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/kfifo.h>
  26 #include <linux/delay.h>
  27 #include <asm/unaligned.h>
  28 #include <net/tcp.h>
  29 #include <scsi/scsi_cmnd.h>
  30 #include <scsi/scsi_device.h>
  31 #include <scsi/scsi_eh.h>
  32 #include <scsi/scsi_tcq.h>
  33 #include <scsi/scsi_host.h>
  34 #include <scsi/scsi.h>
  35 #include <scsi/iscsi_proto.h>
  36 #include <scsi/scsi_transport.h>
  37 #include <scsi/scsi_transport_iscsi.h>
  38 #include <scsi/libiscsi.h>
  39
  40 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 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
  49 #define SNA32_CHECK 2147483648UL
  50
  51 static int iscsi_sna_lt(u32 n1, u32 n2)
  52 {
  53         return n1 != n2 && ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
  54                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
  55 }
  56
  57 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
  58 static int iscsi_sna_lte(u32 n1, u32 n2)
  59 {
  60         return n1 == n2 || ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
  61                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
  62 }
  63
  64 void
  65 iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
  66 {
  67         uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
  68         uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);
  69
  70         /*
  71          * standard specifies this check for when to update expected and
  72          * max sequence numbers
  73          */
  74         if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
  75                 return;
  76
  77         if (exp_cmdsn != session->exp_cmdsn &&
  78             !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
  79                 session->exp_cmdsn = exp_cmdsn;
  80
  81         if (max_cmdsn != session->max_cmdsn &&
  82             !iscsi_sna_lt(max_cmdsn, session->max_cmdsn)) {
  83                 session->max_cmdsn = max_cmdsn;
  84                 /*
  85                  * if the window closed with IO queued, then kick the
  86                  * xmit thread
  87                  */
  88                 if (!list_empty(&session->leadconn->xmitqueue) ||
  89                     __kfifo_len(session->leadconn->mgmtqueue))
  90                         scsi_queue_work(session->host,
  91                                         &session->leadconn->xmitwork);
  92         }
  93 }
  94 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
  95
  96 void iscsi_prep_unsolicit_data_pdu(struct iscsi_cmd_task *ctask,
  97                                    struct iscsi_data *hdr)
  98 {
  99         struct iscsi_conn *conn = ctask->conn;
 100
 101         memset(hdr, 0, sizeof(struct iscsi_data));
 102         hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 103         hdr->datasn = cpu_to_be32(ctask->unsol_datasn);
 104         ctask->unsol_datasn++;
 105         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 106         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
 107
 108         hdr->itt = ctask->hdr->itt;
 109         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 110         hdr->offset = cpu_to_be32(ctask->unsol_offset);
 111
 112         if (ctask->unsol_count > conn->max_xmit_dlength) {
 113                 hton24(hdr->dlength, conn->max_xmit_dlength);
 114                 ctask->data_count = conn->max_xmit_dlength;
 115                 ctask->unsol_offset += ctask->data_count;
 116                 hdr->flags = 0;
 117         } else {
 118                 hton24(hdr->dlength, ctask->unsol_count);
 119                 ctask->data_count = ctask->unsol_count;
 120                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 121         }
 122 }
 123 EXPORT_SYMBOL_GPL(iscsi_prep_unsolicit_data_pdu);
 124
 125 /**
 126  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 127  * @ctask: iscsi cmd task
 128  *
 129  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 130  * fields like dlength or final based on how much data it sends
 131  */
 132 static void iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
 133 {
 134         struct iscsi_conn *conn = ctask->conn;
 135         struct iscsi_session *session = conn->session;
 136         struct iscsi_cmd *hdr = ctask->hdr;
 137         struct scsi_cmnd *sc = ctask->sc;
 138
 139         hdr->opcode = ISCSI_OP_SCSI_CMD;
 140         hdr->flags = ISCSI_ATTR_SIMPLE;
 141         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
 142         hdr->itt = build_itt(ctask->itt, conn->id, session->age);
 143         hdr->data_length = cpu_to_be32(scsi_bufflen(sc));
 144         hdr->cmdsn = cpu_to_be32(session->cmdsn);
 145         session->cmdsn++;
 146         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 147         memcpy(hdr->cdb, sc->cmnd, sc->cmd_len);
 148         if (sc->cmd_len < MAX_COMMAND_SIZE)
 149                 memset(&hdr->cdb[sc->cmd_len], 0,
 150                         MAX_COMMAND_SIZE - sc->cmd_len);
 151
 152         ctask->data_count = 0;
 153         ctask->imm_count = 0;
 154         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 155                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 156                 /*
 157                  * Write counters:
 158                  *
 159                  *      imm_count       bytes to be sent right after
 160                  *                      SCSI PDU Header
 161                  *
 162                  *      unsol_count     bytes(as Data-Out) to be sent
 163                  *                      without R2T ack right after
 164                  *                      immediate data
 165                  *
 166                  *      r2t_data_count  bytes to be sent via R2T ack's
 167                  *
 168                  *      pad_count       bytes to be sent as zero-padding
 169                  */
 170                 ctask->unsol_count = 0;
 171                 ctask->unsol_offset = 0;
 172                 ctask->unsol_datasn = 0;
 173
 174                 if (session->imm_data_en) {
 175                         if (scsi_bufflen(sc) >= session->first_burst)
 176                                 ctask->imm_count = min(session->first_burst,
 177                                                         conn->max_xmit_dlength);
 178                         else
 179                                 ctask->imm_count = min(scsi_bufflen(sc),
 180                                                         conn->max_xmit_dlength);
 181                         hton24(ctask->hdr->dlength, ctask->imm_count);
 182                 } else
 183                         zero_data(ctask->hdr->dlength);
 184
 185                 if (!session->initial_r2t_en) {
 186                         ctask->unsol_count = min((session->first_burst),
 187                                 (scsi_bufflen(sc))) - ctask->imm_count;
 188                         ctask->unsol_offset = ctask->imm_count;
 189                 }
 190
 191                 if (!ctask->unsol_count)
 192                         /* No unsolicit Data-Out's */
 193                         ctask->hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 194         } else {
 195                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 196                 zero_data(hdr->dlength);
 197
 198                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
 199                         hdr->flags |= ISCSI_FLAG_CMD_READ;
 200         }
 201
 202         conn->scsicmd_pdus_cnt++;
 203
 204         debug_scsi("iscsi prep [%s cid %d sc %p cdb 0x%x itt 0x%x len %d "
 205                 "cmdsn %d win %d]\n",
 206                 sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
 207                 conn->id, sc, sc->cmnd[0], ctask->itt, scsi_bufflen(sc),
 208                 session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
 209 }
 210
 211 /**
 212  * iscsi_complete_command - return command back to scsi-ml
 213  * @ctask: iscsi cmd task
 214  *
 215  * Must be called with session lock.
 216  * This function returns the scsi command to scsi-ml and returns
 217  * the cmd task to the pool of available cmd tasks.
 218  */
 219 static void iscsi_complete_command(struct iscsi_cmd_task *ctask)
 220 {
 221         struct iscsi_session *session = ctask->conn->session;
 222         struct scsi_cmnd *sc = ctask->sc;
 223
 224         ctask->state = ISCSI_TASK_COMPLETED;
 225         ctask->sc = NULL;
 226         /* SCSI eh reuses commands to verify us */
 227         sc->SCp.ptr = NULL;
 228         list_del_init(&ctask->running);
 229         __kfifo_put(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
 230         sc->scsi_done(sc);
 231 }
 232
 233 static void __iscsi_get_ctask(struct iscsi_cmd_task *ctask)
 234 {
 235         atomic_inc(&ctask->refcount);
 236 }
 237
 238 static void __iscsi_put_ctask(struct iscsi_cmd_task *ctask)
 239 {
 240         if (atomic_dec_and_test(&ctask->refcount))
 241                 iscsi_complete_command(ctask);
 242 }
 243
 244 /**
 245  * iscsi_cmd_rsp - SCSI Command Response processing
 246  * @conn: iscsi connection
 247  * @hdr: iscsi header
 248  * @ctask: scsi command task
 249  * @data: cmd data buffer
 250  * @datalen: len of buffer
 251  *
 252  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 253  * then completes the command and task.
