SAFE public projects git trees. - safe/jmp/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 "Got CHECK_CONDITION but invalid "
 239                                "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                 switch(opcode) {
 337                 case ISCSI_OP_LOGIN_RSP:
 338                 case ISCSI_OP_TEXT_RSP:
 339                 case ISCSI_OP_LOGOUT_RSP:
 340                         rc = iscsi_check_assign_cmdsn(session,
 341                                                  (struct iscsi_nopin*)hdr);
 342                         if (rc)
 343                                 break;
 344
 345                         rc = iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen);
 346                         list_del(&mtask->running);
 347                         if (conn->login_mtask != mtask)
 348                                 __kfifo_put(session->mgmtpool.queue,
 349                                             (void*)&mtask, sizeof(void*));
 350                         break;
 351                 case ISCSI_OP_SCSI_TMFUNC_RSP:
 352                         rc = iscsi_check_assign_cmdsn(session,
 353                                                  (struct iscsi_nopin*)hdr);
 354                         if (rc)
 355                                 break;
 356
 357                         if (datalen) {
 358                                 rc = ISCSI_ERR_PROTO;
 359                                 break;
 360                         }
 361                         conn->tmfrsp_pdus_cnt++;
 362                         if (conn->tmabort_state == TMABORT_INITIAL) {
 363                                 conn->tmabort_state =
 364                                         ((struct iscsi_tm_rsp *)hdr)->
 365                                         response == ISCSI_TMF_RSP_COMPLETE ?
 366                                                 TMABORT_SUCCESS:TMABORT_FAILED;
 367                                 /* unblock eh_abort() */
 368                                 wake_up(&conn->ehwait);
 369                         }
 370                         break;
 371                 case ISCSI_OP_NOOP_IN:
 372                         if (hdr->ttt != ISCSI_RESERVED_TAG) {
 373                                 rc = ISCSI_ERR_PROTO;
 374                                 break;
 375                         }
 376                         rc = iscsi_check_assign_cmdsn(session,
 377                                                 (struct iscsi_nopin*)hdr);
 378                         if (rc)
 379                                 break;
 380                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 381
 382                         rc = iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen);
 383                         list_del(&mtask->running);
 384                         if (conn->login_mtask != mtask)
 385                                 __kfifo_put(session->mgmtpool.queue,
 386                                             (void*)&mtask, sizeof(void*));
 387                         break;
 388                 default:
 389                         rc = ISCSI_ERR_BAD_OPCODE;
 390                         break;
 391                 }
 392         } else if (itt == ISCSI_RESERVED_TAG) {
 393                 switch(opcode) {
 394                 case ISCSI_OP_NOOP_IN:
 395                         if (!datalen) {
 396                                 rc = iscsi_check_assign_cmdsn(session,
 397                                                  (struct iscsi_nopin*)hdr);
 398                                 if (!rc && hdr->ttt != ISCSI_RESERVED_TAG)
 399                                         rc = iscsi_recv_pdu(conn->cls_conn,
 400                                                             hdr, NULL, 0);
 401                         } else
 402                                 rc = ISCSI_ERR_PROTO;
 403                         break;
 404                 case ISCSI_OP_REJECT:
 405                         /* we need sth like iscsi_reject_rsp()*/
 406                 case ISCSI_OP_ASYNC_EVENT:
 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         return rc;
 418 }
 419 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
 420
 421 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 422                        char *data, int datalen)
 423 {
 424         int rc;
 425
 426         spin_lock(&conn->session->lock);
 427         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
 428         spin_unlock(&conn->session->lock);
 429         return rc;
 430 }
 431 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
 432
 433 /* verify itt (itt encoding: age+cid+itt) */
 434 int iscsi_verify_itt(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 435                      uint32_t *ret_itt)
 436 {
 437         struct iscsi_session *session = conn->session;
 438         struct iscsi_cmd_task *ctask;
 439         uint32_t itt;
 440
 441         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
 442                 if ((hdr->itt & ISCSI_AGE_MASK) !=
 443                     (session->age << ISCSI_AGE_SHIFT)) {
 444                         printk(KERN_ERR "iscsi_tcp: received itt %x expected "
 445                                 "session age (%x)\n", hdr->itt,
 446                                 session->age & ISCSI_AGE_MASK);
 447                         return ISCSI_ERR_BAD_ITT;
 448                 }
 449
 450                 if ((hdr->itt & ISCSI_CID_MASK) !=
 451                     (conn->id << ISCSI_CID_SHIFT)) {
 452                         printk(KERN_ERR "iscsi_tcp: received itt %x, expected "
 453                                 "CID (%x)\n", hdr->itt, conn->id);
 454                         return ISCSI_ERR_BAD_ITT;
 455                 }
 456                 itt = hdr->itt & ISCSI_ITT_MASK;
 457         } else
 458                 itt = hdr->itt;
 459
 460         if (itt < session->cmds_max) {
 461                 ctask = session->cmds[itt];
 462
 463                 if (!ctask->sc) {
 464                         printk(KERN_INFO "iscsi_tcp: dropping ctask with "
 465                                "itt 0x%x\n", ctask->itt);
 466                         /* force drop */
 467                         return ISCSI_ERR_NO_SCSI_CMD;
 468                 }
 469
 470                 if (ctask->sc->SCp.phase != session->age) {
 471                         printk(KERN_ERR "iscsi_tcp: ctask's session age %d, "
 472                                 "expected %d\n", ctask->sc->SCp.phase,
 473                                 session->age);
 474                         return ISCSI_ERR_SESSION_FAILED;
 475                 }
 476         }
 477
 478         *ret_itt = itt;
 479         return 0;
 480 }
 481 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
 482
 483 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
 484 {
 485         struct iscsi_session *session = conn->session;
 486         unsigned long flags;
 487
 488         spin_lock_irqsave(&session->lock, flags);
 489         if (session->conn_cnt == 1 || session->leadconn == conn)
 490                 session->state = ISCSI_STATE_FAILED;
 491         spin_unlock_irqrestore(&session->lock, flags);
 492         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
 493         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
 494         iscsi_conn_error(conn->cls_conn, err);
 495 }
 496 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
 497
 498 /**
 499  * iscsi_data_xmit - xmit any command into the scheduled connection
 500  * @conn: iscsi connection
 501  *
 502  * Notes:
 503  *      The function can return -EAGAIN in which case the caller must
 504  *      re-schedule it again later or recover. '0' return code means
 505  *      successful xmit.
