git.oblomov.eu Git - linux-2.6/blob - drivers/scsi/libiscsi.c

   1 /*
   2  * iSCSI lib functions
   3  *
   4  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   5  * Copyright (C) 2004 - 2006 Mike Christie
   6  * Copyright (C) 2004 - 2005 Dmitry Yusupov
   7  * Copyright (C) 2004 - 2005 Alex Aizman
   8  * maintained by open-iscsi@googlegroups.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  */
  24 #include <linux/types.h>
  25 #include <linux/mutex.h>
  26 #include <linux/kfifo.h>
  27 #include <linux/delay.h>
  28 #include <net/tcp.h>
  29 #include <scsi/scsi_cmnd.h>
  30 #include <scsi/scsi_device.h>
  31 #include <scsi/scsi_eh.h>
  32 #include <scsi/scsi_tcq.h>
  33 #include <scsi/scsi_host.h>
  34 #include <scsi/scsi.h>
  35 #include <scsi/iscsi_proto.h>
  36 #include <scsi/scsi_transport.h>
  37 #include <scsi/scsi_transport_iscsi.h>
  38 #include <scsi/libiscsi.h>
  39
  40 struct iscsi_session *
  41 class_to_transport_session(struct iscsi_cls_session *cls_session)
  42 {
  43         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
  44         return iscsi_hostdata(shost->hostdata);
  45 }
  46 EXPORT_SYMBOL_GPL(class_to_transport_session);
  47
  48 #define INVALID_SN_DELTA        0xffff
  49
  50 int
  51 iscsi_check_assign_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
  52 {
  53         uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
  54         uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);
  55
  56         if (max_cmdsn < exp_cmdsn -1 &&
  57             max_cmdsn > exp_cmdsn - INVALID_SN_DELTA)
  58                 return ISCSI_ERR_MAX_CMDSN;
  59         if (max_cmdsn > session->max_cmdsn ||
  60             max_cmdsn < session->max_cmdsn - INVALID_SN_DELTA)
  61                 session->max_cmdsn = max_cmdsn;
  62         if (exp_cmdsn > session->exp_cmdsn ||
  63             exp_cmdsn < session->exp_cmdsn - INVALID_SN_DELTA)
  64                 session->exp_cmdsn = exp_cmdsn;
  65
  66         return 0;
  67 }
  68 EXPORT_SYMBOL_GPL(iscsi_check_assign_cmdsn);
  69
  70 void iscsi_prep_unsolicit_data_pdu(struct iscsi_cmd_task *ctask,
  71                                    struct iscsi_data *hdr,
  72                                    int transport_data_cnt)
  73 {
  74         struct iscsi_conn *conn = ctask->conn;
  75
  76         memset(hdr, 0, sizeof(struct iscsi_data));
  77         hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
  78         hdr->datasn = cpu_to_be32(ctask->unsol_datasn);
  79         ctask->unsol_datasn++;
  80         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
  81         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
  82
  83         hdr->itt = ctask->hdr->itt;
  84         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
  85
  86         hdr->offset = cpu_to_be32(ctask->total_length -
  87                                   transport_data_cnt -
  88                                   ctask->unsol_count);
  89
  90         if (ctask->unsol_count > conn->max_xmit_dlength) {
  91                 hton24(hdr->dlength, conn->max_xmit_dlength);
  92                 ctask->data_count = conn->max_xmit_dlength;
  93                 hdr->flags = 0;
  94         } else {
  95                 hton24(hdr->dlength, ctask->unsol_count);
  96                 ctask->data_count = ctask->unsol_count;
  97                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
  98         }
  99 }
 100 EXPORT_SYMBOL_GPL(iscsi_prep_unsolicit_data_pdu);
 101
 102 /**
 103  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 104  * @ctask: iscsi cmd task
 105  *
 106  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 107  * fields like dlength or final based on how much data it sends
 108  */
 109 static void iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
 110 {
 111         struct iscsi_conn *conn = ctask->conn;
 112         struct iscsi_session *session = conn->session;
 113         struct iscsi_cmd *hdr = ctask->hdr;
 114         struct scsi_cmnd *sc = ctask->sc;
 115
 116         hdr->opcode = ISCSI_OP_SCSI_CMD;
 117         hdr->flags = ISCSI_ATTR_SIMPLE;
 118         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
 119         hdr->itt = ctask->itt | (conn->id << ISCSI_CID_SHIFT) |
 120                          (session->age << ISCSI_AGE_SHIFT);
 121         hdr->data_length = cpu_to_be32(sc->request_bufflen);
 122         hdr->cmdsn = cpu_to_be32(session->cmdsn);
 123         session->cmdsn++;
 124         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 125         memcpy(hdr->cdb, sc->cmnd, sc->cmd_len);
 126         memset(&hdr->cdb[sc->cmd_len], 0, MAX_COMMAND_SIZE - sc->cmd_len);
 127
 128         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 129                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 130                 /*
 131                  * Write counters:
 132                  *
 133                  *      imm_count       bytes to be sent right after
 134                  *                      SCSI PDU Header
 135                  *
 136                  *      unsol_count     bytes(as Data-Out) to be sent
 137                  *                      without R2T ack right after
 138                  *                      immediate data
 139                  *
 140                  *      r2t_data_count  bytes to be sent via R2T ack's
 141                  *
 142                  *      pad_count       bytes to be sent as zero-padding
 143                  */
 144                 ctask->imm_count = 0;
 145                 ctask->unsol_count = 0;
 146                 ctask->unsol_datasn = 0;
 147
 148                 if (session->imm_data_en) {
 149                         if (ctask->total_length >= session->first_burst)
 150                                 ctask->imm_count = min(session->first_burst,
 151                                                         conn->max_xmit_dlength);
 152                         else
 153                                 ctask->imm_count = min(ctask->total_length,
 154                                                         conn->max_xmit_dlength);
 155                         hton24(ctask->hdr->dlength, ctask->imm_count);
 156                 } else
 157                         zero_data(ctask->hdr->dlength);
 158
 159                 if (!session->initial_r2t_en)
 160                         ctask->unsol_count = min(session->first_burst,
 161                                 ctask->total_length) - ctask->imm_count;
 162                 if (!ctask->unsol_count)
 163                         /* No unsolicit Data-Out's */
 164                         ctask->hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 165         } else {
 166                 ctask->datasn = 0;
 167                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 168                 zero_data(hdr->dlength);
 169
 170                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
 171                         hdr->flags |= ISCSI_FLAG_CMD_READ;
 172         }
 173
 174         conn->scsicmd_pdus_cnt++;
 175 }
 176 EXPORT_SYMBOL_GPL(iscsi_prep_scsi_cmd_pdu);
 177
 178 /**
 179  * iscsi_complete_command - return command back to scsi-ml
 180  * @session: iscsi session
 181  * @ctask: iscsi cmd task
 182  *
 183  * Must be called with session lock.
 184  * This function returns the scsi command to scsi-ml and returns
 185  * the cmd task to the pool of available cmd tasks.
 186  */
 187 static void iscsi_complete_command(struct iscsi_session *session,
 188                                    struct iscsi_cmd_task *ctask)
 189 {
 190         struct scsi_cmnd *sc = ctask->sc;
 191
 192         ctask->sc = NULL;
 193         list_del_init(&ctask->running);
 194         __kfifo_put(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
 195         sc->scsi_done(sc);
 196 }
 197
 198 /**
 199  * iscsi_cmd_rsp - SCSI Command Response processing
 200  * @conn: iscsi connection
 201  * @hdr: iscsi header
 202  * @ctask: scsi command task
 203  * @data: cmd data buffer
 204  * @datalen: len of buffer
 205  *
 206  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 207  * then completes the command and task.
