xref: /openbmc/linux/drivers/scsi/libiscsi.c (revision aac5987a)
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 <linux/log2.h>
28 #include <linux/slab.h>
29 #include <linux/sched/signal.h>
30 #include <linux/module.h>
31 #include <asm/unaligned.h>
32 #include <net/tcp.h>
33 #include <scsi/scsi_cmnd.h>
34 #include <scsi/scsi_device.h>
35 #include <scsi/scsi_eh.h>
36 #include <scsi/scsi_tcq.h>
37 #include <scsi/scsi_host.h>
38 #include <scsi/scsi.h>
39 #include <scsi/iscsi_proto.h>
40 #include <scsi/scsi_transport.h>
41 #include <scsi/scsi_transport_iscsi.h>
42 #include <scsi/libiscsi.h>
43 
44 static int iscsi_dbg_lib_conn;
45 module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
46 		   S_IRUGO | S_IWUSR);
47 MODULE_PARM_DESC(debug_libiscsi_conn,
48 		 "Turn on debugging for connections in libiscsi module. "
49 		 "Set to 1 to turn on, and zero to turn off. Default is off.");
50 
51 static int iscsi_dbg_lib_session;
52 module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
53 		   S_IRUGO | S_IWUSR);
54 MODULE_PARM_DESC(debug_libiscsi_session,
55 		 "Turn on debugging for sessions in libiscsi module. "
56 		 "Set to 1 to turn on, and zero to turn off. Default is off.");
57 
58 static int iscsi_dbg_lib_eh;
59 module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
60 		   S_IRUGO | S_IWUSR);
61 MODULE_PARM_DESC(debug_libiscsi_eh,
62 		 "Turn on debugging for error handling in libiscsi module. "
63 		 "Set to 1 to turn on, and zero to turn off. Default is off.");
64 
65 #define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)			\
66 	do {							\
67 		if (iscsi_dbg_lib_conn)				\
68 			iscsi_conn_printk(KERN_INFO, _conn,	\
69 					     "%s " dbg_fmt,	\
70 					     __func__, ##arg);	\
71 	} while (0);
72 
73 #define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)			\
74 	do {								\
75 		if (iscsi_dbg_lib_session)				\
76 			iscsi_session_printk(KERN_INFO, _session,	\
77 					     "%s " dbg_fmt,		\
78 					     __func__, ##arg);		\
79 	} while (0);
80 
81 #define ISCSI_DBG_EH(_session, dbg_fmt, arg...)				\
82 	do {								\
83 		if (iscsi_dbg_lib_eh)					\
84 			iscsi_session_printk(KERN_INFO, _session,	\
85 					     "%s " dbg_fmt,		\
86 					     __func__, ##arg);		\
87 	} while (0);
88 
89 inline void iscsi_conn_queue_work(struct iscsi_conn *conn)
90 {
91 	struct Scsi_Host *shost = conn->session->host;
92 	struct iscsi_host *ihost = shost_priv(shost);
93 
94 	if (ihost->workq)
95 		queue_work(ihost->workq, &conn->xmitwork);
96 }
97 EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
98 
99 static void __iscsi_update_cmdsn(struct iscsi_session *session,
100 				 uint32_t exp_cmdsn, uint32_t max_cmdsn)
101 {
102 	/*
103 	 * standard specifies this check for when to update expected and
104 	 * max sequence numbers
105 	 */
106 	if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
107 		return;
108 
109 	if (exp_cmdsn != session->exp_cmdsn &&
110 	    !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
111 		session->exp_cmdsn = exp_cmdsn;
112 
113 	if (max_cmdsn != session->max_cmdsn &&
114 	    !iscsi_sna_lt(max_cmdsn, session->max_cmdsn))
115 		session->max_cmdsn = max_cmdsn;
116 }
117 
118 void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
119 {
120 	__iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
121 			     be32_to_cpu(hdr->max_cmdsn));
122 }
123 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
124 
125 /**
126  * iscsi_prep_data_out_pdu - initialize Data-Out
127  * @task: scsi command task
128  * @r2t: R2T info
129  * @hdr: iscsi data in pdu
130  *
131  * Notes:
132  *	Initialize Data-Out within this R2T sequence and finds
133  *	proper data_offset within this SCSI command.
134  *
135  *	This function is called with connection lock taken.
136  **/
137 void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
138 			   struct iscsi_data *hdr)
139 {
140 	struct iscsi_conn *conn = task->conn;
141 	unsigned int left = r2t->data_length - r2t->sent;
142 
143 	task->hdr_len = sizeof(struct iscsi_data);
144 
145 	memset(hdr, 0, sizeof(struct iscsi_data));
146 	hdr->ttt = r2t->ttt;
147 	hdr->datasn = cpu_to_be32(r2t->datasn);
148 	r2t->datasn++;
149 	hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
150 	hdr->lun = task->lun;
151 	hdr->itt = task->hdr_itt;
152 	hdr->exp_statsn = r2t->exp_statsn;
153 	hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
154 	if (left > conn->max_xmit_dlength) {
155 		hton24(hdr->dlength, conn->max_xmit_dlength);
156 		r2t->data_count = conn->max_xmit_dlength;
157 		hdr->flags = 0;
158 	} else {
159 		hton24(hdr->dlength, left);
160 		r2t->data_count = left;
161 		hdr->flags = ISCSI_FLAG_CMD_FINAL;
162 	}
163 	conn->dataout_pdus_cnt++;
164 }
165 EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
166 
167 static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
168 {
169 	unsigned exp_len = task->hdr_len + len;
170 
171 	if (exp_len > task->hdr_max) {
172 		WARN_ON(1);
173 		return -EINVAL;
174 	}
175 
176 	WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
177 	task->hdr_len = exp_len;
178 	return 0;
179 }
180 
181 /*
182  * make an extended cdb AHS
183  */
184 static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
185 {
186 	struct scsi_cmnd *cmd = task->sc;
187 	unsigned rlen, pad_len;
188 	unsigned short ahslength;
189 	struct iscsi_ecdb_ahdr *ecdb_ahdr;
190 	int rc;
191 
192 	ecdb_ahdr = iscsi_next_hdr(task);
193 	rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
194 
195 	BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
196 	ahslength = rlen + sizeof(ecdb_ahdr->reserved);
197 
198 	pad_len = iscsi_padding(rlen);
199 
200 	rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
201 	                   sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
202 	if (rc)
203 		return rc;
204 
205 	if (pad_len)
206 		memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
207 
208 	ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
209 	ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
210 	ecdb_ahdr->reserved = 0;
211 	memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
212 
213 	ISCSI_DBG_SESSION(task->conn->session,
214 			  "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
215 		          "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
216 		          "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
217 		          task->hdr_len);
218 	return 0;
219 }
220 
221 static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
222 {
223 	struct scsi_cmnd *sc = task->sc;
224 	struct iscsi_rlength_ahdr *rlen_ahdr;
225 	int rc;
226 
227 	rlen_ahdr = iscsi_next_hdr(task);
228 	rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
229 	if (rc)
230 		return rc;
231 
232 	rlen_ahdr->ahslength =
233 		cpu_to_be16(sizeof(rlen_ahdr->read_length) +
234 						  sizeof(rlen_ahdr->reserved));
235 	rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
236 	rlen_ahdr->reserved = 0;
237 	rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
238 
239 	ISCSI_DBG_SESSION(task->conn->session,
240 			  "bidi-in rlen_ahdr->read_length(%d) "
241 		          "rlen_ahdr->ahslength(%d)\n",
242 		          be32_to_cpu(rlen_ahdr->read_length),
243 		          be16_to_cpu(rlen_ahdr->ahslength));
244 	return 0;
245 }
246 
247 /**
248  * iscsi_check_tmf_restrictions - check if a task is affected by TMF
249  * @task: iscsi task
250  * @opcode: opcode to check for
251  *
252  * During TMF a task has to be checked if it's affected.
253  * All unrelated I/O can be passed through, but I/O to the
254  * affected LUN should be restricted.
255  * If 'fast_abort' is set we won't be sending any I/O to the
256  * affected LUN.
257  * Otherwise the target is waiting for all TTTs to be completed,
258  * so we have to send all outstanding Data-Out PDUs to the target.
259  */
260 static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
261 {
262 	struct iscsi_conn *conn = task->conn;
263 	struct iscsi_tm *tmf = &conn->tmhdr;
264 	u64 hdr_lun;
265 
266 	if (conn->tmf_state == TMF_INITIAL)
267 		return 0;
268 
269 	if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
270 		return 0;
271 
272 	switch (ISCSI_TM_FUNC_VALUE(tmf)) {
273 	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
274 		/*
275 		 * Allow PDUs for unrelated LUNs
276 		 */
277 		hdr_lun = scsilun_to_int(&tmf->lun);
278 		if (hdr_lun != task->sc->device->lun)
279 			return 0;
280 		/* fall through */
281 	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
282 		/*
283 		 * Fail all SCSI cmd PDUs
284 		 */
285 		if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
286 			iscsi_conn_printk(KERN_INFO, conn,
287 					  "task [op %x/%x itt "
288 					  "0x%x/0x%x] "
289 					  "rejected.\n",
290 					  task->hdr->opcode, opcode,
291 					  task->itt, task->hdr_itt);
292 			return -EACCES;
293 		}
294 		/*
295 		 * And also all data-out PDUs in response to R2T
296 		 * if fast_abort is set.
297 		 */
298 		if (conn->session->fast_abort) {
299 			iscsi_conn_printk(KERN_INFO, conn,
300 					  "task [op %x/%x itt "
301 					  "0x%x/0x%x] fast abort.\n",
302 					  task->hdr->opcode, opcode,
303 					  task->itt, task->hdr_itt);
304 			return -EACCES;
305 		}
306 		break;
307 	case ISCSI_TM_FUNC_ABORT_TASK:
308 		/*
309 		 * the caller has already checked if the task
310 		 * they want to abort was in the pending queue so if
311 		 * we are here the cmd pdu has gone out already, and
312 		 * we will only hit this for data-outs
313 		 */
314 		if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
315 		    task->hdr_itt == tmf->rtt) {
316 			ISCSI_DBG_SESSION(conn->session,
317 					  "Preventing task %x/%x from sending "
318 					  "data-out due to abort task in "
319 					  "progress\n", task->itt,
320 					  task->hdr_itt);
321 			return -EACCES;
322 		}
323 		break;
324 	}
325 
326 	return 0;
327 }
328 
329 /**
330  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
331  * @task: iscsi task
332  *
333  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
334  * fields like dlength or final based on how much data it sends
335  */
336 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
337 {
338 	struct iscsi_conn *conn = task->conn;
339 	struct iscsi_session *session = conn->session;
340 	struct scsi_cmnd *sc = task->sc;
341 	struct iscsi_scsi_req *hdr;
342 	unsigned hdrlength, cmd_len, transfer_length;
343 	itt_t itt;
344 	int rc;
345 
346 	rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
347 	if (rc)
348 		return rc;
349 
350 	if (conn->session->tt->alloc_pdu) {
351 		rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
352 		if (rc)
353 			return rc;
354 	}
355 	hdr = (struct iscsi_scsi_req *)task->hdr;
356 	itt = hdr->itt;
357 	memset(hdr, 0, sizeof(*hdr));
358 
359 	if (session->tt->parse_pdu_itt)
360 		hdr->itt = task->hdr_itt = itt;
361 	else
362 		hdr->itt = task->hdr_itt = build_itt(task->itt,
363 						     task->conn->session->age);
364 	task->hdr_len = 0;
365 	rc = iscsi_add_hdr(task, sizeof(*hdr));
366 	if (rc)
367 		return rc;
368 	hdr->opcode = ISCSI_OP_SCSI_CMD;
369 	hdr->flags = ISCSI_ATTR_SIMPLE;
370 	int_to_scsilun(sc->device->lun, &hdr->lun);
371 	task->lun = hdr->lun;
372 	hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
373 	cmd_len = sc->cmd_len;
374 	if (cmd_len < ISCSI_CDB_SIZE)
375 		memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
376 	else if (cmd_len > ISCSI_CDB_SIZE) {
377 		rc = iscsi_prep_ecdb_ahs(task);
378 		if (rc)
379 			return rc;
380 		cmd_len = ISCSI_CDB_SIZE;
381 	}
382 	memcpy(hdr->cdb, sc->cmnd, cmd_len);
383 
384 	task->imm_count = 0;
385 	if (scsi_bidi_cmnd(sc)) {
386 		hdr->flags |= ISCSI_FLAG_CMD_READ;
387 		rc = iscsi_prep_bidi_ahs(task);
388 		if (rc)
389 			return rc;
390 	}
391 
392 	if (scsi_get_prot_op(sc) != SCSI_PROT_NORMAL)
393 		task->protected = true;
394 
395 	transfer_length = scsi_transfer_length(sc);
396 	hdr->data_length = cpu_to_be32(transfer_length);
397 	if (sc->sc_data_direction == DMA_TO_DEVICE) {
398 		struct iscsi_r2t_info *r2t = &task->unsol_r2t;
399 
400 		hdr->flags |= ISCSI_FLAG_CMD_WRITE;
401 		/*
402 		 * Write counters:
403 		 *
404 		 *	imm_count	bytes to be sent right after
405 		 *			SCSI PDU Header
406 		 *
407 		 *	unsol_count	bytes(as Data-Out) to be sent
408 		 *			without	R2T ack right after
409 		 *			immediate data
410 		 *
411 		 *	r2t data_length bytes to be sent via R2T ack's
412 		 *
413 		 *      pad_count       bytes to be sent as zero-padding
414 		 */
415 		memset(r2t, 0, sizeof(*r2t));
416 
417 		if (session->imm_data_en) {
418 			if (transfer_length >= session->first_burst)
419 				task->imm_count = min(session->first_burst,
420 							conn->max_xmit_dlength);
421 			else
422 				task->imm_count = min(transfer_length,
423 						      conn->max_xmit_dlength);
424 			hton24(hdr->dlength, task->imm_count);
425 		} else
426 			zero_data(hdr->dlength);
427 
428 		if (!session->initial_r2t_en) {
429 			r2t->data_length = min(session->first_burst,
430 					       transfer_length) -
431 					       task->imm_count;
432 			r2t->data_offset = task->imm_count;
433 			r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
434 			r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
435 		}
436 
437 		if (!task->unsol_r2t.data_length)
438 			/* No unsolicit Data-Out's */
439 			hdr->flags |= ISCSI_FLAG_CMD_FINAL;
440 	} else {
441 		hdr->flags |= ISCSI_FLAG_CMD_FINAL;
442 		zero_data(hdr->dlength);
443 
444 		if (sc->sc_data_direction == DMA_FROM_DEVICE)
445 			hdr->flags |= ISCSI_FLAG_CMD_READ;
446 	}
447 
448 	/* calculate size of additional header segments (AHSs) */
449 	hdrlength = task->hdr_len - sizeof(*hdr);
450 
451 	WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
452 	hdrlength /= ISCSI_PAD_LEN;
453 
454 	WARN_ON(hdrlength >= 256);
455 	hdr->hlength = hdrlength & 0xFF;
456 	hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
457 
458 	if (session->tt->init_task && session->tt->init_task(task))
459 		return -EIO;
460 
461 	task->state = ISCSI_TASK_RUNNING;
462 	session->cmdsn++;
463 
464 	conn->scsicmd_pdus_cnt++;
465 	ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
466 			  "itt 0x%x len %d bidi_len %d cmdsn %d win %d]\n",
467 			  scsi_bidi_cmnd(sc) ? "bidirectional" :
468 			  sc->sc_data_direction == DMA_TO_DEVICE ?
