spin_lock_init(&session->lock);
1578
1579         /* initialize immediate command pool */
1580         if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max,
1581                            (void***)&session->mgmt_cmds,
1582                            mgmt_task_size + sizeof(struct iscsi_mgmt_task)))
1583                 goto mgmtpool_alloc_fail;
1584
1585
1586         /* pre-format immediate cmds pool with ITT */
1587         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
1588                 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
1589
1590                 if (mgmt_task_size)
1591                         mtask->dd_data = &mtask[1];
1592                 mtask->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i;
1593                 INIT_LIST_HEAD(&mtask->running);
1594         }
1595
1596         if (scsi_add_host(shost, NULL))
1597                 goto add_host_fail;
1598
1599         if (!try_module_get(iscsit->owner))
1600                 goto cls_session_fail;
1601
1602         cls_session = iscsi_create_session(shost, iscsit, 0);
1603         if (!cls_session)
1604                 goto module_put;
1605         *(unsigned long*)shost->hostdata = (unsigned long)cls_session;
1606
1607         return cls_session;
1608
1609 module_put:
1610         module_put(iscsit->owner);
1611 cls_session_fail:
1612         scsi_remove_host(shost);
1613 add_host_fail:
1614         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1615 mgmtpool_alloc_fail:
1616         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1617 cmdpool_alloc_fail:
1618         scsi_host_put(shost);
1619         return NULL;
1620 }
1621 EXPORT_SYMBOL_GPL(iscsi_session_setup);
1622
1623 /**
1624  * iscsi_session_teardown - destroy session, host, and cls_session
1625  * shost: scsi host
1626  *
1627  * This can be used by software iscsi_transports that allocate
1628  * a session per scsi host.
1629  **/
1630 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
1631 {
1632         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1633         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1634         struct module *owner = cls_session->transport->owner;
1635
1636         iscsi_unblock_session(cls_session);
1637         scsi_remove_host(shost);
1638
1639         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1640         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1641
1642         kfree(session->password);
1643         kfree(session->password_in);
1644         kfree(session->username);
1645         kfree(session->username_in);
1646         kfree(session->targetname);
1647         kfree(session->netdev);
1648         kfree(session->hwaddress);
1649         kfree(session->initiatorname);
1650
1651         iscsi_destroy_session(cls_session);
1652         scsi_host_put(shost);
1653         module_put(owner);
1654 }
1655 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
1656
1657 /**
1658  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
1659  * @cls_session: iscsi_cls_session
1660  * @conn_idx: cid
1661  **/
1662 struct iscsi_cls_conn *
1663 iscsi_conn_setup(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1664 {
1665         struct iscsi_session *session = class_to_transport_session(cls_session);
1666         struct iscsi_conn *conn;
1667         struct iscsi_cls_conn *cls_conn;
1668         char *data;
1669
1670         cls_conn = iscsi_create_conn(cls_session, conn_idx);
1671         if (!cls_conn)
1672                 return NULL;
1673         conn = cls_conn->dd_data;
1674         memset(conn, 0, sizeof(*conn));
1675
1676         conn->session = session;
1677         conn->cls_conn = cls_conn;
1678         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
1679         conn->id = conn_idx;
1680         conn->exp_statsn = 0;
1681         conn->tmf_state = TMF_INITIAL;
1682         INIT_LIST_HEAD(&conn->run_list);
1683         INIT_LIST_HEAD(&conn->mgmt_run_list);
1684         INIT_LIST_HEAD(&conn->mgmtqueue);
1685         INIT_LIST_HEAD(&conn->xmitqueue);
1686         INIT_LIST_HEAD(&conn->requeue);
1687         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
1688
1689         /* allocate login_mtask used for the login/text sequences */
1690         spin_lock_bh(&session->lock);
1691         if (!__kfifo_get(session->mgmtpool.queue,
1692                          (void*)&conn->login_mtask,
1693                          sizeof(void*))) {
