drivers/infiniband/ulp/iser/iscsi_iser.c

   1 /*
   2  * iSCSI Initiator over iSER Data-Path
   3  *
   4  * Copyright (C) 2004 Dmitry Yusupov
   5  * Copyright (C) 2004 Alex Aizman
   6  * Copyright (C) 2005 Mike Christie
   7  * Copyright (c) 2005, 2006 Voltaire, Inc. All rights reserved.
   8  * maintained by openib-general@openib.org
   9  *
  10  * This software is available to you under a choice of one of two
  11  * licenses.  You may choose to be licensed under the terms of the GNU
  12  * General Public License (GPL) Version 2, available from the file
  13  * COPYING in the main directory of this source tree, or the
  14  * OpenIB.org BSD license below:
  15  *
  16  *     Redistribution and use in source and binary forms, with or
  17  *     without modification, are permitted provided that the following
  18  *     conditions are met:
  19  *
  20  *      - Redistributions of source code must retain the above
  21  *        copyright notice, this list of conditions and the following
  22  *        disclaimer.
  23  *
  24  *      - Redistributions in binary form must reproduce the above
  25  *        copyright notice, this list of conditions and the following
  26  *        disclaimer in the documentation and/or other materials
  27  *        provided with the distribution.
  28  *
  29  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  30  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  31  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  32  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  33  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  34  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  35  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  36  * SOFTWARE.
  37  *
  38  * Credits:
  39  *      Christoph Hellwig
  40  *      FUJITA Tomonori
  41  *      Arne Redlich
  42  *      Zhenyu Wang
  43  * Modified by:
  44  *      Erez Zilber
  45  *
  46  *
  47  * $Id: iscsi_iser.c 6965 2006-05-07 11:36:20Z ogerlitz $
  48  */
  49
  50 #include <linux/types.h>
  51 #include <linux/list.h>
  52 #include <linux/hardirq.h>
  53 #include <linux/kfifo.h>
  54 #include <linux/blkdev.h>
  55 #include <linux/init.h>
  56 #include <linux/ioctl.h>
  57 #include <linux/cdev.h>
  58 #include <linux/in.h>
  59 #include <linux/net.h>
  60 #include <linux/scatterlist.h>
  61 #include <linux/delay.h>
  62
  63 #include <net/sock.h>
  64
  65 #include <asm/uaccess.h>
  66
  67 #include <scsi/scsi_cmnd.h>
  68 #include <scsi/scsi_device.h>
  69 #include <scsi/scsi_eh.h>
  70 #include <scsi/scsi_tcq.h>
  71 #include <scsi/scsi_host.h>
  72 #include <scsi/scsi.h>
  73 #include <scsi/scsi_transport_iscsi.h>
  74
  75 #include "iscsi_iser.h"
  76
  77 static unsigned int iscsi_max_lun = 512;
  78 module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
  79
  80 int iser_debug_level = 0;
  81
  82 MODULE_DESCRIPTION("iSER (iSCSI Extensions for RDMA) Datamover "
  83                    "v" DRV_VER " (" DRV_DATE ")");
  84 MODULE_LICENSE("Dual BSD/GPL");
  85 MODULE_AUTHOR("Alex Nezhinsky, Dan Bar Dov, Or Gerlitz");
  86
  87 module_param_named(debug_level, iser_debug_level, int, 0644);
  88 MODULE_PARM_DESC(debug_level, "Enable debug tracing if > 0 (default:disabled)");
  89
  90 struct iser_global ig;
  91
  92 void
  93 iscsi_iser_recv(struct iscsi_conn *conn,
  94                 struct iscsi_hdr *hdr, char *rx_data, int rx_data_len)
  95 {
  96         int rc = 0;
  97         uint32_t ret_itt;
  98         int datalen;
  99         int ahslen;
 100
 101         /* verify PDU length */
 102         datalen = ntoh24(hdr->dlength);
 103         if (datalen != rx_data_len) {
 104                 printk(KERN_ERR "iscsi_iser: datalen %d (hdr) != %d (IB) \n",
 105                        datalen, rx_data_len);
 106                 rc = ISCSI_ERR_DATALEN;
 107                 goto error;
 108         }
 109
 110         /* read AHS */
 111         ahslen = hdr->hlength * 4;
 112
 113         /* verify itt (itt encoding: age+cid+itt) */
 114         rc = iscsi_verify_itt(conn, hdr, &ret_itt);
 115
 116         if (!rc)
 117                 rc = iscsi_complete_pdu(conn, hdr, rx_data, rx_data_len);
 118
 119         if (rc && rc != ISCSI_ERR_NO_SCSI_CMD)
 120                 goto error;