 254  **/
 255 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 256                                struct iscsi_cmd_task *ctask, char *data,
 257                                int datalen)
 258 {
 259         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
 260         struct iscsi_session *session = conn->session;
 261         struct scsi_cmnd *sc = ctask->sc;
 262
 263         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 264         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 265
 266         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 267
 268         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 269                 sc->result = DID_ERROR << 16;
 270                 goto out;
 271         }
 272
 273         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 274                 uint16_t senselen;
 275
 276                 if (datalen < 2) {
 277 invalid_datalen:
 278                         printk(KERN_ERR "iscsi: Got CHECK_CONDITION but "
 279                                "invalid data buffer size of %d\n", datalen);
 280                         sc->result = DID_BAD_TARGET << 16;
 281                         goto out;
 282                 }
 283
 284                 senselen = be16_to_cpu(get_unaligned((__be16 *) data));
 285                 if (datalen < senselen)
 286                         goto invalid_datalen;
 287
 288                 memcpy(sc->sense_buffer, data + 2,
 289                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 290                 debug_scsi("copied %d bytes of sense\n",
 291                            min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 292         }
 293
 294         if (sc->sc_data_direction == DMA_TO_DEVICE)
 295                 goto out;
 296
 297         if (rhdr->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
 298                 int res_count = be32_to_cpu(rhdr->residual_count);
 299
 300                 if (res_count > 0 && res_count <= scsi_bufflen(sc))
 301                         scsi_set_resid(sc, res_count);
 302                 else
 303                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 304         } else if (rhdr->flags & ISCSI_FLAG_CMD_BIDI_UNDERFLOW)
 305                 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 306         else if (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW)
 307                 scsi_set_resid(sc, be32_to_cpu(rhdr->residual_count));
 308
 309 out:
 310         debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 311                    (long)sc, sc->result, ctask->itt);
 312         conn->scsirsp_pdus_cnt++;
 313
 314         __iscsi_put_ctask(ctask);
 315 }
 316
 317 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 318 {
 319         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 320
 321         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 322         conn->tmfrsp_pdus_cnt++;
 323
 324         if (conn->tmabort_state != TMABORT_INITIAL)
 325                 return;
 326
 327         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 328                 conn->tmabort_state = TMABORT_SUCCESS;
 329         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 330                 conn->tmabort_state = TMABORT_NOT_FOUND;
 331         else
 332                 conn->tmabort_state = TMABORT_FAILED;
 333         wake_up(&conn->ehwait);
 334 }
 335
 336 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 337                                char *data, int datalen)
 338 {
 339         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
 340         struct iscsi_hdr rejected_pdu;
 341         uint32_t itt;
 342
 343         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
 344
 345         if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
 346                 if (ntoh24(reject->dlength) > datalen)
 347                         return ISCSI_ERR_PROTO;
 348
 349                 if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
 350                         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
 351                         itt = get_itt(rejected_pdu.itt);
 352                         printk(KERN_ERR "itt 0x%x had pdu (op 0x%x) rejected "
 353                                 "due to DataDigest error.\n", itt,
 354                                 rejected_pdu.opcode);
 355                 }
 356         }
 357         return 0;
 358 }
 359
 360 /**
 361  * __iscsi_complete_pdu - complete pdu
 362  * @conn: iscsi conn
 363  * @hdr: iscsi header
 364  * @data: data buffer
 365  * @datalen: len of data buffer
 366  *
 367  * Completes pdu processing by freeing any resources allocated at
 368  * queuecommand or send generic. session lock must be held and verify
 369  * itt must have been called.
 370  */
 371 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 372                          char *data, int datalen)
 373 {
 374         struct iscsi_session *session = conn->session;
 375         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
 376         struct iscsi_cmd_task *ctask;
 377         struct iscsi_mgmt_task *mtask;
 378         uint32_t itt;
 379
 380         if (hdr->itt != RESERVED_ITT)
 381                 itt = get_itt(hdr->itt);
 382         else
 383                 itt = ~0U;
 384
 385         if (itt < session->cmds_max) {
 386                 ctask = session->cmds[itt];
 387
 388                 debug_scsi("cmdrsp [op 0x%x cid %d itt 0x%x len %d]\n",
 389                            opcode, conn->id, ctask->itt, datalen);
 390
 391                 switch(opcode) {
 392                 case ISCSI_OP_SCSI_CMD_RSP:
 393                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 394                         iscsi_scsi_cmd_rsp(conn, hdr, ctask, data,
 395                                            datalen);
 396                         break;
 397                 case ISCSI_OP_SCSI_DATA_IN:
 398                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
 399                         if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
 400                                 conn->scsirsp_pdus_cnt++;
 401                                 __iscsi_put_ctask(ctask);
 402                         }
 403                         break;
 404                 case ISCSI_OP_R2T:
 405                         /* LLD handles this for now */
 406                         break;
 407                 default:
 408                         rc = ISCSI_ERR_BAD_OPCODE;
 409                         break;
 410                 }
 411         } else if (itt >= ISCSI_MGMT_ITT_OFFSET &&
 412                    itt < ISCSI_MGMT_ITT_OFFSET + session->mgmtpool_max) {
 413                 mtask = session->mgmt_cmds[itt - ISCSI_MGMT_ITT_OFFSET];
 414
 415                 debug_scsi("immrsp [op 0x%x cid %d itt 0x%x len %d]\n",
 416                            opcode, conn->id, mtask->itt, datalen);
 417
 418                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 419                 switch(opcode) {
 420                 case ISCSI_OP_LOGOUT_RSP:
 421                         if (datalen) {
 422                                 rc = ISCSI_ERR_PROTO;
 423                                 break;
 424                         }
 425                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 426                         /* fall through */
 427                 case ISCSI_OP_LOGIN_RSP:
 428                 case ISCSI_OP_TEXT_RSP:
 429                         /*
 430                          * login related PDU's exp_statsn is handled in
 431                          * userspace
 432                          */
 433                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 434                                 rc = ISCSI_ERR_CONN_FAILED;
 435                         list_del(&mtask->running);
 436                         if (conn->login_mtask != mtask)
 437                                 __kfifo_put(session->mgmtpool.queue,
 438                                             (void*)&mtask, sizeof(void*));
 439                         break;
 440                 case ISCSI_OP_SCSI_TMFUNC_RSP:
 441                         if (datalen) {
 442                                 rc = ISCSI_ERR_PROTO;
 443                                 break;
 444                         }
 445
 446                         iscsi_tmf_rsp(conn, hdr);
 447                         break;
 448                 case ISCSI_OP_NOOP_IN:
 449                         if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
 450                                 rc = ISCSI_ERR_PROTO;
 451                                 break;
 452                         }
 453                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 454
 455                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 456                                 rc = ISCSI_ERR_CONN_FAILED;
 457                         list_del(&mtask->running);
 458                         if (conn->login_mtask != mtask)
 459                                 __kfifo_put(session->mgmtpool.queue,
 460                                             (void*)&mtask, sizeof(void*));
 461                         break;
 462                 default:
 463                         rc = ISCSI_ERR_BAD_OPCODE;
 464                         break;
 465                 }
 466         } else if (itt == ~0U) {
 467                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 468
 469                 switch(opcode) {
 470                 case ISCSI_OP_NOOP_IN:
 471                         if (datalen) {
 472                                 rc = ISCSI_ERR_PROTO;
 473                                 break;
 474                         }
 475
 476                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
 477                                 break;
 478
 479                         if (iscsi_recv_pdu(conn->cls_conn, hdr, NULL, 0))
 480                                 rc = ISCSI_ERR_CONN_FAILED;
 481                         break;
 482                 case ISCSI_OP_REJECT:
 483                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
 484                         break;
 485                 case ISCSI_OP_ASYNC_EVENT:
 486                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 487                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 488                                 rc = ISCSI_ERR_CONN_FAILED;
 489                         break;
 490                 default:
 491                         rc = ISCSI_ERR_BAD_OPCODE;
 492                         break;
 493                 }
 494         } else
 495                 rc = ISCSI_ERR_BAD_ITT;
 496
 497         return rc;
 498 }
 499 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
 500
 501 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 502                        char *data, int datalen)
 503 {
 504         int rc;
 505
 506         spin_lock(&conn->session->lock);
 507         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
 508         spin_unlock(&conn->session->lock);
 509         return rc;
 510 }
 511 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
 512
 513 /* verify itt (itt encoding: age+cid+itt) */
 514 int iscsi_verify_itt(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 515                      uint32_t *ret_itt)
 516 {
 517         struct iscsi_session *session = conn->session;
 518         struct iscsi_cmd_task *ctask;
 519         uint32_t itt;
 520
 521         if (hdr->itt != RESERVED_ITT) {
 522                 if (((__force u32)hdr->itt & ISCSI_AGE_MASK) !=
 523                     (session->age << ISCSI_AGE_SHIFT)) {
 524                         printk(KERN_ERR "iscsi: received itt %x expected "
 525                                 "session age (%x)\n", (__force u32)hdr->itt,
 526                                 session->age & ISCSI_AGE_MASK);
 527                         return ISCSI_ERR_BAD_ITT;
 528                 }
 529
 530                 if (((__force u32)hdr->itt & ISCSI_CID_MASK) !=
 531                     (conn->id << ISCSI_CID_SHIFT)) {
 532                         printk(KERN_ERR "iscsi: received itt %x, expected "
 533                                 "CID (%x)\n", (__force u32)hdr->itt, conn->id);
 534                         return ISCSI_ERR_BAD_ITT;
 535                 }
 536                 itt = get_itt(hdr->itt);
 537         } else
 538                 itt = ~0U;
 539
 540         if (itt < session->cmds_max) {
 541                 ctask = session->cmds[itt];
 542
 543                 if (!ctask->sc) {
 544                         printk(KERN_INFO "iscsi: dropping ctask with "
 545                                "itt 0x%x\n", ctask->itt);
 546                         /* force drop */
 547                         return ISCSI_ERR_NO_SCSI_CMD;
 548                 }
 549
 550                 if (ctask->sc->SCp.phase != session->age) {
 551                         printk(KERN_ERR "iscsi: ctask's session age %d, "
 552                                 "expected %d\n", ctask->sc->SCp.phase,
 553                                 session->age);
 554                         return ISCSI_ERR_SESSION_FAILED;
 555                 }
 556         }
 557
 558         *ret_itt = itt;
 559         return 0;
 560 }
 561 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
 562
 563 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
 564 {
 565         struct iscsi_session *session = conn->session;
 566         unsigned long flags;
 567
 568         spin_lock_irqsave(&session->lock, flags);
 569         if (session->state == ISCSI_STATE_FAILED) {
 570                 spin_unlock_irqrestore(&session->lock, flags);
 571                 return;
 572         }
 573
 574         if (conn->stop_stage == 0)
 575                 session->state = ISCSI_STATE_FAILED;
 576         spin_unlock_irqrestore(&session->lock, flags);
 577         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
 578         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
 579         iscsi_conn_error(conn->cls_conn, err);
 580 }
 581 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
 582
 583 static void iscsi_prep_mtask(struct iscsi_conn *conn,
 584                              struct iscsi_mgmt_task *mtask)
 585 {
 586         struct iscsi_session *session = conn->session;
 587         struct iscsi_hdr *hdr = mtask->hdr;
 588         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 589
 590         if (hdr->opcode != (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) &&
 591             hdr->opcode != (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 592                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 593         /*
 594          * pre-format CmdSN for outgoing PDU.
