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                 switch (conn->ctask->state) {
 741                 case ISCSI_TASK_ABORTING:
 742                         break;
 743                 case ISCSI_TASK_PENDING:
 744                         iscsi_prep_scsi_cmd_pdu(conn->ctask);
 745                         conn->session->tt->init_cmd_task(conn->ctask);
 746                         /* fall through */
 747                 default:
 748                         conn->ctask->state = ISCSI_TASK_RUNNING;
 749                         break;
 750                 }
 751                 list_move_tail(conn->xmitqueue.next, &conn->run_list);
 752
 753                 rc = iscsi_xmit_ctask(conn);
 754                 if (rc)
 755                         goto again;
 756                 /*
 757                  * we could continuously get new ctask requests so
 758                  * we need to check the mgmt queue for nops that need to
 759                  * be sent to aviod starvation
 760                  */
 761                 if (__kfifo_len(conn->mgmtqueue))
 762                         goto check_mgmt;
 763         }
 764         spin_unlock_bh(&conn->session->lock);
 765         return -ENODATA;
 766
 767 again:
 768         if (unlikely(conn->suspend_tx))
 769                 rc = -ENODATA;
 770         spin_unlock_bh(&conn->session->lock);
 771         return rc;
 772 }
 773
 774 static void iscsi_xmitworker(struct work_struct *work)
 775 {
 776         struct iscsi_conn *conn =
 777                 container_of(work, struct iscsi_conn, xmitwork);
 778         int rc;
 779         /*
 780          * serialize Xmit worker on a per-connection basis.
 781          */
 782         do {
 783                 rc = iscsi_data_xmit(conn);
 784         } while (rc >= 0 || rc == -EAGAIN);
 785 }
 786
 787 enum {
 788         FAILURE_BAD_HOST = 1,
 789         FAILURE_SESSION_FAILED,
 790         FAILURE_SESSION_FREED,
 791         FAILURE_WINDOW_CLOSED,
 792         FAILURE_OOM,
 793         FAILURE_SESSION_TERMINATE,
 794         FAILURE_SESSION_IN_RECOVERY,
 795         FAILURE_SESSION_RECOVERY_TIMEOUT,
 796 };
 797
 798 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
 799 {
 800         struct Scsi_Host *host;
 801         int reason = 0;
 802         struct iscsi_session *session;
 803         struct iscsi_conn *conn;
 804         struct iscsi_cmd_task *ctask = NULL;
 805
 806         sc->scsi_done = done;
 807         sc->result = 0;
 808         sc->SCp.ptr = NULL;
 809
 810         host = sc->device->host;
 811         session = iscsi_hostdata(host->hostdata);
 812
 813         spin_lock(&session->lock);
 814
 815         /*
 816          * ISCSI_STATE_FAILED is a temp. state. The recovery
 817          * code will decide what is best to do with command queued
 818          * during this time
 819          */
 820         if (session->state != ISCSI_STATE_LOGGED_IN &&
 821             session->state != ISCSI_STATE_FAILED) {
 822                 /*
 823                  * to handle the race between when we set the recovery state
 824                  * and block the session we requeue here (commands could
 825                  * be entering our queuecommand while a block is starting
 826                  * up because the block code is not locked)
 827                  */
 828                 if (session->state == ISCSI_STATE_IN_RECOVERY) {
 829                         reason = FAILURE_SESSION_IN_RECOVERY;
 830                         goto reject;
 831                 }
 832
 833                 if (session->state == ISCSI_STATE_RECOVERY_FAILED)
 834                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
 835                 else if (session->state == ISCSI_STATE_TERMINATE)
 836                         reason = FAILURE_SESSION_TERMINATE;
 837                 else
 838                         reason = FAILURE_SESSION_FREED;
 839                 goto fault;
 840         }
 841
 842         conn = session->leadconn;
 843         if (!conn) {
 844                 reason = FAILURE_SESSION_FREED;
 845                 goto fault;
 846         }
 847
 848         if (iscsi_check_cmdsn_window_closed(conn)) {
 849                 reason = FAILURE_WINDOW_CLOSED;
 850                 goto reject;
 851         }
 852
 853         if (!__kfifo_get(session->cmdpool.queue, (void*)&ctask,
 854                          sizeof(void*))) {
 855                 reason = FAILURE_OOM;
 856                 goto reject;
 857         }
 858         session->queued_cmdsn++;
 859
 860         sc->SCp.phase = session->age;
 861         sc->SCp.ptr = (char *)ctask;
 862
 863         atomic_set(&ctask->refcount, 1);
 864         ctask->state = ISCSI_TASK_PENDING;
 865         ctask->mtask = NULL;
 866         ctask->conn = conn;
 867         ctask->sc = sc;
 868         INIT_LIST_HEAD(&ctask->running);
 869
 870         list_add_tail(&ctask->running, &conn->xmitqueue);
 871         spin_unlock(&session->lock);
 872
 873         scsi_queue_work(host, &conn->xmitwork);
 874         return 0;
 875
 876 reject:
 877         spin_unlock(&session->lock);
 878         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
 879         return SCSI_MLQUEUE_HOST_BUSY;
 880
 881 fault:
 882         spin_unlock(&session->lock);
 883         printk(KERN_ERR "iscsi: cmd 0x%x is not queued (%d)\n",
 884                sc->cmnd[0], reason);
 885         sc->result = (DID_NO_CONNECT << 16);
 886         scsi_set_resid(sc, scsi_bufflen(sc));
 887         sc->scsi_done(sc);
 888         return 0;
 889 }
 890 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
 891
 892 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
 893 {
 894         if (depth > ISCSI_MAX_CMD_PER_LUN)
 895                 depth = ISCSI_MAX_CMD_PER_LUN;
 896         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 897         return sdev->queue_depth;
 898 }
 899 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
 900
 901 static struct iscsi_mgmt_task *
 902 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 903                       char *data, uint32_t data_size)
 904 {
 905         struct iscsi_session *session = conn->session;
 906         struct iscsi_mgmt_task *mtask;
 907
 908         if (session->state == ISCSI_STATE_TERMINATE)
 909                 return NULL;
 910
 911         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
 912             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 913                 /*
 914                  * Login and Text are sent serially, in
 915                  * request-followed-by-response sequence.