 208  **/
 209 static int iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 210                               struct iscsi_cmd_task *ctask, char *data,
 211                               int datalen)
 212 {
 213         int rc;
 214         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
 215         struct iscsi_session *session = conn->session;
 216         struct scsi_cmnd *sc = ctask->sc;
 217
 218         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
 219         if (rc) {
 220                 sc->result = DID_ERROR << 16;
 221                 goto out;
 222         }
 223
 224         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 225
 226         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 227
 228         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 229                 sc->result = DID_ERROR << 16;
 230                 goto out;
 231         }
 232
 233         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 234                 int senselen;
 235
 236                 if (datalen < 2) {
 237 invalid_datalen:
 238                         printk(KERN_ERR "iscsi: Got CHECK_CONDITION but "
 239                                "invalid data buffer size of %d\n", datalen);
 240                         sc->result = DID_BAD_TARGET << 16;
 241                         goto out;
 242                 }
 243
 244                 senselen = (data[0] << 8) | data[1];
 245                 if (datalen < senselen)
 246                         goto invalid_datalen;
 247
 248                 memcpy(sc->sense_buffer, data + 2,
 249                        min(senselen, SCSI_SENSE_BUFFERSIZE));
 250                 debug_scsi("copied %d bytes of sense\n",
 251                            min(senselen, SCSI_SENSE_BUFFERSIZE));
 252         }
 253
 254         if (sc->sc_data_direction == DMA_TO_DEVICE)
 255                 goto out;
 256
 257         if (rhdr->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
 258                 int res_count = be32_to_cpu(rhdr->residual_count);
 259
 260                 if (res_count > 0 && res_count <= sc->request_bufflen)
 261                         sc->resid = res_count;
 262                 else
 263                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 264         } else if (rhdr->flags & ISCSI_FLAG_CMD_BIDI_UNDERFLOW)
 265                 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 266         else if (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW)
 267                 sc->resid = be32_to_cpu(rhdr->residual_count);
 268
 269 out:
 270         debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 271                    (long)sc, sc->result, ctask->itt);
 272         conn->scsirsp_pdus_cnt++;
 273
 274         iscsi_complete_command(conn->session, ctask);
 275         return rc;
 276 }
 277
 278 /**
 279  * __iscsi_complete_pdu - complete pdu
 280  * @conn: iscsi conn
 281  * @hdr: iscsi header
 282  * @data: data buffer
 283  * @datalen: len of data buffer
 284  *
 285  * Completes pdu processing by freeing any resources allocated at
 286  * queuecommand or send generic. session lock must be held and verify
 287  * itt must have been called.
 288  */
 289 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 290                          char *data, int datalen)
 291 {
 292         struct iscsi_session *session = conn->session;
 293         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
 294         struct iscsi_cmd_task *ctask;
 295         struct iscsi_mgmt_task *mtask;
 296         uint32_t itt;
 297
 298         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG))
 299                 itt = hdr->itt & ISCSI_ITT_MASK;
 300         else
 301                 itt = hdr->itt;
 302
 303         if (itt < session->cmds_max) {
 304                 ctask = session->cmds[itt];
 305
 306                 debug_scsi("cmdrsp [op 0x%x cid %d itt 0x%x len %d]\n",
 307                            opcode, conn->id, ctask->itt, datalen);
 308
 309                 switch(opcode) {
 310                 case ISCSI_OP_SCSI_CMD_RSP:
 311                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 312                         rc = iscsi_scsi_cmd_rsp(conn, hdr, ctask, data,
 313                                                 datalen);
 314                         break;
 315                 case ISCSI_OP_SCSI_DATA_IN:
 316                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 317                         if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
 318                                 conn->scsirsp_pdus_cnt++;
 319                                 iscsi_complete_command(session, ctask);
 320                         }
 321                         break;
 322                 case ISCSI_OP_R2T:
 323                         /* LLD handles this for now */
 324                         break;
 325                 default:
 326                         rc = ISCSI_ERR_BAD_OPCODE;
 327                         break;
 328                 }
 329         } else if (itt >= ISCSI_MGMT_ITT_OFFSET &&
 330                    itt < ISCSI_MGMT_ITT_OFFSET + session->mgmtpool_max) {
 331                 mtask = session->mgmt_cmds[itt - ISCSI_MGMT_ITT_OFFSET];
 332
 333                 debug_scsi("immrsp [op 0x%x cid %d itt 0x%x len %d]\n",
 334                            opcode, conn->id, mtask->itt, datalen);
 335
 336                 rc = iscsi_check_assign_cmdsn(session,
 337                                               (struct iscsi_nopin*)hdr);
 338                 if (rc)
 339                         goto done;
 340
 341                 switch(opcode) {
 342                 case ISCSI_OP_LOGOUT_RSP:
 343                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 344                         /* fall through */
 345                 case ISCSI_OP_LOGIN_RSP:
 346                 case ISCSI_OP_TEXT_RSP:
 347                         /*
 348                          * login related PDU's exp_statsn is handled in
 349                          * userspace
 350                          */
 351                         rc = iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen);
 352                         list_del(&mtask->running);
 353                         if (conn->login_mtask != mtask)
 354                                 __kfifo_put(session->mgmtpool.queue,
 355                                             (void*)&mtask, sizeof(void*));
 356                         break;
 357                 case ISCSI_OP_SCSI_TMFUNC_RSP:
 358                         if (datalen) {
 359                                 rc = ISCSI_ERR_PROTO;
 360                                 break;
 361                         }
 362
 363                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 364                         conn->tmfrsp_pdus_cnt++;
 365                         if (conn->tmabort_state == TMABORT_INITIAL) {
 366                                 conn->tmabort_state =
 367                                         ((struct iscsi_tm_rsp *)hdr)->
 368                                         response == ISCSI_TMF_RSP_COMPLETE ?
