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