 121
 122         return;
 123 error:
 124         iscsi_conn_failure(conn, rc);
 125 }
 126
 127
 128 /**
 129  * iscsi_iser_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
 130  *
 131  **/
 132 static void
 133 iscsi_iser_cmd_init(struct iscsi_cmd_task *ctask)
 134 {
 135         struct iscsi_iser_conn     *iser_conn  = ctask->conn->dd_data;
 136         struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
 137         struct scsi_cmnd  *sc = ctask->sc;
 138
 139         iser_ctask->command_sent = 0;
 140         iser_ctask->iser_conn    = iser_conn;
 141
 142         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 143                 BUG_ON(ctask->total_length == 0);
 144                 /* bytes to be sent via RDMA operations */
 145                 iser_ctask->rdma_data_count = ctask->total_length -
 146                                          ctask->imm_count -
 147                                          ctask->unsol_count;
 148
 149                 debug_scsi("cmd [itt %x total %d imm %d unsol_data %d "
 150                            "rdma_data %d]\n",
 151                            ctask->itt, ctask->total_length, ctask->imm_count,
 152                            ctask->unsol_count, iser_ctask->rdma_data_count);
 153         } else
 154                 /* bytes to be sent via RDMA operations */
 155                 iser_ctask->rdma_data_count = ctask->total_length;
 156
 157         iser_ctask_rdma_init(iser_ctask);
 158 }
 159
 160 /**
 161  * iscsi_mtask_xmit - xmit management(immediate) task
 162  * @conn: iscsi connection
 163  * @mtask: task management task
 164  *
 165  * Notes:
 166  *      The function can return -EAGAIN in which case caller must
 167  *      call it again later, or recover. '0' return code means successful
 168  *      xmit.
 169  *
 170  **/
 171 static int
 172 iscsi_iser_mtask_xmit(struct iscsi_conn *conn,
 173                       struct iscsi_mgmt_task *mtask)
 174 {
 175         int error = 0;
 176
 177         debug_scsi("mtask deq [cid %d itt 0x%x]\n", conn->id, mtask->itt);
 178
 179         error = iser_send_control(conn, mtask);
 180
 181         /* since iser xmits control with zero copy, mtasks can not be recycled
 182          * right after sending them.
 183          * The recycling scheme is based on whether a response is expected
 184          * - if yes, the mtask is recycled at iscsi_complete_pdu
 185          * - if no,  the mtask is recycled at iser_snd_completion
 186          */
 187         if (error && error != -EAGAIN)
 188                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 189
 190         return error;
 191 }
 192
 193 static int
 194 iscsi_iser_ctask_xmit_unsol_data(struct iscsi_conn *conn,
 195                                  struct iscsi_cmd_task *ctask)
 196 {
 197         struct iscsi_data  hdr;
 198         int error = 0;
 199         struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
 200
 201         /* Send data-out PDUs while there's still unsolicited data to send */
 202         while (ctask->unsol_count > 0) {
 203                 iscsi_prep_unsolicit_data_pdu(ctask, &hdr,
 204                                               iser_ctask->rdma_data_count);
 205
 206                 debug_scsi("Sending data-out: itt 0x%x, data count %d\n",
 207                            hdr.itt, ctask->data_count);
 208
 209                 /* the buffer description has been passed with the command */
 210                 /* Send the command */
 211                 error = iser_send_data_out(conn, ctask, &hdr);
 212                 if (error) {
 213                         ctask->unsol_datasn--;
 214                         goto iscsi_iser_ctask_xmit_unsol_data_exit;
 215                 }
 216                 ctask->unsol_count -= ctask->data_count;
 217                 debug_scsi("Need to send %d more as data-out PDUs\n",
 218                            ctask->unsol_count);
 219         }
 220
 221 iscsi_iser_ctask_xmit_unsol_data_exit:
 222         return error;
 223 }
 224
 225 static int
 226 iscsi_iser_ctask_xmit(struct iscsi_conn *conn,
 227                       struct iscsi_cmd_task *ctask)
 228 {
 229         struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