 506  **/
 507 static int iscsi_data_xmit(struct iscsi_conn *conn)
 508 {
 509         struct iscsi_transport *tt;
 510
 511         if (unlikely(conn->suspend_tx)) {
 512                 debug_scsi("conn %d Tx suspended!\n", conn->id);
 513                 return 0;
 514         }
 515         tt = conn->session->tt;
 516
 517         /*
 518          * Transmit in the following order:
 519          *
 520          * 1) un-finished xmit (ctask or mtask)
 521          * 2) immediate control PDUs
 522          * 3) write data
 523          * 4) SCSI commands
 524          * 5) non-immediate control PDUs
 525          *
 526          * No need to lock around __kfifo_get as long as
 527          * there's one producer and one consumer.
 528          */
 529
 530         BUG_ON(conn->ctask && conn->mtask);
 531
 532         if (conn->ctask) {
 533                 if (tt->xmit_cmd_task(conn, conn->ctask))
 534                         goto again;
 535                 /* done with this in-progress ctask */
 536                 conn->ctask = NULL;
 537         }
 538         if (conn->mtask) {
 539                 if (tt->xmit_mgmt_task(conn, conn->mtask))
 540                         goto again;
 541                 /* done with this in-progress mtask */
 542                 conn->mtask = NULL;
 543         }
 544
 545         /* process immediate first */
 546         if (unlikely(__kfifo_len(conn->immqueue))) {
 547                 while (__kfifo_get(conn->immqueue, (void*)&conn->mtask,
 548                                    sizeof(void*))) {
 549                         list_add_tail(&conn->mtask->running,
 550                                       &conn->mgmt_run_list);
 551                         if (tt->xmit_mgmt_task(conn, conn->mtask))
 552                                 goto again;
 553                 }
 554                 /* done with this mtask */
 555                 conn->mtask = NULL;
 556         }
 557
 558         /* process command queue */
 559         while (__kfifo_get(conn->xmitqueue, (void*)&conn->ctask,
 560                            sizeof(void*))) {
 561                 /*
 562                  * iscsi tcp may readd the task to the xmitqueue to send
 563                  * write data
 564                  */
 565                 if (list_empty(&conn->ctask->running))
 566                         list_add_tail(&conn->ctask->running, &conn->run_list);
 567                 if (tt->xmit_cmd_task(conn, conn->ctask))
 568                         goto again;
 569         }
 570         /* done with this ctask */
 571         conn->ctask = NULL;
 572
 573         /* process the rest control plane PDUs, if any */
 574         if (unlikely(__kfifo_len(conn->mgmtqueue))) {
 575                 while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask,
 576                                    sizeof(void*))) {
 577                         list_add_tail(&conn->mtask->running,
 578                                       &conn->mgmt_run_list);
 579                         if (tt->xmit_mgmt_task(conn, conn->mtask))
 580                                 goto again;
 581                 }
 582                 /* done with this mtask */
 583                 conn->mtask = NULL;
 584         }
 585
 586         return 0;
 587
 588 again:
 589         if (unlikely(conn->suspend_tx))
 590                 return 0;
 591
 592         return -EAGAIN;
 593 }
 594
 595 static void iscsi_xmitworker(void *data)
 596 {
 597         struct iscsi_conn *conn = data;
 598
 599         /*
 600          * serialize Xmit worker on a per-connection basis.
 601          */
 602         mutex_lock(&conn->xmitmutex);
 603         if (iscsi_data_xmit(conn))
 604                 scsi_queue_work(conn->session->host, &conn->xmitwork);
 605         mutex_unlock(&conn->xmitmutex);
 606 }
 607
 608 enum {
 609         FAILURE_BAD_HOST = 1,
 610         FAILURE_SESSION_FAILED,
 611         FAILURE_SESSION_FREED,
 612         FAILURE_WINDOW_CLOSED,
 613         FAILURE_SESSION_TERMINATE,
 614         FAILURE_SESSION_RECOVERY_TIMEOUT,
 615 };
 616
 617 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
 618 {
 619         struct Scsi_Host *host;
 620         int reason = 0;
 621         struct iscsi_session *session;
 622         struct iscsi_conn *conn;
 623         struct iscsi_cmd_task *ctask = NULL;
 624
 625         sc->scsi_done = done;
 626         sc->result = 0;
 627
 628         host = sc->device->host;
 629         session = iscsi_hostdata(host->hostdata);
 630
 631         spin_lock(&session->lock);
 632
 633         if (session->state != ISCSI_STATE_LOGGED_IN) {
 634                 if (session->recovery_failed) {
 635                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
 636                         goto fault;
 637                 } else if (session->state == ISCSI_STATE_FAILED) {
 638                         reason = FAILURE_SESSION_FAILED;
 639                         goto reject;
 640                 } else if (session->state == ISCSI_STATE_TERMINATE) {
 641                         reason = FAILURE_SESSION_TERMINATE;
 642                         goto fault;
 643                 }
 644                 reason = FAILURE_SESSION_FREED;
 645                 goto fault;
 646         }
 647
 648         /*
 649          * Check for iSCSI window and take care of CmdSN wrap-around
 650          */
 651         if ((int)(session->max_cmdsn - session->cmdsn) < 0) {
 652                 reason = FAILURE_WINDOW_CLOSED;
 653                 goto reject;
 654         }
 655
 656         conn = session->leadconn;
 657
 658         __kfifo_get(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
 659         sc->SCp.phase = session->age;
 660         sc->SCp.ptr = (char *)ctask;
 661
 662         ctask->mtask = NULL;
 663         ctask->conn = conn;
 664         ctask->sc = sc;
 665         INIT_LIST_HEAD(&ctask->running);
 666         ctask->total_length = sc->request_bufflen;
 667         iscsi_prep_scsi_cmd_pdu(ctask);
 668
 669         session->tt->init_cmd_task(ctask);
 670
 671         __kfifo_put(conn->xmitqueue, (void*)&ctask, sizeof(void*));
 672         debug_scsi(
 673                "ctask enq [%s cid %d sc %lx itt 0x%x len %d cmdsn %d win %d]\n",
 674                 sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
 675                 conn->id, (long)sc, ctask->itt, sc->request_bufflen,
 676                 session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
 677         spin_unlock(&session->lock);
 678
 679         scsi_queue_work(host, &conn->xmitwork);
 680         return 0;
 681
 682 reject:
 683         spin_unlock(&session->lock);
 684         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
 685         return SCSI_MLQUEUE_HOST_BUSY;
 686
 687 fault:
 688         spin_unlock(&session->lock);
 689         printk(KERN_ERR "iscsi_tcp: cmd 0x%x is not queued (%d)\n",
 690                sc->cmnd[0], reason);
 691         sc->result = (DID_NO_CONNECT << 16);
 692         sc->resid = sc->request_bufflen;
 693         sc->scsi_done(sc);
 694         return 0;
 695 }
 696 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
 697
 698 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
 699 {
 700         if (depth > ISCSI_MAX_CMD_PER_LUN)
 701                 depth = ISCSI_MAX_CMD_PER_LUN;
 702         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 703         return sdev->queue_depth;
 704 }
 705 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
 706
 707 static int
 708 iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 709                         char *data, uint32_t data_size)
 710 {
 711         struct iscsi_session *session = conn->session;
 712         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 713         struct iscsi_mgmt_task *mtask;
 714
 715         spin_lock_bh(&session->lock);
 716         if (session->state == ISCSI_STATE_TERMINATE) {
 717                 spin_unlock_bh(&session->lock);
 718                 return -EPERM;
 719         }
 720         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
 721             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 722                 /*
 723                  * Login and Text are sent serially, in
 724                  * request-followed-by-response sequence.
