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