 230         int error = 0;
 231
 232         debug_scsi("ctask deq [cid %d itt 0x%x]\n",
 233                    conn->id, ctask->itt);
 234
 235         /*
 236          * serialize with TMF AbortTask
 237          */
 238         if (ctask->mtask)
 239                 return error;
 240
 241         /* Send the cmd PDU */
 242         if (!iser_ctask->command_sent) {
 243                 error = iser_send_command(conn, ctask);
 244                 if (error)
 245                         goto iscsi_iser_ctask_xmit_exit;
 246                 iser_ctask->command_sent = 1;
 247         }
 248
 249         /* Send unsolicited data-out PDU(s) if necessary */
 250         if (ctask->unsol_count)
 251                 error = iscsi_iser_ctask_xmit_unsol_data(conn, ctask);
 252
 253  iscsi_iser_ctask_xmit_exit:
 254         if (error && error != -EAGAIN)
 255                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 256         return error;
 257 }
 258
 259 static void
 260 iscsi_iser_cleanup_ctask(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 261 {
 262         struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
 263
 264         if (iser_ctask->status == ISER_TASK_STATUS_STARTED) {
 265                 iser_ctask->status = ISER_TASK_STATUS_COMPLETED;
 266                 iser_ctask_rdma_finalize(iser_ctask);
 267         }
 268 }
 269
 270 static struct iser_conn *
 271 iscsi_iser_ib_conn_lookup(__u64 ep_handle)
 272 {
 273         struct iser_conn *ib_conn;
 274         struct iser_conn *uib_conn = (struct iser_conn *)(unsigned long)ep_handle;
 275
 276         mutex_lock(&ig.connlist_mutex);
 277         list_for_each_entry(ib_conn, &ig.connlist, conn_list) {
 278                 if (ib_conn == uib_conn) {
 279                         mutex_unlock(&ig.connlist_mutex);
 280                         return ib_conn;
 281                 }
 282         }
 283         mutex_unlock(&ig.connlist_mutex);
 284         iser_err("no conn exists for eph %llx\n",(unsigned long long)ep_handle);
 285         return NULL;
 286 }
 287
 288 static struct iscsi_cls_conn *
 289 iscsi_iser_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
 290 {
 291         struct iscsi_conn *conn;
 292         struct iscsi_cls_conn *cls_conn;
 293         struct iscsi_iser_conn *iser_conn;
 294
 295         cls_conn = iscsi_conn_setup(cls_session, conn_idx);
 296         if (!cls_conn)
 297                 return NULL;
 298         conn = cls_conn->dd_data;
 299
 300         /*
 301          * due to issues with the login code re iser sematics
 302          * this not set in iscsi_conn_setup - FIXME
 303          */
 304         conn->max_recv_dlength = 128;
 305
 306         iser_conn = kzalloc(sizeof(*iser_conn), GFP_KERNEL);
 307         if (!iser_conn)
 308                 goto conn_alloc_fail;
 309
 310         /* currently this is the only field which need to be initiated */
 311         rwlock_init(&iser_conn->lock);
 312
 313         conn->dd_data = iser_conn;
 314         iser_conn->iscsi_conn = conn;
 315
 316         return cls_conn;
 317
 318 conn_alloc_fail:
 319         iscsi_conn_teardown(cls_conn);
 320         return NULL;
 321 }
 322
 323 static void
 324 iscsi_iser_conn_destroy(struct iscsi_cls_conn *cls_conn)
 325 {
 326         struct iscsi_conn *conn = cls_conn->dd_data;
 327         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 328
 329         iscsi_conn_teardown(cls_conn);
 330         kfree(iser_conn);
 331 }
 332
 333 static int
 334 iscsi_iser_conn_bind(struct iscsi_cls_session *cls_session,
 335                      struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
 336                      int is_leading)
 337 {
 338         struct iscsi_conn *conn = cls_conn->dd_data;
 339         struct iscsi_iser_conn *iser_conn;
 340         struct iser_conn *ib_conn;
 341         int error;
 342
 343         error = iscsi_conn_bind(cls_session, cls_conn, is_leading);
 344         if (error)
 345                 return error;
 346
 347         /* the transport ep handle comes from user space so it must be
 348          * verified against the global ib connections list */
 349         ib_conn = iscsi_iser_ib_conn_lookup(transport_eph);
 350         if (!ib_conn) {
 351                 iser_err("can't bind eph %llx\n",