 725                  * Same mtask can be used. Same ITT must be used.
 726                  * Note that login_mtask is preallocated at conn_create().
 727                  */
 728                 mtask = conn->login_mtask;
 729         else {
 730                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 731                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 732
 733                 if (!__kfifo_get(session->mgmtpool.queue,
 734                                  (void*)&mtask, sizeof(void*))) {
 735                         spin_unlock_bh(&session->lock);
 736                         return -ENOSPC;
 737                 }
 738         }
 739
 740         /*
 741          * pre-format CmdSN and ExpStatSN for outgoing PDU.
 742          */
 743         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
 744                 hdr->itt = mtask->itt | (conn->id << ISCSI_CID_SHIFT) |
 745                            (session->age << ISCSI_AGE_SHIFT);
 746                 nop->cmdsn = cpu_to_be32(session->cmdsn);
 747                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 748                     !(hdr->opcode & ISCSI_OP_IMMEDIATE))
 749                         session->cmdsn++;
 750         } else
 751                 /* do not advance CmdSN */
 752                 nop->cmdsn = cpu_to_be32(session->cmdsn);
 753
 754         nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 755
 756         if (data_size) {
 757                 memcpy(mtask->data, data, data_size);
 758                 mtask->data_count = data_size;
 759         } else
 760                 mtask->data_count = 0;
 761
 762         INIT_LIST_HEAD(&mtask->running);
 763         memcpy(mtask->hdr, hdr, sizeof(struct iscsi_hdr));
 764         if (session->tt->init_mgmt_task)
 765                 session->tt->init_mgmt_task(conn, mtask, data, data_size);
 766         spin_unlock_bh(&session->lock);
 767
 768         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
 769                    hdr->opcode, hdr->itt, data_size);
 770
 771         /*
 772          * since send_pdu() could be called at least from two contexts,
 773          * we need to serialize __kfifo_put, so we don't have to take
 774          * additional lock on fast data-path
 775          */
 776         if (hdr->opcode & ISCSI_OP_IMMEDIATE)
 777                 __kfifo_put(conn->immqueue, (void*)&mtask, sizeof(void*));
 778         else
 779                 __kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*));
 780
 781         scsi_queue_work(session->host, &conn->xmitwork);
 782         return 0;
 783 }
 784
 785 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 786                         char *data, uint32_t data_size)
 787 {
 788         struct iscsi_conn *conn = cls_conn->dd_data;
 789         int rc;
 790
 791         mutex_lock(&conn->xmitmutex);
 792         rc = iscsi_conn_send_generic(conn, hdr, data, data_size);
 793         mutex_unlock(&conn->xmitmutex);
 794
 795         return rc;
 796 }
 797 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 798
 799 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
 800 {
 801         struct iscsi_session *session = class_to_transport_session(cls_session);
 802         struct iscsi_conn *conn = session->leadconn;
 803
 804         spin_lock_bh(&session->lock);
 805         if (session->state != ISCSI_STATE_LOGGED_IN) {
 806                 session->recovery_failed = 1;
 807                 if (conn)
 808                         wake_up(&conn->ehwait);
 809         }
 810         spin_unlock_bh(&session->lock);
 811 }
 812 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
 813
 814 int iscsi_eh_host_reset(struct scsi_cmnd *sc)
 815 {
 816         struct Scsi_Host *host = sc->device->host;
 817         struct iscsi_session *session = iscsi_hostdata(host->hostdata);
 818         struct iscsi_conn *conn = session->leadconn;
 819         int fail_session = 0;
 820
 821         spin_lock_bh(&session->lock);
 822         if (session->state == ISCSI_STATE_TERMINATE) {
 823 failed:
 824                 debug_scsi("failing host reset: session terminated "
 825                            "[CID %d age %d]", conn->id, session->age);
 826                 spin_unlock_bh(&session->lock);
 827                 return FAILED;
 828         }
 829
 830         if (sc->SCp.phase == session->age) {
 831                 debug_scsi("failing connection CID %d due to SCSI host reset",
 832                            conn->id);
 833                 fail_session = 1;
 834         }
 835         spin_unlock_bh(&session->lock);
 836
 837         /*
 838          * we drop the lock here but the leadconn cannot be destoyed while
 839          * we are in the scsi eh
 840          */
 841         if (fail_session) {
 842                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 843                 /*
 844                  * if userspace cannot respond then we must kick this off
 845                  * here for it
 846                  */
 847                 iscsi_start_session_recovery(session, conn, STOP_CONN_RECOVER);
 848         }
 849
 850         debug_scsi("iscsi_eh_host_reset wait for relogin\n");
 851         wait_event_interruptible(conn->ehwait,
 852                                  session->state == ISCSI_STATE_TERMINATE ||
 853                                  session->state == ISCSI_STATE_LOGGED_IN ||
 854                                  session->recovery_failed);
 855         if (signal_pending(current))
 856                 flush_signals(current);
 857
 858         spin_lock_bh(&session->lock);
 859         if (session->state == ISCSI_STATE_LOGGED_IN)
 860                 printk(KERN_INFO "host reset succeeded\n");
 861         else
 862                 goto failed;
 863         spin_unlock_bh(&session->lock);
 864
 865         return SUCCESS;
 866 }
 867 EXPORT_SYMBOL_GPL(iscsi_eh_host_reset);
 868
 869 static void iscsi_tmabort_timedout(unsigned long data)
 870 {
 871         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)data;
 872         struct iscsi_conn *conn = ctask->conn;
 873         struct iscsi_session *session = conn->session;
 874
 875         spin_lock(&session->lock);
 876         if (conn->tmabort_state == TMABORT_INITIAL) {
 877                 conn->tmabort_state = TMABORT_TIMEDOUT;
 878                 debug_scsi("tmabort timedout [sc %p itt 0x%x]\n",
 879                         ctask->sc, ctask->itt);
 880                 /* unblock eh_abort() */
 881                 wake_up(&conn->ehwait);
 882         }
 883         spin_unlock(&session->lock);
 884 }
 885
 886 /* must be called with the mutex lock */
 887 static int iscsi_exec_abort_task(struct scsi_cmnd *sc,
 888                                  struct iscsi_cmd_task *ctask)
 889 {
 890         struct iscsi_conn *conn = ctask->conn;
 891         struct iscsi_session *session = conn->session;
 892         struct iscsi_tm *hdr = &conn->tmhdr;
 893         int rc;
 894
 895         /*
 896          * ctask timed out but session is OK requests must be serialized.