1694                 spin_unlock_bh(&session->lock);
1695                 goto login_mtask_alloc_fail;
1696         }
1697         spin_unlock_bh(&session->lock);
1698
1699         data = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN, GFP_KERNEL);
1700         if (!data)
1701                 goto login_mtask_data_alloc_fail;
1702         conn->login_mtask->data = conn->data = data;
1703
1704         init_timer(&conn->tmf_timer);
1705         init_waitqueue_head(&conn->ehwait);
1706
1707         return cls_conn;
1708
1709 login_mtask_data_alloc_fail:
1710         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1711                     sizeof(void*));
1712 login_mtask_alloc_fail:
1713         iscsi_destroy_conn(cls_conn);
1714         return NULL;
1715 }
1716 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
1717
1718 /**
1719  * iscsi_conn_teardown - teardown iscsi connection
1720  * cls_conn: iscsi class connection
1721  *
1722  * TODO: we may need to make this into a two step process
1723  * like scsi-mls remove + put host
1724  */
1725 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
1726 {
1727         struct iscsi_conn *conn = cls_conn->dd_data;
1728         struct iscsi_session *session = conn->session;
1729         unsigned long flags;
1730
1731         spin_lock_bh(&session->lock);
1732         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
1733         if (session->leadconn == conn) {
1734                 /*
1735                  * leading connection? then give up on recovery.
1736                  */
1737                 session->state = ISCSI_STATE_TERMINATE;
1738                 wake_up(&conn->ehwait);
1739         }
1740         spin_unlock_bh(&session->lock);
1741
1742         /*
1743          * Block until all in-progress commands for this connection
1744          * time out or fail.
1745          */
1746         for (;;) {
1747                 spin_lock_irqsave(session->host->host_lock, flags);
1748                 if (!session->host->host_busy) { /* OK for ERL == 0 */
1749                         spin_unlock_irqrestore(session->host->host_lock, flags);
1750                         break;
1751                 }
1752                 spin_unlock_irqrestore(session->host->host_lock, flags);
1753                 msleep_interruptible(500);
1754                 printk(KERN_INFO "iscsi: scsi conn_destroy(): host_busy %d "
1755                        "host_failed %d\n", session->host->host_busy,
1756                        session->host->host_failed);
1757                 /*
1758                  * force eh_abort() to unblock
1759                  */
1760                 wake_up(&conn->ehwait);
1761         }
1762
1763         /* flush queued up work because we free the connection below */
1764         iscsi_suspend_tx(conn);
1765
1766         spin_lock_bh(&session->lock);
1767         kfree(conn->data);
1768         kfree(conn->persistent_address);
1769         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1770                     sizeof(void*));
1771         if (session->leadconn == conn)
1772                 session->leadconn = NULL;
1773         spin_unlock_bh(&session->lock);
1774
1775         iscsi_destroy_conn(cls_conn);
1776 }
1777 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
1778
1779 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
1780 {
1781         struct iscsi_conn *conn = cls_conn->dd_data;
1782         struct iscsi_session *session = conn->session;
1783
1784         if (!session) {
1785                 printk(KERN_ERR "iscsi: can't start unbound connection\n");
1786                 return -EPERM;
1787         }
1788
1789         if ((session->imm_data_en || !session->initial_r2t_en) &&
1790              session->first_burst > session->max_burst) {
1791                 printk("iscsi: invalid burst lengths: "
1792                        "first_burst %d max_burst %d\n",
1793                        session->first_burst, session->max_burst);
1794                 return -EINVAL;
1795         }
1796
1797         spin_lock_bh(&session->lock);
1798         conn->c_stage = ISCSI_CONN_STARTED;
1799         session->state = ISCSI_STATE_LOGGED_IN;
1800         session->queued_cmdsn = session->cmdsn;
1801
1802         switch(conn->stop_stage) {
1803         case STOP_CONN_RECOVER:
1804                 /*
1805                  * unblock eh_abort() if it is blocked. re-try all