 916                  * Same mtask can be used. Same ITT must be used.
 917                  * Note that login_mtask is preallocated at conn_create().
 918                  */
 919                 mtask = conn->login_mtask;
 920         else {
 921                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 922                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 923
 924                 if (!__kfifo_get(session->mgmtpool.queue,
 925                                  (void*)&mtask, sizeof(void*)))
 926                         return NULL;
 927         }
 928
 929         if (data_size) {
 930                 memcpy(mtask->data, data, data_size);
 931                 mtask->data_count = data_size;
 932         } else
 933                 mtask->data_count = 0;
 934
 935         INIT_LIST_HEAD(&mtask->running);
 936         memcpy(mtask->hdr, hdr, sizeof(struct iscsi_hdr));
 937         __kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*));
 938         return mtask;
 939 }
 940
 941 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 942                         char *data, uint32_t data_size)
 943 {
 944         struct iscsi_conn *conn = cls_conn->dd_data;
 945         struct iscsi_session *session = conn->session;
 946         int err = 0;
 947
 948         spin_lock_bh(&session->lock);
 949         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 950                 err = -EPERM;
 951         spin_unlock_bh(&session->lock);
 952         scsi_queue_work(session->host, &conn->xmitwork);
 953         return err;
 954 }
 955 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 956
 957 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
 958 {
 959         struct iscsi_session *session = class_to_transport_session(cls_session);
 960         struct iscsi_conn *conn = session->leadconn;
 961
 962         spin_lock_bh(&session->lock);
 963         if (session->state != ISCSI_STATE_LOGGED_IN) {
 964                 session->state = ISCSI_STATE_RECOVERY_FAILED;
 965                 if (conn)
 966                         wake_up(&conn->ehwait);
 967         }
 968         spin_unlock_bh(&session->lock);
 969 }
 970 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
 971
 972 int iscsi_eh_host_reset(struct scsi_cmnd *sc)
 973 {
 974         struct Scsi_Host *host = sc->device->host;
 975         struct iscsi_session *session = iscsi_hostdata(host->hostdata);
 976         struct iscsi_conn *conn = session->leadconn;
 977         int fail_session = 0;
 978
 979         spin_lock_bh(&session->lock);
 980         if (session->state == ISCSI_STATE_TERMINATE) {
 981 failed:
 982                 debug_scsi("failing host reset: session terminated "
 983                            "[CID %d age %d]\n", conn->id, session->age);
 984                 spin_unlock_bh(&session->lock);
 985                 return FAILED;
 986         }
 987
 988         if (sc->SCp.phase == session->age) {
 989                 debug_scsi("failing connection CID %d due to SCSI host reset\n",
 990                            conn->id);
 991                 fail_session = 1;
 992         }
 993         spin_unlock_bh(&session->lock);
 994
 995         /*
 996          * we drop the lock here but the leadconn cannot be destoyed while
 997          * we are in the scsi eh
 998          */
 999         if (fail_session)
1000                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1001
1002         debug_scsi("iscsi_eh_host_reset wait for relogin\n");
1003         wait_event_interruptible(conn->ehwait,
1004                                  session->state == ISCSI_STATE_TERMINATE ||
1005                                  session->state == ISCSI_STATE_LOGGED_IN ||
1006                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
1007         if (signal_pending(current))
1008                 flush_signals(current);
1009
1010         spin_lock_bh(&session->lock);
1011         if (session->state == ISCSI_STATE_LOGGED_IN)
1012                 printk(KERN_INFO "iscsi: host reset succeeded\n");
1013         else
1014                 goto failed;
1015         spin_unlock_bh(&session->lock);
1016
1017         return SUCCESS;
1018 }
1019 EXPORT_SYMBOL_GPL(iscsi_eh_host_reset);
1020
1021 static void iscsi_tmabort_timedout(unsigned long data)
1022 {
1023         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)data;
1024         struct iscsi_conn *conn = ctask->conn;
1025         struct iscsi_session *session = conn->session;
1026
1027         spin_lock(&session->lock);
1028         if (conn->tmabort_state == TMABORT_INITIAL) {
1029                 conn->tmabort_state = TMABORT_TIMEDOUT;
1030                 debug_scsi("tmabort timedout [sc %p itt 0x%x]\n",
1031                         ctask->sc, ctask->itt);
1032                 /* unblock eh_abort() */
1033                 wake_up(&conn->ehwait);
1034         }
1035         spin_unlock(&session->lock);
1036 }
1037
1038 static int iscsi_exec_abort_task(struct scsi_cmnd *sc,
1039                                  struct iscsi_cmd_task *ctask)
1040 {
1041         struct iscsi_conn *conn = ctask->conn;
1042         struct iscsi_session *session = conn->session;
1043         struct iscsi_tm *hdr = &conn->tmhdr;
1044
1045         /*
1046          * ctask timed out but session is OK requests must be serialized.