 369                                                 TMABORT_SUCCESS:TMABORT_FAILED;
 370                                 /* unblock eh_abort() */
 371                                 wake_up(&conn->ehwait);
 372                         }
 373                         break;
 374                 case ISCSI_OP_NOOP_IN:
 375                         if (hdr->ttt != ISCSI_RESERVED_TAG) {
 376                                 rc = ISCSI_ERR_PROTO;
 377                                 break;
 378                         }
 379                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 380
 381                         rc = iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen);
 382                         list_del(&mtask->running);
 383                         if (conn->login_mtask != mtask)
 384                                 __kfifo_put(session->mgmtpool.queue,
 385                                             (void*)&mtask, sizeof(void*));
 386                         break;
 387                 default:
 388                         rc = ISCSI_ERR_BAD_OPCODE;
 389                         break;
 390                 }
 391         } else if (itt == ISCSI_RESERVED_TAG) {
 392                 switch(opcode) {
 393                 case ISCSI_OP_NOOP_IN:
 394                         if (!datalen) {
 395                                 rc = iscsi_check_assign_cmdsn(session,
 396                                                  (struct iscsi_nopin*)hdr);
 397                                 if (!rc && hdr->ttt != ISCSI_RESERVED_TAG)
 398                                         rc = iscsi_recv_pdu(conn->cls_conn,
 399                                                             hdr, NULL, 0);
 400                         } else
 401                                 rc = ISCSI_ERR_PROTO;
 402                         break;
 403                 case ISCSI_OP_REJECT:
 404                         /* we need sth like iscsi_reject_rsp()*/
 405                 case ISCSI_OP_ASYNC_EVENT:
 406                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 407                         /* we need sth like iscsi_async_event_rsp() */
 408                         rc = ISCSI_ERR_BAD_OPCODE;
 409                         break;
 410                 default:
 411                         rc = ISCSI_ERR_BAD_OPCODE;
 412                         break;
 413                 }
 414         } else
 415                 rc = ISCSI_ERR_BAD_ITT;
 416
 417 done:
 418         return rc;
 419 }
 420 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
 421
 422 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 423                        char *data, int datalen)
 424 {
 425         int rc;
 426
 427         spin_lock(&conn->session->lock);
 428         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
 429         spin_unlock(&conn->session->lock);
 430         return rc;
 431 }
 432 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
 433
 434 /* verify itt (itt encoding: age+cid+itt) */
 435 int iscsi_verify_itt(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 436                      uint32_t *ret_itt)
 437 {
 438         struct iscsi_session *session = conn->session;
 439         struct iscsi_cmd_task *ctask;
 440         uint32_t itt;
 441
 442         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
 443                 if ((hdr->itt & ISCSI_AGE_MASK) !=
 444                     (session->age << ISCSI_AGE_SHIFT)) {
 445                         printk(KERN_ERR "iscsi: received itt %x expected "
 446                                 "session age (%x)\n", hdr->itt,
 447                                 session->age & ISCSI_AGE_MASK);
 448                         return ISCSI_ERR_BAD_ITT;
 449                 }
 450
 451                 if ((hdr->itt & ISCSI_CID_MASK) !=
 452                     (conn->id << ISCSI_CID_SHIFT)) {
 453                         printk(KERN_ERR "iscsi: received itt %x, expected "
 454                                 "CID (%x)\n", hdr->itt, conn->id);
 455                         return ISCSI_ERR_BAD_ITT;
 456                 }
 457                 itt = hdr->itt & ISCSI_ITT_MASK;
 458         } else
 459                 itt = hdr->itt;
 460
 461         if (itt < session->cmds_max) {
 462                 ctask = session->cmds[itt];
 463
 464                 if (!ctask->sc) {
 465                         printk(KERN_INFO "iscsi: dropping ctask with "
 466                                "itt 0x%x\n", ctask->itt);
 467                         /* force drop */
 468                         return ISCSI_ERR_NO_SCSI_CMD;
 469                 }
 470
 471                 if (ctask->sc->SCp.phase != session->age) {
 472                         printk(KERN_ERR "iscsi: ctask's session age %d, "
 473                                 "expected %d\n", ctask->sc->SCp.phase,
 474                                 session->age);
 475                         return ISCSI_ERR_SESSION_FAILED;
 476                 }
 477         }
 478
 479         *ret_itt = itt;
 480         return 0;
 481 }
 482 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
 483
 484 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
 485 {
 486         struct iscsi_session *session = conn->session;
 487         unsigned long flags;
 488
 489         spin_lock_irqsave(&session->lock, flags);
 490         if (session->state == ISCSI_STATE_FAILED) {
 491                 spin_unlock_irqrestore(&session->lock, flags);
 492                 return;
 493         }
 494
 495         if (session->conn_cnt == 1 || session->leadconn == conn)
 496                 session->state = ISCSI_STATE_FAILED;
 497         spin_unlock_irqrestore(&session->lock, flags);
 498         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
 499         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
 500         iscsi_conn_error(conn->cls_conn, err);
 501 }
 502 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
 503
 504 /**
 505  * iscsi_data_xmit - xmit any command into the scheduled connection
 506  * @conn: iscsi connection
 507  *
 508  * Notes:
 509  *      The function can return -EAGAIN in which case the caller must
 510  *      re-schedule it again later or recover. '0' return code means
 511  *      successful xmit.
 512  **/
 513 static int iscsi_data_xmit(struct iscsi_conn *conn)
 514 {
 515         struct iscsi_transport *tt;
 516
 517         if (unlikely(conn->suspend_tx)) {
 518                 debug_scsi("conn %d Tx suspended!\n", conn->id);
 519                 return 0;
 520         }
 521         tt = conn->session->tt;
 522
 523         /*
 524          * Transmit in the following order:
 525          *
 526          * 1) un-finished xmit (ctask or mtask)
 527          * 2) immediate control PDUs
 528          * 3) write data
 529          * 4) SCSI commands
 530          * 5) non-immediate control PDUs
 531          *
 532          * No need to lock around __kfifo_get as long as
 533          * there's one producer and one consumer.
 534          */
 535
 536         BUG_ON(conn->ctask && conn->mtask);
 537
 538         if (conn->ctask) {
 539                 if (tt->xmit_cmd_task(conn, conn->ctask))
 540                         goto again;
 541                 /* done with this in-progress ctask */
 542                 conn->ctask = NULL;
 543         }
 544         if (conn->mtask) {
 545                 if (tt->xmit_mgmt_task(conn, conn->mtask))
 546                         goto again;
 547                 /* done with this in-progress mtask */
 548                 conn->mtask = NULL;
 549         }
 550
 551         /* process immediate first */
 552         if (unlikely(__kfifo_len(conn->immqueue))) {
 553                 while (__kfifo_get(conn->immqueue, (void*)&conn->mtask,
 554                                    sizeof(void*))) {
 555                         list_add_tail(&conn->mtask->running,
 556                                       &conn->mgmt_run_list);
 557                         if (tt->xmit_mgmt_task(conn, conn->mtask))
 558                                 goto again;
 559                 }
 560                 /* done with this mtask */
 561                 conn->mtask = NULL;
 562         }
 563
 564         /* process command queue */
 565         while (__kfifo_get(conn->xmitqueue, (void*)&conn->ctask,
 566                            sizeof(void*))) {
 567                 /*
 568                  * iscsi tcp may readd the task to the xmitqueue to send
 569                  * write data
 570                  */
 571                 if (list_empty(&conn->ctask->running))
 572                         list_add_tail(&conn->ctask->running, &conn->run_list);
 573                 if (tt->xmit_cmd_task(conn, conn->ctask))
 574                         goto again;
 575         }
 576         /* done with this ctask */
 577         conn->ctask = NULL;
 578
 579         /* process the rest control plane PDUs, if any */
 580         if (unlikely(__kfifo_len(conn->mgmtqueue))) {
 581                 while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask,
 582                                    sizeof(void*))) {
 583                         list_add_tail(&conn->mtask->running,
 584                                       &conn->mgmt_run_list);
 585                         if (tt->xmit_mgmt_task(conn, conn->mtask))
 586                                 goto again;
 587                 }
 588                 /* done with this mtask */
 589                 conn->mtask = NULL;
 590         }
 591
 592         return 0;
 593
 594 again:
 595         if (unlikely(conn->suspend_tx))
 596                 return 0;
 597
 598         return -EAGAIN;
 599 }
 600
 601 static void iscsi_xmitworker(void *data)
 602 {
 603         struct iscsi_conn *conn = data;
 604
 605         /*
 606          * serialize Xmit worker on a per-connection basis.