1806                  * commands after successful recovery
1807                  */
1808                 conn->stop_stage = 0;
1809                 conn->tmf_state = TMF_INITIAL;
1810                 session->age++;
1811                 spin_unlock_bh(&session->lock);
1812
1813                 iscsi_unblock_session(session_to_cls(session));
1814                 wake_up(&conn->ehwait);
1815                 return 0;
1816         case STOP_CONN_TERM:
1817                 conn->stop_stage = 0;
1818                 break;
1819         default:
1820                 break;
1821         }
1822         spin_unlock_bh(&session->lock);
1823
1824         return 0;
1825 }
1826 EXPORT_SYMBOL_GPL(iscsi_conn_start);
1827
1828 static void
1829 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
1830 {
1831         struct iscsi_mgmt_task *mtask, *tmp;
1832
1833         /* handle pending */
1834         list_for_each_entry_safe(mtask, tmp, &conn->mgmtqueue, running) {
1835                 debug_scsi("flushing pending mgmt task itt 0x%x\n", mtask->itt);
1836                 list_del_init(&mtask->running);
1837                 if (mtask == conn->login_mtask)
1838                         continue;
1839                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1840                             sizeof(void*));
1841         }
1842
1843         /* handle running */
1844         list_for_each_entry_safe(mtask, tmp, &conn->mgmt_run_list, running) {
1845                 debug_scsi("flushing running mgmt task itt 0x%x\n", mtask->itt);
1846                 list_del_init(&mtask->running);
1847
1848                 if (mtask == conn->login_mtask)
1849                         continue;
1850                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1851                            sizeof(void*));
1852         }
1853
1854         conn->mtask = NULL;
1855 }
1856
1857 static void iscsi_start_session_recovery(struct iscsi_session *session,
1858                                          struct iscsi_conn *conn, int flag)
1859 {
1860         int old_stop_stage;
1861
1862         mutex_lock(&session->eh_mutex);
1863         spin_lock_bh(&session->lock);
1864         if (conn->stop_stage == STOP_CONN_TERM) {
1865                 spin_unlock_bh(&session->lock);
1866                 mutex_unlock(&session->eh_mutex);
1867                 return;
1868         }
1869
1870         /*
1871          * The LLD either freed/unset the lock on us, or userspace called
1872          * stop but did not create a proper connection (connection was never
1873          * bound or it was unbound then stop was called).
1874          */
1875         if (!conn->recv_lock) {
1876                 spin_unlock_bh(&session->lock);
1877                 mutex_unlock(&session->eh_mutex);
1878                 return;
1879         }
1880
1881         /*
1882          * When this is called for the in_login state, we only want to clean
1883          * up the login task and connection. We do not need to block and set
1884          * the recovery state again
1885          */
1886         if (flag == STOP_CONN_TERM)
1887                 session->state = ISCSI_STATE_TERMINATE;
1888         else if (conn->stop_stage != STOP_CONN_RECOVER)
1889                 session->state = ISCSI_STATE_IN_RECOVERY;
1890
1891         old_stop_stage = conn->stop_stage;
1892         conn->stop_stage = flag;
1893         conn->c_stage = ISCSI_CONN_STOPPED;
1894         spin_unlock_bh(&session->lock);
1895
1896         iscsi_suspend_tx(conn);
1897
1898         write_lock_bh(conn->recv_lock);
1899         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1900         write_unlock_bh(conn->recv_lock);
1901
1902         /*
1903          * for connection level recovery we should not calculate
1904          * header digest. conn->hdr_size used for optimization
1905          * in hdr_extract() and will be re-negotiated at
1906          * set_param() time.
1907          */
1908         if (flag == STOP_CONN_RECOVER) {
1909                 conn->hdrdgst_en = 0;
1910                 conn->datadgst_en = 0;
1911                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
1912                     old_stop_stage != STOP_CONN_RECOVER) {
1913                         debug_scsi("blocking session\n");
1914                         iscsi_block_session(session_to_cls(session));
1915                 }
1916         }
1917
1918         /*
1919          * flush queues.