 897          */
 898         memset(hdr, 0, sizeof(struct iscsi_tm));
 899         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
 900         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK;
 901         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 902         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
 903         hdr->rtt = ctask->hdr->itt;
 904         hdr->refcmdsn = ctask->hdr->cmdsn;
 905
 906         rc = iscsi_conn_send_generic(conn, (struct iscsi_hdr *)hdr,
 907                                      NULL, 0);
 908         if (rc) {
 909                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 910                 debug_scsi("abort sent failure [itt 0x%x] %d", ctask->itt, rc);
 911                 return rc;
 912         }
 913
 914         debug_scsi("abort sent [itt 0x%x]\n", ctask->itt);
 915
 916         spin_lock_bh(&session->lock);
 917         ctask->mtask = (struct iscsi_mgmt_task *)
 918                         session->mgmt_cmds[(hdr->itt & ISCSI_ITT_MASK) -
 919                                         ISCSI_MGMT_ITT_OFFSET];
 920
 921         if (conn->tmabort_state == TMABORT_INITIAL) {
 922                 conn->tmfcmd_pdus_cnt++;
 923                 conn->tmabort_timer.expires = 10*HZ + jiffies;
 924                 conn->tmabort_timer.function = iscsi_tmabort_timedout;
 925                 conn->tmabort_timer.data = (unsigned long)ctask;
 926                 add_timer(&conn->tmabort_timer);
 927                 debug_scsi("abort set timeout [itt 0x%x]", ctask->itt);
 928         }
 929         spin_unlock_bh(&session->lock);
 930         mutex_unlock(&conn->xmitmutex);
 931
 932         /*
 933          * block eh thread until:
 934          *
 935          * 1) abort response
 936          * 2) abort timeout
 937          * 3) session is terminated or restarted or userspace has
 938          * given up on recovery
 939          */
 940         wait_event_interruptible(conn->ehwait,
 941                                  sc->SCp.phase != session->age ||
 942                                  session->state != ISCSI_STATE_LOGGED_IN ||
 943                                  conn->tmabort_state != TMABORT_INITIAL ||
 944                                  session->recovery_failed);
 945         if (signal_pending(current))
 946                 flush_signals(current);
 947         del_timer_sync(&conn->tmabort_timer);
 948
 949         mutex_lock(&conn->xmitmutex);
 950         return 0;
 951 }
 952
 953 /*
 954  * xmit mutex and session lock must be held
 955  */
 956 #define iscsi_remove_task(tasktype)                                     \
 957 static struct iscsi_##tasktype *                                        \
 958 iscsi_remove_##tasktype(struct kfifo *fifo, uint32_t itt)               \
 959 {                                                                       \
 960         int i, nr_tasks = __kfifo_len(fifo) / sizeof(void*);            \
 961         struct iscsi_##tasktype *task;                                  \
 962                                                                         \
 963         debug_scsi("searching %d tasks\n", nr_tasks);                   \
 964                                                                         \
 965         for (i = 0; i < nr_tasks; i++) {                                \
 966                 __kfifo_get(fifo, (void*)&task, sizeof(void*));         \
 967                 debug_scsi("check task %u\n", task->itt);               \
 968                                                                         \
 969                 if (task->itt == itt) {                                 \
 970                         debug_scsi("matched task\n");                   \
 971                         break;                                          \
 972                 }                                                       \
 973                                                                         \
 974                 __kfifo_put(fifo, (void*)&task, sizeof(void*));         \
 975         }                                                               \
 976         return NULL;                                                    \
 977 }
 978
 979 iscsi_remove_task(mgmt_task);
 980 iscsi_remove_task(cmd_task);
 981
 982 static int iscsi_ctask_mtask_cleanup(struct iscsi_cmd_task *ctask)
 983 {
 984         struct iscsi_conn *conn = ctask->conn;
 985         struct iscsi_session *session = conn->session;
 986
 987         if (!ctask->mtask)
 988                 return -EINVAL;
 989
 990         if (!iscsi_remove_mgmt_task(conn->immqueue, ctask->mtask->itt))
 991                 list_del(&ctask->mtask->running);
 992         __kfifo_put(session->mgmtpool.queue, (void*)&ctask->mtask,
 993                     sizeof(void*));
 994         ctask->mtask = NULL;
 995         return 0;
 996 }
 997
 998 /*
 999  * session lock and xmitmutex must be held
1000  */
1001 static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1002                          int err)
1003 {
1004         struct scsi_cmnd *sc;
1005
1006         conn->session->tt->cleanup_cmd_task(conn, ctask);
1007         iscsi_ctask_mtask_cleanup(ctask);
1008
1009         sc = ctask->sc;
1010         if (!sc)
1011                 return;
1012         sc->result = err;
1013         sc->resid = sc->request_bufflen;
1014         iscsi_complete_command(conn->session, ctask);
1015 }
1016
1017 int iscsi_eh_abort(struct scsi_cmnd *sc)
1018 {
1019         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
1020         struct iscsi_conn *conn = ctask->conn;
1021         struct iscsi_session *session = conn->session;
1022         struct iscsi_cmd_task *pending_ctask;
1023         int rc;
1024
1025         conn->eh_abort_cnt++;
1026         debug_scsi("aborting [sc %p itt 0x%x]\n", sc, ctask->itt);
1027