1047          */
1048         memset(hdr, 0, sizeof(struct iscsi_tm));
1049         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1050         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK;
1051         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1052         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1053         hdr->rtt = ctask->hdr->itt;
1054         hdr->refcmdsn = ctask->hdr->cmdsn;
1055
1056         ctask->mtask = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1057                                             NULL, 0);
1058         if (!ctask->mtask) {
1059                 spin_unlock_bh(&session->lock);
1060                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1061                 spin_lock_bh(&session->lock)
1062                 debug_scsi("abort sent failure [itt 0x%x]\n", ctask->itt);
1063                 return -EPERM;
1064         }
1065         ctask->state = ISCSI_TASK_ABORTING;
1066
1067         debug_scsi("abort sent [itt 0x%x]\n", ctask->itt);
1068
1069         if (conn->tmabort_state == TMABORT_INITIAL) {
1070                 conn->tmfcmd_pdus_cnt++;
1071                 conn->tmabort_timer.expires = 20*HZ + jiffies;
1072                 conn->tmabort_timer.function = iscsi_tmabort_timedout;
1073                 conn->tmabort_timer.data = (unsigned long)ctask;
1074                 add_timer(&conn->tmabort_timer);
1075                 debug_scsi("abort set timeout [itt 0x%x]\n", ctask->itt);
1076         }
1077         spin_unlock_bh(&session->lock);
1078         mutex_unlock(&session->eh_mutex);
1079         scsi_queue_work(session->host, &conn->xmitwork);
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         mutex_lock(&session->eh_mutex);
1097         spin_lock_bh(&session->lock);
1098         return 0;
1099 }
1100
1101 /*
1102  * 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->mgmtqueue, 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 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         if (ctask->state == ISCSI_TASK_PENDING)
1155                 /*
1156                  * cmd never made it to the xmit thread, so we should not count
1157                  * the cmd in the sequencing
1158                  */
1159                 conn->session->queued_cmdsn--;
1160         else
1161                 conn->session->tt->cleanup_cmd_task(conn, ctask);
1162         iscsi_ctask_mtask_cleanup(ctask);
1163
1164         sc->result = err;
1165         scsi_set_resid(sc, scsi_bufflen(sc));
1166         if (conn->ctask == ctask)
1167                 conn->ctask = NULL;
1168         /* release ref from queuecommand */
1169         __iscsi_put_ctask(ctask);
1170 }
1171
1172 static void iscsi_suspend_tx(struct iscsi_conn *conn)
1173 {
1174         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1175         scsi_flush_work(conn->session->host);
1176 }
1177
1178 static void iscsi_start_tx(struct iscsi_conn *conn)
1179 {
1180         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1181         scsi_queue_work(conn->session->host, &conn->xmitwork);
1182 }
1183
1184 int iscsi_eh_abort(struct scsi_cmnd *sc)
1185 {
1186         struct Scsi_Host *host = sc->device->host;
1187         struct iscsi_session *session = iscsi_hostdata(host->hostdata);
1188         struct iscsi_cmd_task *ctask;
1189         struct iscsi_conn *conn;
1190         int rc;
1191
1192         mutex_lock(&session->eh_mutex);
1193         spin_lock_bh(&session->lock);
1194         /*
1195          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1196          * got the command.
1197          */
1198         if (!sc->SCp.ptr) {
1199                 debug_scsi("sc never reached iscsi layer or it completed.\n");
1200                 spin_unlock_bh(&session->lock);
1201                 mutex_unlock(&session->eh_mutex);
1202                 return SUCCESS;
1203         }
1204
1205         ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
1206         conn = ctask->conn;
1207
1208         conn->eh_abort_cnt++;
1209         debug_scsi("aborting [sc %p itt 0x%x]\n", sc, ctask->itt);
1210
1211         /*
1212          * If we are not logged in or we have started a new session
1213          * then let the host reset code handle this
1214          */
1215         if (session->state != ISCSI_STATE_LOGGED_IN ||
1216             sc->SCp.phase != session->age)
1217                 goto failed;
1218
1219         /* ctask completed before time out */
1220         if (!ctask->sc) {
1221                 debug_scsi("sc completed while abort in progress\n");
1222                 goto success;
1223         }
1224
1225         /* what should we do here ? */
1226         if (conn->ctask == ctask) {
1227                 printk(KERN_INFO "iscsi: sc %p itt 0x%x partially sent. "
1228                        "Failing abort\n", sc, ctask->itt);
1229                 goto failed;
1230         }
1231
1232         if (ctask->state == ISCSI_TASK_PENDING) {
1233                 fail_command(conn, ctask, DID_ABORT << 16);
1234                 goto success;
1235         }
1236
1237         conn->tmabort_state = TMABORT_INITIAL;
1238         rc = iscsi_exec_abort_task(sc, ctask);
1239         if (rc || sc->SCp.phase != session->age ||
1240             session->state != ISCSI_STATE_LOGGED_IN)
1241                 goto failed;
1242         iscsi_ctask_mtask_cleanup(ctask);
1243
1244         switch (conn->tmabort_state) {
1245         case TMABORT_SUCCESS:
1246                 spin_unlock_bh(&session->lock);
1247                 iscsi_suspend_tx(conn);
1248                 /*
1249                  * clean up task if aborted. grab the recv lock as a writer
1250                  */
1251                 write_lock_bh(conn->recv_lock);
1252                 spin_lock(&session->lock);
1253                 fail_command(conn, ctask, DID_ABORT << 16);
1254                 spin_unlock(&session->lock);
1255                 write_unlock_bh(conn->recv_lock);
1256                 iscsi_start_tx(conn);
1257                 goto success_unlocked;
1258         case TMABORT_NOT_FOUND:
1259                 if (!ctask->sc) {
1260                         /* ctask completed before tmf abort response */
1261                         debug_scsi("sc completed while abort in progress\n");
1262                         goto success;
1263                 }
1264                 /* fall through */
1265         default:
1266                 /* timedout or failed */
1267                 spin_unlock_bh(&session->lock);
1268                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1269                 goto failed_unlocked;
1270         }
1271
1272 success:
1273         spin_unlock_bh(&session->lock);
1274 success_unlocked:
1275         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1276         mutex_unlock(&session->eh_mutex);
1277         return SUCCESS;
1278
1279 failed:
1280         spin_unlock_bh(&session->lock);
1281 failed_unlocked:
1282         debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1283         mutex_unlock(&session->eh_mutex);
1284         return FAILED;
1285 }
1286 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1287
1288 int
1289 iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
1290 {
1291         int i;
1292
1293         *items = kmalloc(max * sizeof(void*), GFP_KERNEL);
1294         if (*items == NULL)
1295                 return -ENOMEM;
1296
1297         q->max = max;
1298         q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL);
1299         if (q->pool == NULL) {
1300                 kfree(*items);
1301                 return -ENOMEM;
1302         }
1303
1304         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1305                               GFP_KERNEL, NULL);