469 			  "write" : "read", conn->id, sc, sc->cmnd[0],
470 			  task->itt, transfer_length,
471 			  scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
472 			  session->cmdsn,
473 			  session->max_cmdsn - session->exp_cmdsn + 1);
474 	return 0;
475 }
476 
477 /**
478  * iscsi_free_task - free a task
479  * @task: iscsi cmd task
480  *
481  * Must be called with session back_lock.
482  * This function returns the scsi command to scsi-ml or cleans
483  * up mgmt tasks then returns the task to the pool.
484  */
485 static void iscsi_free_task(struct iscsi_task *task)
486 {
487 	struct iscsi_conn *conn = task->conn;
488 	struct iscsi_session *session = conn->session;
489 	struct scsi_cmnd *sc = task->sc;
490 	int oldstate = task->state;
491 
492 	ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
493 			  task->itt, task->state, task->sc);
494 
495 	session->tt->cleanup_task(task);
496 	task->state = ISCSI_TASK_FREE;
497 	task->sc = NULL;
498 	/*
499 	 * login task is preallocated so do not free
500 	 */
501 	if (conn->login_task == task)
502 		return;
503 
504 	kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
505 
506 	if (sc) {
507 		/* SCSI eh reuses commands to verify us */
508 		sc->SCp.ptr = NULL;
509 		/*
510 		 * queue command may call this to free the task, so
511 		 * it will decide how to return sc to scsi-ml.
512 		 */
513 		if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
514 			sc->scsi_done(sc);
515 	}
516 }
517 
518 void __iscsi_get_task(struct iscsi_task *task)
519 {
520 	atomic_inc(&task->refcount);
521 }
522 EXPORT_SYMBOL_GPL(__iscsi_get_task);
523 
524 void __iscsi_put_task(struct iscsi_task *task)
525 {
526 	if (atomic_dec_and_test(&task->refcount))
527 		iscsi_free_task(task);
528 }
529 EXPORT_SYMBOL_GPL(__iscsi_put_task);
530 
531 void iscsi_put_task(struct iscsi_task *task)
532 {
533 	struct iscsi_session *session = task->conn->session;
534 
535 	/* regular RX path uses back_lock */
536 	spin_lock_bh(&session->back_lock);
537 	__iscsi_put_task(task);
538 	spin_unlock_bh(&session->back_lock);
539 }
540 EXPORT_SYMBOL_GPL(iscsi_put_task);
541 
542 /**
543  * iscsi_complete_task - finish a task
544  * @task: iscsi cmd task
545  * @state: state to complete task with
546  *
547  * Must be called with session back_lock.
548  */
549 static void iscsi_complete_task(struct iscsi_task *task, int state)
550 {
551 	struct iscsi_conn *conn = task->conn;
552 
553 	ISCSI_DBG_SESSION(conn->session,
554 			  "complete task itt 0x%x state %d sc %p\n",
555 			  task->itt, task->state, task->sc);
556 	if (task->state == ISCSI_TASK_COMPLETED ||
557 	    task->state == ISCSI_TASK_ABRT_TMF ||
558 	    task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
559 	    task->state == ISCSI_TASK_REQUEUE_SCSIQ)
560 		return;
561 	WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
562 	task->state = state;
563 
564 	if (!list_empty(&task->running))
565 		list_del_init(&task->running);
566 
567 	if (conn->task == task)
568 		conn->task = NULL;
569 
570 	if (conn->ping_task == task)
571 		conn->ping_task = NULL;
572 
573 	/* release get from queueing */
574 	__iscsi_put_task(task);
575 }
576 
577 /**
578  * iscsi_complete_scsi_task - finish scsi task normally
579  * @task: iscsi task for scsi cmd
580  * @exp_cmdsn: expected cmd sn in cpu format
581  * @max_cmdsn: max cmd sn in cpu format
582  *
583  * This is used when drivers do not need or cannot perform
584  * lower level pdu processing.
585  *
586  * Called with session back_lock
587  */
588 void iscsi_complete_scsi_task(struct iscsi_task *task,
589 			      uint32_t exp_cmdsn, uint32_t max_cmdsn)
590 {
591 	struct iscsi_conn *conn = task->conn;
592 
593 	ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
594 
595 	conn->last_recv = jiffies;
596 	__iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
597 	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
598 }
599 EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
600 
601 
602 /*
603  * session back_lock must be held and if not called for a task that is
604  * still pending or from the xmit thread, then xmit thread must
605  * be suspended.
606  */
607 static void fail_scsi_task(struct iscsi_task *task, int err)
608 {
609 	struct iscsi_conn *conn = task->conn;
610 	struct scsi_cmnd *sc;
611 	int state;
612 
613 	/*
614 	 * if a command completes and we get a successful tmf response
615 	 * we will hit this because the scsi eh abort code does not take
616 	 * a ref to the task.
617 	 */
618 	sc = task->sc;
619 	if (!sc)
620 		return;
621 
622 	if (task->state == ISCSI_TASK_PENDING) {
623 		/*
624 		 * cmd never made it to the xmit thread, so we should not count
625 		 * the cmd in the sequencing
626 		 */
627 		conn->session->queued_cmdsn--;
628 		/* it was never sent so just complete like normal */
629 		state = ISCSI_TASK_COMPLETED;
630 	} else if (err == DID_TRANSPORT_DISRUPTED)
631 		state = ISCSI_TASK_ABRT_SESS_RECOV;
632 	else
633 		state = ISCSI_TASK_ABRT_TMF;
634 
635 	sc->result = err << 16;
636 	if (!scsi_bidi_cmnd(sc))
637 		scsi_set_resid(sc, scsi_bufflen(sc));
638 	else {
639 		scsi_out(sc)->resid = scsi_out(sc)->length;
640 		scsi_in(sc)->resid = scsi_in(sc)->length;
641 	}
642 
643 	/* regular RX path uses back_lock */
644 	spin_lock_bh(&conn->session->back_lock);
645 	iscsi_complete_task(task, state);
646 	spin_unlock_bh(&conn->session->back_lock);
647 }
648 
649 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
650 				struct iscsi_task *task)
651 {
652 	struct iscsi_session *session = conn->session;
653 	struct iscsi_hdr *hdr = task->hdr;
654 	struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
655 	uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
656 
657 	if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
658 		return -ENOTCONN;
659 
660 	if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
661 		nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
662 	/*
663 	 * pre-format CmdSN for outgoing PDU.
664 	 */
665 	nop->cmdsn = cpu_to_be32(session->cmdsn);
666 	if (hdr->itt != RESERVED_ITT) {
667 		/*
668 		 * TODO: We always use immediate for normal session pdus.
669 		 * If we start to send tmfs or nops as non-immediate then
670 		 * we should start checking the cmdsn numbers for mgmt tasks.
671 		 *
672 		 * During discovery sessions iscsid sends TEXT as non immediate,
673 		 * but we always only send one PDU at a time.
674 		 */
675 		if (conn->c_stage == ISCSI_CONN_STARTED &&
676 		    !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
677 			session->queued_cmdsn++;
678 			session->cmdsn++;
679 		}
680 	}
681 
682 	if (session->tt->init_task && session->tt->init_task(task))
683 		return -EIO;
684 
685 	if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
686 		session->state = ISCSI_STATE_LOGGING_OUT;
687 
688 	task->state = ISCSI_TASK_RUNNING;
689 	ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
690 			  "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
691 			  hdr->itt, task->data_count);
692 	return 0;
693 }
694 
695 static struct iscsi_task *
696 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
697 		      char *data, uint32_t data_size)
698 {
699 	struct iscsi_session *session = conn->session;
700 	struct iscsi_host *ihost = shost_priv(session->host);
701 	uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
702 	struct iscsi_task *task;
703 	itt_t itt;
704 
705 	if (session->state == ISCSI_STATE_TERMINATE)
706 		return NULL;
707 
708 	if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
709 		/*
710 		 * Login and Text are sent serially, in
711 		 * request-followed-by-response sequence.
712 		 * Same task can be used. Same ITT must be used.
713 		 * Note that login_task is preallocated at conn_create().
714 		 */
715 		if (conn->login_task->state != ISCSI_TASK_FREE) {
716 			iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
717 					  "progress. Cannot start new task.\n");
718 			return NULL;
719 		}
720 
721 		if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
722 			iscsi_conn_printk(KERN_ERR, conn, "Invalid buffer len of %u for login task. Max len is %u\n", data_size, ISCSI_DEF_MAX_RECV_SEG_LEN);
723 			return NULL;
724 		}
725 
726 		task = conn->login_task;
727 	} else {
728 		if (session->state != ISCSI_STATE_LOGGED_IN)
729 			return NULL;
730 
731 		if (data_size != 0) {
732 			iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
733 			return NULL;
734 		}
735 
736 		BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
737 		BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
738 
739 		if (!kfifo_out(&session->cmdpool.queue,
740 				 (void*)&task, sizeof(void*)))
741 			return NULL;
742 	}
743 	/*
744 	 * released in complete pdu for task we expect a response for, and
745 	 * released by the lld when it has transmitted the task for
746 	 * pdus we do not expect a response for.
747 	 */
748 	atomic_set(&task->refcount, 1);
749 	task->conn = conn;
750 	task->sc = NULL;
751 	INIT_LIST_HEAD(&task->running);
752 	task->state = ISCSI_TASK_PENDING;
753 
754 	if (data_size) {
755 		memcpy(task->data, data, data_size);
756 		task->data_count = data_size;
757 	} else
758 		task->data_count = 0;
759 
760 	if (conn->session->tt->alloc_pdu) {
761 		if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
762 			iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
763 					 "pdu for mgmt task.\n");
764 			goto free_task;
765 		}
766 	}
767 
768 	itt = task->hdr->itt;
769 	task->hdr_len = sizeof(struct iscsi_hdr);
770 	memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
771 
772 	if (hdr->itt != RESERVED_ITT) {
773 		if (session->tt->parse_pdu_itt)
774 			task->hdr->itt = itt;
775 		else
776 			task->hdr->itt = build_itt(task->itt,
777 						   task->conn->session->age);
778 	}
779 
780 	if (!ihost->workq) {
781 		if (iscsi_prep_mgmt_task(conn, task))
782 			goto free_task;
783 
784 		if (session->tt->xmit_task(task))
785 			goto free_task;
786 	} else {
787 		list_add_tail(&task->running, &conn->mgmtqueue);
788 		iscsi_conn_queue_work(conn);
789 	}
790 
791 	return task;
792 
793 free_task:
794 	/* regular RX path uses back_lock */
795 	spin_lock(&session->back_lock);
796 	__iscsi_put_task(task);
797 	spin_unlock(&session->back_lock);
798 	return NULL;
799 }
800 
801 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
802 			char *data, uint32_t data_size)
803 {
804 	struct iscsi_conn *conn = cls_conn->dd_data;
805 	struct iscsi_session *session = conn->session;
806 	int err = 0;
807 
808 	spin_lock_bh(&session->frwd_lock);
809 	if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
810 		err = -EPERM;
811 	spin_unlock_bh(&session->frwd_lock);
812 	return err;
813 }
814 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
815 
816 /**
817  * iscsi_cmd_rsp - SCSI Command Response processing
818  * @conn: iscsi connection
819  * @hdr: iscsi header
820  * @task: scsi command task
821  * @data: cmd data buffer
822  * @datalen: len of buffer
823  *
824  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
825  * then completes the command and task.
826  **/
827 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
828 			       struct iscsi_task *task, char *data,
829 			       int datalen)
830 {
831 	struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
832 	struct iscsi_session *session = conn->session;
833 	struct scsi_cmnd *sc = task->sc;
834 
835 	iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
836 	conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
837 
838 	sc->result = (DID_OK << 16) | rhdr->cmd_status;
839 
840 	if (task->protected) {
841 		sector_t sector;
842 		u8 ascq;
843 
844 		/**
845 		 * Transports that didn't implement check_protection
846 		 * callback but still published T10-PI support to scsi-mid
847 		 * deserve this BUG_ON.