1028         mutex_lock(&conn->xmitmutex);
1029         spin_lock_bh(&session->lock);
1030
1031         /*
1032          * If we are not logged in or we have started a new session
1033          * then let the host reset code handle this
1034          */
1035         if (session->state != ISCSI_STATE_LOGGED_IN ||
1036             sc->SCp.phase != session->age)
1037                 goto failed;
1038
1039         /* ctask completed before time out */
1040         if (!ctask->sc)
1041                 goto success;
1042
1043         /* what should we do here ? */
1044         if (conn->ctask == ctask) {
1045                 printk(KERN_INFO "sc %p itt 0x%x partially sent. Failing "
1046                        "abort\n", sc, ctask->itt);
1047                 goto failed;
1048         }
1049
1050         /* check for the easy pending cmd abort */
1051         pending_ctask = iscsi_remove_cmd_task(conn->xmitqueue, ctask->itt);
1052         if (pending_ctask) {
1053                 /* iscsi_tcp queues write transfers on the xmitqueue */
1054                 if (list_empty(&pending_ctask->running)) {
1055                         debug_scsi("found pending task\n");
1056                         goto success;
1057                 } else
1058                         __kfifo_put(conn->xmitqueue, (void*)&pending_ctask,
1059                                     sizeof(void*));
1060         }
1061
1062         conn->tmabort_state = TMABORT_INITIAL;
1063
1064         spin_unlock_bh(&session->lock);
1065         rc = iscsi_exec_abort_task(sc, ctask);
1066         spin_lock_bh(&session->lock);
1067
1068         iscsi_ctask_mtask_cleanup(ctask);
1069         if (rc || sc->SCp.phase != session->age ||
1070             session->state != ISCSI_STATE_LOGGED_IN)
1071                 goto failed;
1072
1073         /* ctask completed before tmf abort response */
1074         if (!ctask->sc) {
1075                 debug_scsi("sc completed while abort in progress\n");
1076                 goto success;
1077         }
1078
1079         if (conn->tmabort_state != TMABORT_SUCCESS) {
1080                 spin_unlock_bh(&session->lock);
1081                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1082                 spin_lock_bh(&session->lock);
1083                 goto failed;
1084         }
1085
1086 success:
1087         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1088         spin_unlock_bh(&session->lock);
1089
1090         /*
1091          * clean up task if aborted. we have the xmitmutex so grab
1092          * the recv lock as a writer
1093          */
1094         write_lock_bh(conn->recv_lock);
1095         spin_lock(&session->lock);
1096         fail_command(conn, ctask, DID_ABORT << 16);
1097         spin_unlock(&session->lock);
1098         write_unlock_bh(conn->recv_lock);
1099
1100         mutex_unlock(&conn->xmitmutex);
1101         return SUCCESS;
1102
1103 failed:
1104         spin_unlock_bh(&session->lock);
1105         mutex_unlock(&conn->xmitmutex);
1106
1107         debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1108         return FAILED;
1109 }
1110 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1111
1112 int
1113 iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
1114 {
1115         int i;
1116
1117         *items = kmalloc(max * sizeof(void*), GFP_KERNEL);
1118         if (*items == NULL)
1119                 return -ENOMEM;
1120
1121         q->max = max;
1122         q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL);
1123         if (q->pool == NULL) {
1124                 kfree(*items);
1125                 return -ENOMEM;
1126         }
1127
1128         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1129                               GFP_KERNEL, NULL);
1130         if (q->queue == ERR_PTR(-ENOMEM)) {
1131                 kfree(q->pool);
1132                 kfree(*items);
1133                 return -ENOMEM;
1134         }
1135
1136         for (i = 0; i < max; i++) {
1137                 q->pool[i] = kmalloc(item_size, GFP_KERNEL);
1138                 if (q->pool[i] == NULL) {
1139                         int j;
1140
1141                         for (j = 0; j < i; j++)
1142                                 kfree(q->pool[j]);
1143
1144                         kfifo_free(q->queue);
1145                         kfree(q->pool);
1146                         kfree(*items);
1147                         return -ENOMEM;
1148                 }
1149                 memset(q->pool[i], 0, item_size);
1150                 (*items)[i] = q->pool[i];
1151                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1152         }
1153         return 0;
1154 }
1155 EXPORT_SYMBOL_GPL(iscsi_pool_init);
1156
1157 void iscsi_pool_free(struct iscsi_queue *q, void **items)
1158 {
1159         int i;
1160
1161         for (i = 0; i < q->max; i++)
1162                 kfree(items[i]);
1163         kfree(q->pool);
1164         kfree(items);
1165 }
1166 EXPORT_SYMBOL_GPL(iscsi_pool_free);
1167
1168 /*
1169  * iSCSI Session's hostdata organization:
1170  *
1171  *    *------------------* <== hostdata_session(host->hostdata)
1172  *    | ptr to class sess|
1173  *    |------------------| <== iscsi_hostdata(host->hostdata)
1174  *    | iscsi_session    |
1175  *    *------------------*
1176  */
1177
1178 #define hostdata_privsize(_sz)  (sizeof(unsigned long) + _sz + \
1179                                  _sz % sizeof(unsigned long))
1180
1181 #define hostdata_session(_hostdata) (iscsi_ptr(*(unsigned long *)_hostdata))
1182
1183 /**
1184  * iscsi_session_setup - create iscsi cls session and host and session
1185  * @scsit: scsi transport template
1186  * @iscsit: iscsi transport template
1187  * @initial_cmdsn: initial CmdSN
1188  * @hostno: host no allocated
1189  *
1190  * This can be used by software iscsi_transports that allocate
1191  * a session per scsi host.
