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
 145                 debug_scsi("cmd [itt %x total %d imm %d unsol_data %d\n",
 146                            ctask->itt, ctask->total_length, ctask->imm_count,
 147                            ctask->unsol_count);
 148         }
 149
 150         iser_ctask_rdma_init(iser_ctask);
 151 }
 152
 153 /**
 154  * iscsi_mtask_xmit - xmit management(immediate) task
 155  * @conn: iscsi connection
 156  * @mtask: task management task
 157  *
 158  * Notes:
 159  *      The function can return -EAGAIN in which case caller must
 160  *      call it again later, or recover. '0' return code means successful
 161  *      xmit.
 162  *
 163  **/
 164 static int
 165 iscsi_iser_mtask_xmit(struct iscsi_conn *conn,
 166                       struct iscsi_mgmt_task *mtask)
 167 {
 168         int error = 0;
 169
 170         debug_scsi("mtask deq [cid %d itt 0x%x]\n", conn->id, mtask->itt);
 171
 172         error = iser_send_control(conn, mtask);
 173
 174         /* since iser xmits control with zero copy, mtasks can not be recycled
 175          * right after sending them.
 176          * The recycling scheme is based on whether a response is expected
 177          * - if yes, the mtask is recycled at iscsi_complete_pdu
 178          * - if no,  the mtask is recycled at iser_snd_completion
 179          */
 180         if (error && error != -EAGAIN)
 181                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 182
 183         return error;
 184 }
 185
 186 static int
 187 iscsi_iser_ctask_xmit_unsol_data(struct iscsi_conn *conn,
 188                                  struct iscsi_cmd_task *ctask)
 189 {
 190         struct iscsi_data  hdr;
 191         int error = 0;
 192
 193         /* Send data-out PDUs while there's still unsolicited data to send */
 194         while (ctask->unsol_count > 0) {
 195                 iscsi_prep_unsolicit_data_pdu(ctask, &hdr);
 196                 debug_scsi("Sending data-out: itt 0x%x, data count %d\n",
 197                            hdr.itt, ctask->data_count);
 198
 199                 /* the buffer description has been passed with the command */
 200                 /* Send the command */
 201                 error = iser_send_data_out(conn, ctask, &hdr);
 202                 if (error) {
 203                         ctask->unsol_datasn--;
 204                         goto iscsi_iser_ctask_xmit_unsol_data_exit;
 205                 }
 206                 ctask->unsol_count -= ctask->data_count;
 207                 debug_scsi("Need to send %d more as data-out PDUs\n",
 208                            ctask->unsol_count);
 209         }
 210
 211 iscsi_iser_ctask_xmit_unsol_data_exit:
 212         return error;
 213 }
 214
 215 static int
 216 iscsi_iser_ctask_xmit(struct iscsi_conn *conn,
 217                       struct iscsi_cmd_task *ctask)
 218 {
 219         struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
 220         int error = 0;
 221
 222         debug_scsi("ctask deq [cid %d itt 0x%x]\n",
 223                    conn->id, ctask->itt);
 224
 225         /*
 226          * serialize with TMF AbortTask
 227          */
 228         if (ctask->mtask)
 229                 return error;
 230
 231         /* Send the cmd PDU */
 232         if (!iser_ctask->command_sent) {
 233                 error = iser_send_command(conn, ctask);
 234                 if (error)
 235                         goto iscsi_iser_ctask_xmit_exit;
 236                 iser_ctask->command_sent = 1;
 237         }
 238
 239         /* Send unsolicited data-out PDU(s) if necessary */
 240         if (ctask->unsol_count)
 241                 error = iscsi_iser_ctask_xmit_unsol_data(conn, ctask);
 242
 243  iscsi_iser_ctask_xmit_exit:
 244         if (error && error != -EAGAIN)
 245                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 246         return error;
 247 }
 248
 249 static void
 250 iscsi_iser_cleanup_ctask(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 251 {