848 		 **/
849 		BUG_ON(!session->tt->check_protection);
850 
851 		ascq = session->tt->check_protection(task, &sector);
852 		if (ascq) {
853 			sc->result = DRIVER_SENSE << 24 |
854 				     SAM_STAT_CHECK_CONDITION;
855 			scsi_build_sense_buffer(1, sc->sense_buffer,
856 						ILLEGAL_REQUEST, 0x10, ascq);
857 			scsi_set_sense_information(sc->sense_buffer,
858 						   SCSI_SENSE_BUFFERSIZE,
859 						   sector);
860 			goto out;
861 		}
862 	}
863 
864 	if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
865 		sc->result = DID_ERROR << 16;
866 		goto out;
867 	}
868 
869 	if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
870 		uint16_t senselen;
871 
872 		if (datalen < 2) {
873 invalid_datalen:
874 			iscsi_conn_printk(KERN_ERR,  conn,
875 					 "Got CHECK_CONDITION but invalid data "
876 					 "buffer size of %d\n", datalen);
877 			sc->result = DID_BAD_TARGET << 16;
878 			goto out;
879 		}
880 
881 		senselen = get_unaligned_be16(data);
882 		if (datalen < senselen)
883 			goto invalid_datalen;
884 
885 		memcpy(sc->sense_buffer, data + 2,
886 		       min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
887 		ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
888 				  min_t(uint16_t, senselen,
889 				  SCSI_SENSE_BUFFERSIZE));
890 	}
891 
892 	if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
893 			   ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
894 		int res_count = be32_to_cpu(rhdr->bi_residual_count);
895 
896 		if (scsi_bidi_cmnd(sc) && res_count > 0 &&
897 				(rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
898 				 res_count <= scsi_in(sc)->length))
899 			scsi_in(sc)->resid = res_count;
900 		else
901 			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
902 	}
903 
904 	if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
905 	                   ISCSI_FLAG_CMD_OVERFLOW)) {
906 		int res_count = be32_to_cpu(rhdr->residual_count);
907 
908 		if (res_count > 0 &&
909 		    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
910 		     res_count <= scsi_bufflen(sc)))
911 			/* write side for bidi or uni-io set_resid */
912 			scsi_set_resid(sc, res_count);
913 		else
914 			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
915 	}
916 out:
917 	ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
918 			  sc, sc->result, task->itt);
919 	conn->scsirsp_pdus_cnt++;
920 	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
921 }
922 
923 /**
924  * iscsi_data_in_rsp - SCSI Data-In Response processing
925  * @conn: iscsi connection
926  * @hdr:  iscsi pdu
927  * @task: scsi command task
928  **/
929 static void
930 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
931 		  struct iscsi_task *task)
932 {
933 	struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
934 	struct scsi_cmnd *sc = task->sc;
935 
936 	if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
937 		return;
938 
939 	iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
940 	sc->result = (DID_OK << 16) | rhdr->cmd_status;
941 	conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
942 	if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
943 	                   ISCSI_FLAG_DATA_OVERFLOW)) {
944 		int res_count = be32_to_cpu(rhdr->residual_count);
945 
946 		if (res_count > 0 &&
947 		    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
948 		     res_count <= scsi_in(sc)->length))
949 			scsi_in(sc)->resid = res_count;
950 		else
951 			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
952 	}
953 
954 	ISCSI_DBG_SESSION(conn->session, "data in with status done "
955 			  "[sc %p res %d itt 0x%x]\n",
956 			  sc, sc->result, task->itt);
957 	conn->scsirsp_pdus_cnt++;
958 	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
959 }
960 
961 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
962 {
963 	struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
964 
965 	conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
966 	conn->tmfrsp_pdus_cnt++;
967 
968 	if (conn->tmf_state != TMF_QUEUED)
969 		return;
970 
971 	if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
972 		conn->tmf_state = TMF_SUCCESS;
973 	else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
974 		conn->tmf_state = TMF_NOT_FOUND;
975 	else
976 		conn->tmf_state = TMF_FAILED;
977 	wake_up(&conn->ehwait);
978 }
979 
980 static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
981 {
982         struct iscsi_nopout hdr;
983 	struct iscsi_task *task;
984 
985 	if (!rhdr && conn->ping_task)
986 		return -EINVAL;
987 
988 	memset(&hdr, 0, sizeof(struct iscsi_nopout));
989 	hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
990 	hdr.flags = ISCSI_FLAG_CMD_FINAL;
991 
992 	if (rhdr) {
993 		hdr.lun = rhdr->lun;
994 		hdr.ttt = rhdr->ttt;
995 		hdr.itt = RESERVED_ITT;
996 	} else
997 		hdr.ttt = RESERVED_ITT;
998 
999 	task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
1000 	if (!task) {
1001 		iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
1002 		return -EIO;
1003 	} else if (!rhdr) {
1004 		/* only track our nops */
1005 		conn->ping_task = task;
1006 		conn->last_ping = jiffies;
1007 	}
1008 
1009 	return 0;
1010 }
1011 
1012 static int iscsi_nop_out_rsp(struct iscsi_task *task,
1013 			     struct iscsi_nopin *nop, char *data, int datalen)
1014 {
1015 	struct iscsi_conn *conn = task->conn;
1016 	int rc = 0;
1017 
1018 	if (conn->ping_task != task) {
1019 		/*
1020 		 * If this is not in response to one of our
1021 		 * nops then it must be from userspace.
1022 		 */
1023 		if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
1024 				   data, datalen))
1025 			rc = ISCSI_ERR_CONN_FAILED;
1026 	} else
1027 		mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1028 	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1029 	return rc;
1030 }
1031 
1032 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1033 			       char *data, int datalen)
1034 {
1035 	struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1036 	struct iscsi_hdr rejected_pdu;
1037 	int opcode, rc = 0;
1038 
1039 	conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1040 
1041 	if (ntoh24(reject->dlength) > datalen ||
1042 	    ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1043 		iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1044 				  "pdu. Invalid data length (pdu dlength "
1045 				  "%u, datalen %d\n", ntoh24(reject->dlength),
1046 				  datalen);
1047 		return ISCSI_ERR_PROTO;
1048 	}
1049 	memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1050 	opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1051 
1052 	switch (reject->reason) {
1053 	case ISCSI_REASON_DATA_DIGEST_ERROR:
1054 		iscsi_conn_printk(KERN_ERR, conn,
1055 				  "pdu (op 0x%x itt 0x%x) rejected "
1056 				  "due to DataDigest error.\n",
1057 				  opcode, rejected_pdu.itt);
1058 		break;
1059 	case ISCSI_REASON_IMM_CMD_REJECT:
1060 		iscsi_conn_printk(KERN_ERR, conn,
1061 				  "pdu (op 0x%x itt 0x%x) rejected. Too many "
1062 				  "immediate commands.\n",
1063 				  opcode, rejected_pdu.itt);
1064 		/*
1065 		 * We only send one TMF at a time so if the target could not
1066 		 * handle it, then it should get fixed (RFC mandates that
1067 		 * a target can handle one immediate TMF per conn).
1068 		 *
1069 		 * For nops-outs, we could have sent more than one if
1070 		 * the target is sending us lots of nop-ins
1071 		 */
1072 		if (opcode != ISCSI_OP_NOOP_OUT)
1073 			return 0;
1074 
1075 		 if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1076 			/*
1077 			 * nop-out in response to target's nop-out rejected.
1078 			 * Just resend.
1079 			 */
1080 			/* In RX path we are under back lock */
1081 			spin_unlock(&conn->session->back_lock);
1082 			spin_lock(&conn->session->frwd_lock);
1083 			iscsi_send_nopout(conn,
1084 					  (struct iscsi_nopin*)&rejected_pdu);
1085 			spin_unlock(&conn->session->frwd_lock);
1086 			spin_lock(&conn->session->back_lock);
1087 		} else {
1088 			struct iscsi_task *task;
1089 			/*
1090 			 * Our nop as ping got dropped. We know the target
1091 			 * and transport are ok so just clean up
1092 			 */
1093 			task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1094 			if (!task) {
1095 				iscsi_conn_printk(KERN_ERR, conn,
1096 						 "Invalid pdu reject. Could "
1097 						 "not lookup rejected task.\n");
1098 				rc = ISCSI_ERR_BAD_ITT;
1099 			} else
1100 				rc = iscsi_nop_out_rsp(task,
1101 					(struct iscsi_nopin*)&rejected_pdu,
1102 					NULL, 0);
1103 		}
1104 		break;
1105 	default:
1106 		iscsi_conn_printk(KERN_ERR, conn,
1107 				  "pdu (op 0x%x itt 0x%x) rejected. Reason "
1108 				  "code 0x%x\n", rejected_pdu.opcode,
1109 				  rejected_pdu.itt, reject->reason);
1110 		break;
1111 	}
1112 	return rc;
1113 }
1114 
1115 /**
1116  * iscsi_itt_to_task - look up task by itt
1117  * @conn: iscsi connection
1118  * @itt: itt
1119  *
1120  * This should be used for mgmt tasks like login and nops, or if
1121  * the LDD's itt space does not include the session age.
1122  *
1123  * The session back_lock must be held.
1124  */
1125 struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1126 {
1127 	struct iscsi_session *session = conn->session;
1128 	int i;
1129 
1130 	if (itt == RESERVED_ITT)
1131 		return NULL;
1132 
1133 	if (session->tt->parse_pdu_itt)
1134 		session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1135 	else
1136 		i = get_itt(itt);
1137 	if (i >= session->cmds_max)
1138 		return NULL;
1139 
1140 	return session->cmds[i];
1141 }
1142 EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1143 
1144 /**
1145  * __iscsi_complete_pdu - complete pdu
1146  * @conn: iscsi conn
1147  * @hdr: iscsi header
1148  * @data: data buffer
1149  * @datalen: len of data buffer
1150  *
1151  * Completes pdu processing by freeing any resources allocated at
1152  * queuecommand or send generic. session back_lock must be held and verify
1153  * itt must have been called.
1154  */
1155 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1156 			 char *data, int datalen)
1157 {
1158 	struct iscsi_session *session = conn->session;
1159 	int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1160 	struct iscsi_task *task;
1161 	uint32_t itt;
1162 
1163 	conn->last_recv = jiffies;
1164 	rc = iscsi_verify_itt(conn, hdr->itt);
1165 	if (rc)
1166 		return rc;
1167 
1168 	if (hdr->itt != RESERVED_ITT)
1169 		itt = get_itt(hdr->itt);
1170 	else
1171 		itt = ~0U;
1172 
1173 	ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1174 			  opcode, conn->id, itt, datalen);
1175 
1176 	if (itt == ~0U) {
1177 		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1178 
1179 		switch(opcode) {
1180 		case ISCSI_OP_NOOP_IN:
1181 			if (datalen) {
1182 				rc = ISCSI_ERR_PROTO;
1183 				break;
1184 			}
1185 
1186 			if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1187 				break;
1188 
1189 			/* In RX path we are under back lock */
1190 			spin_unlock(&session->back_lock);
1191 			spin_lock(&session->frwd_lock);
1192 			iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1193 			spin_unlock(&session->frwd_lock);
1194 			spin_lock(&session->back_lock);
1195 			break;
1196 		case ISCSI_OP_REJECT:
1197 			rc = iscsi_handle_reject(conn, hdr, data, datalen);
1198 			break;
1199 		case ISCSI_OP_ASYNC_EVENT:
1200 			conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1201 			if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1202 				rc = ISCSI_ERR_CONN_FAILED;
1203 			break;
1204 		default:
1205 			rc = ISCSI_ERR_BAD_OPCODE;
1206 			break;
1207 		}
1208 		goto out;
1209 	}
1210 
1211 	switch(opcode) {
1212 	case ISCSI_OP_SCSI_CMD_RSP:
1213 	case ISCSI_OP_SCSI_DATA_IN:
1214 		task = iscsi_itt_to_ctask(conn, hdr->itt);
1215 		if (!task)
1216 			return ISCSI_ERR_BAD_ITT;
1217 		task->last_xfer = jiffies;
1218 		break;
1219 	case ISCSI_OP_R2T:
1220 		/*
1221 		 * LLD handles R2Ts if they need to.
1222 		 */
1223 		return 0;
1224 	case ISCSI_OP_LOGOUT_RSP:
1225 	case ISCSI_OP_LOGIN_RSP:
1226 	case ISCSI_OP_TEXT_RSP:
1227 	case ISCSI_OP_SCSI_TMFUNC_RSP:
1228 	case ISCSI_OP_NOOP_IN:
1229 		task = iscsi_itt_to_task(conn, hdr->itt);
1230 		if (!task)
1231 			return ISCSI_ERR_BAD_ITT;
1232 		break;
1233 	default:
1234 		return ISCSI_ERR_BAD_OPCODE;
1235 	}
1236 
1237 	switch(opcode) {
1238 	case ISCSI_OP_SCSI_CMD_RSP:
1239 		iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1240 		break;
1241 	case ISCSI_OP_SCSI_DATA_IN:
1242 		iscsi_data_in_rsp(conn, hdr, task);
1243 		break;
1244 	case ISCSI_OP_LOGOUT_RSP:
1245 		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1246 		if (datalen) {
1247 			rc = ISCSI_ERR_PROTO;
1248 			break;
1249 		}
1250 		conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1251 		goto recv_pdu;
1252 	case ISCSI_OP_LOGIN_RSP:
1253 	case ISCSI_OP_TEXT_RSP:
1254 		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1255 		/*
1256 		 * login related PDU's exp_statsn is handled in
1257 		 * userspace
1258 		 */
1259 		goto recv_pdu;
1260 	case ISCSI_OP_SCSI_TMFUNC_RSP:
1261 		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1262 		if (datalen) {
1263 			rc = ISCSI_ERR_PROTO;
1264 			break;
1265 		}
1266 
1267 		iscsi_tmf_rsp(conn, hdr);
1268 		iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1269 		break;
1270 	case ISCSI_OP_NOOP_IN:
1271 		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1272 		if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1273 			rc = ISCSI_ERR_PROTO;
1274 			break;
1275 		}
1276 		conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1277 
1278 		rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1279 				       data, datalen);
1280 		break;
1281 	default:
1282 		rc = ISCSI_ERR_BAD_OPCODE;
1283 		break;
1284 	}
1285 
1286 out:
1287 	return rc;
1288 recv_pdu:
1289 	if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1290 		rc = ISCSI_ERR_CONN_FAILED;
1291 	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1292 	return rc;
1293 }
1294 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1295 
1296 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1297 		       char *data, int datalen)
1298 {
1299 	int rc;
1300 
1301 	spin_lock(&conn->session->back_lock);
1302 	rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1303 	spin_unlock(&conn->session->back_lock);
1304 	return rc;
1305 }
1306 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1307 
1308 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1309 {
1310 	struct iscsi_session *session = conn->session;
1311 	int age = 0, i = 0;
1312 
1313 	if (itt == RESERVED_ITT)
1314 		return 0;
1315 
1316 	if (session->tt->parse_pdu_itt)
1317 		session->tt->parse_pdu_itt(conn, itt, &i, &age);
1318 	else {
1319 		i = get_itt(itt);
1320 		age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1321 	}
1322 
1323 	if (age != session->age) {
1324 		iscsi_conn_printk(KERN_ERR, conn,
1325 				  "received itt %x expected session age (%x)\n",
1326 				  (__force u32)itt, session->age);
1327 		return ISCSI_ERR_BAD_ITT;
1328 	}
1329 
1330 	if (i >= session->cmds_max) {
1331 		iscsi_conn_printk(KERN_ERR, conn,
1332 				  "received invalid itt index %u (max cmds "
1333 				   "%u.\n", i, session->cmds_max);
1334 		return ISCSI_ERR_BAD_ITT;
1335 	}
1336 	return 0;
1337 }
1338 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1339 
1340 /**
1341  * iscsi_itt_to_ctask - look up ctask by itt
1342  * @conn: iscsi connection
1343  * @itt: itt
1344  *
1345  * This should be used for cmd tasks.