1192  **/
1193 struct iscsi_cls_session *
1194 iscsi_session_setup(struct iscsi_transport *iscsit,
1195                     struct scsi_transport_template *scsit,
1196                     int cmd_task_size, int mgmt_task_size,
1197                     uint32_t initial_cmdsn, uint32_t *hostno)
1198 {
1199         struct Scsi_Host *shost;
1200         struct iscsi_session *session;
1201         struct iscsi_cls_session *cls_session;
1202         int cmd_i;
1203
1204         shost = scsi_host_alloc(iscsit->host_template,
1205                                 hostdata_privsize(sizeof(*session)));
1206         if (!shost)
1207                 return NULL;
1208
1209         shost->max_id = 1;
1210         shost->max_channel = 0;
1211         shost->max_lun = iscsit->max_lun;
1212         shost->max_cmd_len = iscsit->max_cmd_len;
1213         shost->transportt = scsit;
1214         shost->transportt->create_work_queue = 1;
1215         *hostno = shost->host_no;
1216
1217         session = iscsi_hostdata(shost->hostdata);
1218         memset(session, 0, sizeof(struct iscsi_session));
1219         session->host = shost;
1220         session->state = ISCSI_STATE_FREE;
1221         session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
1222         session->cmds_max = ISCSI_XMIT_CMDS_MAX;
1223         session->cmdsn = initial_cmdsn;
1224         session->exp_cmdsn = initial_cmdsn + 1;
1225         session->max_cmdsn = initial_cmdsn + 1;
1226         session->max_r2t = 1;
1227         session->tt = iscsit;
1228
1229         /* initialize SCSI PDU commands pool */
1230         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
1231                             (void***)&session->cmds,
1232                             cmd_task_size + sizeof(struct iscsi_cmd_task)))
1233                 goto cmdpool_alloc_fail;
1234
1235         /* pre-format cmds pool with ITT */
1236         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1237                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1238
1239                 if (cmd_task_size)
1240                         ctask->dd_data = &ctask[1];
1241                 ctask->itt = cmd_i;
1242         }
1243
1244         spin_lock_init(&session->lock);
1245         INIT_LIST_HEAD(&session->connections);
1246
1247         /* initialize immediate command pool */
1248         if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max,
1249                            (void***)&session->mgmt_cmds,
1250                            mgmt_task_size + sizeof(struct iscsi_mgmt_task)))
1251                 goto mgmtpool_alloc_fail;
1252
1253
1254         /* pre-format immediate cmds pool with ITT */
1255         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
1256                 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
1257
1258                 if (mgmt_task_size)
1259                         mtask->dd_data = &mtask[1];
1260                 mtask->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i;
1261                 mtask->data = kmalloc(DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH,
1262                                      GFP_KERNEL);
1263                 if (!mtask->data) {
1264                         int j;
1265
1266                         for (j = 0; j < cmd_i; j++)
1267                                 kfree(session->mgmt_cmds[j]->data);
1268                         goto immdata_alloc_fail;
1269                 }
1270         }
1271
1272         if (scsi_add_host(shost, NULL))
1273                 goto add_host_fail;
1274
1275         cls_session = iscsi_create_session(shost, iscsit, 0);
1276         if (!cls_session)
1277                 goto cls_session_fail;
1278         *(unsigned long*)shost->hostdata = (unsigned long)cls_session;
1279
1280         return cls_session;
1281
1282 cls_session_fail:
1283         scsi_remove_host(shost);
1284 add_host_fail:
1285         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++)
1286                 kfree(session->mgmt_cmds[cmd_i]->data);
1287 immdata_alloc_fail:
1288         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1289 mgmtpool_alloc_fail:
1290         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1291 cmdpool_alloc_fail:
1292         scsi_host_put(shost);
1293         return NULL;
1294 }
1295 EXPORT_SYMBOL_GPL(iscsi_session_setup);
1296
1297 /**
1298  * iscsi_session_teardown - destroy session, host, and cls_session
1299  * shost: scsi host
1300  *
1301  * This can be used by software iscsi_transports that allocate
1302  * a session per scsi host.
1303  **/
1304 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
1305 {
1306         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1307         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1308         int cmd_i;
1309
1310         scsi_remove_host(shost);
1311
1312         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++)
1313                 kfree(session->mgmt_cmds[cmd_i]->data);
1314
1315         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1316         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1317
1318         iscsi_destroy_session(cls_session);
1319         scsi_host_put(shost);
1320 }
1321 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
1322
1323 /**
1324  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
1325  * @cls_session: iscsi_cls_session
1326  * @conn_idx: cid
1327  **/
1328 struct iscsi_cls_conn *
1329 iscsi_conn_setup(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1330 {
1331         struct iscsi_session *session = class_to_transport_session(cls_session);
1332         struct iscsi_conn *conn;
1333         struct iscsi_cls_conn *cls_conn;
1334
1335         cls_conn = iscsi_create_conn(cls_session, conn_idx);
1336         if (!cls_conn)
1337                 return NULL;
1338         conn = cls_conn->dd_data;
1339         memset(conn, 0, sizeof(*conn));
1340
1341         conn->session = session;
1342         conn->cls_conn = cls_conn;
1343         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
1344         conn->id = conn_idx;
1345         conn->exp_statsn = 0;
1346         conn->tmabort_state = TMABORT_INITIAL;
1347         INIT_LIST_HEAD(&conn->run_list);
1348         INIT_LIST_HEAD(&conn->mgmt_run_list);
1349
1350         /* initialize general xmit PDU commands queue */
1351         conn->xmitqueue = kfifo_alloc(session->cmds_max * sizeof(void*),
1352                                         GFP_KERNEL, NULL);
1353         if (conn->xmitqueue == ERR_PTR(-ENOMEM))
1354                 goto xmitqueue_alloc_fail;
1355
1356         /* initialize general immediate & non-immediate PDU commands queue */
1357         conn->immqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
1358                                         GFP_KERNEL, NULL);
1359         if (conn->immqueue == ERR_PTR(-ENOMEM))
1360                 goto immqueue_alloc_fail;
1361
1362         conn->mgmtqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
1363                                         GFP_KERNEL, NULL);
1364         if (conn->mgmtqueue == ERR_PTR(-ENOMEM))
1365                 goto mgmtqueue_alloc_fail;
1366
1367         INIT_WORK(&conn->xmitwork, iscsi_xmitworker, conn);
1368
1369         /* allocate login_mtask used for the login/text sequences */
1370         spin_lock_bh(&session->lock);
1371         if (!__kfifo_get(session->mgmtpool.queue,
1372                          (void*)&conn->login_mtask,
1373                          sizeof(void*))) {
1374                 spin_unlock_bh(&session->lock);
1375                 goto login_mtask_alloc_fail;
1376         }
1377         spin_unlock_bh(&session->lock);
1378
1379         init_timer(&conn->tmabort_timer);
1380         mutex_init(&conn->xmitmutex);
1381         init_waitqueue_head(&conn->ehwait);
1382
1383         return cls_conn;
1384
1385 login_mtask_alloc_fail:
1386         kfifo_free(conn->mgmtqueue);