 252         struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
 253
 254         if (iser_ctask->status == ISER_TASK_STATUS_STARTED) {
 255                 iser_ctask->status = ISER_TASK_STATUS_COMPLETED;
 256                 iser_ctask_rdma_finalize(iser_ctask);
 257         }
 258 }
 259
 260 static struct iser_conn *
 261 iscsi_iser_ib_conn_lookup(__u64 ep_handle)
 262 {
 263         struct iser_conn *ib_conn;
 264         struct iser_conn *uib_conn = (struct iser_conn *)(unsigned long)ep_handle;
 265
 266         mutex_lock(&ig.connlist_mutex);
 267         list_for_each_entry(ib_conn, &ig.connlist, conn_list) {
 268                 if (ib_conn == uib_conn) {
 269                         mutex_unlock(&ig.connlist_mutex);
 270                         return ib_conn;
 271                 }
 272         }
 273         mutex_unlock(&ig.connlist_mutex);
 274         iser_err("no conn exists for eph %llx\n",(unsigned long long)ep_handle);
 275         return NULL;
 276 }
 277
 278 static struct iscsi_cls_conn *
 279 iscsi_iser_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
 280 {
 281         struct iscsi_conn *conn;
 282         struct iscsi_cls_conn *cls_conn;
 283         struct iscsi_iser_conn *iser_conn;
 284
 285         cls_conn = iscsi_conn_setup(cls_session, conn_idx);
 286         if (!cls_conn)
 287                 return NULL;
 288         conn = cls_conn->dd_data;
 289
 290         /*
 291          * due to issues with the login code re iser sematics
 292          * this not set in iscsi_conn_setup - FIXME
 293          */
 294         conn->max_recv_dlength = 128;
 295
 296         iser_conn = kzalloc(sizeof(*iser_conn), GFP_KERNEL);
 297         if (!iser_conn)
 298                 goto conn_alloc_fail;
 299
 300         /* currently this is the only field which need to be initiated */
 301         rwlock_init(&iser_conn->lock);
 302
 303         conn->dd_data = iser_conn;
 304         iser_conn->iscsi_conn = conn;
 305
 306         return cls_conn;
 307
 308 conn_alloc_fail:
 309         iscsi_conn_teardown(cls_conn);
 310         return NULL;
 311 }
 312
 313 static void
 314 iscsi_iser_conn_destroy(struct iscsi_cls_conn *cls_conn)
 315 {
 316         struct iscsi_conn *conn = cls_conn->dd_data;
 317         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 318
 319         iscsi_conn_teardown(cls_conn);
 320         kfree(iser_conn);
 321 }
 322
 323 static int
 324 iscsi_iser_conn_bind(struct iscsi_cls_session *cls_session,
 325                      struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
 326                      int is_leading)
 327 {
 328         struct iscsi_conn *conn = cls_conn->dd_data;
 329         struct iscsi_iser_conn *iser_conn;
 330         struct iser_conn *ib_conn;
 331         int error;
 332
 333         error = iscsi_conn_bind(cls_session, cls_conn, is_leading);
 334         if (error)
 335                 return error;
 336
 337         /* the transport ep handle comes from user space so it must be
 338          * verified against the global ib connections list */
 339         ib_conn = iscsi_iser_ib_conn_lookup(transport_eph);
 340         if (!ib_conn) {
 341                 iser_err("can't bind eph %llx\n",
 342                          (unsigned long long)transport_eph);
 343                 return -EINVAL;
 344         }
 345         /* binds the iSER connection retrieved from the previously
 346          * connected ep_handle to the iSCSI layer connection. exchanges
 347          * connection pointers */
 348         iser_err("binding iscsi conn %p to iser_conn %p\n",conn,ib_conn);
 349         iser_conn = conn->dd_data;
 350         ib_conn->iser_conn = iser_conn;
 351         iser_conn->ib_conn  = ib_conn;
 352
 353         conn->recv_lock = &iser_conn->lock;
 354
 355         return 0;
 356 }
 357
 358 static int
 359 iscsi_iser_conn_start(struct iscsi_cls_conn *cls_conn)
 360 {
 361         struct iscsi_conn *conn = cls_conn->dd_data;