1346  *
1347  * The session back_lock must be held.
1348  */
1349 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1350 {
1351 	struct iscsi_task *task;
1352 
1353 	if (iscsi_verify_itt(conn, itt))
1354 		return NULL;
1355 
1356 	task = iscsi_itt_to_task(conn, itt);
1357 	if (!task || !task->sc)
1358 		return NULL;
1359 
1360 	if (task->sc->SCp.phase != conn->session->age) {
1361 		iscsi_session_printk(KERN_ERR, conn->session,
1362 				  "task's session age %d, expected %d\n",
1363 				  task->sc->SCp.phase, conn->session->age);
1364 		return NULL;
1365 	}
1366 
1367 	return task;
1368 }
1369 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1370 
1371 void iscsi_session_failure(struct iscsi_session *session,
1372 			   enum iscsi_err err)
1373 {
1374 	struct iscsi_conn *conn;
1375 	struct device *dev;
1376 
1377 	spin_lock_bh(&session->frwd_lock);
1378 	conn = session->leadconn;
1379 	if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1380 		spin_unlock_bh(&session->frwd_lock);
1381 		return;
1382 	}
1383 
1384 	dev = get_device(&conn->cls_conn->dev);
1385 	spin_unlock_bh(&session->frwd_lock);
1386 	if (!dev)
1387 	        return;
1388 	/*
1389 	 * if the host is being removed bypass the connection
1390 	 * recovery initialization because we are going to kill
1391 	 * the session.
1392 	 */
1393 	if (err == ISCSI_ERR_INVALID_HOST)
1394 		iscsi_conn_error_event(conn->cls_conn, err);
1395 	else
1396 		iscsi_conn_failure(conn, err);
1397 	put_device(dev);
1398 }
1399 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1400 
1401 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1402 {
1403 	struct iscsi_session *session = conn->session;
1404 
1405 	spin_lock_bh(&session->frwd_lock);
1406 	if (session->state == ISCSI_STATE_FAILED) {
1407 		spin_unlock_bh(&session->frwd_lock);
1408 		return;
1409 	}
1410 
1411 	if (conn->stop_stage == 0)
1412 		session->state = ISCSI_STATE_FAILED;
1413 	spin_unlock_bh(&session->frwd_lock);
1414 
1415 	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1416 	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1417 	iscsi_conn_error_event(conn->cls_conn, err);
1418 }
1419 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1420 
1421 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1422 {
1423 	struct iscsi_session *session = conn->session;
1424 
1425 	/*
1426 	 * Check for iSCSI window and take care of CmdSN wrap-around
1427 	 */
1428 	if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1429 		ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1430 				  "%u MaxCmdSN %u CmdSN %u/%u\n",
1431 				  session->exp_cmdsn, session->max_cmdsn,
1432 				  session->cmdsn, session->queued_cmdsn);
1433 		return -ENOSPC;
1434 	}
1435 	return 0;
1436 }
1437 
1438 static int iscsi_xmit_task(struct iscsi_conn *conn)
1439 {
1440 	struct iscsi_task *task = conn->task;
1441 	int rc;
1442 
1443 	if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
1444 		return -ENODATA;
1445 
1446 	__iscsi_get_task(task);
1447 	spin_unlock_bh(&conn->session->frwd_lock);
1448 	rc = conn->session->tt->xmit_task(task);
1449 	spin_lock_bh(&conn->session->frwd_lock);
1450 	if (!rc) {
1451 		/* done with this task */
1452 		task->last_xfer = jiffies;
1453 		conn->task = NULL;
1454 	}
1455 	/* regular RX path uses back_lock */
1456 	spin_lock(&conn->session->back_lock);
1457 	__iscsi_put_task(task);
1458 	spin_unlock(&conn->session->back_lock);
1459 	return rc;
1460 }
1461 
1462 /**
1463  * iscsi_requeue_task - requeue task to run from session workqueue
1464  * @task: task to requeue
1465  *
1466  * LLDs that need to run a task from the session workqueue should call
1467  * this. The session frwd_lock must be held. This should only be called
1468  * by software drivers.
1469  */
1470 void iscsi_requeue_task(struct iscsi_task *task)
1471 {
1472 	struct iscsi_conn *conn = task->conn;
1473 
1474 	/*
1475 	 * this may be on the requeue list already if the xmit_task callout
1476 	 * is handling the r2ts while we are adding new ones
1477 	 */
1478 	if (list_empty(&task->running))
1479 		list_add_tail(&task->running, &conn->requeue);
1480 	iscsi_conn_queue_work(conn);
1481 }
1482 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1483 
1484 /**
1485  * iscsi_data_xmit - xmit any command into the scheduled connection
1486  * @conn: iscsi connection
1487  *
1488  * Notes:
1489  *	The function can return -EAGAIN in which case the caller must
1490  *	re-schedule it again later or recover. '0' return code means
1491  *	successful xmit.
1492  **/
1493 static int iscsi_data_xmit(struct iscsi_conn *conn)
1494 {
1495 	struct iscsi_task *task;
1496 	int rc = 0;
1497 
1498 	spin_lock_bh(&conn->session->frwd_lock);
1499 	if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1500 		ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1501 		spin_unlock_bh(&conn->session->frwd_lock);
1502 		return -ENODATA;
1503 	}
1504 
1505 	if (conn->task) {
1506 		rc = iscsi_xmit_task(conn);
1507 	        if (rc)
1508 		        goto done;
1509 	}
1510 
1511 	/*
1512 	 * process mgmt pdus like nops before commands since we should
1513 	 * only have one nop-out as a ping from us and targets should not
1514 	 * overflow us with nop-ins
1515 	 */
1516 check_mgmt:
1517 	while (!list_empty(&conn->mgmtqueue)) {
1518 		conn->task = list_entry(conn->mgmtqueue.next,
1519 					 struct iscsi_task, running);
1520 		list_del_init(&conn->task->running);
1521 		if (iscsi_prep_mgmt_task(conn, conn->task)) {
1522 			/* regular RX path uses back_lock */
1523 			spin_lock_bh(&conn->session->back_lock);
1524 			__iscsi_put_task(conn->task);
1525 			spin_unlock_bh(&conn->session->back_lock);
1526 			conn->task = NULL;
1527 			continue;
1528 		}
1529 		rc = iscsi_xmit_task(conn);
1530 		if (rc)
1531 			goto done;
1532 	}
1533 
1534 	/* process pending command queue */
1535 	while (!list_empty(&conn->cmdqueue)) {
1536 		conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1537 					running);
1538 		list_del_init(&conn->task->running);
1539 		if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1540 			fail_scsi_task(conn->task, DID_IMM_RETRY);
1541 			continue;
1542 		}
1543 		rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1544 		if (rc) {
1545 			if (rc == -ENOMEM || rc == -EACCES) {
1546 				list_add_tail(&conn->task->running,
1547 					      &conn->cmdqueue);
1548 				conn->task = NULL;
1549 				goto done;
1550 			} else
1551 				fail_scsi_task(conn->task, DID_ABORT);
1552 			continue;
1553 		}
1554 		rc = iscsi_xmit_task(conn);
1555 		if (rc)
1556 			goto done;
1557 		/*
1558 		 * we could continuously get new task requests so
1559 		 * we need to check the mgmt queue for nops that need to
1560 		 * be sent to aviod starvation
1561 		 */
1562 		if (!list_empty(&conn->mgmtqueue))
1563 			goto check_mgmt;
1564 	}
1565 
1566 	while (!list_empty(&conn->requeue)) {
1567 		/*
1568 		 * we always do fastlogout - conn stop code will clean up.
1569 		 */
1570 		if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1571 			break;
1572 
1573 		task = list_entry(conn->requeue.next, struct iscsi_task,
1574 				  running);
1575 		if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1576 			break;
1577 
1578 		conn->task = task;
1579 		list_del_init(&conn->task->running);
1580 		conn->task->state = ISCSI_TASK_RUNNING;
1581 		rc = iscsi_xmit_task(conn);
1582 		if (rc)
1583 			goto done;
1584 		if (!list_empty(&conn->mgmtqueue))
1585 			goto check_mgmt;
1586 	}
1587 	spin_unlock_bh(&conn->session->frwd_lock);
1588 	return -ENODATA;
1589 
1590 done:
1591 	spin_unlock_bh(&conn->session->frwd_lock);
1592 	return rc;
1593 }
1594 
1595 static void iscsi_xmitworker(struct work_struct *work)
1596 {
1597 	struct iscsi_conn *conn =
1598 		container_of(work, struct iscsi_conn, xmitwork);
1599 	int rc;
1600 	/*
1601 	 * serialize Xmit worker on a per-connection basis.
1602 	 */
1603 	do {
1604 		rc = iscsi_data_xmit(conn);
1605 	} while (rc >= 0 || rc == -EAGAIN);
1606 }
1607 
1608 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1609 						  struct scsi_cmnd *sc)
1610 {
1611 	struct iscsi_task *task;
1612 
1613 	if (!kfifo_out(&conn->session->cmdpool.queue,
1614 			 (void *) &task, sizeof(void *)))
1615 		return NULL;
1616 
1617 	sc->SCp.phase = conn->session->age;
1618 	sc->SCp.ptr = (char *) task;
1619 
1620 	atomic_set(&task->refcount, 1);
1621 	task->state = ISCSI_TASK_PENDING;
1622 	task->conn = conn;
1623 	task->sc = sc;
1624 	task->have_checked_conn = false;
1625 	task->last_timeout = jiffies;
1626 	task->last_xfer = jiffies;
1627 	task->protected = false;
1628 	INIT_LIST_HEAD(&task->running);
1629 	return task;
1630 }
1631 
1632 enum {
1633 	FAILURE_BAD_HOST = 1,
1634 	FAILURE_SESSION_FAILED,
1635 	FAILURE_SESSION_FREED,
1636 	FAILURE_WINDOW_CLOSED,
1637 	FAILURE_OOM,
1638 	FAILURE_SESSION_TERMINATE,
1639 	FAILURE_SESSION_IN_RECOVERY,
1640 	FAILURE_SESSION_RECOVERY_TIMEOUT,
1641 	FAILURE_SESSION_LOGGING_OUT,
1642 	FAILURE_SESSION_NOT_READY,
1643 };
1644 
1645 int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1646 {
1647 	struct iscsi_cls_session *cls_session;
1648 	struct iscsi_host *ihost;
1649 	int reason = 0;
1650 	struct iscsi_session *session;
1651 	struct iscsi_conn *conn;
1652 	struct iscsi_task *task = NULL;
1653 
1654 	sc->result = 0;
1655 	sc->SCp.ptr = NULL;
1656 
1657 	ihost = shost_priv(host);
1658 
1659 	cls_session = starget_to_session(scsi_target(sc->device));
1660 	session = cls_session->dd_data;
1661 	spin_lock_bh(&session->frwd_lock);
1662 
1663 	reason = iscsi_session_chkready(cls_session);
1664 	if (reason) {
1665 		sc->result = reason;
1666 		goto fault;
1667 	}
1668 
1669 	if (session->state != ISCSI_STATE_LOGGED_IN) {
1670 		/*
1671 		 * to handle the race between when we set the recovery state
1672 		 * and block the session we requeue here (commands could
1673 		 * be entering our queuecommand while a block is starting
1674 		 * up because the block code is not locked)
1675 		 */
1676 		switch (session->state) {
1677 		case ISCSI_STATE_FAILED:
1678 		case ISCSI_STATE_IN_RECOVERY:
1679 			reason = FAILURE_SESSION_IN_RECOVERY;
1680 			sc->result = DID_IMM_RETRY << 16;
1681 			break;
1682 		case ISCSI_STATE_LOGGING_OUT:
1683 			reason = FAILURE_SESSION_LOGGING_OUT;
1684 			sc->result = DID_IMM_RETRY << 16;
1685 			break;
1686 		case ISCSI_STATE_RECOVERY_FAILED:
1687 			reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1688 			sc->result = DID_TRANSPORT_FAILFAST << 16;
1689 			break;
1690 		case ISCSI_STATE_TERMINATE:
1691 			reason = FAILURE_SESSION_TERMINATE;
1692 			sc->result = DID_NO_CONNECT << 16;
1693 			break;
1694 		default:
1695 			reason = FAILURE_SESSION_FREED;
1696 			sc->result = DID_NO_CONNECT << 16;
1697 		}
1698 		goto fault;
1699 	}
1700 
1701 	conn = session->leadconn;
1702 	if (!conn) {
1703 		reason = FAILURE_SESSION_FREED;
1704 		sc->result = DID_NO_CONNECT << 16;
1705 		goto fault;
1706 	}
1707 
1708 	if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1709 		reason = FAILURE_SESSION_IN_RECOVERY;
1710 		sc->result = DID_REQUEUE;
1711 		goto fault;
1712 	}
1713 
1714 	if (iscsi_check_cmdsn_window_closed(conn)) {
1715 		reason = FAILURE_WINDOW_CLOSED;
1716 		goto reject;
1717 	}
1718 
1719 	task = iscsi_alloc_task(conn, sc);
1720 	if (!task) {
1721 		reason = FAILURE_OOM;
1722 		goto reject;
1723 	}
1724 
1725 	if (!ihost->workq) {
1726 		reason = iscsi_prep_scsi_cmd_pdu(task);
1727 		if (reason) {
1728 			if (reason == -ENOMEM ||  reason == -EACCES) {
1729 				reason = FAILURE_OOM;
1730 				goto prepd_reject;
1731 			} else {
1732 				sc->result = DID_ABORT << 16;
1733 				goto prepd_fault;
1734 			}
1735 		}
1736 		if (session->tt->xmit_task(task)) {
1737 			session->cmdsn--;
1738 			reason = FAILURE_SESSION_NOT_READY;
1739 			goto prepd_reject;
1740 		}
1741 	} else {
1742 		list_add_tail(&task->running, &conn->cmdqueue);
1743 		iscsi_conn_queue_work(conn);
1744 	}
1745 
1746 	session->queued_cmdsn++;
1747 	spin_unlock_bh(&session->frwd_lock);
1748 	return 0;
1749 
1750 prepd_reject:
1751 	iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1752 reject:
1753 	spin_unlock_bh(&session->frwd_lock);
1754 	ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1755 			  sc->cmnd[0], reason);
1756 	return SCSI_MLQUEUE_TARGET_BUSY;
1757 
1758 prepd_fault:
1759 	iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1760 fault:
1761 	spin_unlock_bh(&session->frwd_lock);
1762 	ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1763 			  sc->cmnd[0], reason);
1764 	if (!scsi_bidi_cmnd(sc))
1765 		scsi_set_resid(sc, scsi_bufflen(sc));
1766 	else {