 607          */
 608         mutex_lock(&conn->xmitmutex);
 609         if (iscsi_data_xmit(conn))
 610                 scsi_queue_work(conn->session->host, &conn->xmitwork);
 611         mutex_unlock(&conn->xmitmutex);
 612 }
 613
 614 enum {
 615         FAILURE_BAD_HOST = 1,
 616         FAILURE_SESSION_FAILED,
 617         FAILURE_SESSION_FREED,
 618         FAILURE_WINDOW_CLOSED,
 619         FAILURE_SESSION_TERMINATE,
 620         FAILURE_SESSION_IN_RECOVERY,
 621         FAILURE_SESSION_RECOVERY_TIMEOUT,
 622 };
 623
 624 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
 625 {
 626         struct Scsi_Host *host;
 627         int reason = 0;
 628         struct iscsi_session *session;
 629         struct iscsi_conn *conn;
 630         struct iscsi_cmd_task *ctask = NULL;
 631
 632         sc->scsi_done = done;
 633         sc->result = 0;
 634
 635         host = sc->device->host;
 636         session = iscsi_hostdata(host->hostdata);
 637
 638         spin_lock(&session->lock);
 639
 640         /*
 641          * ISCSI_STATE_FAILED is a temp. state. The recovery
 642          * code will decide what is best to do with command queued
 643          * during this time
 644          */
 645         if (session->state != ISCSI_STATE_LOGGED_IN &&
 646             session->state != ISCSI_STATE_FAILED) {
 647                 /*
 648                  * to handle the race between when we set the recovery state
 649                  * and block the session we requeue here (commands could
 650                  * be entering our queuecommand while a block is starting
 651                  * up because the block code is not locked)
 652                  */
 653                 if (session->state == ISCSI_STATE_IN_RECOVERY) {
 654                         reason = FAILURE_SESSION_IN_RECOVERY;
 655                         goto fault;
 656                 }
 657
 658                 if (session->state == ISCSI_STATE_RECOVERY_FAILED)
 659                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
 660                 else if (session->state == ISCSI_STATE_TERMINATE)
 661                         reason = FAILURE_SESSION_TERMINATE;
 662                 else
 663                         reason = FAILURE_SESSION_FREED;
 664                 goto fault;
 665         }
 666
 667         /*
 668          * Check for iSCSI window and take care of CmdSN wrap-around
 669          */
 670         if ((int)(session->max_cmdsn - session->cmdsn) < 0) {
 671                 reason = FAILURE_WINDOW_CLOSED;
 672                 goto reject;
 673         }
 674
 675         conn = session->leadconn;
 676
 677         __kfifo_get(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
 678         sc->SCp.phase = session->age;
 679         sc->SCp.ptr = (char *)ctask;
 680
 681         ctask->mtask = NULL;
 682         ctask->conn = conn;
 683         ctask->sc = sc;
 684         INIT_LIST_HEAD(&ctask->running);
 685         ctask->total_length = sc->request_bufflen;
 686         iscsi_prep_scsi_cmd_pdu(ctask);
 687
 688         session->tt->init_cmd_task(ctask);
 689
 690         __kfifo_put(conn->xmitqueue, (void*)&ctask, sizeof(void*));
 691         debug_scsi(
 692                "ctask enq [%s cid %d sc %lx itt 0x%x len %d cmdsn %d win %d]\n",
 693                 sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
 694                 conn->id, (long)sc, ctask->itt, sc->request_bufflen,
 695                 session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
 696         spin_unlock(&session->lock);
 697
 698         scsi_queue_work(host, &conn->xmitwork);
 699         return 0;
 700
 701 reject:
 702         spin_unlock(&session->lock);
 703         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
 704         return SCSI_MLQUEUE_HOST_BUSY;
 705
 706 fault:
 707         spin_unlock(&session->lock);
 708         printk(KERN_ERR "iscsi: cmd 0x%x is not queued (%d)\n",
 709                sc->cmnd[0], reason);
 710         sc->result = (DID_NO_CONNECT << 16);
 711         sc->resid = sc->request_bufflen;
 712         sc->scsi_done(sc);
 713         return 0;
 714 }
 715 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
 716
 717 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
 718 {
 719         if (depth > ISCSI_MAX_CMD_PER_LUN)
 720                 depth = ISCSI_MAX_CMD_PER_LUN;
 721         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 722         return sdev->queue_depth;
 723 }
 724 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
 725
 726 static int
 727 iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 728                         char *data, uint32_t data_size)
 729 {
 730         struct iscsi_session *session = conn->session;
 731         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 732         struct iscsi_mgmt_task *mtask;
 733
 734         spin_lock_bh(&session->lock);
 735         if (session->state == ISCSI_STATE_TERMINATE) {
 736                 spin_unlock_bh(&session->lock);
 737                 return -EPERM;
 738         }
 739         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
 740             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 741                 /*
 742                  * Login and Text are sent serially, in
 743                  * request-followed-by-response sequence.
 744                  * Same mtask can be used. Same ITT must be used.
 745                  * Note that login_mtask is preallocated at conn_create().
 746                  */
 747                 mtask = conn->login_mtask;
 748         else {
 749                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 750                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 751
 752                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 753                 if (!__kfifo_get(session->mgmtpool.queue,
 754                                  (void*)&mtask, sizeof(void*))) {
 755                         spin_unlock_bh(&session->lock);
 756                         return -ENOSPC;
 757                 }
 758         }
 759
 760         /*
 761          * pre-format CmdSN for outgoing PDU.
 762          */
 763         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
 764                 hdr->itt = mtask->itt | (conn->id << ISCSI_CID_SHIFT) |
 765                            (session->age << ISCSI_AGE_SHIFT);
 766                 nop->cmdsn = cpu_to_be32(session->cmdsn);
 767                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 768                     !(hdr->opcode & ISCSI_OP_IMMEDIATE))
 769                         session->cmdsn++;
 770         } else
 771                 /* do not advance CmdSN */
 772                 nop->cmdsn = cpu_to_be32(session->cmdsn);
 773
 774         if (data_size) {
 775                 memcpy(mtask->data, data, data_size);
 776                 mtask->data_count = data_size;
 777         } else
 778                 mtask->data_count = 0;
 779
 780         INIT_LIST_HEAD(&mtask->running);
 781         memcpy(mtask->hdr, hdr, sizeof(struct iscsi_hdr));
 782         if (session->tt->init_mgmt_task)
 783                 session->tt->init_mgmt_task(conn, mtask, data, data_size);
 784         spin_unlock_bh(&session->lock);
 785
 786         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
 787                    hdr->opcode, hdr->itt, data_size);
 788
 789         /*
 790          * since send_pdu() could be called at least from two contexts,
 791          * we need to serialize __kfifo_put, so we don't have to take
 792          * additional lock on fast data-path
 793          */
 794         if (hdr->opcode & ISCSI_OP_IMMEDIATE)
 795                 __kfifo_put(conn->immqueue, (void*)&mtask, sizeof(void*));
 796         else
 797                 __kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*));
 798
 799         scsi_queue_work(session->host, &conn->xmitwork);
 800         return 0;
 801 }
 802
 803 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 804                         char *data, uint32_t data_size)
 805 {
 806         struct iscsi_conn *conn = cls_conn->dd_data;
 807         int rc;
 808
 809         mutex_lock(&conn->xmitmutex);
 810         rc = iscsi_conn_send_generic(conn, hdr, data, data_size);
 811         mutex_unlock(&conn->xmitmutex);
 812
 813         return rc;
 814 }
 815 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 816
 817 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
 818 {
 819         struct iscsi_session *session = class_to_transport_session(cls_session);
 820         struct iscsi_conn *conn = session->leadconn;
 821
 822         spin_lock_bh(&session->lock);
 823         if (session->state != ISCSI_STATE_LOGGED_IN) {
 824                 session->state = ISCSI_STATE_RECOVERY_FAILED;
 825                 if (conn)
 826                         wake_up(&conn->ehwait);
 827         }
 828         spin_unlock_bh(&session->lock);
 829 }
 830 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
 831
 832 int iscsi_eh_host_reset(struct scsi_cmnd *sc)
 833 {
 834         struct Scsi_Host *host = sc->device->host;
 835         struct iscsi_session *session = iscsi_hostdata(host->hostdata);
 836         struct iscsi_conn *conn = session->leadconn;
 837         int fail_session = 0;
 838
 839         spin_lock_bh(&session->lock);
 840         if (session->state == ISCSI_STATE_TERMINATE) {
 841 failed:
 842                 debug_scsi("failing host reset: session terminated "
 843                            "[CID %d age %d]", conn->id, session->age);
 844                 spin_unlock_bh(&session->lock);
 845                 return FAILED;
 846         }
 847
 848         if (sc->SCp.phase == session->age) {
 849                 debug_scsi("failing connection CID %d due to SCSI host reset",
 850                            conn->id);
 851                 fail_session = 1;
 852         }
 853         spin_unlock_bh(&session->lock);
 854
 855         /*
 856          * we drop the lock here but the leadconn cannot be destoyed while
 857          * we are in the scsi eh
 858          */
 859         if (fail_session)
 860                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 861
 862         debug_scsi("iscsi_eh_host_reset wait for relogin\n");
 863         wait_event_interruptible(conn->ehwait,
 864                                  session->state == ISCSI_STATE_TERMINATE ||
 865                                  session->state == ISCSI_STATE_LOGGED_IN ||
 866                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
 867         if (signal_pending(current))
 868                 flush_signals(current);
 869
 870         spin_lock_bh(&session->lock);
 871         if (session->state == ISCSI_STATE_LOGGED_IN)
 872                 printk(KERN_INFO "iscsi: host reset succeeded\n");
 873         else
 874                 goto failed;
 875         spin_unlock_bh(&session->lock);
 876
 877         return SUCCESS;
 878 }
 879 EXPORT_SYMBOL_GPL(iscsi_eh_host_reset);
 880
 881 static void iscsi_tmabort_timedout(unsigned long data)
 882 {
 883         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)data;
 884         struct iscsi_conn *conn = ctask->conn;
 885         struct iscsi_session *session = conn->session;
 886
 887         spin_lock(&session->lock);
 888         if (conn->tmabort_state == TMABORT_INITIAL) {
 889                 conn->tmabort_state = TMABORT_TIMEDOUT;
 890                 debug_scsi("tmabort timedout [sc %p itt 0x%x]\n",
 891                         ctask->sc, ctask->itt);
 892                 /* unblock eh_abort() */
 893                 wake_up(&conn->ehwait);
 894         }
 895         spin_unlock(&session->lock);
 896 }
 897
 898 /* must be called with the mutex lock */
 899 static int iscsi_exec_abort_task(struct scsi_cmnd *sc,
 900                                  struct iscsi_cmd_task *ctask)
 901 {
 902         struct iscsi_conn *conn = ctask->conn;
 903         struct iscsi_session *session = conn->session;
 904         struct iscsi_tm *hdr = &conn->tmhdr;
 905         int rc;
 906
 907         /*
 908          * ctask timed out but session is OK requests must be serialized.