1306         if (q->queue == ERR_PTR(-ENOMEM)) {
1307                 kfree(q->pool);
1308                 kfree(*items);
1309                 return -ENOMEM;
1310         }
1311
1312         for (i = 0; i < max; i++) {
1313                 q->pool[i] = kmalloc(item_size, GFP_KERNEL);
1314                 if (q->pool[i] == NULL) {
1315                         int j;
1316
1317                         for (j = 0; j < i; j++)
1318                                 kfree(q->pool[j]);
1319
1320                         kfifo_free(q->queue);
1321                         kfree(q->pool);
1322                         kfree(*items);
1323                         return -ENOMEM;
1324                 }
1325                 memset(q->pool[i], 0, item_size);
1326                 (*items)[i] = q->pool[i];
1327                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1328         }
1329         return 0;
1330 }
1331 EXPORT_SYMBOL_GPL(iscsi_pool_init);
1332
1333 void iscsi_pool_free(struct iscsi_queue *q, void **items)
1334 {
1335         int i;
1336
1337         for (i = 0; i < q->max; i++)
1338                 kfree(items[i]);
1339         kfree(q->pool);
1340         kfree(items);
1341 }
1342 EXPORT_SYMBOL_GPL(iscsi_pool_free);
1343
1344 /*
1345  * iSCSI Session's hostdata organization:
1346  *
1347  *    *------------------* <== hostdata_session(host->hostdata)
1348  *    | ptr to class sess|
1349  *    |------------------| <== iscsi_hostdata(host->hostdata)
1350  *    | iscsi_session    |
1351  *    *------------------*
1352  */
1353
1354 #define hostdata_privsize(_sz)  (sizeof(unsigned long) + _sz + \
1355                                  _sz % sizeof(unsigned long))
1356
1357 #define hostdata_session(_hostdata) (iscsi_ptr(*(unsigned long *)_hostdata))
1358
1359 /**
1360  * iscsi_session_setup - create iscsi cls session and host and session
1361  * @scsit: scsi transport template
1362  * @iscsit: iscsi transport template
1363  * @cmds_max: scsi host can queue
1364  * @qdepth: scsi host cmds per lun
1365  * @cmd_task_size: LLD ctask private data size
1366  * @mgmt_task_size: LLD mtask private data size
1367  * @initial_cmdsn: initial CmdSN
1368  * @hostno: host no allocated
1369  *
1370  * This can be used by software iscsi_transports that allocate
1371  * a session per scsi host.
1372  **/
1373 struct iscsi_cls_session *
1374 iscsi_session_setup(struct iscsi_transport *iscsit,
1375                     struct scsi_transport_template *scsit,
1376                     uint16_t cmds_max, uint16_t qdepth,
1377                     int cmd_task_size, int mgmt_task_size,
1378                     uint32_t initial_cmdsn, uint32_t *hostno)
1379 {
1380         struct Scsi_Host *shost;
1381         struct iscsi_session *session;
1382         struct iscsi_cls_session *cls_session;
1383         int cmd_i;
1384
1385         if (qdepth > ISCSI_MAX_CMD_PER_LUN || qdepth < 1) {
1386                 if (qdepth != 0)
1387                         printk(KERN_ERR "iscsi: invalid queue depth of %d. "
1388                               "Queue depth must be between 1 and %d.\n",
1389                               qdepth, ISCSI_MAX_CMD_PER_LUN);
1390                 qdepth = ISCSI_DEF_CMD_PER_LUN;
1391         }
1392
1393         if (cmds_max < 2 || (cmds_max & (cmds_max - 1)) ||
1394             cmds_max >= ISCSI_MGMT_ITT_OFFSET) {
1395                 if (cmds_max != 0)
1396                         printk(KERN_ERR "iscsi: invalid can_queue of %d. "
1397                                "can_queue must be a power of 2 and between "
1398                                "2 and %d - setting to %d.\n", cmds_max,
1399                                ISCSI_MGMT_ITT_OFFSET, ISCSI_DEF_XMIT_CMDS_MAX);
1400                 cmds_max = ISCSI_DEF_XMIT_CMDS_MAX;
1401         }
1402
1403         shost = scsi_host_alloc(iscsit->host_template,
1404                                 hostdata_privsize(sizeof(*session)));
1405         if (!shost)
1406                 return NULL;
1407
1408         /* the iscsi layer takes one task for reserve */
1409         shost->can_queue = cmds_max - 1;
1410         shost->cmd_per_lun = qdepth;
1411         shost->max_id = 1;
1412         shost->max_channel = 0;
1413         shost->max_lun = iscsit->max_lun;
1414         shost->max_cmd_len = iscsit->max_cmd_len;
1415         shost->transportt = scsit;
1416         shost->transportt->create_work_queue = 1;
1417         *hostno = shost->host_no;
1418
1419         session = iscsi_hostdata(shost->hostdata);
1420         memset(session, 0, sizeof(struct iscsi_session));
1421         session->host = shost;
1422         session->state = ISCSI_STATE_FREE;
1423         session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
1424         session->cmds_max = cmds_max;
1425         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
1426         session->exp_cmdsn = initial_cmdsn + 1;
1427         session->max_cmdsn = initial_cmdsn + 1;
1428         session->max_r2t = 1;
1429         session->tt = iscsit;
1430         mutex_init(&session->eh_mutex);
1431
1432         /* initialize SCSI PDU commands pool */
1433         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
1434                             (void***)&session->cmds,
1435                             cmd_task_size + sizeof(struct iscsi_cmd_task)))
1436                 goto cmdpool_alloc_fail;
1437
1438         /* pre-format cmds pool with ITT */
1439         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1440                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1441
1442                 if (cmd_task_size)
1443                         ctask->dd_data = &ctask[1];
1444                 ctask->itt = cmd_i;
1445                 INIT_LIST_HEAD(&ctask->running);
1446         }
1447
1448         spin_lock_init(&session->lock);
1449
1450         /* initialize immediate command pool */
1451         if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max,
1452                            (void***)&session->mgmt_cmds,
1453                            mgmt_task_size + sizeof(struct iscsi_mgmt_task)))
1454                 goto mgmtpool_alloc_fail;
1455
1456
1457         /* pre-format immediate cmds pool with ITT */
1458         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
1459                 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
1460
1461                 if (mgmt_task_size)
1462                         mtask->dd_data = &mtask[1];
1463                 mtask->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i;
1464                 INIT_LIST_HEAD(&mtask->running);
1465         }
1466
1467         if (scsi_add_host(shost, NULL))
1468                 goto add_host_fail;
1469
1470         if (!try_module_get(iscsit->owner))
1471                 goto cls_session_fail;
1472
1473         cls_session = iscsi_create_session(shost, iscsit, 0);
1474         if (!cls_session)
1475                 goto module_put;
1476         *(unsigned long*)shost->hostdata = (unsigned long)cls_session;
1477
1478         return cls_session;
1479
1480 module_put:
1481         module_put(iscsit->owner);
1482 cls_session_fail:
1483         scsi_remove_host(shost);
1484 add_host_fail:
1485         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1486 mgmtpool_alloc_fail:
1487         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1488 cmdpool_alloc_fail:
1489         scsi_host_put(shost);
1490         return NULL;
1491 }
1492 EXPORT_SYMBOL_GPL(iscsi_session_setup);
1493
1494 /**
1495  * iscsi_session_teardown - destroy session, host, and cls_session
1496  * shost: scsi host
1497  *
1498  * This can be used by software iscsi_transports that allocate
1499  * a session per scsi host.
