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 int
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 
138 	iser_ctask->command_sent = 0;
139 	iser_ctask->iser_conn    = iser_conn;
140 	iser_ctask_rdma_init(iser_ctask);
141 	return 0;
142 }
143 
144 /**
145  * iscsi_mtask_xmit - xmit management(immediate) task
146  * @conn: iscsi connection
147  * @mtask: task management task
148  *
149  * Notes:
150  *	The function can return -EAGAIN in which case caller must
151  *	call it again later, or recover. '0' return code means successful
152  *	xmit.
153  *
154  **/
155 static int
156 iscsi_iser_mtask_xmit(struct iscsi_conn *conn,
157 		      struct iscsi_mgmt_task *mtask)
158 {
159 	int error = 0;
160 
161 	debug_scsi("mtask deq [cid %d itt 0x%x]\n", conn->id, mtask->itt);
162 
163 	error = iser_send_control(conn, mtask);
164 
165 	/* since iser xmits control with zero copy, mtasks can not be recycled
166 	 * right after sending them.
167 	 * The recycling scheme is based on whether a response is expected
168 	 * - if yes, the mtask is recycled at iscsi_complete_pdu
169 	 * - if no,  the mtask is recycled at iser_snd_completion
170 	 */
171 	if (error && error != -ENOBUFS)
172 		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
173 
174 	return error;
175 }
176 
177 static int
178 iscsi_iser_ctask_xmit_unsol_data(struct iscsi_conn *conn,
179 				 struct iscsi_cmd_task *ctask)
180 {
181 	struct iscsi_data  hdr;
182 	int error = 0;
183 
184 	/* Send data-out PDUs while there's still unsolicited data to send */
185 	while (ctask->unsol_count > 0) {
186 		iscsi_prep_unsolicit_data_pdu(ctask, &hdr);
187 		debug_scsi("Sending data-out: itt 0x%x, data count %d\n",
188 			   hdr.itt, ctask->data_count);
189 
190 		/* the buffer description has been passed with the command */
191 		/* Send the command */
192 		error = iser_send_data_out(conn, ctask, &hdr);
193 		if (error) {
194 			ctask->unsol_datasn--;
195 			goto iscsi_iser_ctask_xmit_unsol_data_exit;
196 		}
197 		ctask->unsol_count -= ctask->data_count;
198 		debug_scsi("Need to send %d more as data-out PDUs\n",
199 			   ctask->unsol_count);
200 	}
201 
202 iscsi_iser_ctask_xmit_unsol_data_exit:
203 	return error;
204 }
205 
206 static int
207 iscsi_iser_ctask_xmit(struct iscsi_conn *conn,
208 		      struct iscsi_cmd_task *ctask)
209 {
210 	struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
211 	int error = 0;
212 
213 	if (ctask->sc->sc_data_direction == DMA_TO_DEVICE) {
214 		BUG_ON(scsi_bufflen(ctask->sc) == 0);
215 
216 		debug_scsi("cmd [itt %x total %d imm %d unsol_data %d\n",
217 			   ctask->itt, scsi_bufflen(ctask->sc),
218 			   ctask->imm_count, ctask->unsol_count);
219 	}
220 
221 	debug_scsi("ctask deq [cid %d itt 0x%x]\n",
222 		   conn->id, ctask->itt);
223 
224 	/* Send the cmd PDU */
225 	if (!iser_ctask->command_sent) {
226 		error = iser_send_command(conn, ctask);
227 		if (error)
228 			goto iscsi_iser_ctask_xmit_exit;
229 		iser_ctask->command_sent = 1;
230 	}
231 
232 	/* Send unsolicited data-out PDU(s) if necessary */
233 	if (ctask->unsol_count)
234 		error = iscsi_iser_ctask_xmit_unsol_data(conn, ctask);
235 
236  iscsi_iser_ctask_xmit_exit:
237 	if (error && error != -ENOBUFS)
238 		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
239 	return error;
240 }
241 
242 static void