 909          */
 910         memset(hdr, 0, sizeof(struct iscsi_tm));
 911         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
 912         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK;
 913         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 914         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
 915         hdr->rtt = ctask->hdr->itt;
 916         hdr->refcmdsn = ctask->hdr->cmdsn;
 917
 918         rc = iscsi_conn_send_generic(conn, (struct iscsi_hdr *)hdr,
 919                                      NULL, 0);
 920         if (rc) {
 921                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 922                 debug_scsi("abort sent failure [itt 0x%x] %d", ctask->itt, rc);
 923                 return rc;
 924         }
 925
 926         debug_scsi("abort sent [itt 0x%x]\n", ctask->itt);
 927
 928         spin_lock_bh(&session->lock);
 929         ctask->mtask = (struct iscsi_mgmt_task *)
 930                         session->mgmt_cmds[(hdr->itt & ISCSI_ITT_MASK) -
 931                                         ISCSI_MGMT_ITT_OFFSET];
 932
 933         if (conn->tmabort_state == TMABORT_INITIAL) {
 934                 conn->tmfcmd_pdus_cnt++;
 935                 conn->tmabort_timer.expires = 10*HZ + jiffies;
 936                 conn->tmabort_timer.function = iscsi_tmabort_timedout;
 937                 conn->tmabort_timer.data = (unsigned long)ctask;
 938                 add_timer(&conn->tmabort_timer);
 939                 debug_scsi("abort set timeout [itt 0x%x]", ctask->itt);
 940         }
 941         spin_unlock_bh(&session->lock);
 942         mutex_unlock(&conn->xmitmutex);
 943
 944         /*
 945          * block eh thread until:
 946          *
 947          * 1) abort response
 948          * 2) abort timeout
 949          * 3) session is terminated or restarted or userspace has
 950          * given up on recovery
 951          */
 952         wait_event_interruptible(conn->ehwait,
 953                                  sc->SCp.phase != session->age ||
 954                                  session->state != ISCSI_STATE_LOGGED_IN ||
 955                                  conn->tmabort_state != TMABORT_INITIAL);
 956         if (signal_pending(current))
 957                 flush_signals(current);
 958         del_timer_sync(&conn->tmabort_timer);
 959
 960         mutex_lock(&conn->xmitmutex);
 961         return 0;
 962 }
 963
 964 /*
 965  * xmit mutex and session lock must be held
 966  */
 967 #define iscsi_remove_task(tasktype)                                     \
 968 static struct iscsi_##tasktype *                                        \
 969 iscsi_remove_##tasktype(struct kfifo *fifo, uint32_t itt)               \
 970 {                                                                       \
 971         int i, nr_tasks = __kfifo_len(fifo) / sizeof(void*);            \
 972         struct iscsi_##tasktype *task;                                  \
 973                                                                         \
 974         debug_scsi("searching %d tasks\n", nr_tasks);                   \
 975                                                                         \
 976         for (i = 0; i < nr_tasks; i++) {                                \
 977                 __kfifo_get(fifo, (void*)&task, sizeof(void*));         \
 978                 debug_scsi("check task %u\n", task->itt);               \
 979                                                                         \
 980                 if (task->itt == itt) {                                 \
 981                         debug_scsi("matched task\n");                   \
 982                         break;                                          \
 983                 }                                                       \
 984                                                                         \
 985                 __kfifo_put(fifo, (void*)&task, sizeof(void*));         \
 986         }                                                               \
 987         return NULL;                                                    \
 988 }
 989
 990 iscsi_remove_task(mgmt_task);
 991 iscsi_remove_task(cmd_task);
 992
 993 static int iscsi_ctask_mtask_cleanup(struct iscsi_cmd_task *ctask)
 994 {
 995         struct iscsi_conn *conn = ctask->conn;
 996         struct iscsi_session *session = conn->session;
 997
 998         if (!ctask->mtask)
 999                 return -EINVAL;
1000
1001         if (!iscsi_remove_mgmt_task(conn->immqueue, ctask->mtask->itt))
1002                 list_del(&ctask->mtask->running);
1003         __kfifo_put(session->mgmtpool.queue, (void*)&ctask->mtask,
1004                     sizeof(void*));
1005         ctask->mtask = NULL;
1006         return 0;
1007 }
1008
1009 /*
1010  * session lock and xmitmutex must be held
1011  */
1012 static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1013                          int err)
1014 {
1015         struct scsi_cmnd *sc;
1016
1017         conn->session->tt->cleanup_cmd_task(conn, ctask);
1018         iscsi_ctask_mtask_cleanup(ctask);
1019
1020         sc = ctask->sc;
1021         if (!sc)
1022                 return;
1023         sc->result = err;
1024         sc->resid = sc->request_bufflen;
1025         iscsi_complete_command(conn->session, ctask);
1026 }
1027
1028 int iscsi_eh_abort(struct scsi_cmnd *sc)
1029 {
1030         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
1031         struct iscsi_conn *conn = ctask->conn;
1032         struct iscsi_session *session = conn->session;
1033         struct iscsi_cmd_task *pending_ctask;
1034         int rc;
1035
1036         conn->eh_abort_cnt++;
1037         debug_scsi("aborting [sc %p itt 0x%x]\n", sc, ctask->itt);
1038
1039         mutex_lock(&conn->xmitmutex);
1040         spin_lock_bh(&session->lock);
1041
1042         /*
1043          * If we are not logged in or we have started a new session
1044          * then let the host reset code handle this
1045          */
1046         if (session->state != ISCSI_STATE_LOGGED_IN ||
1047             sc->SCp.phase != session->age)
1048                 goto failed;
1049
1050         /* ctask completed before time out */
1051         if (!ctask->sc)
1052                 goto success;
1053
1054         /* what should we do here ? */
1055         if (conn->ctask == ctask) {
1056                 printk(KERN_INFO "iscsi: sc %p itt 0x%x partially sent. "
1057                        "Failing abort\n", sc, ctask->itt);
1058                 goto failed;
1059         }
1060
1061         /* check for the easy pending cmd abort */
1062         pending_ctask = iscsi_remove_cmd_task(conn->xmitqueue, ctask->itt);
1063         if (pending_ctask) {
1064                 /* iscsi_tcp queues write transfers on the xmitqueue */
1065                 if (list_empty(&pending_ctask->running)) {
1066                         debug_scsi("found pending task\n");
1067                         goto success;
1068                 } else
1069                         __kfifo_put(conn->xmitqueue, (void*)&pending_ctask,
1070                                     sizeof(void*));
1071         }
1072
1073         conn->tmabort_state = TMABORT_INITIAL;
1074
1075         spin_unlock_bh(&session->lock);
1076         rc = iscsi_exec_abort_task(sc, ctask);
1077         spin_lock_bh(&session->lock);
1078
1079         iscsi_ctask_mtask_cleanup(ctask);
1080         if (rc || sc->SCp.phase != session->age ||
1081             session->state != ISCSI_STATE_LOGGED_IN)
1082                 goto failed;
1083
1084         /* ctask completed before tmf abort response */
1085         if (!ctask->sc) {
1086                 debug_scsi("sc completed while abort in progress\n");
1087                 goto success;
1088         }
1089