 595          */
 596         nop->cmdsn = cpu_to_be32(session->cmdsn);
 597         if (hdr->itt != RESERVED_ITT) {
 598                 hdr->itt = build_itt(mtask->itt, conn->id, session->age);
 599                 /*
 600                  * TODO: We always use immediate, so we never hit this.
 601                  * If we start to send tmfs or nops as non-immediate then
 602                  * we should start checking the cmdsn numbers for mgmt tasks.
 603                  */
 604                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 605                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 606                         session->queued_cmdsn++;
 607                         session->cmdsn++;
 608                 }
 609         }
 610
 611         if (session->tt->init_mgmt_task)
 612                 session->tt->init_mgmt_task(conn, mtask);
 613
 614         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
 615                    hdr->opcode, hdr->itt, mtask->data_count);
 616 }
 617
 618 static int iscsi_xmit_mtask(struct iscsi_conn *conn)
 619 {
 620         struct iscsi_hdr *hdr = conn->mtask->hdr;
 621         int rc, was_logout = 0;
 622
 623         spin_unlock_bh(&conn->session->lock);
 624         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT) {
 625                 conn->session->state = ISCSI_STATE_IN_RECOVERY;
 626                 iscsi_block_session(session_to_cls(conn->session));
 627                 was_logout = 1;
 628         }
 629         rc = conn->session->tt->xmit_mgmt_task(conn, conn->mtask);
 630         spin_lock_bh(&conn->session->lock);
 631         if (rc)
 632                 return rc;
 633
 634         /* done with this in-progress mtask */
 635         conn->mtask = NULL;
 636
 637         if (was_logout) {
 638                 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
 639                 return -ENODATA;
 640         }
 641         return 0;
 642 }
 643
 644 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
 645 {
 646         struct iscsi_session *session = conn->session;
 647
 648         /*
 649          * Check for iSCSI window and take care of CmdSN wrap-around
 650          */
 651         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
 652                 debug_scsi("iSCSI CmdSN closed. ExpCmdSn %u MaxCmdSN %u "
 653                            "CmdSN %u/%u\n", session->exp_cmdsn,
 654                            session->max_cmdsn, session->cmdsn,
 655                            session->queued_cmdsn);
 656                 return -ENOSPC;
 657         }
 658         return 0;
 659 }
 660
 661 static int iscsi_xmit_ctask(struct iscsi_conn *conn)
 662 {
 663         struct iscsi_cmd_task *ctask = conn->ctask;
 664         int rc = 0;
 665
 666         /*
 667          * serialize with TMF AbortTask
 668          */
 669         if (ctask->state == ISCSI_TASK_ABORTING)
 670                 goto done;
 671
 672         __iscsi_get_ctask(ctask);
 673         spin_unlock_bh(&conn->session->lock);
 674         rc = conn->session->tt->xmit_cmd_task(conn, ctask);
 675         spin_lock_bh(&conn->session->lock);
 676         __iscsi_put_ctask(ctask);
 677
 678 done:
 679         if (!rc)
 680                 /* done with this ctask */
 681                 conn->ctask = NULL;
 682         return rc;
 683 }
 684
 685 /**
 686  * iscsi_data_xmit - xmit any command into the scheduled connection
 687  * @conn: iscsi connection
 688  *
 689  * Notes:
 690  *      The function can return -EAGAIN in which case the caller must
 691  *      re-schedule it again later or recover. '0' return code means
 692  *      successful xmit.
 693  **/
 694 static int iscsi_data_xmit(struct iscsi_conn *conn)
 695 {
 696         int rc = 0;
 697
 698         spin_lock_bh(&conn->session->lock);
 699         if (unlikely(conn->suspend_tx)) {
 700                 debug_scsi("conn %d Tx suspended!\n", conn->id);
 701                 spin_unlock_bh(&conn->session->lock);
 702                 return -ENODATA;
 703         }
 704
 705         if (conn->ctask) {
 706                 rc = iscsi_xmit_ctask(conn);
 707                 if (rc)
 708                         goto again;
 709         }
 710
 711         if (conn->mtask) {
 712                 rc = iscsi_xmit_mtask(conn);
 713                 if (rc)
 714                         goto again;
 715         }
 716
 717         /*
 718          * process mgmt pdus like nops before commands since we should
 719          * only have one nop-out as a ping from us and targets should not
 720          * overflow us with nop-ins
 721          */
 722 check_mgmt:
 723         while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask,
 724                            sizeof(void*))) {
 725                 iscsi_prep_mtask(conn, conn->mtask);
 726                 list_add_tail(&conn->mtask->running, &conn->mgmt_run_list);
 727                 rc = iscsi_xmit_mtask(conn);
 728                 if (rc)
 729                         goto again;
 730         }
 731
 732         /* process command queue */
 733         while (!list_empty(&conn->xmitqueue)) {
 734                 /*
 735                  * iscsi tcp may readd the task to the xmitqueue to send
 736                  * write data
 737                  */
 738                 conn->ctask = list_entry(conn->xmitqueue.next,
 739                                          struct iscsi_cmd_task, running);
 740                 if (conn->ctask->state == ISCSI_TASK_PENDING) {
 741                         iscsi_prep_scsi_cmd_pdu(conn->ctask);
 742                         conn->session->tt->init_cmd_task(conn->ctask);
 743                 }
 744                 conn->ctask->state = ISCSI_TASK_RUNNING;
 745                 list_move_tail(conn->xmitqueue.next, &conn->run_list);
 746                 rc = iscsi_xmit_ctask(conn);
 747                 if (rc)
 748                         goto again;
 749                 /*
 750                  * we could continuously get new ctask requests so
 751                  * we need to check the mgmt queue for nops that need to
 752                  * be sent to aviod starvation
 753                  */
 754                 if (__kfifo_len(conn->mgmtqueue))
 755                         goto check_mgmt;
 756         }
 757         spin_unlock_bh(&conn->session->lock);
 758         return -ENODATA;
 759
 760 again:
 761         if (unlikely(conn->suspend_tx))
 762                 rc = -ENODATA;
 763         spin_unlock_bh(&conn->session->lock);
 764         return rc;
 765 }
 766
 767 static void iscsi_xmitworker(struct work_struct *work)
 768 {
 769         struct iscsi_conn *conn =
 770                 container_of(work, struct iscsi_conn, xmitwork);
 771         int rc;
 772         /*
 773          * serialize Xmit worker on a per-connection basis.