 362         int err;
 363
 364         err = iscsi_conn_start(cls_conn);
 365         if (err)
 366                 return err;
 367
 368         return iser_conn_set_full_featured_mode(conn);
 369 }
 370
 371 static struct iscsi_transport iscsi_iser_transport;
 372
 373 static struct iscsi_cls_session *
 374 iscsi_iser_session_create(struct iscsi_transport *iscsit,
 375                          struct scsi_transport_template *scsit,
 376                           uint32_t initial_cmdsn, uint32_t *hostno)
 377 {
 378         struct iscsi_cls_session *cls_session;
 379         struct iscsi_session *session;
 380         int i;
 381         uint32_t hn;
 382         struct iscsi_cmd_task  *ctask;
 383         struct iscsi_mgmt_task *mtask;
 384         struct iscsi_iser_cmd_task *iser_ctask;
 385         struct iser_desc *desc;
 386
 387         cls_session = iscsi_session_setup(iscsit, scsit,
 388                                           sizeof(struct iscsi_iser_cmd_task),
 389                                           sizeof(struct iser_desc),
 390                                           initial_cmdsn, &hn);
 391         if (!cls_session)
 392         return NULL;
 393
 394         *hostno = hn;
 395         session = class_to_transport_session(cls_session);
 396
 397         /* libiscsi setup itts, data and pool so just set desc fields */
 398         for (i = 0; i < session->cmds_max; i++) {
 399                 ctask      = session->cmds[i];
 400                 iser_ctask = ctask->dd_data;
 401                 ctask->hdr = (struct iscsi_cmd *)&iser_ctask->desc.iscsi_header;
 402         }
 403
 404         for (i = 0; i < session->mgmtpool_max; i++) {
 405                 mtask      = session->mgmt_cmds[i];
 406                 desc       = mtask->dd_data;
 407                 mtask->hdr = &desc->iscsi_header;
 408                 desc->data = mtask->data;
 409         }
 410
 411         return cls_session;
 412 }
 413
 414 static int
 415 iscsi_iser_set_param(struct iscsi_cls_conn *cls_conn,
 416                      enum iscsi_param param, char *buf, int buflen)
 417 {
 418         int value;
 419
 420         switch (param) {
 421         case ISCSI_PARAM_MAX_RECV_DLENGTH:
 422                 /* TBD */
 423                 break;
 424         case ISCSI_PARAM_HDRDGST_EN:
 425                 sscanf(buf, "%d", &value);
 426                 if (value) {
 427                         printk(KERN_ERR "DataDigest wasn't negotiated to None");
 428                         return -EPROTO;
 429                 }
 430                 break;
 431         case ISCSI_PARAM_DATADGST_EN:
 432                 sscanf(buf, "%d", &value);
 433                 if (value) {
 434                         printk(KERN_ERR "DataDigest wasn't negotiated to None");
 435                         return -EPROTO;
 436                 }
 437                 break;
 438         case ISCSI_PARAM_IFMARKER_EN:
 439                 sscanf(buf, "%d", &value);
 440                 if (value) {
 441                         printk(KERN_ERR "IFMarker wasn't negotiated to No");
 442                         return -EPROTO;
 443                 }
 444                 break;
 445         case ISCSI_PARAM_OFMARKER_EN:
 446                 sscanf(buf, "%d", &value);
 447                 if (value) {
 448                         printk(KERN_ERR "OFMarker wasn't negotiated to No");
 449                         return -EPROTO;
 450                 }
 451                 break;
 452         default:
 453                 return iscsi_set_param(cls_conn, param, buf, buflen);
 454         }
 455
 456         return 0;
 457 }
 458
 459 static void
 460 iscsi_iser_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
 461 {
 462         struct iscsi_conn *conn = cls_conn->dd_data;
 463
 464         stats->txdata_octets = conn->txdata_octets;
 465         stats->rxdata_octets = conn->rxdata_octets;
 466         stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
 467         stats->dataout_pdus = conn->dataout_pdus_cnt;