1920          */
1921         spin_lock_bh(&session->lock);
1922         fail_all_commands(conn, -1);
1923         flush_control_queues(session, conn);
1924         spin_unlock_bh(&session->lock);
1925         mutex_unlock(&session->eh_mutex);
1926 }
1927
1928 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1929 {
1930         struct iscsi_conn *conn = cls_conn->dd_data;
1931         struct iscsi_session *session = conn->session;
1932
1933         switch (flag) {
1934         case STOP_CONN_RECOVER:
1935         case STOP_CONN_TERM:
1936                 iscsi_start_session_recovery(session, conn, flag);
1937                 break;
1938         default:
1939                 printk(KERN_ERR "iscsi: invalid stop flag %d\n", flag);
1940         }
1941 }
1942 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
1943
1944 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
1945                     struct iscsi_cls_conn *cls_conn, int is_leading)
1946 {
1947         struct iscsi_session *session = class_to_transport_session(cls_session);
1948         struct iscsi_conn *conn = cls_conn->dd_data;
1949
1950         spin_lock_bh(&session->lock);
1951         if (is_leading)
1952                 session->leadconn = conn;
1953         spin_unlock_bh(&session->lock);
1954
1955         /*
1956          * Unblock xmitworker(), Login Phase will pass through.
1957          */
1958         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1959         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1960         return 0;
1961 }
1962 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
1963
1964
1965 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
1966                     enum iscsi_param param, char *buf, int buflen)
1967 {
1968         struct iscsi_conn *conn = cls_conn->dd_data;
1969         struct iscsi_session *session = conn->session;
1970         uint32_t value;
1971
1972         switch(param) {
1973         case ISCSI_PARAM_FAST_ABORT:
1974                 sscanf(buf, "%d", &session->fast_abort);
1975                 break;
1976         case ISCSI_PARAM_MAX_RECV_DLENGTH:
1977                 sscanf(buf, "%d", &conn->max_recv_dlength);
1978                 break;
1979         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
1980                 sscanf(buf, "%d", &conn->max_xmit_dlength);
1981                 break;
1982         case ISCSI_PARAM_HDRDGST_EN:
1983                 sscanf(buf, "%d", &conn->hdrdgst_en);
1984                 break;
1985         case ISCSI_PARAM_DATADGST_EN:
1986                 sscanf(buf, "%d", &conn->datadgst_en);
1987                 break;
1988         case ISCSI_PARAM_INITIAL_R2T_EN:
1989                 sscanf(buf, "%d", &session->initial_r2t_en);
1990                 break;
1991         case ISCSI_PARAM_MAX_R2T:
1992                 sscanf(buf, "%d", &session->max_r2t);
1993                 break;
1994         case ISCSI_PARAM_IMM_DATA_EN:
1995                 sscanf(buf, "%d", &session->imm_data_en);
1996                 break;
1997         case ISCSI_PARAM_FIRST_BURST:
1998                 sscanf(buf, "%d", &session->first_burst);
1999                 break;
2000         case ISCSI_PARAM_MAX_BURST:
2001                 sscanf(buf, "%d", &session->max_burst);
2002                 break;
2003         case ISCSI_PARAM_PDU_INORDER_EN:
2004                 sscanf(buf, "%d", &session->pdu_inorder_en);
2005                 break;
2006         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2007                 sscanf(buf, "%d", &session->dataseq_inorder_en);
2008                 break;
2009         case ISCSI_PARAM_ERL:
2010                 sscanf(buf, "%d", &session->erl);
2011                 break;
2012         case ISCSI_PARAM_IFMARKER_EN:
2013                 sscanf(buf, "%d", &value);
2014                 BUG_ON(value);
2015                 break;
2016         case ISCSI_PARAM_OFMARKER_EN:
2017                 sscanf(buf, "%d", &value);
2018                 BUG_ON(value);
2019                 break;
2020         case ISCSI_PARAM_EXP_STATSN:
2021                 sscanf(buf, "%u", &conn->exp_statsn);
2022                 break;
2023         case ISCSI_PARAM_USERNAME:
2024                 kfree(session->username);
2025                 session->username = kstrdup(buf, GFP_KERNEL);
2026                 if (!session->username)
2027                         return -ENOMEM;
2028                 break;
2029         case ISCSI_PARAM_USERNAME_IN:
2030                 kfree(session->username_in);
2031                 session->username_in = kstrdup(buf, GFP_KERNEL);
2032                 if (!session->username_in)
2033                         return -ENOMEM;
2034                 break;
2035         case ISCSI_PARAM_PASSWORD:
2036                 kfree(session->password);
2037                 session->password = kstrdup(buf, GFP_KERNEL);
2038                 if (!session->password)
2039                         return -ENOMEM;
2040                 break;
2041         case ISCSI_PARAM_PASSWORD_IN:
2042                 kfree(session->password_in);
2043                 session->password_in = kstrdup(buf, GFP_KERNEL);
2044                 if (!session->password_in)
2045                         return -ENOMEM;
2046                 break;
2047         case ISCSI_PARAM_TARGET_NAME:
2048                 /* this should not change between logins */
2049                 if (session->targetname)
2050                         break;
2051
2052                 session->targetname = kstrdup(buf, GFP_KERNEL);
2053                 if (!session->targetname)
2054                         return -ENOMEM;
2055                 break;
2056         case ISCSI_PARAM_TPGT:
2057                 sscanf(buf, "%d", &session->tpgt);
2058                 break;
2059         case ISCSI_PARAM_PERSISTENT_PORT:
2060                 sscanf(buf, "%d", &conn->persistent_port);
2061                 break;
2062         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2063                 /*
2064                  * this is the address returned in discovery so it should
2065                  * not change between logins.
2066                  */
2067                 if (conn->persistent_address)
2068                         break;
2069
2070                 conn->persistent_address = kstrdup(buf, GFP_KERNEL);
2071                 if (!conn->persistent_address)
2072                         return -ENOMEM;
2073                 break;
2074         default:
2075                 return -ENOSYS;
2076         }
2077
2078         return 0;
2079 }
2080 EXPORT_SYMBOL_GPL(iscsi_set_param);
2081
2082 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
2083                             enum iscsi_param param, char *buf)
2084 {
2085         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
2086         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2087         int len;
2088
2089         switch(param) {
2090         case ISCSI_PARAM_FAST_ABORT:
2091                 len = sprintf(buf, "%d\n", session->fast_abort);
2092                 break;
2093         case ISCSI_PARAM_INITIAL_R2T_EN:
2094                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
2095                 break;
2096         case ISCSI_PARAM_MAX_R2T:
2097                 len = sprintf(buf, "%hu\n", session->max_r2t);
2098                 break;
2099         case ISCSI_PARAM_IMM_DATA_EN:
2100                 len = sprintf(buf, "%d\n", session->imm_data_en);
2101                 break;
2102         case ISCSI_PARAM_FIRST_BURST:
2103                 len = sprintf(buf, "%u\n", session->first_burst);
2104                 break;
2105         case ISCSI_PARAM_MAX_BURST:
2106                 len = sprintf(buf, "%u\n", session->max_burst);
2107                 break;
2108         case ISCSI_PARAM_PDU_INORDER_EN:
2109                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
2110                 break;
2111         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2112                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
2113                 break;
2114         case ISCSI_PARAM_ERL:
2115                 len = sprintf(buf, "%d\n", session->erl);
2116                 break;
2117         case ISCSI_PARAM_TARGET_NAME:
2118                 len = sprintf(buf, "%s\n", session->targetname);
2119                 break;
2120         case ISCSI_PARAM_TPGT:
2121                 len = sprintf(buf, "%d\n", session->tpgt);
2122                 break;
2123         case ISCSI_PARAM_USERNAME:
2124                 len = sprintf(buf, "%s\n", session->username);
2125                 break;
2126         case ISCSI_PARAM_USERNAME_IN:
2127                 len = sprintf(buf, "%s\n", session->username_in);
2128                 break;
2129         case ISCSI_PARAM_PASSWORD:
2130                 len = sprintf(buf, "%s\n", session->password);
2131                 break;
2132         case ISCSI_PARAM_PASSWORD_IN:
2133                 len = sprintf(buf, "%s\n", session->password_in);
2134                 break;
2135         default:
2136                 return -ENOSYS;
2137         }
2138
2139         return len;
2140 }
2141 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
2142
2143 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2144                          enum iscsi_param param, char *buf)
2145 {
2146         struct iscsi_conn *conn = cls_conn->dd_data;
2147         int len;
2148
2149         switch(param) {
2150         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2151                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
2152                 break;
2153         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2154                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
2155                 break;
2156         case ISCSI_PARAM_HDRDGST_EN:
2157                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
2158                 break;
2159         case ISCSI_PARAM_DATADGST_EN:
2160                 len = sprintf(buf, "%d\n", conn->datadgst_en);
2161                 break;
2162         case ISCSI_PARAM_IFMARKER_EN:
2163                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
2164                 break;
2165         case ISCSI_PARAM_OFMARKER_EN:
2166                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
2167                 break;
2168         case ISCSI_PARAM_EXP_STATSN:
2169                 len = sprintf(buf, "%u\n", conn->exp_statsn);
2170                 break;
2171         case ISCSI_PARAM_PERSISTENT_PORT:
2172                 len = sprintf(buf, "%d\n", conn->persistent_port);
2173                 break;
2174         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2175                 len = sprintf(buf, "%s\n", conn->persistent_address);
2176                 break;
2177         default:
2178                 return -ENOSYS;
2179         }
2180
2181         return len;
2182 }
2183 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
2184
2185 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2186                          char *buf)
2187 {
2188         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2189         int len;
2190
2191         switch (param) {
2192         case ISCSI_HOST_PARAM_NETDEV_NAME:
2193                 if (!session->netdev)
2194                         len = sprintf(buf, "%s\n", "default");
2195                 else
2196                         len = sprintf(buf, "%s\n", session->netdev);
2197                 break;
2198         case ISCSI_HOST_PARAM_HWADDRESS:
2199                 if (!session->hwaddress)
2200                         len = sprintf(buf, "%s\n", "default");
2201                 else
2202                         len = sprintf(buf, "%s\n", session->hwaddress);
2203                 break;
2204         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2205                 if (!session->initiatorname)
2206                         len = sprintf(buf, "%s\n", "unknown");
2207                 else
2208                         len = sprintf(buf, "%s\n", session->initiatorname);
2209                 break;
2210
2211         default:
2212                 return -ENOSYS;
2213         }
2214
2215         return len;
2216 }
2217 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
2218
2219 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2220                          char *buf, int buflen)
2221 {
2222         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2223
2224         switch (param) {
2225         case ISCSI_HOST_PARAM_NETDEV_NAME:
2226                 if (!session->netdev)
2227                         session->netdev = kstrdup(buf, GFP_KERNEL);
2228                 break;
2229         case ISCSI_HOST_PARAM_HWADDRESS:
2230                 if (!session->hwaddress)
2231                         session->hwaddress = kstrdup(buf, GFP_KERNEL);
2232                 break;
2233         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2234                 if (!session->initiatorname)
2235                         session->initiatorname = kstrdup(buf, GFP_KERNEL);
2236                 break;
2237         default:
2238                 return -ENOSYS;
2239         }
2240
2241         return 0;
2242 }
2243 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
2244
2245 MODULE_AUTHOR("Mike Christie");
2246 MODULE_DESCRIPTION("iSCSI library functions");
2247 MODULE_LICENSE("GPL");