 774          */
 775         do {
 776                 rc = iscsi_data_xmit(conn);
 777         } while (rc >= 0 || rc == -EAGAIN);
 778 }
 779
 780 enum {
 781         FAILURE_BAD_HOST = 1,
 782         FAILURE_SESSION_FAILED,
 783         FAILURE_SESSION_FREED,
 784         FAILURE_WINDOW_CLOSED,
 785         FAILURE_OOM,
 786         FAILURE_SESSION_TERMINATE,
 787         FAILURE_SESSION_IN_RECOVERY,
 788         FAILURE_SESSION_RECOVERY_TIMEOUT,
 789 };
 790
 791 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
 792 {
 793         struct Scsi_Host *host;
 794         int reason = 0;
 795         struct iscsi_session *session;
 796         struct iscsi_conn *conn;
 797         struct iscsi_cmd_task *ctask = NULL;
 798
 799         sc->scsi_done = done;
 800         sc->result = 0;
 801         sc->SCp.ptr = NULL;
 802
 803         host = sc->device->host;
 804         session = iscsi_hostdata(host->hostdata);
 805
 806         spin_lock(&session->lock);
 807
 808         /*
 809          * ISCSI_STATE_FAILED is a temp. state. The recovery
 810          * code will decide what is best to do with command queued
 811          * during this time
 812          */
 813         if (session->state != ISCSI_STATE_LOGGED_IN &&
 814             session->state != ISCSI_STATE_FAILED) {
 815                 /*
 816                  * to handle the race between when we set the recovery state
 817                  * and block the session we requeue here (commands could
 818                  * be entering our queuecommand while a block is starting
 819                  * up because the block code is not locked)
 820                  */
 821                 if (session->state == ISCSI_STATE_IN_RECOVERY) {
 822                         reason = FAILURE_SESSION_IN_RECOVERY;
 823                         goto reject;
 824                 }
 825
 826                 if (session->state == ISCSI_STATE_RECOVERY_FAILED)
 827                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
 828                 else if (session->state == ISCSI_STATE_TERMINATE)
 829                         reason = FAILURE_SESSION_TERMINATE;
 830                 else
 831                         reason = FAILURE_SESSION_FREED;
 832                 goto fault;
 833         }
 834
 835         conn = session->leadconn;
 836         if (!conn) {
 837                 reason = FAILURE_SESSION_FREED;
 838                 goto fault;
 839         }
 840
 841         if (iscsi_check_cmdsn_window_closed(conn)) {
 842                 reason = FAILURE_WINDOW_CLOSED;
 843                 goto reject;
 844         }
 845
 846         if (!__kfifo_get(session->cmdpool.queue, (void*)&ctask,
 847                          sizeof(void*))) {
 848                 reason = FAILURE_OOM;
 849                 goto reject;
 850         }
 851         session->queued_cmdsn++;
 852
 853         sc->SCp.phase = session->age;
 854         sc->SCp.ptr = (char *)ctask;
 855
 856         atomic_set(&ctask->refcount, 1);
 857         ctask->state = ISCSI_TASK_PENDING;
 858         ctask->mtask = NULL;
 859         ctask->conn = conn;
 860         ctask->sc = sc;
 861         INIT_LIST_HEAD(&ctask->running);
 862
 863         list_add_tail(&ctask->running, &conn->xmitqueue);
 864         spin_unlock(&session->lock);
 865
 866         scsi_queue_work(host, &conn->xmitwork);
 867         return 0;
 868
 869 reject:
 870         spin_unlock(&session->lock);
 871         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
 872         return SCSI_MLQUEUE_HOST_BUSY;
 873
 874 fault:
 875         spin_unlock(&session->lock);
 876         printk(KERN_ERR "iscsi: cmd 0x%x is not queued (%d)\n",
 877                sc->cmnd[0], reason);
 878         sc->result = (DID_NO_CONNECT << 16);
 879         scsi_set_resid(sc, scsi_bufflen(sc));
 880         sc->scsi_done(sc);
 881         return 0;
 882 }
 883 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
 884
 885 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
 886 {
 887         if (depth > ISCSI_MAX_CMD_PER_LUN)
 888                 depth = ISCSI_MAX_CMD_PER_LUN;
 889         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 890         return sdev->queue_depth;
 891 }
 892 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
 893
 894 static struct iscsi_mgmt_task *
 895 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 896                       char *data, uint32_t data_size)
 897 {
 898         struct iscsi_session *session = conn->session;
 899         struct iscsi_mgmt_task *mtask;
 900
 901         if (session->state == ISCSI_STATE_TERMINATE)
 902                 return NULL;
 903
 904         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
 905             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 906                 /*
 907                  * Login and Text are sent serially, in
 908                  * request-followed-by-response sequence.
 909                  * Same mtask can be used. Same ITT must be used.
 910                  * Note that login_mtask is preallocated at conn_create().
 911                  */
 912                 mtask = conn->login_mtask;
 913         else {
 914                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 915                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 916
 917                 if (!__kfifo_get(session->mgmtpool.queue,
 918                                  (void*)&mtask, sizeof(void*)))
 919                         return NULL;
 920         }
 921
 922         if (data_size) {
 923                 memcpy(mtask->data, data, data_size);
 924                 mtask->data_count = data_size;
 925         } else
 926                 mtask->data_count = 0;
 927
 928         INIT_LIST_HEAD(&mtask->running);
 929         memcpy(mtask->hdr, hdr, sizeof(struct iscsi_hdr));
 930         __kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*));
 931         return mtask;
 932 }
 933
 934 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 935                         char *data, uint32_t data_size)
 936 {
 937         struct iscsi_conn *conn = cls_conn->dd_data;
 938         struct iscsi_session *session = conn->session;
 939         int err = 0;
 940
 941         spin_lock_bh(&session->lock);
 942         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 943                 err = -EPERM;
 944         spin_unlock_bh(&session->lock);
 945         scsi_queue_work(session->host, &conn->xmitwork);
 946         return err;
 947 }
 948 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 949
 950 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
 951 {
 952         struct iscsi_session *session = class_to_transport_session(cls_session);
 953         struct iscsi_conn *conn = session->leadconn;
 954
 955         spin_lock_bh(&session->lock);
 956         if (session->state != ISCSI_STATE_LOGGED_IN) {
 957                 session->state = ISCSI_STATE_RECOVERY_FAILED;
 958                 if (conn)
 959                         wake_up(&conn->ehwait);
 960         }
 961         spin_unlock_bh(&session->lock);
 962 }
 963 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
 964
 965 int iscsi_eh_host_reset(struct scsi_cmnd *sc)
 966 {
 967         struct Scsi_Host *host = sc->device->host;
 968         struct iscsi_session *session = iscsi_hostdata(host->hostdata);
 969         struct iscsi_conn *conn = session->leadconn;
 970         int fail_session = 0;
 971
 972         spin_lock_bh(&session->lock);
 973         if (session->state == ISCSI_STATE_TERMINATE) {
 974 failed:
 975                 debug_scsi("failing host reset: session terminated "
 976                            "[CID %d age %d]\n", conn->id, session->age);
 977                 spin_unlock_bh(&session->lock);
 978                 return FAILED;
 979         }
 980
 981         if (sc->SCp.phase == session->age) {
 982                 debug_scsi("failing connection CID %d due to SCSI host reset\n",
 983                            conn->id);
 984                 fail_session = 1;
 985         }
 986         spin_unlock_bh(&session->lock);
 987
 988         /*
 989          * we drop the lock here but the leadconn cannot be destoyed while
 990          * we are in the scsi eh
 991          */
 992         if (fail_session)
 993                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 994
 995         debug_scsi("iscsi_eh_host_reset wait for relogin\n");
 996         wait_event_interruptible(conn->ehwait,
 997                                  session->state == ISCSI_STATE_TERMINATE ||
 998                                  session->state == ISCSI_STATE_LOGGED_IN ||
 999                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
1000         if (signal_pending(current))
1001                 flush_signals(current);
1002
1003         spin_lock_bh(&session->lock);
1004         if (session->state == ISCSI_STATE_LOGGED_IN)
1005                 printk(KERN_INFO "iscsi: host reset succeeded\n");
1006         else
1007                 goto failed;
1008         spin_unlock_bh(&session->lock);
1009
1010         return SUCCESS;
1011 }
1012 EXPORT_SYMBOL_GPL(iscsi_eh_host_reset);
1013
1014 static void iscsi_tmabort_timedout(unsigned long data)
1015 {
1016         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)data;
1017         struct iscsi_conn *conn = ctask->conn;
1018         struct iscsi_session *session = conn->session;
1019
1020         spin_lock(&session->lock);
1021         if (conn->tmabort_state == TMABORT_INITIAL) {
1022                 conn->tmabort_state = TMABORT_TIMEDOUT;
1023                 debug_scsi("tmabort timedout [sc %p itt 0x%x]\n",
1024                         ctask->sc, ctask->itt);
1025                 /* unblock eh_abort() */
1026                 wake_up(&conn->ehwait);
1027         }
1028         spin_unlock(&session->lock);
1029 }
1030
1031 static int iscsi_exec_abort_task(struct scsi_cmnd *sc,
1032                                  struct iscsi_cmd_task *ctask)
1033 {
1034         struct iscsi_conn *conn = ctask->conn;
1035         struct iscsi_session *session = conn->session;
1036         struct iscsi_tm *hdr = &conn->tmhdr;
1037
1038         /*
1039          * ctask timed out but session is OK requests must be serialized.