1767 		scsi_out(sc)->resid = scsi_out(sc)->length;
1768 		scsi_in(sc)->resid = scsi_in(sc)->length;
1769 	}
1770 	sc->scsi_done(sc);
1771 	return 0;
1772 }
1773 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1774 
1775 int iscsi_target_alloc(struct scsi_target *starget)
1776 {
1777 	struct iscsi_cls_session *cls_session = starget_to_session(starget);
1778 	struct iscsi_session *session = cls_session->dd_data;
1779 
1780 	starget->can_queue = session->scsi_cmds_max;
1781 	return 0;
1782 }
1783 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1784 
1785 static void iscsi_tmf_timedout(unsigned long data)
1786 {
1787 	struct iscsi_conn *conn = (struct iscsi_conn *)data;
1788 	struct iscsi_session *session = conn->session;
1789 
1790 	spin_lock(&session->frwd_lock);
1791 	if (conn->tmf_state == TMF_QUEUED) {
1792 		conn->tmf_state = TMF_TIMEDOUT;
1793 		ISCSI_DBG_EH(session, "tmf timedout\n");
1794 		/* unblock eh_abort() */
1795 		wake_up(&conn->ehwait);
1796 	}
1797 	spin_unlock(&session->frwd_lock);
1798 }
1799 
1800 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1801 				   struct iscsi_tm *hdr, int age,
1802 				   int timeout)
1803 {
1804 	struct iscsi_session *session = conn->session;
1805 	struct iscsi_task *task;
1806 
1807 	task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1808 				      NULL, 0);
1809 	if (!task) {
1810 		spin_unlock_bh(&session->frwd_lock);
1811 		iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1812 		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1813 		spin_lock_bh(&session->frwd_lock);
1814 		return -EPERM;
1815 	}
1816 	conn->tmfcmd_pdus_cnt++;
1817 	conn->tmf_timer.expires = timeout * HZ + jiffies;
1818 	conn->tmf_timer.function = iscsi_tmf_timedout;
1819 	conn->tmf_timer.data = (unsigned long)conn;
1820 	add_timer(&conn->tmf_timer);
1821 	ISCSI_DBG_EH(session, "tmf set timeout\n");
1822 
1823 	spin_unlock_bh(&session->frwd_lock);
1824 	mutex_unlock(&session->eh_mutex);
1825 
1826 	/*
1827 	 * block eh thread until:
1828 	 *
1829 	 * 1) tmf response
1830 	 * 2) tmf timeout
1831 	 * 3) session is terminated or restarted or userspace has
1832 	 * given up on recovery
1833 	 */
1834 	wait_event_interruptible(conn->ehwait, age != session->age ||
1835 				 session->state != ISCSI_STATE_LOGGED_IN ||
1836 				 conn->tmf_state != TMF_QUEUED);
1837 	if (signal_pending(current))
1838 		flush_signals(current);
1839 	del_timer_sync(&conn->tmf_timer);
1840 
1841 	mutex_lock(&session->eh_mutex);
1842 	spin_lock_bh(&session->frwd_lock);
1843 	/* if the session drops it will clean up the task */
1844 	if (age != session->age ||
1845 	    session->state != ISCSI_STATE_LOGGED_IN)
1846 		return -ENOTCONN;
1847 	return 0;
1848 }
1849 
1850 /*
1851  * Fail commands. session lock held and recv side suspended and xmit
1852  * thread flushed
1853  */
1854 static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
1855 {
1856 	struct iscsi_task *task;
1857 	int i;
1858 
1859 	for (i = 0; i < conn->session->cmds_max; i++) {
1860 		task = conn->session->cmds[i];
1861 		if (!task->sc || task->state == ISCSI_TASK_FREE)
1862 			continue;
1863 
1864 		if (lun != -1 && lun != task->sc->device->lun)
1865 			continue;
1866 
1867 		ISCSI_DBG_SESSION(conn->session,
1868 				  "failing sc %p itt 0x%x state %d\n",
1869 				  task->sc, task->itt, task->state);
1870 		fail_scsi_task(task, error);
1871 	}
1872 }
1873 
1874 /**
1875  * iscsi_suspend_queue - suspend iscsi_queuecommand
1876  * @conn: iscsi conn to stop queueing IO on
1877  *
1878  * This grabs the session frwd_lock to make sure no one is in
1879  * xmit_task/queuecommand, and then sets suspend to prevent
1880  * new commands from being queued. This only needs to be called
1881  * by offload drivers that need to sync a path like ep disconnect
1882  * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1883  * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1884  */
1885 void iscsi_suspend_queue(struct iscsi_conn *conn)
1886 {
1887 	spin_lock_bh(&conn->session->frwd_lock);
1888 	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1889 	spin_unlock_bh(&conn->session->frwd_lock);
1890 }
1891 EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1892 
1893 /**
1894  * iscsi_suspend_tx - suspend iscsi_data_xmit
1895  * @conn: iscsi conn tp stop processing IO on.
1896  *
1897  * This function sets the suspend bit to prevent iscsi_data_xmit
1898  * from sending new IO, and if work is queued on the xmit thread
1899  * it will wait for it to be completed.
1900  */
1901 void iscsi_suspend_tx(struct iscsi_conn *conn)
1902 {
1903 	struct Scsi_Host *shost = conn->session->host;
1904 	struct iscsi_host *ihost = shost_priv(shost);
1905 
1906 	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1907 	if (ihost->workq)
1908 		flush_workqueue(ihost->workq);
1909 }
1910 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1911 
1912 static void iscsi_start_tx(struct iscsi_conn *conn)
1913 {
1914 	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1915 	iscsi_conn_queue_work(conn);
1916 }
1917 
1918 /*
1919  * We want to make sure a ping is in flight. It has timed out.
1920  * And we are not busy processing a pdu that is making
1921  * progress but got started before the ping and is taking a while
1922  * to complete so the ping is just stuck behind it in a queue.
1923  */
1924 static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1925 {
1926 	if (conn->ping_task &&
1927 	    time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1928 			   (conn->ping_timeout * HZ), jiffies))
1929 		return 1;
1930 	else
1931 		return 0;
1932 }
1933 
1934 enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1935 {
1936 	enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1937 	struct iscsi_task *task = NULL, *running_task;
1938 	struct iscsi_cls_session *cls_session;
1939 	struct iscsi_session *session;
1940 	struct iscsi_conn *conn;
1941 	int i;
1942 
1943 	cls_session = starget_to_session(scsi_target(sc->device));
1944 	session = cls_session->dd_data;
1945 
1946 	ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1947 
1948 	spin_lock(&session->frwd_lock);
1949 	task = (struct iscsi_task *)sc->SCp.ptr;
1950 	if (!task) {
1951 		/*
1952 		 * Raced with completion. Blk layer has taken ownership
1953 		 * so let timeout code complete it now.
1954 		 */
1955 		rc = BLK_EH_HANDLED;
1956 		goto done;
1957 	}
1958 
1959 	if (session->state != ISCSI_STATE_LOGGED_IN) {
1960 		/*
1961 		 * We are probably in the middle of iscsi recovery so let
1962 		 * that complete and handle the error.
1963 		 */
1964 		rc = BLK_EH_RESET_TIMER;
1965 		goto done;
1966 	}
1967 
1968 	conn = session->leadconn;
1969 	if (!conn) {
1970 		/* In the middle of shuting down */
1971 		rc = BLK_EH_RESET_TIMER;
1972 		goto done;
1973 	}
1974 
1975 	/*
1976 	 * If we have sent (at least queued to the network layer) a pdu or
1977 	 * recvd one for the task since the last timeout ask for
1978 	 * more time. If on the next timeout we have not made progress
1979 	 * we can check if it is the task or connection when we send the
1980 	 * nop as a ping.
1981 	 */
1982 	if (time_after(task->last_xfer, task->last_timeout)) {
1983 		ISCSI_DBG_EH(session, "Command making progress. Asking "
1984 			     "scsi-ml for more time to complete. "
1985 			     "Last data xfer at %lu. Last timeout was at "
1986 			     "%lu\n.", task->last_xfer, task->last_timeout);
1987 		task->have_checked_conn = false;
1988 		rc = BLK_EH_RESET_TIMER;
1989 		goto done;
1990 	}
1991 
1992 	if (!conn->recv_timeout && !conn->ping_timeout)
1993 		goto done;
1994 	/*
1995 	 * if the ping timedout then we are in the middle of cleaning up
1996 	 * and can let the iscsi eh handle it
1997 	 */
1998 	if (iscsi_has_ping_timed_out(conn)) {
1999 		rc = BLK_EH_RESET_TIMER;
2000 		goto done;
2001 	}
2002 
2003 	for (i = 0; i < conn->session->cmds_max; i++) {
2004 		running_task = conn->session->cmds[i];
2005 		if (!running_task->sc || running_task == task ||
2006 		     running_task->state != ISCSI_TASK_RUNNING)
2007 			continue;
2008 
2009 		/*
2010 		 * Only check if cmds started before this one have made
2011 		 * progress, or this could never fail
2012 		 */
2013 		if (time_after(running_task->sc->jiffies_at_alloc,
2014 			       task->sc->jiffies_at_alloc))
2015 			continue;
2016 
2017 		if (time_after(running_task->last_xfer, task->last_timeout)) {
2018 			/*
2019 			 * This task has not made progress, but a task
2020 			 * started before us has transferred data since
2021 			 * we started/last-checked. We could be queueing
2022 			 * too many tasks or the LU is bad.
2023 			 *
2024 			 * If the device is bad the cmds ahead of us on
2025 			 * other devs will complete, and this loop will
2026 			 * eventually fail starting the scsi eh.
2027 			 */
2028 			ISCSI_DBG_EH(session, "Command has not made progress "
2029 				     "but commands ahead of it have. "
2030 				     "Asking scsi-ml for more time to "
2031 				     "complete. Our last xfer vs running task "
2032 				     "last xfer %lu/%lu. Last check %lu.\n",
2033 				     task->last_xfer, running_task->last_xfer,
2034 				     task->last_timeout);
2035 			rc = BLK_EH_RESET_TIMER;
2036 			goto done;
2037 		}
2038 	}
2039 
2040 	/* Assumes nop timeout is shorter than scsi cmd timeout */
2041 	if (task->have_checked_conn)
2042 		goto done;
2043 
2044 	/*
2045 	 * Checking the transport already or nop from a cmd timeout still
2046 	 * running
2047 	 */
2048 	if (conn->ping_task) {
2049 		task->have_checked_conn = true;
2050 		rc = BLK_EH_RESET_TIMER;
2051 		goto done;
2052 	}
2053 
2054 	/* Make sure there is a transport check done */
2055 	iscsi_send_nopout(conn, NULL);
2056 	task->have_checked_conn = true;
2057 	rc = BLK_EH_RESET_TIMER;
2058 
2059 done:
2060 	if (task)
2061 		task->last_timeout = jiffies;
2062 	spin_unlock(&session->frwd_lock);
2063 	ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2064 		     "timer reset" : "nh");
2065 	return rc;
2066 }
2067 EXPORT_SYMBOL_GPL(iscsi_eh_cmd_timed_out);
2068 
2069 static void iscsi_check_transport_timeouts(unsigned long data)
2070 {
2071 	struct iscsi_conn *conn = (struct iscsi_conn *)data;
2072 	struct iscsi_session *session = conn->session;
2073 	unsigned long recv_timeout, next_timeout = 0, last_recv;
2074 
2075 	spin_lock(&session->frwd_lock);
2076 	if (session->state != ISCSI_STATE_LOGGED_IN)
2077 		goto done;
2078 
2079 	recv_timeout = conn->recv_timeout;
2080 	if (!recv_timeout)
2081 		goto done;
2082 
2083 	recv_timeout *= HZ;
2084 	last_recv = conn->last_recv;
2085 
2086 	if (iscsi_has_ping_timed_out(conn)) {
2087 		iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2088 				  "expired, recv timeout %d, last rx %lu, "
2089 				  "last ping %lu, now %lu\n",
2090 				  conn->ping_timeout, conn->recv_timeout,
2091 				  last_recv, conn->last_ping, jiffies);
2092 		spin_unlock(&session->frwd_lock);
2093 		iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2094 		return;
2095 	}
2096 
2097 	if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2098 		/* send a ping to try to provoke some traffic */
2099 		ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2100 		if (iscsi_send_nopout(conn, NULL))
2101 			next_timeout = jiffies + (1 * HZ);
2102 		else
2103 			next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2104 	} else
2105 		next_timeout = last_recv + recv_timeout;
2106 
2107 	ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2108 	mod_timer(&conn->transport_timer, next_timeout);
2109 done:
2110 	spin_unlock(&session->frwd_lock);
2111 }
2112 
2113 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2114 				      struct iscsi_tm *hdr)
2115 {
2116 	memset(hdr, 0, sizeof(*hdr));
2117 	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2118 	hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2119 	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2120 	hdr->lun = task->lun;
2121 	hdr->rtt = task->hdr_itt;
2122 	hdr->refcmdsn = task->cmdsn;
2123 }
2124 
2125 int iscsi_eh_abort(struct scsi_cmnd *sc)
2126 {
2127 	struct iscsi_cls_session *cls_session;
2128 	struct iscsi_session *session;
2129 	struct iscsi_conn *conn;
2130 	struct iscsi_task *task;
2131 	struct iscsi_tm *hdr;
2132 	int age;
2133 
2134 	cls_session = starget_to_session(scsi_target(sc->device));
2135 	session = cls_session->dd_data;
2136 
2137 	ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2138 
2139 	mutex_lock(&session->eh_mutex);
2140 	spin_lock_bh(&session->frwd_lock);
2141 	/*
2142 	 * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2143 	 * got the command.