243 iscsi_iser_cleanup_ctask(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
244 {
245 	struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
246 
247 	if (iser_ctask->status == ISER_TASK_STATUS_STARTED) {
248 		iser_ctask->status = ISER_TASK_STATUS_COMPLETED;
249 		iser_ctask_rdma_finalize(iser_ctask);
250 	}
251 }
252 
253 static struct iser_conn *
254 iscsi_iser_ib_conn_lookup(__u64 ep_handle)
255 {
256 	struct iser_conn *ib_conn;
257 	struct iser_conn *uib_conn = (struct iser_conn *)(unsigned long)ep_handle;
258 
259 	mutex_lock(&ig.connlist_mutex);
260 	list_for_each_entry(ib_conn, &ig.connlist, conn_list) {
261 		if (ib_conn == uib_conn) {
262 			mutex_unlock(&ig.connlist_mutex);
263 			return ib_conn;
264 		}
265 	}
266 	mutex_unlock(&ig.connlist_mutex);
267 	iser_err("no conn exists for eph %llx\n",(unsigned long long)ep_handle);
268 	return NULL;
269 }
270 
271 static struct iscsi_cls_conn *
272 iscsi_iser_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
273 {
274 	struct iscsi_conn *conn;
275 	struct iscsi_cls_conn *cls_conn;
276 	struct iscsi_iser_conn *iser_conn;
277 
278 	cls_conn = iscsi_conn_setup(cls_session, conn_idx);
279 	if (!cls_conn)
280 		return NULL;
281 	conn = cls_conn->dd_data;
282 
283 	/*
284 	 * due to issues with the login code re iser sematics
285 	 * this not set in iscsi_conn_setup - FIXME
286 	 */
287 	conn->max_recv_dlength = 128;
288 
289 	iser_conn = kzalloc(sizeof(*iser_conn), GFP_KERNEL);
290 	if (!iser_conn)
291 		goto conn_alloc_fail;
292 
293 	/* currently this is the only field which need to be initiated */
294 	rwlock_init(&iser_conn->lock);
295 
296 	conn->dd_data = iser_conn;
297 	iser_conn->iscsi_conn = conn;
298 
299 	return cls_conn;
300 
301 conn_alloc_fail:
302 	iscsi_conn_teardown(cls_conn);
303 	return NULL;
304 }
305 
306 static void
307 iscsi_iser_conn_destroy(struct iscsi_cls_conn *cls_conn)
308 {
309 	struct iscsi_conn *conn = cls_conn->dd_data;
310 	struct iscsi_iser_conn *iser_conn = conn->dd_data;
311 
312 	iscsi_conn_teardown(cls_conn);
313 	if (iser_conn->ib_conn)
314 		iser_conn->ib_conn->iser_conn = NULL;
315 	kfree(iser_conn);
316 }
317 
318 static int
319 iscsi_iser_conn_bind(struct iscsi_cls_session *cls_session,
320 		     struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
321 		     int is_leading)
322 {
323 	struct iscsi_conn *conn = cls_conn->dd_data;
324 	struct iscsi_iser_conn *iser_conn;
325 	struct iser_conn *ib_conn;
326 	int error;
327 
328 	error = iscsi_conn_bind(cls_session, cls_conn, is_leading);
329 	if (error)
330 		return error;
331 
332 	/* the transport ep handle comes from user space so it must be
333 	 * verified against the global ib connections list */
334 	ib_conn = iscsi_iser_ib_conn_lookup(transport_eph);
335 	if (!ib_conn) {
336 		iser_err("can't bind eph %llx\n",
337 			 (unsigned long long)transport_eph);
338 		return -EINVAL;
339 	}
340 	/* binds the iSER connection retrieved from the previously
341 	 * connected ep_handle to the iSCSI layer connection. exchanges
342 	 * connection pointers */
343 	iser_err("binding iscsi conn %p to iser_conn %p\n",conn,ib_conn);
344 	iser_conn = conn->dd_data;
345 	ib_conn->iser_conn = iser_conn;
346 	iser_conn->ib_conn  = ib_conn;
347 
348 	conn->recv_lock = &iser_conn->lock;
349 
350 	return 0;
351 }
352 
353 static int
354 iscsi_iser_conn_start(struct iscsi_cls_conn *cls_conn)