 352                          (unsigned long long)transport_eph);
 353                 return -EINVAL;
 354         }
 355         /* binds the iSER connection retrieved from the previously
 356          * connected ep_handle to the iSCSI layer connection. exchanges
 357          * connection pointers */
 358         iser_err("binding iscsi conn %p to iser_conn %p\n",conn,ib_conn);
 359         iser_conn = conn->dd_data;
 360         ib_conn->iser_conn = iser_conn;
 361         iser_conn->ib_conn  = ib_conn;
 362
 363         conn->recv_lock = &iser_conn->lock;
 364
 365         return 0;
 366 }
 367
 368 static int
 369 iscsi_iser_conn_start(struct iscsi_cls_conn *cls_conn)
 370 {
 371         struct iscsi_conn *conn = cls_conn->dd_data;
 372         int err;
 373
 374         err = iscsi_conn_start(cls_conn);
 375         if (err)
 376                 return err;
 377
 378         return iser_conn_set_full_featured_mode(conn);
 379 }
 380
 381 static struct iscsi_transport iscsi_iser_transport;
 382
 383 static struct iscsi_cls_session *
 384 iscsi_iser_session_create(struct iscsi_transport *iscsit,
 385                          struct scsi_transport_template *scsit,
 386                           uint32_t initial_cmdsn, uint32_t *hostno)
 387 {
 388         struct iscsi_cls_session *cls_session;
 389         struct iscsi_session *session;
 390         int i;
 391         uint32_t hn;
 392         struct iscsi_cmd_task  *ctask;
 393         struct iscsi_mgmt_task *mtask;
 394         struct iscsi_iser_cmd_task *iser_ctask;
 395         struct iser_desc *desc;
 396
 397         cls_session = iscsi_session_setup(iscsit, scsit,
 398                                           sizeof(struct iscsi_iser_cmd_task),
 399                                           sizeof(struct iser_desc),
 400                                           initial_cmdsn, &hn);
 401         if (!cls_session)
 402         return NULL;
 403
 404         *hostno = hn;
 405         session = class_to_transport_session(cls_session);
 406
 407         /* libiscsi setup itts, data and pool so just set desc fields */
 408         for (i = 0; i < session->cmds_max; i++) {
 409                 ctask      = session->cmds[i];
 410                 iser_ctask = ctask->dd_data;
 411                 ctask->hdr = (struct iscsi_cmd *)&iser_ctask->desc.iscsi_header;
 412         }
 413
 414         for (i = 0; i < session->mgmtpool_max; i++) {
 415                 mtask      = session->mgmt_cmds[i];
 416                 desc       = mtask->dd_data;
 417                 mtask->hdr = &desc->iscsi_header;
 418                 desc->data = mtask->data;
 419         }
 420
 421         return cls_session;
 422 }
 423
 424 static int
 425 iscsi_iser_set_param(struct iscsi_cls_conn *cls_conn,
 426                      enum iscsi_param param, char *buf, int buflen)
 427 {
 428         int value;
 429
 430         switch (param) {
 431         case ISCSI_PARAM_MAX_RECV_DLENGTH:
 432                 /* TBD */
 433                 break;
 434         case ISCSI_PARAM_HDRDGST_EN:
 435                 sscanf(buf, "%d", &value);
 436                 if (value) {
 437                         printk(KERN_ERR "DataDigest wasn't negotiated to None");
 438                         return -EPROTO;
 439                 }
 440                 break;
 441         case ISCSI_PARAM_DATADGST_EN:
 442                 sscanf(buf, "%d", &value);
 443                 if (value) {
 444                         printk(KERN_ERR "DataDigest wasn't negotiated to None");
 445                         return -EPROTO;
 446                 }
 447                 break;
 448         case ISCSI_PARAM_IFMARKER_EN:
 449                 sscanf(buf, "%d", &value);
 450                 if (value) {
 451                         printk(KERN_ERR "IFMarker wasn't negotiated to No");
 452                         return -EPROTO;
 453                 }
 454                 break;
 455         case ISCSI_PARAM_OFMARKER_EN:
 456                 sscanf(buf, "%d", &value);
 457                 if (value) {
 458                         printk(KERN_ERR "OFMarker wasn't negotiated to No");
 459                         return -EPROTO;
 460                 }
 461                 break;