1500  **/
1501 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
1502 {
1503         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1504         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1505         struct module *owner = cls_session->transport->owner;
1506
1507         iscsi_unblock_session(cls_session);
1508         scsi_remove_host(shost);
1509
1510         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1511         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1512
1513         kfree(session->password);
1514         kfree(session->password_in);
1515         kfree(session->username);
1516         kfree(session->username_in);
1517         kfree(session->targetname);
1518         kfree(session->netdev);
1519         kfree(session->hwaddress);
1520         kfree(session->initiatorname);
1521
1522         iscsi_destroy_session(cls_session);
1523         scsi_host_put(shost);
1524         module_put(owner);
1525 }
1526 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
1527
1528 /**
1529  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
1530  * @cls_session: iscsi_cls_session
1531  * @conn_idx: cid
1532  **/
1533 struct iscsi_cls_conn *
1534 iscsi_conn_setup(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1535 {
1536         struct iscsi_session *session = class_to_transport_session(cls_session);
1537         struct iscsi_conn *conn;
1538         struct iscsi_cls_conn *cls_conn;
1539         char *data;
1540
1541         cls_conn = iscsi_create_conn(cls_session, conn_idx);
1542         if (!cls_conn)
1543                 return NULL;
1544         conn = cls_conn->dd_data;
1545         memset(conn, 0, sizeof(*conn));
1546
1547         conn->session = session;
1548         conn->cls_conn = cls_conn;
1549         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
1550         conn->id = conn_idx;
1551         conn->exp_statsn = 0;
1552         conn->tmabort_state = TMABORT_INITIAL;
1553         INIT_LIST_HEAD(&conn->run_list);
1554         INIT_LIST_HEAD(&conn->mgmt_run_list);
1555         INIT_LIST_HEAD(&conn->xmitqueue);
1556
1557         /* initialize general immediate & non-immediate PDU commands queue */
1558         conn->mgmtqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
1559                                         GFP_KERNEL, NULL);
1560         if (conn->mgmtqueue == ERR_PTR(-ENOMEM))
1561                 goto mgmtqueue_alloc_fail;
1562
1563         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
1564
1565         /* allocate login_mtask used for the login/text sequences */
1566         spin_lock_bh(&session->lock);
1567         if (!__kfifo_get(session->mgmtpool.queue,
1568                          (void*)&conn->login_mtask,
1569                          sizeof(void*))) {
1570                 spin_unlock_bh(&session->lock);
1571                 goto login_mtask_alloc_fail;
1572         }
1573         spin_unlock_bh(&session->lock);
1574
1575         data = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN, GFP_KERNEL);
1576         if (!data)
1577                 goto login_mtask_data_alloc_fail;
1578         conn->login_mtask->data = conn->data = data;
1579
1580         init_timer(&conn->tmabort_timer);
1581         init_waitqueue_head(&conn->ehwait);
1582
1583         return cls_conn;
1584
1585 login_mtask_data_alloc_fail:
1586         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1587                     sizeof(void*));
1588 login_mtask_alloc_fail:
1589         kfifo_free(conn->mgmtqueue);
1590 mgmtqueue_alloc_fail:
1591         iscsi_destroy_conn(cls_conn);
1592         return NULL;
1593 }
1594 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
1595
1596 /**
1597  * iscsi_conn_teardown - teardown iscsi connection
1598  * cls_conn: iscsi class connection
1599  *
1600  * TODO: we may need to make this into a two step process
1601  * like scsi-mls remove + put host
1602  */
1603 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
1604 {
1605         struct iscsi_conn *conn = cls_conn->dd_data;
1606         struct iscsi_session *session = conn->session;
1607         unsigned long flags;
1608
1609         spin_lock_bh(&session->lock);
1610         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1611         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
1612         if (session->leadconn == conn) {
1613                 /*
1614                  * leading connection? then give up on recovery.
1615                  */
1616                 session->state = ISCSI_STATE_TERMINATE;
1617                 wake_up(&conn->ehwait);
1618         }
1619         spin_unlock_bh(&session->lock);
1620
1621         /*
1622          * Block until all in-progress commands for this connection
1623          * time out or fail.