2144 	 */
2145 	if (!sc->SCp.ptr) {
2146 		ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2147 				      "it completed.\n");
2148 		spin_unlock_bh(&session->frwd_lock);
2149 		mutex_unlock(&session->eh_mutex);
2150 		return SUCCESS;
2151 	}
2152 
2153 	/*
2154 	 * If we are not logged in or we have started a new session
2155 	 * then let the host reset code handle this
2156 	 */
2157 	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2158 	    sc->SCp.phase != session->age) {
2159 		spin_unlock_bh(&session->frwd_lock);
2160 		mutex_unlock(&session->eh_mutex);
2161 		ISCSI_DBG_EH(session, "failing abort due to dropped "
2162 				  "session.\n");
2163 		return FAILED;
2164 	}
2165 
2166 	conn = session->leadconn;
2167 	conn->eh_abort_cnt++;
2168 	age = session->age;
2169 
2170 	task = (struct iscsi_task *)sc->SCp.ptr;
2171 	ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2172 		     sc, task->itt);
2173 
2174 	/* task completed before time out */
2175 	if (!task->sc) {
2176 		ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2177 		goto success;
2178 	}
2179 
2180 	if (task->state == ISCSI_TASK_PENDING) {
2181 		fail_scsi_task(task, DID_ABORT);
2182 		goto success;
2183 	}
2184 
2185 	/* only have one tmf outstanding at a time */
2186 	if (conn->tmf_state != TMF_INITIAL)
2187 		goto failed;
2188 	conn->tmf_state = TMF_QUEUED;
2189 
2190 	hdr = &conn->tmhdr;
2191 	iscsi_prep_abort_task_pdu(task, hdr);
2192 
2193 	if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout))
2194 		goto failed;
2195 
2196 	switch (conn->tmf_state) {
2197 	case TMF_SUCCESS:
2198 		spin_unlock_bh(&session->frwd_lock);
2199 		/*
2200 		 * stop tx side incase the target had sent a abort rsp but
2201 		 * the initiator was still writing out data.
2202 		 */
2203 		iscsi_suspend_tx(conn);
2204 		/*
2205 		 * we do not stop the recv side because targets have been
2206 		 * good and have never sent us a successful tmf response
2207 		 * then sent more data for the cmd.
2208 		 */
2209 		spin_lock_bh(&session->frwd_lock);
2210 		fail_scsi_task(task, DID_ABORT);
2211 		conn->tmf_state = TMF_INITIAL;
2212 		memset(hdr, 0, sizeof(*hdr));
2213 		spin_unlock_bh(&session->frwd_lock);
2214 		iscsi_start_tx(conn);
2215 		goto success_unlocked;
2216 	case TMF_TIMEDOUT:
2217 		spin_unlock_bh(&session->frwd_lock);
2218 		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2219 		goto failed_unlocked;
2220 	case TMF_NOT_FOUND:
2221 		if (!sc->SCp.ptr) {
2222 			conn->tmf_state = TMF_INITIAL;
2223 			memset(hdr, 0, sizeof(*hdr));
2224 			/* task completed before tmf abort response */
2225 			ISCSI_DBG_EH(session, "sc completed while abort	in "
2226 					      "progress\n");
2227 			goto success;
2228 		}
2229 		/* fall through */
2230 	default:
2231 		conn->tmf_state = TMF_INITIAL;
2232 		goto failed;
2233 	}
2234 
2235 success:
2236 	spin_unlock_bh(&session->frwd_lock);
2237 success_unlocked:
2238 	ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2239 		     sc, task->itt);
2240 	mutex_unlock(&session->eh_mutex);
2241 	return SUCCESS;
2242 
2243 failed:
2244 	spin_unlock_bh(&session->frwd_lock);
2245 failed_unlocked:
2246 	ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2247 		     task ? task->itt : 0);
2248 	mutex_unlock(&session->eh_mutex);
2249 	return FAILED;
2250 }
2251 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2252 
2253 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2254 {
2255 	memset(hdr, 0, sizeof(*hdr));
2256 	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2257 	hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2258 	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2259 	int_to_scsilun(sc->device->lun, &hdr->lun);
2260 	hdr->rtt = RESERVED_ITT;
2261 }
2262 
2263 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2264 {
2265 	struct iscsi_cls_session *cls_session;
2266 	struct iscsi_session *session;
2267 	struct iscsi_conn *conn;
2268 	struct iscsi_tm *hdr;
2269 	int rc = FAILED;
2270 
2271 	cls_session = starget_to_session(scsi_target(sc->device));
2272 	session = cls_session->dd_data;
2273 
2274 	ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2275 		     sc->device->lun);
2276 
2277 	mutex_lock(&session->eh_mutex);
2278 	spin_lock_bh(&session->frwd_lock);
2279 	/*
2280 	 * Just check if we are not logged in. We cannot check for
2281 	 * the phase because the reset could come from a ioctl.
2282 	 */
2283 	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2284 		goto unlock;
2285 	conn = session->leadconn;
2286 
2287 	/* only have one tmf outstanding at a time */
2288 	if (conn->tmf_state != TMF_INITIAL)
2289 		goto unlock;
2290 	conn->tmf_state = TMF_QUEUED;
2291 
2292 	hdr = &conn->tmhdr;
2293 	iscsi_prep_lun_reset_pdu(sc, hdr);
2294 
2295 	if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2296 				    session->lu_reset_timeout)) {
2297 		rc = FAILED;
2298 		goto unlock;
2299 	}
2300 
2301 	switch (conn->tmf_state) {
2302 	case TMF_SUCCESS:
2303 		break;
2304 	case TMF_TIMEDOUT:
2305 		spin_unlock_bh(&session->frwd_lock);
2306 		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2307 		goto done;
2308 	default:
2309 		conn->tmf_state = TMF_INITIAL;
2310 		goto unlock;
2311 	}
2312 
2313 	rc = SUCCESS;
2314 	spin_unlock_bh(&session->frwd_lock);
2315 
2316 	iscsi_suspend_tx(conn);
2317 
2318 	spin_lock_bh(&session->frwd_lock);
2319 	memset(hdr, 0, sizeof(*hdr));
2320 	fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2321 	conn->tmf_state = TMF_INITIAL;
2322 	spin_unlock_bh(&session->frwd_lock);
2323 
2324 	iscsi_start_tx(conn);
2325 	goto done;
2326 
2327 unlock:
2328 	spin_unlock_bh(&session->frwd_lock);
2329 done:
2330 	ISCSI_DBG_EH(session, "dev reset result = %s\n",
2331 		     rc == SUCCESS ? "SUCCESS" : "FAILED");
2332 	mutex_unlock(&session->eh_mutex);
2333 	return rc;
2334 }
2335 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2336 
2337 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2338 {
2339 	struct iscsi_session *session = cls_session->dd_data;
2340 
2341 	spin_lock_bh(&session->frwd_lock);
2342 	if (session->state != ISCSI_STATE_LOGGED_IN) {
2343 		session->state = ISCSI_STATE_RECOVERY_FAILED;
2344 		if (session->leadconn)
2345 			wake_up(&session->leadconn->ehwait);
2346 	}
2347 	spin_unlock_bh(&session->frwd_lock);
2348 }
2349 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2350 
2351 /**
2352  * iscsi_eh_session_reset - drop session and attempt relogin
2353  * @sc: scsi command
2354  *
2355  * This function will wait for a relogin, session termination from
2356  * userspace, or a recovery/replacement timeout.
2357  */
2358 int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2359 {
2360 	struct iscsi_cls_session *cls_session;
2361 	struct iscsi_session *session;
2362 	struct iscsi_conn *conn;
2363 
2364 	cls_session = starget_to_session(scsi_target(sc->device));
2365 	session = cls_session->dd_data;
2366 	conn = session->leadconn;
2367 
2368 	mutex_lock(&session->eh_mutex);
2369 	spin_lock_bh(&session->frwd_lock);
2370 	if (session->state == ISCSI_STATE_TERMINATE) {
2371 failed:
2372 		ISCSI_DBG_EH(session,
2373 			     "failing session reset: Could not log back into "
2374 			     "%s, %s [age %d]\n", session->targetname,
2375 			     conn->persistent_address, session->age);
2376 		spin_unlock_bh(&session->frwd_lock);
2377 		mutex_unlock(&session->eh_mutex);
2378 		return FAILED;
2379 	}
2380 
2381 	spin_unlock_bh(&session->frwd_lock);
2382 	mutex_unlock(&session->eh_mutex);
2383 	/*
2384 	 * we drop the lock here but the leadconn cannot be destoyed while
2385 	 * we are in the scsi eh
2386 	 */
2387 	iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2388 
2389 	ISCSI_DBG_EH(session, "wait for relogin\n");
2390 	wait_event_interruptible(conn->ehwait,
2391 				 session->state == ISCSI_STATE_TERMINATE ||
2392 				 session->state == ISCSI_STATE_LOGGED_IN ||
2393 				 session->state == ISCSI_STATE_RECOVERY_FAILED);
2394 	if (signal_pending(current))
2395 		flush_signals(current);
2396 
2397 	mutex_lock(&session->eh_mutex);
2398 	spin_lock_bh(&session->frwd_lock);
2399 	if (session->state == ISCSI_STATE_LOGGED_IN) {
2400 		ISCSI_DBG_EH(session,
2401 			     "session reset succeeded for %s,%s\n",
2402 			     session->targetname, conn->persistent_address);
2403 	} else
2404 		goto failed;
2405 	spin_unlock_bh(&session->frwd_lock);
2406 	mutex_unlock(&session->eh_mutex);
2407 	return SUCCESS;
2408 }
2409 EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2410 
2411 static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2412 {
2413 	memset(hdr, 0, sizeof(*hdr));
2414 	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2415 	hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2416 	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2417 	hdr->rtt = RESERVED_ITT;
2418 }
2419 
2420 /**
2421  * iscsi_eh_target_reset - reset target
2422  * @sc: scsi command
2423  *
2424  * This will attempt to send a warm target reset.
2425  */
2426 static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2427 {
2428 	struct iscsi_cls_session *cls_session;
2429 	struct iscsi_session *session;
2430 	struct iscsi_conn *conn;
2431 	struct iscsi_tm *hdr;
2432 	int rc = FAILED;
2433 
2434 	cls_session = starget_to_session(scsi_target(sc->device));
2435 	session = cls_session->dd_data;
2436 
2437 	ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2438 		     session->targetname);
2439 
2440 	mutex_lock(&session->eh_mutex);
2441 	spin_lock_bh(&session->frwd_lock);
2442 	/*
2443 	 * Just check if we are not logged in. We cannot check for
2444 	 * the phase because the reset could come from a ioctl.
2445 	 */
2446 	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2447 		goto unlock;
2448 	conn = session->leadconn;
2449 
2450 	/* only have one tmf outstanding at a time */
2451 	if (conn->tmf_state != TMF_INITIAL)
2452 		goto unlock;
2453 	conn->tmf_state = TMF_QUEUED;
2454 
2455 	hdr = &conn->tmhdr;
2456 	iscsi_prep_tgt_reset_pdu(sc, hdr);
2457 
2458 	if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2459 				    session->tgt_reset_timeout)) {
2460 		rc = FAILED;
2461 		goto unlock;
2462 	}
2463 
2464 	switch (conn->tmf_state) {
2465 	case TMF_SUCCESS:
2466 		break;
2467 	case TMF_TIMEDOUT:
2468 		spin_unlock_bh(&session->frwd_lock);
2469 		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2470 		goto done;
2471 	default:
2472 		conn->tmf_state = TMF_INITIAL;
2473 		goto unlock;
2474 	}
2475 
2476 	rc = SUCCESS;
2477 	spin_unlock_bh(&session->frwd_lock);
2478 
2479 	iscsi_suspend_tx(conn);
2480 
2481 	spin_lock_bh(&session->frwd_lock);
2482 	memset(hdr, 0, sizeof(*hdr));
2483 	fail_scsi_tasks(conn, -1, DID_ERROR);
2484 	conn->tmf_state = TMF_INITIAL;
2485 	spin_unlock_bh(&session->frwd_lock);
2486 
2487 	iscsi_start_tx(conn);
2488 	goto done;
2489 
2490 unlock:
2491 	spin_unlock_bh(&session->frwd_lock);
2492 done:
2493 	ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2494 		     rc == SUCCESS ? "SUCCESS" : "FAILED");
2495 	mutex_unlock(&session->eh_mutex);
2496 	return rc;
2497 }
2498 
2499 /**
2500  * iscsi_eh_recover_target - reset target and possibly the session
2501  * @sc: scsi command
2502  *
2503  * This will attempt to send a warm target reset. If that fails,
2504  * we will escalate to ERL0 session recovery.
2505  */
2506 int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2507 {
2508 	int rc;
2509 
2510 	rc = iscsi_eh_target_reset(sc);
2511 	if (rc == FAILED)
2512 		rc = iscsi_eh_session_reset(sc);
2513 	return rc;
2514 }
2515 EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2516 
2517 /*
2518  * Pre-allocate a pool of @max items of @item_size. By default, the pool
2519  * should be accessed via kfifo_{get,put} on q->queue.