 462         default:
 463                 return iscsi_set_param(cls_conn, param, buf, buflen);
 464         }
 465
 466         return 0;
 467 }
 468
 469 static void
 470 iscsi_iser_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
 471 {
 472         struct iscsi_conn *conn = cls_conn->dd_data;
 473
 474         stats->txdata_octets = conn->txdata_octets;
 475         stats->rxdata_octets = conn->rxdata_octets;
 476         stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
 477         stats->dataout_pdus = conn->dataout_pdus_cnt;
 478         stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
 479         stats->datain_pdus = conn->datain_pdus_cnt; /* always 0 */
 480         stats->r2t_pdus = conn->r2t_pdus_cnt; /* always 0 */
 481         stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
 482         stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
 483         stats->custom_length = 3;
 484         strcpy(stats->custom[0].desc, "qp_tx_queue_full");
 485         stats->custom[0].value = 0; /* TB iser_conn->qp_tx_queue_full; */
 486         strcpy(stats->custom[1].desc, "fmr_map_not_avail");
 487         stats->custom[1].value = 0; /* TB iser_conn->fmr_map_not_avail */;
 488         strcpy(stats->custom[2].desc, "eh_abort_cnt");
 489         stats->custom[2].value = conn->eh_abort_cnt;
 490 }
 491
 492 static int
 493 iscsi_iser_ep_connect(struct sockaddr *dst_addr, int non_blocking,
 494                       __u64 *ep_handle)
 495 {
 496         int err;
 497         struct iser_conn *ib_conn;
 498
 499         err = iser_conn_init(&ib_conn);
 500         if (err)
 501                 goto out;
 502
 503         err = iser_connect(ib_conn, NULL, (struct sockaddr_in *)dst_addr, non_blocking);
 504         if (!err)
 505                 *ep_handle = (__u64)(unsigned long)ib_conn;
 506
 507 out:
 508         return err;
 509 }
 510
 511 static int
 512 iscsi_iser_ep_poll(__u64 ep_handle, int timeout_ms)
 513 {
 514         struct iser_conn *ib_conn = iscsi_iser_ib_conn_lookup(ep_handle);
 515         int rc;
 516
 517         if (!ib_conn)
 518                 return -EINVAL;
 519
 520         rc = wait_event_interruptible_timeout(ib_conn->wait,
 521                              ib_conn->state == ISER_CONN_UP,
 522                              msecs_to_jiffies(timeout_ms));
 523
 524         /* if conn establishment failed, return error code to iscsi */
 525         if (!rc &&
 526             (ib_conn->state == ISER_CONN_TERMINATING ||
 527              ib_conn->state == ISER_CONN_DOWN))
 528                 rc = -1;
 529
 530         iser_err("ib conn %p rc = %d\n", ib_conn, rc);
 531
 532         if (rc > 0)
 533                 return 1; /* success, this is the equivalent of POLLOUT */
 534         else if (!rc)
 535                 return 0; /* timeout */
 536         else
 537                 return rc; /* signal */
 538 }
 539
 540 static void
 541 iscsi_iser_ep_disconnect(__u64 ep_handle)
 542 {
 543         struct iser_conn *ib_conn;
 544
 545         ib_conn = iscsi_iser_ib_conn_lookup(ep_handle);
 546         if (!ib_conn)
 547                 return;
 548
 549         iser_err("ib conn %p state %d\n",ib_conn, ib_conn->state);
 550         iser_conn_terminate(ib_conn);
 551 }
 552
 553 static struct scsi_host_template iscsi_iser_sht = {
 554         .name                   = "iSCSI Initiator over iSER, v." DRV_VER,
 555         .queuecommand           = iscsi_queuecommand,
 556         .can_queue              = ISCSI_XMIT_CMDS_MAX - 1,
 557         .sg_tablesize           = ISCSI_ISER_SG_TABLESIZE,
 558         .max_sectors            = 1024,
 559         .cmd_per_lun            = ISCSI_MAX_CMD_PER_LUN,
 560         .eh_abort_handler       = iscsi_eh_abort,
 561         .eh_host_reset_handler  = iscsi_eh_host_reset,
 562         .use_clustering         = DISABLE_CLUSTERING,
 563         .proc_name              = "iscsi_iser",
 564         .this_id                = -1,
 565 };
 566
 567 static struct iscsi_transport iscsi_iser_transport = {
 568         .owner                  = THIS_MODULE,
 569         .name                   = "iser",
 570         .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T,
 571         .param_mask             = ISCSI_MAX_RECV_DLENGTH |