1624          */
1625         for (;;) {
1626                 spin_lock_irqsave(session->host->host_lock, flags);
1627                 if (!session->host->host_busy) { /* OK for ERL == 0 */
1628                         spin_unlock_irqrestore(session->host->host_lock, flags);
1629                         break;
1630                 }
1631                 spin_unlock_irqrestore(session->host->host_lock, flags);
1632                 msleep_interruptible(500);
1633                 printk(KERN_INFO "iscsi: scsi conn_destroy(): host_busy %d "
1634                        "host_failed %d\n", session->host->host_busy,
1635                        session->host->host_failed);
1636                 /*
1637                  * force eh_abort() to unblock
1638                  */
1639                 wake_up(&conn->ehwait);
1640         }
1641
1642         /* flush queued up work because we free the connection below */
1643         scsi_flush_work(session->host);
1644
1645         spin_lock_bh(&session->lock);
1646         kfree(conn->data);
1647         kfree(conn->persistent_address);
1648         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1649                     sizeof(void*));
1650         if (session->leadconn == conn)
1651                 session->leadconn = NULL;
1652         spin_unlock_bh(&session->lock);
1653
1654         kfifo_free(conn->mgmtqueue);
1655
1656         iscsi_destroy_conn(cls_conn);
1657 }
1658 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
1659
1660 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
1661 {
1662         struct iscsi_conn *conn = cls_conn->dd_data;
1663         struct iscsi_session *session = conn->session;
1664
1665         if (!session) {
1666                 printk(KERN_ERR "iscsi: can't start unbound connection\n");
1667                 return -EPERM;
1668         }
1669
1670         if ((session->imm_data_en || !session->initial_r2t_en) &&
1671              session->first_burst > session->max_burst) {
1672                 printk("iscsi: invalid burst lengths: "
1673                        "first_burst %d max_burst %d\n",
1674                        session->first_burst, session->max_burst);
1675                 return -EINVAL;
1676         }
1677
1678         spin_lock_bh(&session->lock);
1679         conn->c_stage = ISCSI_CONN_STARTED;
1680         session->state = ISCSI_STATE_LOGGED_IN;
1681         session->queued_cmdsn = session->cmdsn;
1682
1683         switch(conn->stop_stage) {
1684         case STOP_CONN_RECOVER:
1685                 /*
1686                  * unblock eh_abort() if it is blocked. re-try all
1687                  * commands after successful recovery
1688                  */
1689                 conn->stop_stage = 0;
1690                 conn->tmabort_state = TMABORT_INITIAL;
1691                 session->age++;
1692                 spin_unlock_bh(&session->lock);
1693
1694                 iscsi_unblock_session(session_to_cls(session));
1695                 wake_up(&conn->ehwait);
1696                 return 0;
1697         case STOP_CONN_TERM:
1698                 conn->stop_stage = 0;
1699                 break;
1700         default:
1701                 break;
1702         }
1703         spin_unlock_bh(&session->lock);
1704
1705         return 0;
1706 }
1707 EXPORT_SYMBOL_GPL(iscsi_conn_start);
1708
1709 static void
1710 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
1711 {
1712         struct iscsi_mgmt_task *mtask, *tmp;
1713
1714         /* handle pending */
1715         while (__kfifo_get(conn->mgmtqueue, (void*)&mtask, sizeof(void*))) {
1716                 if (mtask == conn->login_mtask)
1717                         continue;
1718                 debug_scsi("flushing pending mgmt task itt 0x%x\n", mtask->itt);
1719                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1720                             sizeof(void*));
1721         }
1722
1723         /* handle running */
1724         list_for_each_entry_safe(mtask, tmp, &conn->mgmt_run_list, running) {
1725                 debug_scsi("flushing running mgmt task itt 0x%x\n", mtask->itt);
1726                 list_del(&mtask->running);
1727
1728                 if (mtask == conn->login_mtask)
1729                         continue;
1730                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1731                            sizeof(void*));
1732         }
1733
1734         conn->mtask = NULL;
1735 }
1736
1737 /* Fail commands. Mutex and session lock held and recv side suspended */
1738 static void fail_all_commands(struct iscsi_conn *conn)
1739 {
1740         struct iscsi_cmd_task *ctask, *tmp;
1741
1742         /* flush pending */
1743         list_for_each_entry_safe(ctask, tmp, &conn->xmitqueue, running) {
1744                 debug_scsi("failing pending sc %p itt 0x%x\n", ctask->sc,
1745                            ctask->itt);
1746                 fail_command(conn, ctask, DID_BUS_BUSY << 16);
1747         }
1748
1749         /* fail all other running */
1750         list_for_each_entry_safe(ctask, tmp, &conn->run_list, running) {
1751                 debug_scsi("failing in progress sc %p itt 0x%x\n",
1752                            ctask->sc, ctask->itt);
1753                 fail_command(conn, ctask, DID_BUS_BUSY << 16);
1754         }
1755
1756         conn->ctask = NULL;
1757 }
1758
1759 static void iscsi_start_session_recovery(struct iscsi_session *session,
1760                                          struct iscsi_conn *conn, int flag)
1761 {
1762         int old_stop_stage;
1763
1764         mutex_lock(&session->eh_mutex);
1765         spin_lock_bh(&session->lock);
1766         if (conn->stop_stage == STOP_CONN_TERM) {
1767                 spin_unlock_bh(&session->lock);
1768                 mutex_unlock(&session->eh_mutex);
1769                 return;
1770         }
1771
1772         /*
1773          * The LLD either freed/unset the lock on us, or userspace called
1774          * stop but did not create a proper connection (connection was never
1775          * bound or it was unbound then stop was called).
1776          */
1777         if (!conn->recv_lock) {
1778                 spin_unlock_bh(&session->lock);
1779                 mutex_unlock(&session->eh_mutex);
1780                 return;
1781         }
1782
1783         /*
1784          * When this is called for the in_login state, we only want to clean
1785          * up the login task and connection. We do not need to block and set
1786          * the recovery state again
1787          */
1788         if (flag == STOP_CONN_TERM)
1789                 session->state = ISCSI_STATE_TERMINATE;
1790         else if (conn->stop_stage != STOP_CONN_RECOVER)
1791                 session->state = ISCSI_STATE_IN_RECOVERY;
1792
1793         old_stop_stage = conn->stop_stage;
1794         conn->stop_stage = flag;
1795         conn->c_stage = ISCSI_CONN_STOPPED;
1796         spin_unlock_bh(&session->lock);
1797
1798         iscsi_suspend_tx(conn);
1799
1800         write_lock_bh(conn->recv_lock);
1801         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1802         write_unlock_bh(conn->recv_lock);
1803
1804         /*
1805          * for connection level recovery we should not calculate
1806          * header digest. conn->hdr_size used for optimization
1807          * in hdr_extract() and will be re-negotiated at
1808          * set_param() time.