 468         stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
 469         stats->datain_pdus = conn->datain_pdus_cnt; /* always 0 */
 470         stats->r2t_pdus = conn->r2t_pdus_cnt; /* always 0 */
 471         stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
 472         stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
 473         stats->custom_length = 3;
 474         strcpy(stats->custom[0].desc, "qp_tx_queue_full");
 475         stats->custom[0].value = 0; /* TB iser_conn->qp_tx_queue_full; */
 476         strcpy(stats->custom[1].desc, "fmr_map_not_avail");
 477         stats->custom[1].value = 0; /* TB iser_conn->fmr_map_not_avail */;
 478         strcpy(stats->custom[2].desc, "eh_abort_cnt");
 479         stats->custom[2].value = conn->eh_abort_cnt;
 480 }
 481
 482 static int
 483 iscsi_iser_ep_connect(struct sockaddr *dst_addr, int non_blocking,
 484                       __u64 *ep_handle)
 485 {
 486         int err;
 487         struct iser_conn *ib_conn;
 488
 489         err = iser_conn_init(&ib_conn);
 490         if (err)
 491                 goto out;
 492
 493         err = iser_connect(ib_conn, NULL, (struct sockaddr_in *)dst_addr, non_blocking);
 494         if (!err)
 495                 *ep_handle = (__u64)(unsigned long)ib_conn;
 496
 497 out:
 498         return err;
 499 }
 500
 501 static int
 502 iscsi_iser_ep_poll(__u64 ep_handle, int timeout_ms)
 503 {
 504         struct iser_conn *ib_conn = iscsi_iser_ib_conn_lookup(ep_handle);
 505         int rc;
 506
 507         if (!ib_conn)
 508                 return -EINVAL;
 509
 510         rc = wait_event_interruptible_timeout(ib_conn->wait,
 511                              ib_conn->state == ISER_CONN_UP,
 512                              msecs_to_jiffies(timeout_ms));
 513
 514         /* if conn establishment failed, return error code to iscsi */
 515         if (!rc &&
 516             (ib_conn->state == ISER_CONN_TERMINATING ||
 517              ib_conn->state == ISER_CONN_DOWN))
 518                 rc = -1;
 519
 520         iser_err("ib conn %p rc = %d\n", ib_conn, rc);
 521
 522         if (rc > 0)
 523                 return 1; /* success, this is the equivalent of POLLOUT */
 524         else if (!rc)
 525                 return 0; /* timeout */
 526         else
 527                 return rc; /* signal */
 528 }
 529
 530 static void
 531 iscsi_iser_ep_disconnect(__u64 ep_handle)
 532 {
 533         struct iser_conn *ib_conn;
 534
 535         ib_conn = iscsi_iser_ib_conn_lookup(ep_handle);
 536         if (!ib_conn)
 537                 return;
 538
 539         iser_err("ib conn %p state %d\n",ib_conn, ib_conn->state);
 540         iser_conn_terminate(ib_conn);
 541 }
 542
 543 static struct scsi_host_template iscsi_iser_sht = {
 544         .name                   = "iSCSI Initiator over iSER, v." DRV_VER,
 545         .queuecommand           = iscsi_queuecommand,
 546         .can_queue              = ISCSI_XMIT_CMDS_MAX - 1,
 547         .sg_tablesize           = ISCSI_ISER_SG_TABLESIZE,
 548         .max_sectors            = 1024,
 549         .cmd_per_lun            = ISCSI_MAX_CMD_PER_LUN,
 550         .eh_abort_handler       = iscsi_eh_abort,
 551         .eh_host_reset_handler  = iscsi_eh_host_reset,
 552         .use_clustering         = DISABLE_CLUSTERING,
 553         .proc_name              = "iscsi_iser",
 554         .this_id                = -1,
 555 };
 556
 557 static struct iscsi_transport iscsi_iser_transport = {
 558         .owner                  = THIS_MODULE,
 559         .name                   = "iser",
 560         .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T,
 561         .param_mask             = ISCSI_MAX_RECV_DLENGTH |
 562                                   ISCSI_MAX_XMIT_DLENGTH |
 563                                   ISCSI_HDRDGST_EN |
 564                                   ISCSI_DATADGST_EN |
 565                                   ISCSI_INITIAL_R2T_EN |