2520  * Optionally, the caller can obtain the array of object pointers
2521  * by passing in a non-NULL @items pointer
2522  */
2523 int
2524 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2525 {
2526 	int i, num_arrays = 1;
2527 
2528 	memset(q, 0, sizeof(*q));
2529 
2530 	q->max = max;
2531 
2532 	/* If the user passed an items pointer, he wants a copy of
2533 	 * the array. */
2534 	if (items)
2535 		num_arrays++;
2536 	q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
2537 	if (q->pool == NULL)
2538 		return -ENOMEM;
2539 
2540 	kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2541 
2542 	for (i = 0; i < max; i++) {
2543 		q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2544 		if (q->pool[i] == NULL) {
2545 			q->max = i;
2546 			goto enomem;
2547 		}
2548 		kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2549 	}
2550 
2551 	if (items) {
2552 		*items = q->pool + max;
2553 		memcpy(*items, q->pool, max * sizeof(void *));
2554 	}
2555 
2556 	return 0;
2557 
2558 enomem:
2559 	iscsi_pool_free(q);
2560 	return -ENOMEM;
2561 }
2562 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2563 
2564 void iscsi_pool_free(struct iscsi_pool *q)
2565 {
2566 	int i;
2567 
2568 	for (i = 0; i < q->max; i++)
2569 		kfree(q->pool[i]);
2570 	kfree(q->pool);
2571 }
2572 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2573 
2574 /**
2575  * iscsi_host_add - add host to system
2576  * @shost: scsi host
2577  * @pdev: parent device
2578  *
2579  * This should be called by partial offload and software iscsi drivers
2580  * to add a host to the system.
2581  */
2582 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2583 {
2584 	if (!shost->can_queue)
2585 		shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2586 
2587 	if (!shost->cmd_per_lun)
2588 		shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2589 
2590 	return scsi_add_host(shost, pdev);
2591 }
2592 EXPORT_SYMBOL_GPL(iscsi_host_add);
2593 
2594 /**
2595  * iscsi_host_alloc - allocate a host and driver data
2596  * @sht: scsi host template
2597  * @dd_data_size: driver host data size
2598  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2599  *
2600  * This should be called by partial offload and software iscsi drivers.
2601  * To access the driver specific memory use the iscsi_host_priv() macro.
2602  */
2603 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2604 				   int dd_data_size, bool xmit_can_sleep)
2605 {
2606 	struct Scsi_Host *shost;
2607 	struct iscsi_host *ihost;
2608 
2609 	shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2610 	if (!shost)
2611 		return NULL;
2612 	ihost = shost_priv(shost);
2613 
2614 	if (xmit_can_sleep) {
2615 		snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2616 			"iscsi_q_%d", shost->host_no);
2617 		ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2618 		if (!ihost->workq)
2619 			goto free_host;
2620 	}
2621 
2622 	spin_lock_init(&ihost->lock);
2623 	ihost->state = ISCSI_HOST_SETUP;
2624 	ihost->num_sessions = 0;
2625 	init_waitqueue_head(&ihost->session_removal_wq);
2626 	return shost;
2627 
2628 free_host:
2629 	scsi_host_put(shost);
2630 	return NULL;
2631 }
2632 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2633 
2634 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2635 {
2636 	iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2637 }
2638 
2639 /**
2640  * iscsi_host_remove - remove host and sessions
2641  * @shost: scsi host
2642  *
2643  * If there are any sessions left, this will initiate the removal and wait
2644  * for the completion.
2645  */
2646 void iscsi_host_remove(struct Scsi_Host *shost)
2647 {
2648 	struct iscsi_host *ihost = shost_priv(shost);
2649 	unsigned long flags;
2650 
2651 	spin_lock_irqsave(&ihost->lock, flags);
2652 	ihost->state = ISCSI_HOST_REMOVED;
2653 	spin_unlock_irqrestore(&ihost->lock, flags);
2654 
2655 	iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2656 	wait_event_interruptible(ihost->session_removal_wq,
2657 				 ihost->num_sessions == 0);
2658 	if (signal_pending(current))
2659 		flush_signals(current);
2660 
2661 	scsi_remove_host(shost);
2662 	if (ihost->workq)
2663 		destroy_workqueue(ihost->workq);
2664 }
2665 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2666 
2667 void iscsi_host_free(struct Scsi_Host *shost)
2668 {
2669 	struct iscsi_host *ihost = shost_priv(shost);
2670 
2671 	kfree(ihost->netdev);
2672 	kfree(ihost->hwaddress);
2673 	kfree(ihost->initiatorname);
2674 	scsi_host_put(shost);
2675 }
2676 EXPORT_SYMBOL_GPL(iscsi_host_free);
2677 
2678 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2679 {
2680 	struct iscsi_host *ihost = shost_priv(shost);
2681 	unsigned long flags;
2682 
2683 	shost = scsi_host_get(shost);
2684 	if (!shost) {
2685 		printk(KERN_ERR "Invalid state. Cannot notify host removal "
2686 		      "of session teardown event because host already "
2687 		      "removed.\n");
2688 		return;
2689 	}
2690 
2691 	spin_lock_irqsave(&ihost->lock, flags);
2692 	ihost->num_sessions--;
2693 	if (ihost->num_sessions == 0)
2694 		wake_up(&ihost->session_removal_wq);
2695 	spin_unlock_irqrestore(&ihost->lock, flags);
2696 	scsi_host_put(shost);
2697 }
2698 
2699 /**
2700  * iscsi_session_setup - create iscsi cls session and host and session
2701  * @iscsit: iscsi transport template
2702  * @shost: scsi host
2703  * @cmds_max: session can queue
2704  * @cmd_task_size: LLD task private data size
2705  * @initial_cmdsn: initial CmdSN
2706  *
2707  * This can be used by software iscsi_transports that allocate
2708  * a session per scsi host.
2709  *
2710  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2711  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2712  * for nop handling and login/logout requests.
2713  */
2714 struct iscsi_cls_session *
2715 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2716 		    uint16_t cmds_max, int dd_size, int cmd_task_size,
2717 		    uint32_t initial_cmdsn, unsigned int id)
2718 {
2719 	struct iscsi_host *ihost = shost_priv(shost);
2720 	struct iscsi_session *session;
2721 	struct iscsi_cls_session *cls_session;
2722 	int cmd_i, scsi_cmds, total_cmds = cmds_max;
2723 	unsigned long flags;
2724 
2725 	spin_lock_irqsave(&ihost->lock, flags);
2726 	if (ihost->state == ISCSI_HOST_REMOVED) {
2727 		spin_unlock_irqrestore(&ihost->lock, flags);
2728 		return NULL;
2729 	}
2730 	ihost->num_sessions++;
2731 	spin_unlock_irqrestore(&ihost->lock, flags);
2732 
2733 	if (!total_cmds)
2734 		total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2735 	/*
2736 	 * The iscsi layer needs some tasks for nop handling and tmfs,
2737 	 * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2738 	 * + 1 command for scsi IO.
2739 	 */
2740 	if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2741 		printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2742 		       "must be a power of two that is at least %d.\n",
2743 		       total_cmds, ISCSI_TOTAL_CMDS_MIN);
2744 		goto dec_session_count;
2745 	}
2746 
2747 	if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2748 		printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2749 		       "must be a power of 2 less than or equal to %d.\n",
2750 		       cmds_max, ISCSI_TOTAL_CMDS_MAX);
2751 		total_cmds = ISCSI_TOTAL_CMDS_MAX;
2752 	}
2753 
2754 	if (!is_power_of_2(total_cmds)) {
2755 		printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2756 		       "must be a power of 2.\n", total_cmds);
2757 		total_cmds = rounddown_pow_of_two(total_cmds);
2758 		if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2759 			return NULL;
2760 		printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2761 		       total_cmds);
2762 	}
2763 	scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2764 
2765 	cls_session = iscsi_alloc_session(shost, iscsit,
2766 					  sizeof(struct iscsi_session) +
2767 					  dd_size);
2768 	if (!cls_session)
2769 		goto dec_session_count;
2770 	session = cls_session->dd_data;
2771 	session->cls_session = cls_session;
2772 	session->host = shost;
2773 	session->state = ISCSI_STATE_FREE;
2774 	session->fast_abort = 1;
2775 	session->tgt_reset_timeout = 30;
2776 	session->lu_reset_timeout = 15;
2777 	session->abort_timeout = 10;
2778 	session->scsi_cmds_max = scsi_cmds;
2779 	session->cmds_max = total_cmds;
2780 	session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2781 	session->exp_cmdsn = initial_cmdsn + 1;
2782 	session->max_cmdsn = initial_cmdsn + 1;
2783 	session->max_r2t = 1;
2784 	session->tt = iscsit;
2785 	session->dd_data = cls_session->dd_data + sizeof(*session);
2786 
2787 	mutex_init(&session->eh_mutex);
2788 	spin_lock_init(&session->frwd_lock);
2789 	spin_lock_init(&session->back_lock);
2790 
2791 	/* initialize SCSI PDU commands pool */
2792 	if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2793 			    (void***)&session->cmds,
2794 			    cmd_task_size + sizeof(struct iscsi_task)))
2795 		goto cmdpool_alloc_fail;
2796 
2797 	/* pre-format cmds pool with ITT */
2798 	for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2799 		struct iscsi_task *task = session->cmds[cmd_i];
2800 
2801 		if (cmd_task_size)
2802 			task->dd_data = &task[1];
2803 		task->itt = cmd_i;
2804 		task->state = ISCSI_TASK_FREE;
2805 		INIT_LIST_HEAD(&task->running);
2806 	}
2807 
2808 	if (!try_module_get(iscsit->owner))
2809 		goto module_get_fail;
2810 
2811 	if (iscsi_add_session(cls_session, id))
2812 		goto cls_session_fail;
2813 
2814 	return cls_session;
2815 
2816 cls_session_fail:
2817 	module_put(iscsit->owner);
2818 module_get_fail:
2819 	iscsi_pool_free(&session->cmdpool);
2820 cmdpool_alloc_fail:
2821 	iscsi_free_session(cls_session);
2822 dec_session_count:
2823 	iscsi_host_dec_session_cnt(shost);
2824 	return NULL;
2825 }
2826 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2827 
2828 /**
2829  * iscsi_session_teardown - destroy session, host, and cls_session
2830  * @cls_session: iscsi session
2831  *
2832  * The driver must have called iscsi_remove_session before
2833  * calling this.
2834  */
2835 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2836 {
2837 	struct iscsi_session *session = cls_session->dd_data;
2838 	struct module *owner = cls_session->transport->owner;
2839 	struct Scsi_Host *shost = session->host;
2840 
2841 	iscsi_pool_free(&session->cmdpool);
2842 
2843 	kfree(session->password);
2844 	kfree(session->password_in);
2845 	kfree(session->username);
2846 	kfree(session->username_in);
2847 	kfree(session->targetname);
2848 	kfree(session->targetalias);
2849 	kfree(session->initiatorname);
2850 	kfree(session->boot_root);
2851 	kfree(session->boot_nic);
2852 	kfree(session->boot_target);
2853 	kfree(session->ifacename);
2854 	kfree(session->portal_type);
2855 	kfree(session->discovery_parent_type);
2856 
2857 	iscsi_destroy_session(cls_session);
2858 	iscsi_host_dec_session_cnt(shost);
2859 	module_put(owner);
2860 }
2861 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2862 
2863 /**
2864  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2865  * @cls_session: iscsi_cls_session
2866  * @dd_size: private driver data size
2867  * @conn_idx: cid
2868  */
2869 struct iscsi_cls_conn *
2870 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2871 		 uint32_t conn_idx)
2872 {
2873 	struct iscsi_session *session = cls_session->dd_data;
2874 	struct iscsi_conn *conn;
2875 	struct iscsi_cls_conn *cls_conn;
2876 	char *data;
2877 
2878 	cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2879 				     conn_idx);
2880 	if (!cls_conn)
2881 		return NULL;
2882 	conn = cls_conn->dd_data;
2883 	memset(conn, 0, sizeof(*conn) + dd_size);
2884 
2885 	conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2886 	conn->session = session;
2887 	conn->cls_conn = cls_conn;
2888 	conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2889 	conn->id = conn_idx;
2890 	conn->exp_statsn = 0;
2891 	conn->tmf_state = TMF_INITIAL;
2892 
2893 	init_timer(&conn->transport_timer);
2894 	conn->transport_timer.data = (unsigned long)conn;
2895 	conn->transport_timer.function = iscsi_check_transport_timeouts;
2896 
2897 	INIT_LIST_HEAD(&conn->mgmtqueue);
2898 	INIT_LIST_HEAD(&conn->cmdqueue);
2899 	INIT_LIST_HEAD(&conn->requeue);
2900 	INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2901 
2902 	/* allocate login_task used for the login/text sequences */
2903 	spin_lock_bh(&session->frwd_lock);
2904 	if (!kfifo_out(&session->cmdpool.queue,
2905                          (void*)&conn->login_task,
2906 			 sizeof(void*))) {
2907 		spin_unlock_bh(&session->frwd_lock);
2908 		goto login_task_alloc_fail;
2909 	}
2910 	spin_unlock_bh(&session->frwd_lock);
2911 
2912 	data = (char *) __get_free_pages(GFP_KERNEL,
2913 					 get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2914 	if (!data)
2915 		goto login_task_data_alloc_fail;
2916 	conn->login_task->data = conn->data = data;
2917 
2918 	init_timer(&conn->tmf_timer);
2919 	init_waitqueue_head(&conn->ehwait);
2920 
2921 	return cls_conn;
2922 
2923 login_task_data_alloc_fail:
2924 	kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2925 		    sizeof(void*));
2926 login_task_alloc_fail:
2927 	iscsi_destroy_conn(cls_conn);
2928 	return NULL;
2929 }
2930 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2931 
2932 /**
2933  * iscsi_conn_teardown - teardown iscsi connection
2934  * cls_conn: iscsi class connection
2935  *
2936  * TODO: we may need to make this into a two step process
2937  * like scsi-mls remove + put host
2938  */
2939 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2940 {
2941 	struct iscsi_conn *conn = cls_conn->dd_data;
2942 	struct iscsi_session *session = conn->session;
2943 
2944 	del_timer_sync(&conn->transport_timer);
2945 
2946 	mutex_lock(&session->eh_mutex);
2947 	spin_lock_bh(&session->frwd_lock);
2948 	conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2949 	if (session->leadconn == conn) {
2950 		/*
2951 		 * leading connection? then give up on recovery.