1090         if (conn->tmabort_state != TMABORT_SUCCESS) {
1091                 spin_unlock_bh(&session->lock);
1092                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1093                 spin_lock_bh(&session->lock);
1094                 goto failed;
1095         }
1096
1097 success:
1098         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1099         spin_unlock_bh(&session->lock);
1100
1101         /*
1102          * clean up task if aborted. we have the xmitmutex so grab
1103          * the recv lock as a writer
1104          */
1105         write_lock_bh(conn->recv_lock);
1106         spin_lock(&session->lock);
1107         fail_command(conn, ctask, DID_ABORT << 16);
1108         spin_unlock(&session->lock);
1109         write_unlock_bh(conn->recv_lock);
1110
1111         mutex_unlock(&conn->xmitmutex);
1112         return SUCCESS;
1113
1114 failed:
1115         spin_unlock_bh(&session->lock);
1116         mutex_unlock(&conn->xmitmutex);
1117
1118         debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1119         return FAILED;
1120 }
1121 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1122
1123 int
1124 iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
1125 {
1126         int i;
1127
1128         *items = kmalloc(max * sizeof(void*), GFP_KERNEL);
1129         if (*items == NULL)
1130                 return -ENOMEM;
1131
1132         q->max = max;
1133         q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL);
1134         if (q->pool == NULL) {
1135                 kfree(*items);
1136                 return -ENOMEM;
1137         }
1138
1139         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1140                               GFP_KERNEL, NULL);
1141         if (q->queue == ERR_PTR(-ENOMEM)) {
1142                 kfree(q->pool);
1143                 kfree(*items);
1144                 return -ENOMEM;
1145         }
1146
1147         for (i = 0; i < max; i++) {
1148                 q->pool[i] = kmalloc(item_size, GFP_KERNEL);
1149                 if (q->pool[i] == NULL) {
1150                         int j;
1151
1152                         for (j = 0; j < i; j++)
1153                                 kfree(q->pool[j]);
1154
1155                         kfifo_free(q->queue);
1156                         kfree(q->pool);
1157                         kfree(*items);
1158                         return -ENOMEM;
1159                 }
1160                 memset(q->pool[i], 0, item_size);
1161                 (*items)[i] = q->pool[i];
1162                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1163         }
1164         return 0;
1165 }
1166 EXPORT_SYMBOL_GPL(iscsi_pool_init);
1167
1168 void iscsi_pool_free(struct iscsi_queue *q, void **items)
1169 {
1170         int i;
1171
1172         for (i = 0; i < q->max; i++)
1173                 kfree(items[i]);
1174         kfree(q->pool);
1175         kfree(items);
1176 }
1177 EXPORT_SYMBOL_GPL(iscsi_pool_free);
1178
1179 /*
1180  * iSCSI Session's hostdata organization:
1181  *
1182  *    *------------------* <== hostdata_session(host->hostdata)
1183  *    | ptr to class sess|
1184  *    |------------------| <== iscsi_hostdata(host->hostdata)
1185  *    | iscsi_session    |
1186  *    *------------------*
1187  */
1188
1189 #define hostdata_privsize(_sz)  (sizeof(unsigned long) + _sz + \
1190                                  _sz % sizeof(unsigned long))
1191
1192 #define hostdata_session(_hostdata) (iscsi_ptr(*(unsigned long *)_hostdata))
1193
1194 /**
1195  * iscsi_session_setup - create iscsi cls session and host and session
1196  * @scsit: scsi transport template
1197  * @iscsit: iscsi transport template
1198  * @initial_cmdsn: initial CmdSN
1199  * @hostno: host no allocated
1200  *
1201  * This can be used by software iscsi_transports that allocate
1202  * a session per scsi host.
1203  **/
1204 struct iscsi_cls_session *
1205 iscsi_session_setup(struct iscsi_transport *iscsit,
1206                     struct scsi_transport_template *scsit,
1207                     int cmd_task_size, int mgmt_task_size,
1208                     uint32_t initial_cmdsn, uint32_t *hostno)
1209 {
1210         struct Scsi_Host *shost;
1211         struct iscsi_session *session;
1212         struct iscsi_cls_session *cls_session;
1213         int cmd_i;
1214
1215         shost = scsi_host_alloc(iscsit->host_template,
1216                                 hostdata_privsize(sizeof(*session)));
1217         if (!shost)
1218                 return NULL;
1219
1220         shost->max_id = 1;
1221         shost->max_channel = 0;
1222         shost->max_lun = iscsit->max_lun;
1223         shost->max_cmd_len = iscsit->max_cmd_len;
1224         shost->transportt = scsit;
1225         shost->transportt->create_work_queue = 1;
1226         *hostno = shost->host_no;
1227
1228         session = iscsi_hostdata(shost->hostdata);
1229         memset(session, 0, sizeof(struct iscsi_session));
1230         session->host = shost;
1231         session->state = ISCSI_STATE_FREE;
1232         session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
1233         session->cmds_max = ISCSI_XMIT_CMDS_MAX;
1234         session->cmdsn = initial_cmdsn;
1235         session->exp_cmdsn = initial_cmdsn + 1;
1236         session->max_cmdsn = initial_cmdsn + 1;
1237         session->max_r2t = 1;
1238         session->tt = iscsit;
1239
1240         /* initialize SCSI PDU commands pool */
1241         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
1242                             (void***)&session->cmds,
1243                             cmd_task_size + sizeof(struct iscsi_cmd_task)))
1244                 goto cmdpool_alloc_fail;
1245
1246         /* pre-format cmds pool with ITT */
1247         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1248                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1249
1250                 if (cmd_task_size)
1251                         ctask->dd_data = &ctask[1];
1252                 ctask->itt = cmd_i;
1253         }
1254
1255         spin_lock_init(&session->lock);
1256         INIT_LIST_HEAD(&session->connections);
1257
1258         /* initialize immediate command pool */
1259         if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max,
1260                            (void***)&session->mgmt_cmds,
1261                            mgmt_task_size + sizeof(struct iscsi_mgmt_task)))
1262                 goto mgmtpool_alloc_fail;
1263
1264
1265         /* pre-format immediate cmds pool with ITT */
1266         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
1267                 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
1268
1269                 if (mgmt_task_size)
1270                         mtask->dd_data = &mtask[1];
1271                 mtask->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i;
1272         }
1273
1274         if (scsi_add_host(shost, NULL))
1275                 goto add_host_fail;
1276
1277         cls_session = iscsi_create_session(shost, iscsit, 0);
1278         if (!cls_session)
1279                 goto cls_session_fail;
1280         *(unsigned long*)shost->hostdata = (unsigned long)cls_session;
1281
1282         return cls_session;
1283
1284 cls_session_fail:
1285         scsi_remove_host(shost);
1286 add_host_fail:
1287         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1288 mgmtpool_alloc_fail:
1289         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1290 cmdpool_alloc_fail:
1291         scsi_host_put(shost);
1292         return NULL;
1293 }
1294 EXPORT_SYMBOL_GPL(iscsi_session_setup);
1295
1296 /**
1297  * iscsi_session_teardown - destroy session, host, and cls_session
1298  * shost: scsi host
1299  *
1300  * This can be used by software iscsi_transports that allocate
1301  * a session per scsi host.