1387 mgmtqueue_alloc_fail:
1388         kfifo_free(conn->immqueue);
1389 immqueue_alloc_fail:
1390         kfifo_free(conn->xmitqueue);
1391 xmitqueue_alloc_fail:
1392         iscsi_destroy_conn(cls_conn);
1393         return NULL;
1394 }
1395 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
1396
1397 /**
1398  * iscsi_conn_teardown - teardown iscsi connection
1399  * cls_conn: iscsi class connection
1400  *
1401  * TODO: we may need to make this into a two step process
1402  * like scsi-mls remove + put host
1403  */
1404 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
1405 {
1406         struct iscsi_conn *conn = cls_conn->dd_data;
1407         struct iscsi_session *session = conn->session;
1408         unsigned long flags;
1409
1410         mutex_lock(&conn->xmitmutex);
1411         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1412         if (conn->c_stage == ISCSI_CONN_INITIAL_STAGE) {
1413                 if (session->tt->suspend_conn_recv)
1414                         session->tt->suspend_conn_recv(conn);
1415
1416                 session->tt->terminate_conn(conn);
1417         }
1418
1419         spin_lock_bh(&session->lock);
1420         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
1421         if (session->leadconn == conn) {
1422                 /*
1423                  * leading connection? then give up on recovery.
1424                  */
1425                 session->state = ISCSI_STATE_TERMINATE;
1426                 wake_up(&conn->ehwait);
1427         }
1428         spin_unlock_bh(&session->lock);
1429
1430         mutex_unlock(&conn->xmitmutex);
1431
1432         /*
1433          * Block until all in-progress commands for this connection
1434          * time out or fail.
1435          */
1436         for (;;) {
1437                 spin_lock_irqsave(session->host->host_lock, flags);
1438                 if (!session->host->host_busy) { /* OK for ERL == 0 */
1439                         spin_unlock_irqrestore(session->host->host_lock, flags);
1440                         break;
1441                 }
1442                 spin_unlock_irqrestore(session->host->host_lock, flags);
1443                 msleep_interruptible(500);
1444                 printk("conn_destroy(): host_busy %d host_failed %d\n",
1445                         session->host->host_busy, session->host->host_failed);
1446                 /*
1447                  * force eh_abort() to unblock
1448                  */
1449                 wake_up(&conn->ehwait);
1450         }
1451
1452         spin_lock_bh(&session->lock);
1453         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1454                     sizeof(void*));
1455         list_del(&conn->item);
1456         if (list_empty(&session->connections))
1457                 session->leadconn = NULL;
1458         if (session->leadconn && session->leadconn == conn)
1459                 session->leadconn = container_of(session->connections.next,
1460                         struct iscsi_conn, item);
1461
1462         if (session->leadconn == NULL)
1463                 /* no connections exits.. reset sequencing */
1464                 session->cmdsn = session->max_cmdsn = session->exp_cmdsn = 1;
1465         spin_unlock_bh(&session->lock);
1466
1467         kfifo_free(conn->xmitqueue);
1468         kfifo_free(conn->immqueue);
1469         kfifo_free(conn->mgmtqueue);
1470
1471         iscsi_destroy_conn(cls_conn);
1472 }
1473 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
1474
1475 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
1476 {
1477         struct iscsi_conn *conn = cls_conn->dd_data;
1478         struct iscsi_session *session = conn->session;
1479
1480         if (session == NULL) {
1481                 printk(KERN_ERR "iscsi: can't start unbound connection\n");
1482                 return -EPERM;
1483         }
1484
1485         spin_lock_bh(&session->lock);
1486         conn->c_stage = ISCSI_CONN_STARTED;
1487         session->state = ISCSI_STATE_LOGGED_IN;
1488
1489         switch(conn->stop_stage) {
1490         case STOP_CONN_RECOVER:
1491                 /*
1492                  * unblock eh_abort() if it is blocked. re-try all
1493                  * commands after successful recovery
1494                  */
1495                 session->conn_cnt++;
1496                 conn->stop_stage = 0;
1497                 conn->tmabort_state = TMABORT_INITIAL;
1498                 session->age++;
1499                 session->recovery_failed = 0;
1500                 spin_unlock_bh(&session->lock);
1501
1502                 iscsi_unblock_session(session_to_cls(session));
1503                 wake_up(&conn->ehwait);
1504                 return 0;
1505         case STOP_CONN_TERM:
1506                 session->conn_cnt++;
1507                 conn->stop_stage = 0;
1508                 break;
1509         case STOP_CONN_SUSPEND:
1510                 conn->stop_stage = 0;
1511                 clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1512                 clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1513                 break;
1514         default:
1515                 break;
1516         }
1517         spin_unlock_bh(&session->lock);
1518
1519         return 0;
1520 }
1521 EXPORT_SYMBOL_GPL(iscsi_conn_start);
1522
1523 static void
1524 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
1525 {
1526         struct iscsi_mgmt_task *mtask, *tmp;
1527
1528         /* handle pending */
1529         while (__kfifo_get(conn->immqueue, (void*)&mtask, sizeof(void*)) ||
1530                __kfifo_get(conn->mgmtqueue, (void*)&mtask, sizeof(void*))) {
1531                 if (mtask == conn->login_mtask)
1532                         continue;
1533                 debug_scsi("flushing pending mgmt task itt 0x%x\n", mtask->itt);
1534                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1535                             sizeof(void*));
1536         }
1537
1538         /* handle running */
1539         list_for_each_entry_safe(mtask, tmp, &conn->mgmt_run_list, running) {
1540                 debug_scsi("flushing running mgmt task itt 0x%x\n", mtask->itt);
1541                 list_del(&mtask->running);
1542
1543                 if (mtask == conn->login_mtask)
1544                         continue;
1545                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1546                            sizeof(void*));
1547         }
1548
1549         conn->mtask = NULL;
1550 }
1551
1552 /* Fail commands. Mutex and session lock held and recv side suspended */
1553 static void fail_all_commands(struct iscsi_conn *conn)
1554 {
1555         struct iscsi_cmd_task *ctask, *tmp;
1556
1557         /* flush pending */
1558         while (__kfifo_get(conn->xmitqueue, (void*)&ctask, sizeof(void*))) {
1559                 debug_scsi("failing pending sc %p itt 0x%x\n", ctask->sc,
1560                            ctask->itt);
1561                 fail_command(conn, ctask, DID_BUS_BUSY << 16);
1562         }
1563
1564         /* fail all other running */
1565         list_for_each_entry_safe(ctask, tmp, &conn->run_list, running) {
1566                 debug_scsi("failing in progress sc %p itt 0x%x\n",
1567                            ctask->sc, ctask->itt);
1568                 fail_command(conn, ctask, DID_BUS_BUSY << 16);
1569         }
1570
1571         conn->ctask = NULL;
1572 }
1573
1574 void iscsi_start_session_recovery(struct iscsi_session *session,
1575                                   struct iscsi_conn *conn, int flag)
1576 {
1577         int old_stop_stage;
1578
1579         spin_lock_bh(&session->lock);
1580         if (conn->stop_stage == STOP_CONN_TERM) {
1581                 spin_unlock_bh(&session->lock);
1582                 return;
1583         }
1584
1585         /*
1586          * When this is called for the in_login state, we only want to clean
1587          * up the login task and connection.