1809          */
1810         if (flag == STOP_CONN_RECOVER) {
1811                 conn->hdrdgst_en = 0;
1812                 conn->datadgst_en = 0;
1813                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
1814                     old_stop_stage != STOP_CONN_RECOVER) {
1815                         debug_scsi("blocking session\n");
1816                         iscsi_block_session(session_to_cls(session));
1817                 }
1818         }
1819
1820         /*
1821          * flush queues.
1822          */
1823         spin_lock_bh(&session->lock);
1824         fail_all_commands(conn);
1825         flush_control_queues(session, conn);
1826         spin_unlock_bh(&session->lock);
1827         mutex_unlock(&session->eh_mutex);
1828 }
1829
1830 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1831 {
1832         struct iscsi_conn *conn = cls_conn->dd_data;
1833         struct iscsi_session *session = conn->session;
1834
1835         switch (flag) {
1836         case STOP_CONN_RECOVER:
1837         case STOP_CONN_TERM:
1838                 iscsi_start_session_recovery(session, conn, flag);
1839                 break;
1840         default:
1841                 printk(KERN_ERR "iscsi: invalid stop flag %d\n", flag);
1842         }
1843 }
1844 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
1845
1846 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
1847                     struct iscsi_cls_conn *cls_conn, int is_leading)
1848 {
1849         struct iscsi_session *session = class_to_transport_session(cls_session);
1850         struct iscsi_conn *conn = cls_conn->dd_data;
1851
1852         spin_lock_bh(&session->lock);
1853         if (is_leading)
1854                 session->leadconn = conn;
1855         spin_unlock_bh(&session->lock);
1856
1857         /*
1858          * Unblock xmitworker(), Login Phase will pass through.
1859          */
1860         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1861         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1862         return 0;
1863 }
1864 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
1865
1866
1867 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
1868                     enum iscsi_param param, char *buf, int buflen)
1869 {
1870         struct iscsi_conn *conn = cls_conn->dd_data;
1871         struct iscsi_session *session = conn->session;
1872         uint32_t value;
1873
1874         switch(param) {
1875         case ISCSI_PARAM_MAX_RECV_DLENGTH:
1876                 sscanf(buf, "%d", &conn->max_recv_dlength);
1877                 break;
1878         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
1879                 sscanf(buf, "%d", &conn->max_xmit_dlength);
1880                 break;
1881         case ISCSI_PARAM_HDRDGST_EN:
1882                 sscanf(buf, "%d", &conn->hdrdgst_en);
1883                 break;
1884         case ISCSI_PARAM_DATADGST_EN:
1885                 sscanf(buf, "%d", &conn->datadgst_en);
1886                 break;
1887         case ISCSI_PARAM_INITIAL_R2T_EN:
1888                 sscanf(buf, "%d", &session->initial_r2t_en);
1889                 break;
1890         case ISCSI_PARAM_MAX_R2T:
1891                 sscanf(buf, "%d", &session->max_r2t);
1892                 break;
1893         case ISCSI_PARAM_IMM_DATA_EN:
1894                 sscanf(buf, "%d", &session->imm_data_en);
1895                 break;
1896         case ISCSI_PARAM_FIRST_BURST:
1897                 sscanf(buf, "%d", &session->first_burst);
1898                 break;
1899         case ISCSI_PARAM_MAX_BURST:
1900                 sscanf(buf, "%d", &session->max_burst);
1901                 break;
1902         case ISCSI_PARAM_PDU_INORDER_EN:
1903                 sscanf(buf, "%d", &session->pdu_inorder_en);
1904                 break;
1905         case ISCSI_PARAM_DATASEQ_INORDER_EN:
1906                 sscanf(buf, "%d", &session->dataseq_inorder_en);
1907                 break;
1908         case ISCSI_PARAM_ERL:
1909                 sscanf(buf, "%d", &session->erl);
1910                 break;
1911         case ISCSI_PARAM_IFMARKER_EN:
1912                 sscanf(buf, "%d", &value);
1913                 BUG_ON(value);
1914                 break;
1915         case ISCSI_PARAM_OFMARKER_EN:
1916                 sscanf(buf, "%d", &value);
1917                 BUG_ON(value);
1918                 break;
1919         case ISCSI_PARAM_EXP_STATSN:
1920                 sscanf(buf, "%u", &conn->exp_statsn);
1921                 break;
1922         case ISCSI_PARAM_USERNAME:
1923                 kfree(session->username);
1924                 session->username = kstrdup(buf, GFP_KERNEL);
1925                 if (!session->username)
1926                         return -ENOMEM;
1927                 break;
1928         case ISCSI_PARAM_USERNAME_IN:
1929                 kfree(session->username_in);
1930                 session->username_in = kstrdup(buf, GFP_KERNEL);
1931                 if (!session->username_in)
1932                         return -ENOMEM;
1933                 break;
1934         case ISCSI_PARAM_PASSWORD:
1935                 kfree(session->password);
1936                 session->password = kstrdup(buf, GFP_KERNEL);
1937                 if (!session->password)
1938                         return -ENOMEM;
1939                 break;
1940         case ISCSI_PARAM_PASSWORD_IN:
1941                 kfree(session->password_in);
1942                 session->password_in = kstrdup(buf, GFP_KERNEL);
1943                 if (!session->password_in)
1944                         return -ENOMEM;
1945                 break;
1946         case ISCSI_PARAM_TARGET_NAME:
1947                 /* this should not change between logins */
1948                 if (session->targetname)
1949                         break;
1950
1951                 session->targetname = kstrdup(buf, GFP_KERNEL);
1952                 if (!session->targetname)
1953                         return -ENOMEM;
1954                 break;
1955         case ISCSI_PARAM_TPGT:
1956                 sscanf(buf, "%d", &session->tpgt);
1957                 break;
1958         case ISCSI_PARAM_PERSISTENT_PORT:
1959                 sscanf(buf, "%d", &conn->persistent_port);
1960                 break;
1961         case ISCSI_PARAM_PERSISTENT_ADDRESS:
1962                 /*
1963                  * this is the address returned in discovery so it should
1964                  * not change between logins.