1040          */
1041         memset(hdr, 0, sizeof(struct iscsi_tm));
1042         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1043         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK;
1044         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1045         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1046         hdr->rtt = ctask->hdr->itt;
1047         hdr->refcmdsn = ctask->hdr->cmdsn;
1048
1049         ctask->mtask = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1050                                             NULL, 0);
1051         if (!ctask->mtask) {
1052                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1053                 debug_scsi("abort sent failure [itt 0x%x]\n", ctask->itt);
1054                 return -EPERM;
1055         }
1056         ctask->state = ISCSI_TASK_ABORTING;
1057
1058         debug_scsi("abort sent [itt 0x%x]\n", ctask->itt);
1059
1060         if (conn->tmabort_state == TMABORT_INITIAL) {
1061                 conn->tmfcmd_pdus_cnt++;
1062                 conn->tmabort_timer.expires = 20*HZ + jiffies;
1063                 conn->tmabort_timer.function = iscsi_tmabort_timedout;
1064                 conn->tmabort_timer.data = (unsigned long)ctask;
1065                 add_timer(&conn->tmabort_timer);
1066                 debug_scsi("abort set timeout [itt 0x%x]\n", ctask->itt);
1067         }
1068         spin_unlock_bh(&session->lock);
1069         scsi_queue_work(session->host, &conn->xmitwork);
1070
1071         /*
1072          * block eh thread until:
1073          *
1074          * 1) abort response
1075          * 2) abort timeout
1076          * 3) session is terminated or restarted or userspace has
1077          * given up on recovery
1078          */
1079         wait_event_interruptible(conn->ehwait,
1080                                  sc->SCp.phase != session->age ||
1081                                  session->state != ISCSI_STATE_LOGGED_IN ||
1082                                  conn->tmabort_state != TMABORT_INITIAL);
1083         if (signal_pending(current))
1084                 flush_signals(current);
1085         del_timer_sync(&conn->tmabort_timer);
1086         spin_lock_bh(&session->lock);
1087         return 0;
1088 }
1089
1090 /*
1091  * session lock must be held
1092  */
1093 static struct iscsi_mgmt_task *
1094 iscsi_remove_mgmt_task(struct kfifo *fifo, uint32_t itt)
1095 {
1096         int i, nr_tasks = __kfifo_len(fifo) / sizeof(void*);
1097         struct iscsi_mgmt_task *task;
1098
1099         debug_scsi("searching %d tasks\n", nr_tasks);
1100
1101         for (i = 0; i < nr_tasks; i++) {
1102                 __kfifo_get(fifo, (void*)&task, sizeof(void*));
1103                 debug_scsi("check task %u\n", task->itt);
1104
1105                 if (task->itt == itt) {
1106                         debug_scsi("matched task\n");
1107                         return task;
1108                 }
1109
1110                 __kfifo_put(fifo, (void*)&task, sizeof(void*));
1111         }
1112         return NULL;
1113 }
1114
1115 static int iscsi_ctask_mtask_cleanup(struct iscsi_cmd_task *ctask)
1116 {
1117         struct iscsi_conn *conn = ctask->conn;
1118         struct iscsi_session *session = conn->session;
1119
1120         if (!ctask->mtask)
1121                 return -EINVAL;
1122
1123         if (!iscsi_remove_mgmt_task(conn->mgmtqueue, ctask->mtask->itt))
1124                 list_del(&ctask->mtask->running);
1125         __kfifo_put(session->mgmtpool.queue, (void*)&ctask->mtask,
1126                     sizeof(void*));
1127         ctask->mtask = NULL;
1128         return 0;
1129 }
1130
1131 /*
1132  * session lock must be held
1133  */
1134 static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1135                          int err)
1136 {
1137         struct scsi_cmnd *sc;
1138
1139         sc = ctask->sc;
1140         if (!sc)
1141                 return;
1142
1143         if (ctask->state == ISCSI_TASK_PENDING)
1144                 /*
1145                  * cmd never made it to the xmit thread, so we should not count
1146                  * the cmd in the sequencing
1147                  */
1148                 conn->session->queued_cmdsn--;
1149         else
1150                 conn->session->tt->cleanup_cmd_task(conn, ctask);
1151         iscsi_ctask_mtask_cleanup(ctask);
1152
1153         sc->result = err;
1154         scsi_set_resid(sc, scsi_bufflen(sc));
1155         if (conn->ctask == ctask)
1156                 conn->ctask = NULL;
1157         /* release ref from queuecommand */
1158         __iscsi_put_ctask(ctask);
1159 }
1160
1161 int iscsi_eh_abort(struct scsi_cmnd *sc)
1162 {
1163         struct iscsi_cmd_task *ctask;
1164         struct iscsi_conn *conn;
1165         struct iscsi_session *session;
1166         int rc;
1167
1168         /*
1169          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1170          * got the command.
1171          */
1172         if (!sc->SCp.ptr) {
1173                 debug_scsi("sc never reached iscsi layer or it completed.\n");
1174                 return SUCCESS;
1175         }
1176
1177         ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
1178         conn = ctask->conn;
1179         session = conn->session;
1180
1181         conn->eh_abort_cnt++;
1182         debug_scsi("aborting [sc %p itt 0x%x]\n", sc, ctask->itt);
1183
1184         spin_lock_bh(&session->lock);
1185
1186         /*
1187          * If we are not logged in or we have started a new session
1188          * then let the host reset code handle this
1189          */
1190         if (session->state != ISCSI_STATE_LOGGED_IN ||
1191             sc->SCp.phase != session->age)
1192                 goto failed;
1193
1194         /* ctask completed before time out */
1195         if (!ctask->sc) {
1196                 debug_scsi("sc completed while abort in progress\n");
1197                 goto success;
1198         }
1199
1200         /* what should we do here ? */
1201         if (conn->ctask == ctask) {
1202                 printk(KERN_INFO "iscsi: sc %p itt 0x%x partially sent. "
1203                        "Failing abort\n", sc, ctask->itt);
1204                 goto failed;
1205         }
1206
1207         if (ctask->state == ISCSI_TASK_PENDING) {
1208                 fail_command(conn, ctask, DID_ABORT << 16);
1209                 goto success;
1210         }
1211
1212         conn->tmabort_state = TMABORT_INITIAL;
1213         rc = iscsi_exec_abort_task(sc, ctask);
1214         if (rc || sc->SCp.phase != session->age ||
1215             session->state != ISCSI_STATE_LOGGED_IN)
1216                 goto failed;
1217         iscsi_ctask_mtask_cleanup(ctask);
1218
1219         switch (conn->tmabort_state) {
1220         case TMABORT_SUCCESS:
1221                 spin_unlock_bh(&session->lock);
1222                 /*
1223                  * clean up task if aborted. grab the recv lock as a writer
1224                  */
1225                 write_lock_bh(conn->recv_lock);
1226                 spin_lock(&session->lock);
1227                 fail_command(conn, ctask, DID_ABORT << 16);
1228                 spin_unlock(&session->lock);
1229                 write_unlock_bh(conn->recv_lock);
1230                 /*
1231                  * make sure xmit thread is not still touching the
1232                  * ctask/scsi_cmnd
1233                  */
1234                 scsi_flush_work(session->host);
1235                 goto success_unlocked;
1236         case TMABORT_NOT_FOUND:
1237                 if (!ctask->sc) {
1238                         /* ctask completed before tmf abort response */
1239                         debug_scsi("sc completed while abort in progress\n");
1240                         goto success;
1241                 }
1242                 /* fall through */
1243         default:
1244                 /* timedout or failed */
1245                 spin_unlock_bh(&session->lock);
1246                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1247                 goto failed_unlocked;
1248         }
1249
1250 success:
1251         spin_unlock_bh(&session->lock);
1252 success_unlocked:
1253         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1254         return SUCCESS;
1255
1256 failed:
1257         spin_unlock_bh(&session->lock);
1258 failed_unlocked:
1259         debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1260         return FAILED;
1261 }
1262 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1263
1264 int
1265 iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
1266 {
1267         int i;
1268
1269         *items = kmalloc(max * sizeof(void*), GFP_KERNEL);
1270         if (*items == NULL)
1271                 return -ENOMEM;
1272
1273         q->max = max;
1274         q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL);
1275         if (q->pool == NULL) {
1276                 kfree(*items);
1277                 return -ENOMEM;
1278         }
1279
1280         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1281                               GFP_KERNEL, NULL);
1282         if (q->queue == ERR_PTR(-ENOMEM)) {
1283                 kfree(q->pool);
1284                 kfree(*items);
1285                 return -ENOMEM;
1286         }
1287
1288         for (i = 0; i < max; i++) {
1289                 q->pool[i] = kmalloc(item_size, GFP_KERNEL);
1290                 if (q->pool[i] == NULL) {
1291                         int j;
1292
1293                         for (j = 0; j < i; j++)
1294                                 kfree(q->pool[j]);
1295
1296                         kfifo_free(q->queue);
1297                         kfree(q->pool);
1298                         kfree(*items);
1299                         return -ENOMEM;
1300                 }
1301                 memset(q->pool[i], 0, item_size);
1302                 (*items)[i] = q->pool[i];
1303                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1304         }
1305         return 0;
1306 }
1307 EXPORT_SYMBOL_GPL(iscsi_pool_init);
1308
1309 void iscsi_pool_free(struct iscsi_queue *q, void **items)
1310 {
1311         int i;
1312
1313         for (i = 0; i < q->max; i++)
1314                 kfree(items[i]);
1315         kfree(q->pool);
1316         kfree(items);
1317 }
1318 EXPORT_SYMBOL_GPL(iscsi_pool_free);
1319
1320 /*
1321  * iSCSI Session's hostdata organization:
1322  *
1323  *    *------------------* <== hostdata_session(host->hostdata)
1324  *    | ptr to class sess|
1325  *    |------------------| <== iscsi_hostdata(host->hostdata)
1326  *    | iscsi_session    |
1327  *    *------------------*
1328  */
1329
1330 #define hostdata_privsize(_sz)  (sizeof(unsigned long) + _sz + \
1331                                  _sz % sizeof(unsigned long))
1332
1333 #define hostdata_session(_hostdata) (iscsi_ptr(*(unsigned long *)_hostdata))
1334
1335 /**
1336  * iscsi_session_setup - create iscsi cls session and host and session
1337  * @scsit: scsi transport template
1338  * @iscsit: iscsi transport template
1339  * @cmds_max: scsi host can queue
1340  * @qdepth: scsi host cmds per lun
1341  * @cmd_task_size: LLD ctask private data size
1342  * @mgmt_task_size: LLD mtask private data size
1343  * @initial_cmdsn: initial CmdSN
1344  * @hostno: host no allocated
1345  *
1346  * This can be used by software iscsi_transports that allocate
1347  * a session per scsi host.