355 {
356 	struct iscsi_conn *conn = cls_conn->dd_data;
357 	int err;
358 
359 	err = iser_conn_set_full_featured_mode(conn);
360 	if (err)
361 		return err;
362 
363 	return iscsi_conn_start(cls_conn);
364 }
365 
366 static struct iscsi_transport iscsi_iser_transport;
367 
368 static struct iscsi_cls_session *
369 iscsi_iser_session_create(struct iscsi_transport *iscsit,
370 			 struct scsi_transport_template *scsit,
371 			 uint16_t cmds_max, uint16_t qdepth,
372 			 uint32_t initial_cmdsn, uint32_t *hostno)
373 {
374 	struct iscsi_cls_session *cls_session;
375 	struct iscsi_session *session;
376 	int i;
377 	uint32_t hn;
378 	struct iscsi_cmd_task  *ctask;
379 	struct iscsi_mgmt_task *mtask;
380 	struct iscsi_iser_cmd_task *iser_ctask;
381 	struct iser_desc *desc;
382 
383 	/*
384 	 * we do not support setting can_queue cmd_per_lun from userspace yet
385 	 * because we preallocate so many resources
386 	 */
387 	cls_session = iscsi_session_setup(iscsit, scsit,
388 					  ISCSI_DEF_XMIT_CMDS_MAX,
389 					  ISCSI_MAX_CMD_PER_LUN,
390 					  sizeof(struct iscsi_iser_cmd_task),
391 					  sizeof(struct iser_desc),
392 					  initial_cmdsn, &hn);
393 	if (!cls_session)
394 	return NULL;
395 
396 	*hostno = hn;
397 	session = class_to_transport_session(cls_session);
398 
399 	/* libiscsi setup itts, data and pool so just set desc fields */
400 	for (i = 0; i < session->cmds_max; i++) {
401 		ctask      = session->cmds[i];
402 		iser_ctask = ctask->dd_data;
403 		ctask->hdr = (struct iscsi_cmd *)&iser_ctask->desc.iscsi_header;
404 		ctask->hdr_max = sizeof(iser_ctask->desc.iscsi_header);
405 	}
406 
407 	for (i = 0; i < session->mgmtpool_max; i++) {
408 		mtask      = session->mgmt_cmds[i];
409 		desc       = mtask->dd_data;
410 		mtask->hdr = &desc->iscsi_header;
411 		desc->data = mtask->data;
412 	}
413 
414 	return cls_session;
415 }
416 
417 static int
418 iscsi_iser_set_param(struct iscsi_cls_conn *cls_conn,
419 		     enum iscsi_param param, char *buf, int buflen)
420 {
421 	int value;
422 
423 	switch (param) {
424 	case ISCSI_PARAM_MAX_RECV_DLENGTH:
425 		/* TBD */
426 		break;
427 	case ISCSI_PARAM_HDRDGST_EN:
428 		sscanf(buf, "%d", &value);
429 		if (value) {
430 			printk(KERN_ERR "DataDigest wasn't negotiated to None");
431 			return -EPROTO;
432 		}
433 		break;
434 	case ISCSI_PARAM_DATADGST_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_IFMARKER_EN:
442 		sscanf(buf, "%d", &value);
443 		if (value) {
444 			printk(KERN_ERR "IFMarker wasn't negotiated to No");
445 			return -EPROTO;
446 		}
447 		break;
448 	case ISCSI_PARAM_OFMARKER_EN:
449 		sscanf(buf, "%d", &value);
450 		if (value) {
451 			printk(KERN_ERR "OFMarker wasn't negotiated to No");
452 			return -EPROTO;
453 		}
454 		break;
455 	default:
456 		return iscsi_set_param(cls_conn, param, buf, buflen);
457 	}
458 
459 	return 0;
460 }
461 
462 static void
463 iscsi_iser_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
464 {
465 	struct iscsi_conn *conn = cls_conn->dd_data;
466 
467 	stats->txdata_octets = conn->txdata_octets;
468 	stats->rxdata_octets = conn->rxdata_octets;
469 	stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
470 	stats->dataout_pdus = conn->dataout_pdus_cnt;
471 	stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
472 	stats->datain_pdus = conn->datain_pdus_cnt; /* always 0 */