1588          */
1589         if (conn->stop_stage != STOP_CONN_RECOVER)
1590                 session->conn_cnt--;
1591
1592         old_stop_stage = conn->stop_stage;
1593         conn->stop_stage = flag;
1594         spin_unlock_bh(&session->lock);
1595
1596         if (session->tt->suspend_conn_recv)
1597                 session->tt->suspend_conn_recv(conn);
1598
1599         mutex_lock(&conn->xmitmutex);
1600         spin_lock_bh(&session->lock);
1601         conn->c_stage = ISCSI_CONN_STOPPED;
1602         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1603
1604         if (session->conn_cnt == 0 || session->leadconn == conn)
1605                 session->state = ISCSI_STATE_FAILED;
1606
1607         spin_unlock_bh(&session->lock);
1608
1609         session->tt->terminate_conn(conn);
1610         /*
1611          * flush queues.
1612          */
1613         spin_lock_bh(&session->lock);
1614         fail_all_commands(conn);
1615         flush_control_queues(session, conn);
1616         spin_unlock_bh(&session->lock);
1617
1618         /*
1619          * for connection level recovery we should not calculate
1620          * header digest. conn->hdr_size used for optimization
1621          * in hdr_extract() and will be re-negotiated at
1622          * set_param() time.
1623          */
1624         if (flag == STOP_CONN_RECOVER) {
1625                 conn->hdrdgst_en = 0;
1626                 conn->datadgst_en = 0;
1627
1628                 /*
1629                  * if this is called from the eh and and from userspace
1630                  * then we only need to block once.
1631                  */
1632                 if (session->state == ISCSI_STATE_FAILED &&
1633                     old_stop_stage != STOP_CONN_RECOVER)
1634                         iscsi_block_session(session_to_cls(session));
1635         }
1636         mutex_unlock(&conn->xmitmutex);
1637 }
1638 EXPORT_SYMBOL_GPL(iscsi_start_session_recovery);
1639
1640 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1641 {
1642         struct iscsi_conn *conn = cls_conn->dd_data;
1643         struct iscsi_session *session = conn->session;
1644
1645         switch (flag) {
1646         case STOP_CONN_RECOVER:
1647         case STOP_CONN_TERM:
1648                 iscsi_start_session_recovery(session, conn, flag);
1649                 return;
1650         case STOP_CONN_SUSPEND:
1651                 if (session->tt->suspend_conn_recv)
1652                         session->tt->suspend_conn_recv(conn);
1653
1654                 mutex_lock(&conn->xmitmutex);
1655                 spin_lock_bh(&session->lock);
1656
1657                 conn->stop_stage = flag;
1658                 conn->c_stage = ISCSI_CONN_STOPPED;
1659                 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1660
1661                 spin_unlock_bh(&session->lock);
1662                 mutex_unlock(&conn->xmitmutex);
1663                 break;
1664         default:
1665                 printk(KERN_ERR "invalid stop flag %d\n", flag);
1666         }
1667 }
1668 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
1669
1670 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
1671                     struct iscsi_cls_conn *cls_conn, int is_leading)
1672 {
1673         struct iscsi_session *session = class_to_transport_session(cls_session);
1674         struct iscsi_conn *tmp = ERR_PTR(-EEXIST), *conn = cls_conn->dd_data;
1675
1676         /* lookup for existing connection */
1677         spin_lock_bh(&session->lock);
1678         list_for_each_entry(tmp, &session->connections, item) {
1679                 if (tmp == conn) {
1680                         if (conn->c_stage != ISCSI_CONN_STOPPED ||
1681                             conn->stop_stage == STOP_CONN_TERM) {
1682                                 printk(KERN_ERR "iscsi_tcp: can't bind "
1683                                        "non-stopped connection (%d:%d)\n",
1684                                        conn->c_stage, conn->stop_stage);
1685                                 spin_unlock_bh(&session->lock);
1686                                 return -EIO;
1687                         }
1688                         break;
1689                 }
1690         }
1691         if (tmp != conn) {
1692                 /* bind new iSCSI connection to session */
1693                 conn->session = session;
1694                 list_add(&conn->item, &session->connections);
1695         }
1696         spin_unlock_bh(&session->lock);
1697
1698         if (is_leading)
1699                 session->leadconn = conn;
1700
1701         /*
1702          * Unblock xmitworker(), Login Phase will pass through.
1703          */
1704         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1705         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1706         return 0;
1707 }
1708 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
1709
1710 MODULE_AUTHOR("Mike Christie");
1711 MODULE_DESCRIPTION("iSCSI library functions");
1712 MODULE_LICENSE("GPL");