1348  **/
1349 struct iscsi_cls_session *
1350 iscsi_session_setup(struct iscsi_transport *iscsit,
1351                     struct scsi_transport_template *scsit,
1352                     uint16_t cmds_max, uint16_t qdepth,
1353                     int cmd_task_size, int mgmt_task_size,
1354                     uint32_t initial_cmdsn, uint32_t *hostno)
1355 {
1356         struct Scsi_Host *shost;
1357         struct iscsi_session *session;
1358         struct iscsi_cls_session *cls_session;
1359         int cmd_i;
1360
1361         if (qdepth > ISCSI_MAX_CMD_PER_LUN || qdepth < 1) {
1362                 if (qdepth != 0)
1363                         printk(KERN_ERR "iscsi: invalid queue depth of %d. "
1364                               "Queue depth must be between 1 and %d.\n",
1365                               qdepth, ISCSI_MAX_CMD_PER_LUN);
1366                 qdepth = ISCSI_DEF_CMD_PER_LUN;
1367         }
1368
1369         if (cmds_max < 2 || (cmds_max & (cmds_max - 1)) ||
1370             cmds_max >= ISCSI_MGMT_ITT_OFFSET) {
1371                 if (cmds_max != 0)
1372                         printk(KERN_ERR "iscsi: invalid can_queue of %d. "
1373                                "can_queue must be a power of 2 and between "
1374                                "2 and %d - setting to %d.\n", cmds_max,
1375                                ISCSI_MGMT_ITT_OFFSET, ISCSI_DEF_XMIT_CMDS_MAX);
1376                 cmds_max = ISCSI_DEF_XMIT_CMDS_MAX;
1377         }
1378
1379         shost = scsi_host_alloc(iscsit->host_template,
1380                                 hostdata_privsize(sizeof(*session)));
1381         if (!shost)
1382                 return NULL;
1383
1384         /* the iscsi layer takes one task for reserve */
1385         shost->can_queue = cmds_max - 1;
1386         shost->cmd_per_lun = qdepth;
1387         shost->max_id = 1;
1388         shost->max_channel = 0;
1389         shost->max_lun = iscsit->max_lun;
1390         shost->max_cmd_len = iscsit->max_cmd_len;
1391         shost->transportt = scsit;
1392         shost->transportt->create_work_queue = 1;
1393         *hostno = shost->host_no;
1394
1395         session = iscsi_hostdata(shost->hostdata);
1396         memset(session, 0, sizeof(struct iscsi_session));
1397         session->host = shost;
1398         session->state = ISCSI_STATE_FREE;
1399         session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
1400         session->cmds_max = cmds_max;
1401         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
1402         session->exp_cmdsn = initial_cmdsn + 1;
1403         session->max_cmdsn = initial_cmdsn + 1;
1404         session->max_r2t = 1;
1405         session->tt = iscsit;
1406
1407         /* initialize SCSI PDU commands pool */
1408         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
1409                             (void***)&session->cmds,
1410                             cmd_task_size + sizeof(struct iscsi_cmd_task)))
1411                 goto cmdpool_alloc_fail;
1412
1413         /* pre-format cmds pool with ITT */
1414         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1415                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1416
1417                 if (cmd_task_size)
1418                         ctask->dd_data = &ctask[1];
1419                 ctask->itt = cmd_i;
1420                 INIT_LIST_HEAD(&ctask->running);
1421         }
1422
1423         spin_lock_init(&session->lock);
1424
1425         /* initialize immediate command pool */
1426         if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max,
1427                            (void***)&session->mgmt_cmds,
1428                            mgmt_task_size + sizeof(struct iscsi_mgmt_task)))
1429                 goto mgmtpool_alloc_fail;
1430
1431
1432         /* pre-format immediate cmds pool with ITT */
1433         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
1434                 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
1435
1436                 if (mgmt_task_size)
1437                         mtask->dd_data = &mtask[1];
1438                 mtask->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i;
1439                 INIT_LIST_HEAD(&mtask->running);
1440         }
1441
1442         if (scsi_add_host(shost, NULL))
1443                 goto add_host_fail;
1444
1445         if (!try_module_get(iscsit->owner))
1446                 goto cls_session_fail;
1447
1448         cls_session = iscsi_create_session(shost, iscsit, 0);
1449         if (!cls_session)
1450                 goto module_put;
1451         *(unsigned long*)shost->hostdata = (unsigned long)cls_session;
1452
1453         return cls_session;
1454
1455 module_put:
1456         module_put(iscsit->owner);
1457 cls_session_fail:
1458         scsi_remove_host(shost);
1459 add_host_fail:
1460         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1461 mgmtpool_alloc_fail:
1462         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1463 cmdpool_alloc_fail:
1464         scsi_host_put(shost);
1465         return NULL;
1466 }
1467 EXPORT_SYMBOL_GPL(iscsi_session_setup);
1468
1469 /**
1470  * iscsi_session_teardown - destroy session, host, and cls_session
1471  * shost: scsi host
1472  *
1473  * This can be used by software iscsi_transports that allocate
1474  * a session per scsi host.
1475  **/
1476 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
1477 {
1478         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1479         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1480         struct module *owner = cls_session->transport->owner;
1481
1482         iscsi_unblock_session(cls_session);
1483         scsi_remove_host(shost);
1484
1485         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1486         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1487
1488         kfree(session->password);
1489         kfree(session->password_in);
1490         kfree(session->username);
1491         kfree(session->username_in);
1492         kfree(session->targetname);
1493         kfree(session->netdev);
1494         kfree(session->hwaddress);
1495         kfree(session->initiatorname);
1496
1497         iscsi_destroy_session(cls_session);
1498         scsi_host_put(shost);
1499         module_put(owner);
1500 }
1501 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
1502
1503 /**
1504  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
1505  * @cls_session: iscsi_cls_session
1506  * @conn_idx: cid
1507  **/
1508 struct iscsi_cls_conn *
1509 iscsi_conn_setup(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1510 {
1511         struct iscsi_session *session = class_to_transport_session(cls_session);
1512         struct iscsi_conn *conn;
1513         struct iscsi_cls_conn *cls_conn;
1514         char *data;
1515
1516         cls_conn = iscsi_create_conn(cls_session, conn_idx);
1517         if (!cls_conn)
1518                 return NULL;
1519         conn = cls_conn->dd_data;
1520         memset(conn, 0, sizeof(*conn));
1521
1522         conn->session = session;
1523         conn->cls_conn = cls_conn;
1524         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
1525         conn->id = conn_idx;
1526         conn->exp_statsn = 0;
1527         conn->tmabort_state = TMABORT_INITIAL;
1528         INIT_LIST_HEAD(&conn->run_list);
1529         INIT_LIST_HEAD(&conn->mgmt_run_list);
1530         INIT_LIST_HEAD(&conn->xmitqueue);
1531
1532         /* initialize general immediate & non-immediate PDU commands queue */
1533         conn->mgmtqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
1534                                         GFP_KERNEL, NULL);
1535         if (conn->mgmtqueue == ERR_PTR(-ENOMEM))
1536                 goto mgmtqueue_alloc_fail;
1537
1538         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
1539
1540         /* allocate login_mtask used for the login/text sequences */
1541         spin_lock_bh(&session->lock);
1542         if (!__kfifo_get(session->mgmtpool.queue,
1543                          (void*)&conn->login_mtask,
1544                          sizeof(void*))) {
1545                 spin_unlock_bh(&session->lock);
1546                 goto login_mtask_alloc_fail;
1547         }
1548         spin_unlock_bh(&session->lock);
1549
1550         data = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN, GFP_KERNEL);
1551         if (!data)
1552                 goto login_mtask_data_alloc_fail;
1553         conn->login_mtask->data = conn->data = data;
1554
1555         init_timer(&conn->tmabort_timer);
1556         init_waitqueue_head(&conn->ehwait);
1557
1558         return cls_conn;
1559
1560 login_mtask_data_alloc_fail:
1561         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1562                     sizeof(void*));
1563 login_mtask_alloc_fail:
1564         kfifo_free(conn->mgmtqueue);
1565 mgmtqueue_alloc_fail:
1566         iscsi_destroy_conn(cls_conn);
1567         return NULL;
1568 }
1569 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
1570
1571 /**
1572  * iscsi_conn_teardown - teardown iscsi connection
1573  * cls_conn: iscsi class connection
1574  *
1575  * TODO: we may need to make this into a two step process
1576  * like scsi-mls remove + put host
1577  */
1578 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
1579 {
1580         struct iscsi_conn *conn = cls_conn->dd_data;
1581         struct iscsi_session *session = conn->session;
1582         unsigned long flags;
1583
1584         spin_lock_bh(&session->lock);
1585         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1586         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
1587         if (session->leadconn == conn) {
1588                 /*
1589                  * leading connection? then give up on recovery.