473 	stats->r2t_pdus = conn->r2t_pdus_cnt; /* always 0 */
474 	stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
475 	stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
476 	stats->custom_length = 3;
477 	strcpy(stats->custom[0].desc, "qp_tx_queue_full");
478 	stats->custom[0].value = 0; /* TB iser_conn->qp_tx_queue_full; */
479 	strcpy(stats->custom[1].desc, "fmr_map_not_avail");
480 	stats->custom[1].value = 0; /* TB iser_conn->fmr_map_not_avail */;
481 	strcpy(stats->custom[2].desc, "eh_abort_cnt");
482 	stats->custom[2].value = conn->eh_abort_cnt;
483 }
484 
485 static int
486 iscsi_iser_ep_connect(struct sockaddr *dst_addr, int non_blocking,
487 		      __u64 *ep_handle)
488 {
489 	int err;
490 	struct iser_conn *ib_conn;
491 
492 	err = iser_conn_init(&ib_conn);
493 	if (err)
494 		goto out;
495 
496 	err = iser_connect(ib_conn, NULL, (struct sockaddr_in *)dst_addr, non_blocking);
497 	if (!err)
498 		*ep_handle = (__u64)(unsigned long)ib_conn;
499 
500 out:
501 	return err;
502 }
503 
504 static int
505 iscsi_iser_ep_poll(__u64 ep_handle, int timeout_ms)
506 {
507 	struct iser_conn *ib_conn = iscsi_iser_ib_conn_lookup(ep_handle);
508 	int rc;
509 
510 	if (!ib_conn)
511 		return -EINVAL;
512 
513 	rc = wait_event_interruptible_timeout(ib_conn->wait,
514 			     ib_conn->state == ISER_CONN_UP,
515 			     msecs_to_jiffies(timeout_ms));
516 
517 	/* if conn establishment failed, return error code to iscsi */
518 	if (!rc &&
519 	    (ib_conn->state == ISER_CONN_TERMINATING ||
520 	     ib_conn->state == ISER_CONN_DOWN))
521 		rc = -1;
522 
523 	iser_err("ib conn %p rc = %d\n", ib_conn, rc);
524 
525 	if (rc > 0)
526 		return 1; /* success, this is the equivalent of POLLOUT */
527 	else if (!rc)
528 		return 0; /* timeout */
529 	else
530 		return rc; /* signal */
531 }
532 
533 static void
534 iscsi_iser_ep_disconnect(__u64 ep_handle)
535 {
536 	struct iser_conn *ib_conn;
537 
538 	ib_conn = iscsi_iser_ib_conn_lookup(ep_handle);
539 	if (!ib_conn)
540 		return;
541 
542 	iser_err("ib conn %p state %d\n",ib_conn, ib_conn->state);
543 	iser_conn_terminate(ib_conn);
544 }
545 
546 static struct scsi_host_template iscsi_iser_sht = {
547 	.module                 = THIS_MODULE,
548 	.name                   = "iSCSI Initiator over iSER, v." DRV_VER,
549 	.queuecommand           = iscsi_queuecommand,
550 	.change_queue_depth	= iscsi_change_queue_depth,
551 	.can_queue		= ISCSI_DEF_XMIT_CMDS_MAX - 1,
552 	.sg_tablesize           = ISCSI_ISER_SG_TABLESIZE,
553 	.max_sectors		= 1024,
554 	.cmd_per_lun            = ISCSI_MAX_CMD_PER_LUN,
555 	.eh_abort_handler       = iscsi_eh_abort,
556 	.eh_device_reset_handler= iscsi_eh_device_reset,
557 	.eh_host_reset_handler	= iscsi_eh_host_reset,
558 	.use_clustering         = DISABLE_CLUSTERING,
559 	.proc_name              = "iscsi_iser",
560 	.this_id                = -1,
561 };
562 
563 static struct iscsi_transport iscsi_iser_transport = {
564 	.owner                  = THIS_MODULE,
565 	.name                   = "iser",
566 	.caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T,
567 	.param_mask		= ISCSI_MAX_RECV_DLENGTH |
568 				  ISCSI_MAX_XMIT_DLENGTH |
569 				  ISCSI_HDRDGST_EN |
570 				  ISCSI_DATADGST_EN |
571 				  ISCSI_INITIAL_R2T_EN |
572 				  ISCSI_MAX_R2T |
573 				  ISCSI_IMM_DATA_EN |
574 				  ISCSI_FIRST_BURST |
575 				  ISCSI_MAX_BURST |