1965                  */
1966                 if (conn->persistent_address)
1967                         break;
1968
1969                 conn->persistent_address = kstrdup(buf, GFP_KERNEL);
1970                 if (!conn->persistent_address)
1971                         return -ENOMEM;
1972                 break;
1973         default:
1974                 return -ENOSYS;
1975         }
1976
1977         return 0;
1978 }
1979 EXPORT_SYMBOL_GPL(iscsi_set_param);
1980
1981 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
1982                             enum iscsi_param param, char *buf)
1983 {
1984         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1985         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1986         int len;
1987
1988         switch(param) {
1989         case ISCSI_PARAM_INITIAL_R2T_EN:
1990                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
1991                 break;
1992         case ISCSI_PARAM_MAX_R2T:
1993                 len = sprintf(buf, "%hu\n", session->max_r2t);
1994                 break;
1995         case ISCSI_PARAM_IMM_DATA_EN:
1996                 len = sprintf(buf, "%d\n", session->imm_data_en);
1997                 break;
1998         case ISCSI_PARAM_FIRST_BURST:
1999                 len = sprintf(buf, "%u\n", session->first_burst);
2000                 break;
2001         case ISCSI_PARAM_MAX_BURST:
2002                 len = sprintf(buf, "%u\n", session->max_burst);
2003                 break;
2004         case ISCSI_PARAM_PDU_INORDER_EN:
2005                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
2006                 break;
2007         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2008                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
2009                 break;
2010         case ISCSI_PARAM_ERL:
2011                 len = sprintf(buf, "%d\n", session->erl);
2012                 break;
2013         case ISCSI_PARAM_TARGET_NAME:
2014                 len = sprintf(buf, "%s\n", session->targetname);
2015                 break;
2016         case ISCSI_PARAM_TPGT:
2017                 len = sprintf(buf, "%d\n", session->tpgt);
2018                 break;
2019         case ISCSI_PARAM_USERNAME:
2020                 len = sprintf(buf, "%s\n", session->username);
2021                 break;
2022         case ISCSI_PARAM_USERNAME_IN:
2023                 len = sprintf(buf, "%s\n", session->username_in);
2024                 break;
2025         case ISCSI_PARAM_PASSWORD:
2026                 len = sprintf(buf, "%s\n", session->password);
2027                 break;
2028         case ISCSI_PARAM_PASSWORD_IN:
2029                 len = sprintf(buf, "%s\n", session->password_in);
2030                 break;
2031         default:
2032                 return -ENOSYS;
2033         }
2034
2035         return len;
2036 }
2037 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
2038
2039 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2040                          enum iscsi_param param, char *buf)
2041 {
2042         struct iscsi_conn *conn = cls_conn->dd_data;
2043         int len;
2044
2045         switch(param) {
2046         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2047                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
2048                 break;
2049         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2050                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
2051                 break;
2052         case ISCSI_PARAM_HDRDGST_EN:
2053                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
2054                 break;
2055         case ISCSI_PARAM_DATADGST_EN:
2056                 len = sprintf(buf, "%d\n", conn->datadgst_en);
2057                 break;
2058         case ISCSI_PARAM_IFMARKER_EN:
2059                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
2060                 break;
2061         case ISCSI_PARAM_OFMARKER_EN:
2062                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
2063                 break;
2064         case ISCSI_PARAM_EXP_STATSN:
2065                 len = sprintf(buf, "%u\n", conn->exp_statsn);
2066                 break;
2067         case ISCSI_PARAM_PERSISTENT_PORT:
2068                 len = sprintf(buf, "%d\n", conn->persistent_port);
2069                 break;
2070         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2071                 len = sprintf(buf, "%s\n", conn->persistent_address);
2072                 break;
2073         default:
2074                 return -ENOSYS;
2075         }
2076
2077         return len;
2078 }
2079 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
2080
2081 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2082                          char *buf)
2083 {
2084         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2085         int len;
2086
2087         switch (param) {
2088         case ISCSI_HOST_PARAM_NETDEV_NAME:
2089                 if (!session->netdev)
2090                         len = sprintf(buf, "%s\n", "default");
2091                 else
2092                         len = sprintf(buf, "%s\n", session->netdev);
2093                 break;
2094         case ISCSI_HOST_PARAM_HWADDRESS:
2095                 if (!session->hwaddress)
2096                         len = sprintf(buf, "%s\n", "default");
2097                 else
2098                         len = sprintf(buf, "%s\n", session->hwaddress);
2099                 break;
2100         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2101                 if (!session->initiatorname)
2102                         len = sprintf(buf, "%s\n", "unknown");
2103                 else
2104                         len = sprintf(buf, "%s\n", session->initiatorname);
2105                 break;
2106
2107         default:
2108                 return -ENOSYS;
2109         }
2110
2111         return len;
2112 }
2113 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
2114
2115 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2116                          char *buf, int buflen)
2117 {
2118         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
2119
2120         switch (param) {
2121         case ISCSI_HOST_PARAM_NETDEV_NAME:
2122                 if (!session->netdev)
2123                         session->netdev = kstrdup(buf, GFP_KERNEL);
2124                 break;
2125         case ISCSI_HOST_PARAM_HWADDRESS:
2126                 if (!session->hwaddress)
2127                         session->hwaddress = kstrdup(buf, GFP_KERNEL);
2128                 break;
2129         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2130                 if (!session->initiatorname)
2131                         session->initiatorname = kstrdup(buf, GFP_KERNEL);
2132                 break;
2133         default:
2134                 return -ENOSYS;
2135         }
2136
2137         return 0;
2138 }
2139 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
2140
2141 MODULE_AUTHOR("Mike Christie");
2142 MODULE_DESCRIPTION("iSCSI library functions");
2143 MODULE_LICENSE("GPL");