1590                  */
1591                 session->state = ISCSI_STATE_TERMINATE;
1592                 wake_up(&conn->ehwait);
1593         }
1594         spin_unlock_bh(&session->lock);
1595
1596         /*
1597          * Block until all in-progress commands for this connection
1598          * time out or fail.
1599          */
1600         for (;;) {
1601                 spin_lock_irqsave(session->host->host_lock, flags);
1602                 if (!session->host->host_busy) { /* OK for ERL == 0 */
1603                         spin_unlock_irqrestore(session->host->host_lock, flags);
1604                         break;
1605                 }
1606                 spin_unlock_irqrestore(session->host->host_lock, flags);
1607                 msleep_interruptible(500);
1608                 printk(KERN_INFO "iscsi: scsi conn_destroy(): host_busy %d "
1609                        "host_failed %d\n", session->host->host_busy,
1610                        session->host->host_failed);
1611                 /*
1612                  * force eh_abort() to unblock
1613                  */
1614                 wake_up(&conn->ehwait);
1615         }
1616
1617         /* flush queued up work because we free the connection below */
1618         scsi_flush_work(session->host);
1619
1620         spin_lock_bh(&session->lock);
1621         kfree(conn->data);
1622         kfree(conn->persistent_address);
1623         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1624                     sizeof(void*));
1625         if (session->leadconn == conn)
1626                 session->leadconn = NULL;
1627         spin_unlock_bh(&session->lock);
1628
1629         kfifo_free(conn->mgmtqueue);
1630
1631         iscsi_destroy_conn(cls_conn);
1632 }
1633 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
1634
1635 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
1636 {
1637         struct iscsi_conn *conn = cls_conn->dd_data;
1638         struct iscsi_session *session = conn->session;
1639
1640         if (!session) {
1641                 printk(KERN_ERR "iscsi: can't start unbound connection\n");
1642                 return -EPERM;
1643         }
1644
1645         if ((session->imm_data_en || !session->initial_r2t_en) &&
1646              session->first_burst > session->max_burst) {
1647                 printk("iscsi: invalid burst lengths: "
1648                        "first_burst %d max_burst %d\n",
1649                        session->first_burst, session->max_burst);
1650                 return -EINVAL;
1651         }
1652
1653         spin_lock_bh(&session->lock);
1654         conn->c_stage = ISCSI_CONN_STARTED;
1655         session->state = ISCSI_STATE_LOGGED_IN;
1656         session->queued_cmdsn = session->cmdsn;
1657
1658         switch(conn->stop_stage) {
1659         case STOP_CONN_RECOVER:
1660                 /*
1661                  * unblock eh_abort() if it is blocked. re-try all
1662                  * commands after successful recovery
1663                  */
1664                 conn->stop_stage = 0;
1665                 conn->tmabort_state = TMABORT_INITIAL;
1666                 session->age++;
1667                 spin_unlock_bh(&session->lock);
1668
1669                 iscsi_unblock_session(session_to_cls(session));
1670                 wake_up(&conn->ehwait);
1671                 return 0;
1672         case STOP_CONN_TERM:
1673                 conn->stop_stage = 0;
1674                 break;
1675         default:
1676                 break;
1677         }
1678         spin_unlock_bh(&session->lock);
1679
1680         return 0;
1681 }
1682 EXPORT_SYMBOL_GPL(iscsi_conn_start);
1683
1684 static void
1685 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
1686 {
1687         struct iscsi_mgmt_task *mtask, *tmp;
1688
1689         /* handle pending */
1690         while (__kfifo_get(conn->mgmtqueue, (void*)&mtask, sizeof(void*))) {
1691                 if (mtask == conn->login_mtask)
1692                         continue;
1693                 debug_scsi("flushing pending mgmt task itt 0x%x\n", mtask->itt);
1694                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1695                             sizeof(void*));
1696         }
1697
1698         /* handle running */
1699         list_for_each_entry_safe(mtask, tmp, &conn->mgmt_run_list, running) {
1700                 debug_scsi("flushing running mgmt task itt 0x%x\n", mtask->itt);
1701                 list_del(&mtask->running);
1702
1703                 if (mtask == conn->login_mtask)
1704                         continue;
1705                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1706                            sizeof(void*));
1707         }
1708
1709         conn->mtask = NULL;
1710 }
1711
1712 /* Fail commands. Mutex and session lock held and recv side suspended */
1713 static void fail_all_commands(struct iscsi_conn *conn)
1714 {
1715         struct iscsi_cmd_task *ctask, *tmp;
1716
1717         /* flush pending */
1718         list_for_each_entry_safe(ctask, tmp, &conn->xmitqueue, running) {
1719                 debug_scsi("failing pending sc %p itt 0x%x\n", ctask->sc,
1720                            ctask->itt);
1721                 fail_command(conn, ctask, DID_BUS_BUSY << 16);
1722         }
1723
1724         /* fail all other running */
1725         list_for_each_entry_safe(ctask, tmp, &conn->run_list, running) {
1726                 debug_scsi("failing in progress sc %p itt 0x%x\n",
1727                            ctask->sc, ctask->itt);
1728                 fail_command(conn, ctask, DID_BUS_BUSY << 16);
1729         }
1730
1731         conn->ctask = NULL;
1732 }
1733
1734 static void iscsi_start_session_recovery(struct iscsi_session *session,
1735                                          struct iscsi_conn *conn, int flag)
1736 {
1737         int old_stop_stage;
1738
1739         spin_lock_bh(&session->lock);
1740         if (conn->stop_stage == STOP_CONN_TERM) {
1741                 spin_unlock_bh(&session->lock);
1742                 return;
1743         }
1744
1745         /*
1746          * When this is called for the in_login state, we only want to clean
1747          * up the login task and connection. We do not need to block and set
1748          * the recovery state again
1749          */
1750         if (flag == STOP_CONN_TERM)
1751                 session->state = ISCSI_STATE_TERMINATE;
1752         else if (conn->stop_stage != STOP_CONN_RECOVER)
1753                 session->state = ISCSI_STATE_IN_RECOVERY;
1754
1755         old_stop_stage = conn->stop_stage;
1756         conn->stop_stage = flag;
1757         conn->c_stage = ISCSI_CONN_STOPPED;
1758         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1759         spin_unlock_bh(&session->lock);
1760         scsi_flush_work(session->host);
1761
1762         write_lock_bh(conn->recv_lock);
1763         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1764         write_unlock_bh(conn->recv_lock);
1765
1766         /*
1767          * for connection level recovery we should not calculate
1768          * header digest. conn->hdr_size used for optimization
1769          * in hdr_extract() and will be re-negotiated at
1770          * set_param() time.
1771          */
1772         if (flag == STOP_CONN_RECOVER) {
1773                 conn->hdrdgst_en = 0;
1774                 conn->datadgst_en = 0;
1775                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
1776                     old_stop_stage != STOP_CONN_RECOVER) {
1777                         debug_scsi("blocking session\n");
1778                         iscsi_block_session(session_to_cls(session));
1779                 }
1780         }
1781
1782         /*
1783          * flush queues.
1784          */
1785         spin_lock_bh(&session->lock);
1786         fail_all_commands(conn);
1787         flush_control_queues(session, conn);
1788         spin_unlock_bh(&session->lock);
1789 }
1790
1791 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1792 {
1793         struct iscsi_conn *conn = cls_conn->dd_data;
1794         struct iscsi_session *session = conn->session;
1795
1796         switch (flag) {
1797         case STOP_CONN_RECOVER:
1798         case STOP_CONN_TERM:
1799                 iscsi_start_session_recovery(session, conn, flag);
1800                 break;
1801         default:
1802                 printk(KERN_ERR "iscsi: invalid stop flag %d\n", flag);
1803         }
1804 }
1805 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
1806
1807 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
1808                     struct iscsi_cls_conn *cls_conn, int is_leading)
1809 {
1810         struct iscsi_session *session = class_to_transport_session(cls_session);
1811         struct iscsi_conn *conn = cls_conn->dd_data;
1812
1813         spin_lock_bh(&session->lock);
1814         if (is_leading)
1815                 session->leadconn = conn;
1816         spin_unlock_bh(&session->lock);
1817
1818         /*
1819          * Unblock xmitworker(), Login Phase will pass through.