 566                                   ISCSI_MAX_R2T |
 567                                   ISCSI_IMM_DATA_EN |
 568                                   ISCSI_FIRST_BURST |
 569                                   ISCSI_MAX_BURST |
 570                                   ISCSI_PDU_INORDER_EN |
 571                                   ISCSI_DATASEQ_INORDER_EN |
 572                                   ISCSI_EXP_STATSN |
 573                                   ISCSI_PERSISTENT_PORT |
 574                                   ISCSI_PERSISTENT_ADDRESS |
 575                                   ISCSI_TARGET_NAME |
 576                                   ISCSI_TPGT,
 577         .host_template          = &iscsi_iser_sht,
 578         .conndata_size          = sizeof(struct iscsi_conn),
 579         .max_lun                = ISCSI_ISER_MAX_LUN,
 580         .max_cmd_len            = ISCSI_ISER_MAX_CMD_LEN,
 581         /* session management */
 582         .create_session         = iscsi_iser_session_create,
 583         .destroy_session        = iscsi_session_teardown,
 584         /* connection management */
 585         .create_conn            = iscsi_iser_conn_create,
 586         .bind_conn              = iscsi_iser_conn_bind,
 587         .destroy_conn           = iscsi_iser_conn_destroy,
 588         .set_param              = iscsi_iser_set_param,
 589         .get_conn_param         = iscsi_conn_get_param,
 590         .get_session_param      = iscsi_session_get_param,
 591         .start_conn             = iscsi_iser_conn_start,
 592         .stop_conn              = iscsi_conn_stop,
 593         /* IO */
 594         .send_pdu               = iscsi_conn_send_pdu,
 595         .get_stats              = iscsi_iser_conn_get_stats,
 596         .init_cmd_task          = iscsi_iser_cmd_init,
 597         .xmit_cmd_task          = iscsi_iser_ctask_xmit,
 598         .xmit_mgmt_task         = iscsi_iser_mtask_xmit,
 599         .cleanup_cmd_task       = iscsi_iser_cleanup_ctask,
 600         /* recovery */
 601         .session_recovery_timedout = iscsi_session_recovery_timedout,
 602
 603         .ep_connect             = iscsi_iser_ep_connect,
 604         .ep_poll                = iscsi_iser_ep_poll,
 605         .ep_disconnect          = iscsi_iser_ep_disconnect
 606 };
 607
 608 static int __init iser_init(void)
 609 {
 610         int err;
 611
 612         iser_dbg("Starting iSER datamover...\n");
 613
 614         if (iscsi_max_lun < 1) {
 615                 printk(KERN_ERR "Invalid max_lun value of %u\n", iscsi_max_lun);
 616                 return -EINVAL;
 617         }
 618
 619         iscsi_iser_transport.max_lun = iscsi_max_lun;
 620
 621         memset(&ig, 0, sizeof(struct iser_global));
 622
 623         ig.desc_cache = kmem_cache_create("iser_descriptors",
 624                                           sizeof (struct iser_desc),
 625                                           0, SLAB_HWCACHE_ALIGN,
 626                                           NULL, NULL);
 627         if (ig.desc_cache == NULL)
 628                 return -ENOMEM;
 629
 630         /* device init is called only after the first addr resolution */
 631         mutex_init(&ig.device_list_mutex);
 632         INIT_LIST_HEAD(&ig.device_list);
 633         mutex_init(&ig.connlist_mutex);
 634         INIT_LIST_HEAD(&ig.connlist);
 635
 636         if (!iscsi_register_transport(&iscsi_iser_transport)) {
 637                 iser_err("iscsi_register_transport failed\n");
 638                 err = -EINVAL;
 639                 goto register_transport_failure;
 640         }
 641
 642         return 0;
 643
 644 register_transport_failure:
 645         kmem_cache_destroy(ig.desc_cache);
 646
 647         return err;
 648 }
 649
 650 static void __exit iser_exit(void)
 651 {
 652         iser_dbg("Removing iSER datamover...\n");
 653         iscsi_unregister_transport(&iscsi_iser_transport);
 654         kmem_cache_destroy(ig.desc_cache);
 655 }
 656
 657 module_init(iser_init);
 658 module_exit(iser_exit);