1302  **/
1303 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
1304 {
1305         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1306         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1307
1308         scsi_remove_host(shost);
1309
1310         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1311         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1312
1313         iscsi_destroy_session(cls_session);
1314         scsi_host_put(shost);
1315 }
1316 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
1317
1318 /**
1319  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
1320  * @cls_session: iscsi_cls_session
1321  * @conn_idx: cid
1322  **/
1323 struct iscsi_cls_conn *
1324 iscsi_conn_setup(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1325 {
1326         struct iscsi_session *session = class_to_transport_session(cls_session);
1327         struct iscsi_conn *conn;
1328         struct iscsi_cls_conn *cls_conn;
1329         char *data;
1330
1331         cls_conn = iscsi_create_conn(cls_session, conn_idx);
1332         if (!cls_conn)
1333                 return NULL;
1334         conn = cls_conn->dd_data;
1335         memset(conn, 0, sizeof(*conn));
1336
1337         conn->session = session;
1338         conn->cls_conn = cls_conn;
1339         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
1340         conn->id = conn_idx;
1341         conn->exp_statsn = 0;
1342         conn->tmabort_state = TMABORT_INITIAL;
1343         INIT_LIST_HEAD(&conn->run_list);
1344         INIT_LIST_HEAD(&conn->mgmt_run_list);
1345
1346         /* initialize general xmit PDU commands queue */
1347         conn->xmitqueue = kfifo_alloc(session->cmds_max * sizeof(void*),
1348                                         GFP_KERNEL, NULL);
1349         if (conn->xmitqueue == ERR_PTR(-ENOMEM))
1350                 goto xmitqueue_alloc_fail;
1351
1352         /* initialize general immediate & non-immediate PDU commands queue */
1353         conn->immqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
1354                                         GFP_KERNEL, NULL);
1355         if (conn->immqueue == ERR_PTR(-ENOMEM))
1356                 goto immqueue_alloc_fail;
1357
1358         conn->mgmtqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
1359                                         GFP_KERNEL, NULL);
1360         if (conn->mgmtqueue == ERR_PTR(-ENOMEM))
1361                 goto mgmtqueue_alloc_fail;
1362
1363         INIT_WORK(&conn->xmitwork, iscsi_xmitworker, conn);
1364
1365         /* allocate login_mtask used for the login/text sequences */
1366         spin_lock_bh(&session->lock);
1367         if (!__kfifo_get(session->mgmtpool.queue,
1368                          (void*)&conn->login_mtask,
1369                          sizeof(void*))) {
1370                 spin_unlock_bh(&session->lock);
1371                 goto login_mtask_alloc_fail;
1372         }
1373         spin_unlock_bh(&session->lock);
1374
1375         data = kmalloc(DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH, GFP_KERNEL);
1376         if (!data)
1377                 goto login_mtask_data_alloc_fail;
1378         conn->login_mtask->data = data;
1379
1380         init_timer(&conn->tmabort_timer);
1381         mutex_init(&conn->xmitmutex);
1382         init_waitqueue_head(&conn->ehwait);
1383
1384         return cls_conn;
1385
1386 login_mtask_data_alloc_fail:
1387         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1388                     sizeof(void*));
1389 login_mtask_alloc_fail:
1390         kfifo_free(conn->mgmtqueue);
1391 mgmtqueue_alloc_fail:
1392         kfifo_free(conn->immqueue);
1393 immqueue_alloc_fail:
1394         kfifo_free(conn->xmitqueue);
1395 xmitqueue_alloc_fail:
1396         iscsi_destroy_conn(cls_conn);
1397         return NULL;
1398 }
1399 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
1400
1401 /**
1402  * iscsi_conn_teardown - teardown iscsi connection
1403  * cls_conn: iscsi class connection
1404  *
1405  * TODO: we may need to make this into a two step process
1406  * like scsi-mls remove + put host
1407  */
1408 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
1409 {
1410         struct iscsi_conn *conn = cls_conn->dd_data;
1411         struct iscsi_session *session = conn->session;
1412         unsigned long flags;
1413
1414         mutex_lock(&conn->xmitmutex);
1415         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1416         if (conn->c_stage == ISCSI_CONN_INITIAL_STAGE) {
1417                 if (session->tt->suspend_conn_recv)
1418                         session->tt->suspend_conn_recv(conn);
1419
1420                 session->tt->terminate_conn(conn);
1421         }
1422
1423         spin_lock_bh(&session->lock);
1424         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
1425         if (session->leadconn == conn) {
1426                 /*
1427                  * leading connection? then give up on recovery.
1428                  */
1429                 session->state = ISCSI_STATE_TERMINATE;
1430                 wake_up(&conn->ehwait);
1431         }
1432         spin_unlock_bh(&session->lock);
1433
1434         mutex_unlock(&conn->xmitmutex);
1435
1436         /*
1437          * Block until all in-progress commands for this connection
1438          * time out or fail.