1820          */
1821         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1822         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1823         return 0;
1824 }
1825 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
1826
1827
1828 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
1829                     enum iscsi_param param, char *buf, int buflen)
1830 {
1831         struct iscsi_conn *conn = cls_conn->dd_data;
1832         struct iscsi_session *session = conn->session;
1833         uint32_t value;
1834
1835         switch(param) {
1836         case ISCSI_PARAM_MAX_RECV_DLENGTH:
1837                 sscanf(buf, "%d", &conn->max_recv_dlength);
1838                 break;
1839         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
1840                 sscanf(buf, "%d", &conn->max_xmit_dlength);
1841                 break;
1842         case ISCSI_PARAM_HDRDGST_EN:
1843                 sscanf(buf, "%d", &conn->hdrdgst_en);
1844                 break;
1845         case ISCSI_PARAM_DATADGST_EN:
1846                 sscanf(buf, "%d", &conn->datadgst_en);
1847                 break;
1848         case ISCSI_PARAM_INITIAL_R2T_EN:
1849                 sscanf(buf, "%d", &session->initial_r2t_en);
1850                 break;
1851         case ISCSI_PARAM_MAX_R2T:
1852                 sscanf(buf, "%d", &session->max_r2t);
1853                 break;
1854         case ISCSI_PARAM_IMM_DATA_EN:
1855                 sscanf(buf, "%d", &session->imm_data_en);
1856                 break;
1857         case ISCSI_PARAM_FIRST_BURST:
1858                 sscanf(buf, "%d", &session->first_burst);
1859                 break;
1860         case ISCSI_PARAM_MAX_BURST:
1861                 sscanf(buf, "%d", &session->max_burst);
1862                 break;
1863         case ISCSI_PARAM_PDU_INORDER_EN:
1864                 sscanf(buf, "%d", &session->pdu_inorder_en);
1865                 break;
1866         case ISCSI_PARAM_DATASEQ_INORDER_EN:
1867                 sscanf(buf, "%d", &session->dataseq_inorder_en);
1868                 break;
1869         case ISCSI_PARAM_ERL:
1870                 sscanf(buf, "%d", &session->erl);
1871                 break;
1872         case ISCSI_PARAM_IFMARKER_EN:
1873                 sscanf(buf, "%d", &value);
1874                 BUG_ON(value);
1875                 break;
1876         case ISCSI_PARAM_OFMARKER_EN:
1877                 sscanf(buf, "%d", &value);
1878                 BUG_ON(value);
1879                 break;
1880         case ISCSI_PARAM_EXP_STATSN:
1881                 sscanf(buf, "%u", &conn->exp_statsn);
1882                 break;
1883         case ISCSI_PARAM_USERNAME:
1884                 kfree(session->username);
1885                 session->username = kstrdup(buf, GFP_KERNEL);
1886                 if (!session->username)
1887                         return -ENOMEM;
1888                 break;
1889         case ISCSI_PARAM_USERNAME_IN:
1890                 kfree(session->username_in);
1891                 session->username_in = kstrdup(buf, GFP_KERNEL);
1892                 if (!session->username_in)
1893                         return -ENOMEM;
1894                 break;
1895         case ISCSI_PARAM_PASSWORD:
1896                 kfree(session->password);
1897                 session->password = kstrdup(buf, GFP_KERNEL);
1898                 if (!session->password)
1899                         return -ENOMEM;
1900                 break;
1901         case ISCSI_PARAM_PASSWORD_IN:
1902                 kfree(session->password_in);
1903                 session->password_in = kstrdup(buf, GFP_KERNEL);
1904                 if (!session->password_in)
1905                         return -ENOMEM;
1906                 break;
1907         case ISCSI_PARAM_TARGET_NAME:
1908                 /* this should not change between logins */
1909                 if (session->targetname)
1910                         break;
1911
1912                 session->targetname = kstrdup(buf, GFP_KERNEL);
1913                 if (!session->targetname)
1914                         return -ENOMEM;
1915                 break;
1916         case ISCSI_PARAM_TPGT:
1917                 sscanf(buf, "%d", &session->tpgt);
1918                 break;
1919         case ISCSI_PARAM_PERSISTENT_PORT:
1920                 sscanf(buf, "%d", &conn->persistent_port);
1921                 break;
1922         case ISCSI_PARAM_PERSISTENT_ADDRESS:
1923                 /*
1924                  * this is the address returned in discovery so it should
1925                  * not change between logins.
1926                  */
1927                 if (conn->persistent_address)
1928                         break;
1929
1930                 conn->persistent_address = kstrdup(buf, GFP_KERNEL);
1931                 if (!conn->persistent_address)
1932                         return -ENOMEM;
1933                 break;
1934         default:
1935                 return -ENOSYS;
1936         }
1937
1938         return 0;
1939 }
1940 EXPORT_SYMBOL_GPL(iscsi_set_param);
1941
1942 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
1943                             enum iscsi_param param, char *buf)
1944 {
1945         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1946         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1947         int len;
1948
1949         switch(param) {
1950         case ISCSI_PARAM_INITIAL_R2T_EN:
1951                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
1952                 break;
1953         case ISCSI_PARAM_MAX_R2T:
1954                 len = sprintf(buf, "%hu\n", session->max_r2t);
1955                 break;
1956         case ISCSI_PARAM_IMM_DATA_EN:
1957                 len = sprintf(buf, "%d\n", session->imm_data_en);
1958                 break;
1959         case ISCSI_PARAM_FIRST_BURST:
1960                 len = sprintf(buf, "%u\n", session->first_burst);
1961                 break;
1962         case ISCSI_PARAM_MAX_BURST:
1963                 len = sprintf(buf, "%u\n", session->max_burst);
1964                 break;
1965         case ISCSI_PARAM_PDU_INORDER_EN:
1966                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
1967                 break;
1968         case ISCSI_PARAM_DATASEQ_INORDER_EN:
1969                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
1970                 break;
1971         case ISCSI_PARAM_ERL:
1972                 len = sprintf(buf, "%d\n", session->erl);
1973                 break;
1974         case ISCSI_PARAM_TARGET_NAME:
1975                 len = sprintf(buf, "%s\n", session->targetname);
1976                 break;
1977         case ISCSI_PARAM_TPGT:
1978                 len = sprintf(buf, "%d\n", session->tpgt);
1979                 break;
1980         case ISCSI_PARAM_USERNAME:
1981                 len = sprintf(buf, "%s\n", session->username);
1982                 break;
1983         case ISCSI_PARAM_USERNAME_IN:
1984                 len = sprintf(buf, "%s\n", session->username_in);
1985                 break;
1986         case ISCSI_PARAM_PASSWORD:
1987                 len = sprintf(buf, "%s\n", session->password);
1988                 break;
1989         case ISCSI_PARAM_PASSWORD_IN:
1990                 len = sprintf(buf, "%s\n", session->password_in);
1991                 break;
1992         default:
1993                 return -ENOSYS;
1994         }
1995
1996         return len;
1997 }
1998 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
1999
2000 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2001                          enum iscsi_param param, char *buf)
2002 {
2003         struct iscsi_conn *conn = cls_conn->dd_data;
2004         int len;
2005
2006         switch(param) {
2007         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2008                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
2009                 break;
2010         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2011                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
2012                 break;
2013         case ISCSI_PARAM_HDRDGST_EN:
2014                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
2015                 break;
2016         case ISCSI_PARAM_DATADGST_EN:
2017                 len = sprintf(buf, "%d\n", conn->datadgst_en);
2018                 break;
2019         case ISCSI_PARAM_IFMARKER_EN:
2020                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
2021                 break;
2022         case ISCSI_PARAM_OFMARKER_EN:
2023                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
2024                 break;
2025         case ISCSI_PARAM_EXP_STATSN:
2026                 len = sprintf(buf, "%u\n", conn->exp_statsn);
2027                 break;
2028         case ISCSI_PARAM_PERSISTENT_PORT:
2029                 len = sprintf(buf, "%d\n", conn->persistent_port);
2030                 break;
2031         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2032                 len = sprintf(buf, "%s\n", conn->persistent_address);
2033                 break;
2034         default:
2035                 return -ENOSYS;
2036         }
2037
2038         return len;
2039 }
2040 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
2041
2042 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2043                          char *buf)
2044 {
2045         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2046         int len;
2047
2048         switch (param) {
2049         case ISCSI_HOST_PARAM_NETDEV_NAME:
2050                 if (!session->netdev)
2051                         len = sprintf(buf, "%s\n", "default");
2052                 else
2053                         len = sprintf(buf, "%s\n", session->netdev);
2054                 break;
2055         case ISCSI_HOST_PARAM_HWADDRESS:
2056                 if (!session->hwaddress)
2057                         len = sprintf(buf, "%s\n", "default");
2058                 else
2059                         len = sprintf(buf, "%s\n", session->hwaddress);
2060                 break;
2061         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2062                 if (!session->initiatorname)
2063                         len = sprintf(buf, "%s\n", "unknown");
2064                 else
2065                         len = sprintf(buf, "%s\n", session->initiatorname);
2066                 break;
2067
2068         default:
2069                 return -ENOSYS;
2070         }
2071
2072         return len;
2073 }
2074 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
2075
2076 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2077                          char *buf, int buflen)
2078 {
2079         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2080
2081         switch (param) {
2082         case ISCSI_HOST_PARAM_NETDEV_NAME:
2083                 if (!session->netdev)
2084                         session->netdev = kstrdup(buf, GFP_KERNEL);
2085                 break;
2086         case ISCSI_HOST_PARAM_HWADDRESS:
2087                 if (!session->hwaddress)
2088                         session->hwaddress = kstrdup(buf, GFP_KERNEL);
2089                 break;
2090         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2091                 if (!session->initiatorname)
2092                         session->initiatorname = kstrdup(buf, GFP_KERNEL);
2093                 break;
2094         default:
2095                 return -ENOSYS;
2096         }
2097
2098         return 0;
2099 }
2100 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
2101
2102 MODULE_AUTHOR("Mike Christie");
2103 MODULE_DESCRIPTION("iSCSI library functions");
2104 MODULE_LICENSE("GPL");