 572                                   ISCSI_MAX_XMIT_DLENGTH |
 573                                   ISCSI_HDRDGST_EN |
 574                                   ISCSI_DATADGST_EN |
 575                                   ISCSI_INITIAL_R2T_EN |
 576                                   ISCSI_MAX_R2T |
 577                                   ISCSI_IMM_DATA_EN |
 578                                   ISCSI_FIRST_BURST |
 579                                   ISCSI_MAX_BURST |
 580                                   ISCSI_PDU_INORDER_EN |
 581                                   ISCSI_DATASEQ_INORDER_EN |
 582                                   ISCSI_EXP_STATSN |
 583                                   ISCSI_PERSISTENT_PORT |
 584                                   ISCSI_PERSISTENT_ADDRESS |
 585                                   ISCSI_TARGET_NAME |
 586                                   ISCSI_TPGT,
 587         .host_template          = &iscsi_iser_sht,
 588         .conndata_size          = sizeof(struct iscsi_conn),
 589         .max_lun                = ISCSI_ISER_MAX_LUN,
 590         .max_cmd_len            = ISCSI_ISER_MAX_CMD_LEN,
 591         /* session management */
 592         .create_session         = iscsi_iser_session_create,
 593         .destroy_session        = iscsi_session_teardown,
 594         /* connection management */
 595         .create_conn            = iscsi_iser_conn_create,
 596         .bind_conn              = iscsi_iser_conn_bind,
 597         .destroy_conn           = iscsi_iser_conn_destroy,
 598         .set_param              = iscsi_iser_set_param,
 599         .get_conn_param         = iscsi_conn_get_param,
 600         .get_session_param      = iscsi_session_get_param,
 601         .start_conn             = iscsi_iser_conn_start,
 602         .stop_conn              = iscsi_conn_stop,
 603         /* IO */
 604         .send_pdu               = iscsi_conn_send_pdu,
 605         .get_stats              = iscsi_iser_conn_get_stats,
 606         .init_cmd_task          = iscsi_iser_cmd_init,
 607         .xmit_cmd_task          = iscsi_iser_ctask_xmit,
 608         .xmit_mgmt_task         = iscsi_iser_mtask_xmit,
 609         .cleanup_cmd_task       = iscsi_iser_cleanup_ctask,
 610         /* recovery */
 611         .session_recovery_timedout = iscsi_session_recovery_timedout,
 612
 613         .ep_connect             = iscsi_iser_ep_connect,
 614         .ep_poll                = iscsi_iser_ep_poll,
 615         .ep_disconnect          = iscsi_iser_ep_disconnect
 616 };
 617
 618 static int __init iser_init(void)
 619 {
 620         int err;
 621
 622         iser_dbg("Starting iSER datamover...\n");
 623
 624         if (iscsi_max_lun < 1) {
 625                 printk(KERN_ERR "Invalid max_lun value of %u\n", iscsi_max_lun);
 626                 return -EINVAL;
 627         }
 628
 629         iscsi_iser_transport.max_lun = iscsi_max_lun;
 630
 631         memset(&ig, 0, sizeof(struct iser_global));
 632
 633         ig.desc_cache = kmem_cache_create("iser_descriptors",
 634                                           sizeof (struct iser_desc),
 635                                           0, SLAB_HWCACHE_ALIGN,
 636                                           NULL, NULL);
 637         if (ig.desc_cache == NULL)
 638                 return -ENOMEM;
 639
 640         /* device init is called only after the first addr resolution */
 641         mutex_init(&ig.device_list_mutex);
 642         INIT_LIST_HEAD(&ig.device_list);
 643         mutex_init(&ig.connlist_mutex);
 644         INIT_LIST_HEAD(&ig.connlist);
 645
 646         if (!iscsi_register_transport(&iscsi_iser_transport)) {
 647                 iser_err("iscsi_register_transport failed\n");
 648                 err = -EINVAL;
 649                 goto register_transport_failure;
 650         }
 651
 652         return 0;
 653
 654 register_transport_failure:
 655         kmem_cache_destroy(ig.desc_cache);
 656
 657         return err;
 658 }
 659
 660 static void __exit iser_exit(void)
 661 {
 662         iser_dbg("Removing iSER datamover...\n");
 663         iscsi_unregister_transport(&iscsi_iser_transport);
 664         kmem_cache_destroy(ig.desc_cache);
 665 }
 666
 667 module_init(iser_init);
 668 module_exit(iser_exit);