576 				  ISCSI_PDU_INORDER_EN |
577 				  ISCSI_DATASEQ_INORDER_EN |
578 				  ISCSI_EXP_STATSN |
579 				  ISCSI_PERSISTENT_PORT |
580 				  ISCSI_PERSISTENT_ADDRESS |
581 				  ISCSI_TARGET_NAME | ISCSI_TPGT |
582 				  ISCSI_USERNAME | ISCSI_PASSWORD |
583 				  ISCSI_USERNAME_IN | ISCSI_PASSWORD_IN |
584 				  ISCSI_FAST_ABORT | ISCSI_ABORT_TMO |
585 				  ISCSI_PING_TMO | ISCSI_RECV_TMO,
586 	.host_param_mask	= ISCSI_HOST_HWADDRESS |
587 				  ISCSI_HOST_NETDEV_NAME |
588 				  ISCSI_HOST_INITIATOR_NAME,
589 	.host_template          = &iscsi_iser_sht,
590 	.conndata_size		= sizeof(struct iscsi_conn),
591 	.max_lun                = ISCSI_ISER_MAX_LUN,
592 	.max_cmd_len            = ISCSI_ISER_MAX_CMD_LEN,
593 	/* session management */
594 	.create_session         = iscsi_iser_session_create,
595 	.destroy_session        = iscsi_session_teardown,
596 	/* connection management */
597 	.create_conn            = iscsi_iser_conn_create,
598 	.bind_conn              = iscsi_iser_conn_bind,
599 	.destroy_conn           = iscsi_iser_conn_destroy,
600 	.set_param              = iscsi_iser_set_param,
601 	.get_conn_param		= iscsi_conn_get_param,
602 	.get_session_param	= iscsi_session_get_param,
603 	.start_conn             = iscsi_iser_conn_start,
604 	.stop_conn              = iscsi_conn_stop,
605 	/* iscsi host params */
606 	.get_host_param		= iscsi_host_get_param,
607 	.set_host_param		= iscsi_host_set_param,
608 	/* IO */
609 	.send_pdu		= iscsi_conn_send_pdu,
610 	.get_stats		= iscsi_iser_conn_get_stats,
611 	.init_cmd_task		= iscsi_iser_cmd_init,
612 	.xmit_cmd_task		= iscsi_iser_ctask_xmit,
613 	.xmit_mgmt_task		= iscsi_iser_mtask_xmit,
614 	.cleanup_cmd_task	= iscsi_iser_cleanup_ctask,
615 	/* recovery */
616 	.session_recovery_timedout = iscsi_session_recovery_timedout,
617 
618 	.ep_connect             = iscsi_iser_ep_connect,
619 	.ep_poll                = iscsi_iser_ep_poll,
620 	.ep_disconnect          = iscsi_iser_ep_disconnect
621 };
622 
623 static int __init iser_init(void)
624 {
625 	int err;
626 
627 	iser_dbg("Starting iSER datamover...\n");
628 
629 	if (iscsi_max_lun < 1) {
630 		printk(KERN_ERR "Invalid max_lun value of %u\n", iscsi_max_lun);
631 		return -EINVAL;
632 	}
633 
634 	iscsi_iser_transport.max_lun = iscsi_max_lun;
635 
636 	memset(&ig, 0, sizeof(struct iser_global));
637 
638 	ig.desc_cache = kmem_cache_create("iser_descriptors",
639 					  sizeof (struct iser_desc),
640 					  0, SLAB_HWCACHE_ALIGN,
641 					  NULL);
642 	if (ig.desc_cache == NULL)
643 		return -ENOMEM;
644 
645 	/* device init is called only after the first addr resolution */
646 	mutex_init(&ig.device_list_mutex);
647 	INIT_LIST_HEAD(&ig.device_list);
648 	mutex_init(&ig.connlist_mutex);
649 	INIT_LIST_HEAD(&ig.connlist);
650 
651 	if (!iscsi_register_transport(&iscsi_iser_transport)) {
652 		iser_err("iscsi_register_transport failed\n");
653 		err = -EINVAL;
654 		goto register_transport_failure;
655 	}
656 
657 	return 0;
658 
659 register_transport_failure:
660 	kmem_cache_destroy(ig.desc_cache);
661 
662 	return err;
663 }
664 
665 static void __exit iser_exit(void)
666 {
667 	iser_dbg("Removing iSER datamover...\n");
668 	iscsi_unregister_transport(&iscsi_iser_transport);
669 	kmem_cache_destroy(ig.desc_cache);
670 }
671 
672 module_init(iser_init);
673 module_exit(iser_exit);
674