1439          */
1440         for (;;) {
1441                 spin_lock_irqsave(session->host->host_lock, flags);
1442                 if (!session->host->host_busy) { /* OK for ERL == 0 */
1443                         spin_unlock_irqrestore(session->host->host_lock, flags);
1444                         break;
1445                 }
1446                 spin_unlock_irqrestore(session->host->host_lock, flags);
1447                 msleep_interruptible(500);
1448                 printk(KERN_INFO "iscsi: scsi conn_destroy(): host_busy %d "
1449                        "host_failed %d\n", session->host->host_busy,
1450                        session->host->host_failed);
1451                 /*
1452                  * force eh_abort() to unblock
1453                  */
1454                 wake_up(&conn->ehwait);
1455         }
1456
1457         spin_lock_bh(&session->lock);
1458         kfree(conn->login_mtask->data);
1459         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1460                     sizeof(void*));
1461         list_del(&conn->item);
1462         if (list_empty(&session->connections))
1463                 session->leadconn = NULL;
1464         if (session->leadconn && session->leadconn == conn)
1465                 session->leadconn = container_of(session->connections.next,
1466                         struct iscsi_conn, item);
1467
1468         if (session->leadconn == NULL)
1469                 /* no connections exits.. reset sequencing */
1470                 session->cmdsn = session->max_cmdsn = session->exp_cmdsn = 1;
1471         spin_unlock_bh(&session->lock);
1472
1473         kfifo_free(conn->xmitqueue);
1474         kfifo_free(conn->immqueue);
1475         kfifo_free(conn->mgmtqueue);
1476
1477         iscsi_destroy_conn(cls_conn);
1478 }
1479 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
1480
1481 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
1482 {
1483         struct iscsi_conn *conn = cls_conn->dd_data;
1484         struct iscsi_session *session = conn->session;
1485
1486         if (session == NULL) {
1487                 printk(KERN_ERR "iscsi: can't start unbound connection\n");
1488                 return -EPERM;
1489         }
1490
1491         spin_lock_bh(&session->lock);
1492         conn->c_stage = ISCSI_CONN_STARTED;
1493         session->state = ISCSI_STATE_LOGGED_IN;
1494
1495         switch(conn->stop_stage) {
1496         case STOP_CONN_RECOVER:
1497                 /*
1498                  * unblock eh_abort() if it is blocked. re-try all
1499                  * commands after successful recovery
1500                  */
1501                 session->conn_cnt++;
1502                 conn->stop_stage = 0;
1503                 conn->tmabort_state = TMABORT_INITIAL;
1504                 session->age++;
1505                 spin_unlock_bh(&session->lock);
1506
1507                 iscsi_unblock_session(session_to_cls(session));
1508                 wake_up(&conn->ehwait);
1509                 return 0;
1510         case STOP_CONN_TERM:
1511                 session->conn_cnt++;
1512                 conn->stop_stage = 0;
1513                 break;
1514         case STOP_CONN_SUSPEND:
1515                 conn->stop_stage = 0;
1516                 clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1517                 clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1518                 break;
1519         default:
1520                 break;
1521         }
1522         spin_unlock_bh(&session->lock);
1523
1524         return 0;
1525 }
1526 EXPORT_SYMBOL_GPL(iscsi_conn_start);
1527
1528 static void
1529 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
1530 {
1531         struct iscsi_mgmt_task *mtask, *tmp;
1532
1533         /* handle pending */
1534         while (__kfifo_get(conn->immqueue, (void*)&mtask, sizeof(void*)) ||
1535                __kfifo_get(conn->mgmtqueue, (void*)&mtask, sizeof(void*))) {
1536                 if (mtask == conn->login_mtask)
1537                         continue;
1538                 debug_scsi("flushing pending mgmt task itt 0x%x\n", mtask->itt);
1539                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1540                             sizeof(void*));
1541         }
1542
1543         /* handle running */
1544         list_for_each_entry_safe(mtask, tmp, &conn->mgmt_run_list, running) {
1545                 debug_scsi("flushing running mgmt task itt 0x%x\n", mtask->itt);
1546                 list_del(&mtask->running);
1547
1548                 if (mtask == conn->login_mtask)
1549                         continue;
1550                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1551                            sizeof(void*));
1552         }
1553
1554         conn->mtask = NULL;
1555 }
1556
1557 /* Fail commands. Mutex and session lock held and recv side suspended */
1558 static void fail_all_commands(struct iscsi_conn *conn)
1559 {
1560         struct iscsi_cmd_task *ctask, *tmp;
1561
1562         /* flush pending */
1563         while (__kfifo_get(conn->xmitqueue, (void*)&ctask, sizeof(void*))) {
1564                 debug_scsi("failing pending sc %p itt 0x%x\n", ctask->sc,
1565                            ctask->itt);
1566                 fail_command(conn, ctask, DID_BUS_BUSY << 16);
1567         }
1568
1569         /* fail all other running */
1570         list_for_each_entry_safe(ctask, tmp, &conn->run_list, running) {
1571                 debug_scsi("failing in progress sc %p itt 0x%x\n",
1572                            ctask->sc, ctask->itt);
1573                 fail_command(conn, ctask, DID_BUS_BUSY << 16);
1574         }
1575
1576         conn->ctask = NULL;
1577 }
1578
1579 static void iscsi_start_session_recovery(struct iscsi_session *session,
1580                                          struct iscsi_conn *conn, int flag)
1581 {
1582         int old_stop_stage;
1583
1584         spin_lock_bh(&session->lock);
1585         if (conn->stop_stage == STOP_CONN_TERM) {
1586                 spin_unlock_bh(&session->lock);
1587                 return;
1588         }
1589
1590         /*
1591          * When this is called for the in_login state, we only want to clean
1592          * up the login task and connection.
1593          */
1594         if (conn->stop_stage != STOP_CONN_RECOVER)
1595                 session->conn_cnt--;
1596
1597         old_stop_stage = conn->stop_stage;
1598         conn->stop_stage = flag;
1599         spin_unlock_bh(&session->lock);
1600
1601         if (session->tt->suspend_conn_recv)
1602                 session->tt->suspend_conn_recv(conn);
1603
1604         mutex_lock(&conn->xmitmutex);
1605         spin_lock_bh(&session->lock);
1606         conn->c_stage = ISCSI_CONN_STOPPED;
1607         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1608
1609         if (session->conn_cnt == 0 || session->leadconn == conn)
1610                 session->state = ISCSI_STATE_IN_RECOVERY;
1611
1612         spin_unlock_bh(&session->lock);
1613
1614         /*
1615          * for connection level recovery we should not calculate
1616          * header digest. conn->hdr_size used for optimization
1617          * in hdr_extract() and will be re-negotiated at
1618          * set_param() time.
1619          */
1620         if (flag == STOP_CONN_RECOVER) {
1621                 conn->hdrdgst_en = 0;
1622                 conn->datadgst_en = 0;
1623                 /*
1624                  * if this is called from the eh and and from userspace
1625                  * then we only need to block once.
1626                  */
1627                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
1628                     old_stop_stage != STOP_CONN_RECOVER)
1629                         iscsi_block_session(session_to_cls(session));
1630         }
1631
1632         session->tt->terminate_conn(conn);
1633         /*
1634          * flush queues.
1635          */
1636         spin_lock_bh(&session->lock);
1637         fail_all_commands(conn);
1638         flush_control_queues(session, conn);
1639         spin_unlock_bh(&session->lock);
1640
1641         mutex_unlock(&conn->xmitmutex);
1642 }
1643
1644 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1645 {
1646         struct iscsi_conn *conn = cls_conn->dd_data;
1647         struct iscsi_session *session = conn->session;
1648
1649         switch (flag) {
1650         case STOP_CONN_RECOVER:
1651         case STOP_CONN_TERM:
1652                 iscsi_start_session_recovery(session, conn, flag);
1653                 break;
1654         case STOP_CONN_SUSPEND:
1655                 if (session->tt->suspend_conn_recv)
1656                         session->tt->suspend_conn_recv(conn);
1657
1658                 mutex_lock(&conn->xmitmutex);
1659                 spin_lock_bh(&session->lock);
1660
1661                 conn->stop_stage = flag;
1662                 conn->c_stage = ISCSI_CONN_STOPPED;
1663                 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1664
1665                 spin_unlock_bh(&session->lock);
1666                 mutex_unlock(&conn->xmitmutex);
1667                 break;
1668         default:
1669                 printk(KERN_ERR "iscsi: invalid stop flag %d\n", flag);
1670         }
1671 }
1672 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
1673
1674 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
1675                     struct iscsi_cls_conn *cls_conn, int is_leading)
1676 {
1677         struct iscsi_session *session = class_to_transport_session(cls_session);
1678         struct iscsi_conn *tmp = ERR_PTR(-EEXIST), *conn = cls_conn->dd_data;
1679
1680         /* lookup for existing connection */
1681         spin_lock_bh(&session->lock);
1682         list_for_each_entry(tmp, &session->connections, item) {
1683                 if (tmp == conn) {
1684                         if (conn->c_stage != ISCSI_CONN_STOPPED ||
1685                             conn->stop_stage == STOP_CONN_TERM) {
1686                                 printk(KERN_ERR "iscsi: can't bind "
1687                                        "non-stopped connection (%d:%d)\n",
1688                                        conn->c_stage, conn->stop_stage);
1689                                 spin_unlock_bh(&session->lock);
1690                                 return -EIO;
1691                         }
1692                         break;
1693                 }
1694         }
1695         if (tmp != conn) {
1696                 /* bind new iSCSI connection to session */
1697                 conn->session = session;
1698                 list_add(&conn->item, &session->connections);
1699         }
1700         spin_unlock_bh(&session->lock);
1701
1702         if (is_leading)
1703                 session->leadconn = conn;
1704
1705         /*
1706          * Unblock xmitworker(), Login Phase will pass through.
1707          */
1708         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1709         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1710         return 0;
1711 }
1712 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
1713
1714 MODULE_AUTHOR("Mike Christie");
1715 MODULE_DESCRIPTION("iSCSI library functions");
1716 MODULE_LICENSE("GPL");