2952 		 */
2953 		session->state = ISCSI_STATE_TERMINATE;
2954 		wake_up(&conn->ehwait);
2955 	}
2956 	spin_unlock_bh(&session->frwd_lock);
2957 
2958 	/* flush queued up work because we free the connection below */
2959 	iscsi_suspend_tx(conn);
2960 
2961 	spin_lock_bh(&session->frwd_lock);
2962 	free_pages((unsigned long) conn->data,
2963 		   get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2964 	kfree(conn->persistent_address);
2965 	kfree(conn->local_ipaddr);
2966 	/* regular RX path uses back_lock */
2967 	spin_lock_bh(&session->back_lock);
2968 	kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2969 		    sizeof(void*));
2970 	spin_unlock_bh(&session->back_lock);
2971 	if (session->leadconn == conn)
2972 		session->leadconn = NULL;
2973 	spin_unlock_bh(&session->frwd_lock);
2974 	mutex_unlock(&session->eh_mutex);
2975 
2976 	iscsi_destroy_conn(cls_conn);
2977 }
2978 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2979 
2980 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2981 {
2982 	struct iscsi_conn *conn = cls_conn->dd_data;
2983 	struct iscsi_session *session = conn->session;
2984 
2985 	if (!session) {
2986 		iscsi_conn_printk(KERN_ERR, conn,
2987 				  "can't start unbound connection\n");
2988 		return -EPERM;
2989 	}
2990 
2991 	if ((session->imm_data_en || !session->initial_r2t_en) &&
2992 	     session->first_burst > session->max_burst) {
2993 		iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2994 				  "first_burst %d max_burst %d\n",
2995 				  session->first_burst, session->max_burst);
2996 		return -EINVAL;
2997 	}
2998 
2999 	if (conn->ping_timeout && !conn->recv_timeout) {
3000 		iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3001 				  "zero. Using 5 seconds\n.");
3002 		conn->recv_timeout = 5;
3003 	}
3004 
3005 	if (conn->recv_timeout && !conn->ping_timeout) {
3006 		iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3007 				  "zero. Using 5 seconds.\n");
3008 		conn->ping_timeout = 5;
3009 	}
3010 
3011 	spin_lock_bh(&session->frwd_lock);
3012 	conn->c_stage = ISCSI_CONN_STARTED;
3013 	session->state = ISCSI_STATE_LOGGED_IN;
3014 	session->queued_cmdsn = session->cmdsn;
3015 
3016 	conn->last_recv = jiffies;
3017 	conn->last_ping = jiffies;
3018 	if (conn->recv_timeout && conn->ping_timeout)
3019 		mod_timer(&conn->transport_timer,
3020 			  jiffies + (conn->recv_timeout * HZ));
3021 
3022 	switch(conn->stop_stage) {
3023 	case STOP_CONN_RECOVER:
3024 		/*
3025 		 * unblock eh_abort() if it is blocked. re-try all
3026 		 * commands after successful recovery
3027 		 */
3028 		conn->stop_stage = 0;
3029 		conn->tmf_state = TMF_INITIAL;
3030 		session->age++;
3031 		if (session->age == 16)
3032 			session->age = 0;
3033 		break;
3034 	case STOP_CONN_TERM:
3035 		conn->stop_stage = 0;
3036 		break;
3037 	default:
3038 		break;
3039 	}
3040 	spin_unlock_bh(&session->frwd_lock);
3041 
3042 	iscsi_unblock_session(session->cls_session);
3043 	wake_up(&conn->ehwait);
3044 	return 0;
3045 }
3046 EXPORT_SYMBOL_GPL(iscsi_conn_start);
3047 
3048 static void
3049 fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3050 {
3051 	struct iscsi_task *task;
3052 	int i, state;
3053 
3054 	for (i = 0; i < conn->session->cmds_max; i++) {
3055 		task = conn->session->cmds[i];
3056 		if (task->sc)
3057 			continue;
3058 
3059 		if (task->state == ISCSI_TASK_FREE)
3060 			continue;
3061 
3062 		ISCSI_DBG_SESSION(conn->session,
3063 				  "failing mgmt itt 0x%x state %d\n",
3064 				  task->itt, task->state);
3065 		state = ISCSI_TASK_ABRT_SESS_RECOV;
3066 		if (task->state == ISCSI_TASK_PENDING)
3067 			state = ISCSI_TASK_COMPLETED;
3068 		iscsi_complete_task(task, state);
3069 
3070 	}
3071 }
3072 
3073 static void iscsi_start_session_recovery(struct iscsi_session *session,
3074 					 struct iscsi_conn *conn, int flag)
3075 {
3076 	int old_stop_stage;
3077 
3078 	mutex_lock(&session->eh_mutex);
3079 	spin_lock_bh(&session->frwd_lock);
3080 	if (conn->stop_stage == STOP_CONN_TERM) {
3081 		spin_unlock_bh(&session->frwd_lock);
3082 		mutex_unlock(&session->eh_mutex);
3083 		return;
3084 	}
3085 
3086 	/*
3087 	 * When this is called for the in_login state, we only want to clean
3088 	 * up the login task and connection. We do not need to block and set
3089 	 * the recovery state again
3090 	 */
3091 	if (flag == STOP_CONN_TERM)
3092 		session->state = ISCSI_STATE_TERMINATE;
3093 	else if (conn->stop_stage != STOP_CONN_RECOVER)
3094 		session->state = ISCSI_STATE_IN_RECOVERY;
3095 
3096 	old_stop_stage = conn->stop_stage;
3097 	conn->stop_stage = flag;
3098 	spin_unlock_bh(&session->frwd_lock);
3099 
3100 	del_timer_sync(&conn->transport_timer);
3101 	iscsi_suspend_tx(conn);
3102 
3103 	spin_lock_bh(&session->frwd_lock);
3104 	conn->c_stage = ISCSI_CONN_STOPPED;
3105 	spin_unlock_bh(&session->frwd_lock);
3106 
3107 	/*
3108 	 * for connection level recovery we should not calculate
3109 	 * header digest. conn->hdr_size used for optimization
3110 	 * in hdr_extract() and will be re-negotiated at
3111 	 * set_param() time.
3112 	 */
3113 	if (flag == STOP_CONN_RECOVER) {
3114 		conn->hdrdgst_en = 0;
3115 		conn->datadgst_en = 0;
3116 		if (session->state == ISCSI_STATE_IN_RECOVERY &&
3117 		    old_stop_stage != STOP_CONN_RECOVER) {
3118 			ISCSI_DBG_SESSION(session, "blocking session\n");
3119 			iscsi_block_session(session->cls_session);
3120 		}
3121 	}
3122 
3123 	/*
3124 	 * flush queues.
3125 	 */
3126 	spin_lock_bh(&session->frwd_lock);
3127 	fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3128 	fail_mgmt_tasks(session, conn);
3129 	memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3130 	spin_unlock_bh(&session->frwd_lock);
3131 	mutex_unlock(&session->eh_mutex);
3132 }
3133 
3134 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3135 {
3136 	struct iscsi_conn *conn = cls_conn->dd_data;
3137 	struct iscsi_session *session = conn->session;
3138 
3139 	switch (flag) {
3140 	case STOP_CONN_RECOVER:
3141 	case STOP_CONN_TERM:
3142 		iscsi_start_session_recovery(session, conn, flag);
3143 		break;
3144 	default:
3145 		iscsi_conn_printk(KERN_ERR, conn,
3146 				  "invalid stop flag %d\n", flag);
3147 	}
3148 }
3149 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3150 
3151 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3152 		    struct iscsi_cls_conn *cls_conn, int is_leading)
3153 {
3154 	struct iscsi_session *session = cls_session->dd_data;
3155 	struct iscsi_conn *conn = cls_conn->dd_data;
3156 
3157 	spin_lock_bh(&session->frwd_lock);
3158 	if (is_leading)
3159 		session->leadconn = conn;
3160 	spin_unlock_bh(&session->frwd_lock);
3161 
3162 	/*
3163 	 * Unblock xmitworker(), Login Phase will pass through.
3164 	 */
3165 	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3166 	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3167 	return 0;
3168 }
3169 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3170 
3171 int iscsi_switch_str_param(char **param, char *new_val_buf)
3172 {
3173 	char *new_val;
3174 
3175 	if (*param) {
3176 		if (!strcmp(*param, new_val_buf))
3177 			return 0;
3178 	}
3179 
3180 	new_val = kstrdup(new_val_buf, GFP_NOIO);
3181 	if (!new_val)
3182 		return -ENOMEM;
3183 
3184 	kfree(*param);
3185 	*param = new_val;
3186 	return 0;
3187 }
3188 EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3189 
3190 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3191 		    enum iscsi_param param, char *buf, int buflen)
3192 {
3193 	struct iscsi_conn *conn = cls_conn->dd_data;
3194 	struct iscsi_session *session = conn->session;
3195 	int val;
3196 
3197 	switch(param) {
3198 	case ISCSI_PARAM_FAST_ABORT:
3199 		sscanf(buf, "%d", &session->fast_abort);
3200 		break;
3201 	case ISCSI_PARAM_ABORT_TMO:
3202 		sscanf(buf, "%d", &session->abort_timeout);
3203 		break;
3204 	case ISCSI_PARAM_LU_RESET_TMO:
3205 		sscanf(buf, "%d", &session->lu_reset_timeout);
3206 		break;
3207 	case ISCSI_PARAM_TGT_RESET_TMO:
3208 		sscanf(buf, "%d", &session->tgt_reset_timeout);
3209 		break;
3210 	case ISCSI_PARAM_PING_TMO:
3211 		sscanf(buf, "%d", &conn->ping_timeout);
3212 		break;
3213 	case ISCSI_PARAM_RECV_TMO:
3214 		sscanf(buf, "%d", &conn->recv_timeout);
3215 		break;
3216 	case ISCSI_PARAM_MAX_RECV_DLENGTH:
3217 		sscanf(buf, "%d", &conn->max_recv_dlength);
3218 		break;
3219 	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3220 		sscanf(buf, "%d", &conn->max_xmit_dlength);
3221 		break;
3222 	case ISCSI_PARAM_HDRDGST_EN:
3223 		sscanf(buf, "%d", &conn->hdrdgst_en);
3224 		break;
3225 	case ISCSI_PARAM_DATADGST_EN:
3226 		sscanf(buf, "%d", &conn->datadgst_en);
3227 		break;
3228 	case ISCSI_PARAM_INITIAL_R2T_EN:
3229 		sscanf(buf, "%d", &session->initial_r2t_en);
3230 		break;
3231 	case ISCSI_PARAM_MAX_R2T:
3232 		sscanf(buf, "%hu", &session->max_r2t);
3233 		break;
3234 	case ISCSI_PARAM_IMM_DATA_EN:
3235 		sscanf(buf, "%d", &session->imm_data_en);
3236 		break;
3237 	case ISCSI_PARAM_FIRST_BURST:
3238 		sscanf(buf, "%d", &session->first_burst);
3239 		break;
3240 	case ISCSI_PARAM_MAX_BURST:
3241 		sscanf(buf, "%d", &session->max_burst);
3242 		break;
3243 	case ISCSI_PARAM_PDU_INORDER_EN:
3244 		sscanf(buf, "%d", &session->pdu_inorder_en);
3245 		break;
3246 	case ISCSI_PARAM_DATASEQ_INORDER_EN:
3247 		sscanf(buf, "%d", &session->dataseq_inorder_en);
3248 		break;
3249 	case ISCSI_PARAM_ERL:
3250 		sscanf(buf, "%d", &session->erl);
3251 		break;
3252 	case ISCSI_PARAM_EXP_STATSN:
3253 		sscanf(buf, "%u", &conn->exp_statsn);
3254 		break;
3255 	case ISCSI_PARAM_USERNAME:
3256 		return iscsi_switch_str_param(&session->username, buf);
3257 	case ISCSI_PARAM_USERNAME_IN:
3258 		return iscsi_switch_str_param(&session->username_in, buf);
3259 	case ISCSI_PARAM_PASSWORD:
3260 		return iscsi_switch_str_param(&session->password, buf);
3261 	case ISCSI_PARAM_PASSWORD_IN:
3262 		return iscsi_switch_str_param(&session->password_in, buf);
3263 	case ISCSI_PARAM_TARGET_NAME:
3264 		return iscsi_switch_str_param(&session->targetname, buf);
3265 	case ISCSI_PARAM_TARGET_ALIAS:
3266 		return iscsi_switch_str_param(&session->targetalias, buf);
3267 	case ISCSI_PARAM_TPGT:
3268 		sscanf(buf, "%d", &session->tpgt);
3269 		break;
3270 	case ISCSI_PARAM_PERSISTENT_PORT:
3271 		sscanf(buf, "%d", &conn->persistent_port);
3272 		break;
3273 	case ISCSI_PARAM_PERSISTENT_ADDRESS:
3274 		return iscsi_switch_str_param(&conn->persistent_address, buf);
3275 	case ISCSI_PARAM_IFACE_NAME:
3276 		return iscsi_switch_str_param(&session->ifacename, buf);
3277 	case ISCSI_PARAM_INITIATOR_NAME:
3278 		return iscsi_switch_str_param(&session->initiatorname, buf);
3279 	case ISCSI_PARAM_BOOT_ROOT:
3280 		return iscsi_switch_str_param(&session->boot_root, buf);
3281 	case ISCSI_PARAM_BOOT_NIC:
3282 		return iscsi_switch_str_param(&session->boot_nic, buf);
3283 	case ISCSI_PARAM_BOOT_TARGET:
3284 		return iscsi_switch_str_param(&session->boot_target, buf);
3285 	case ISCSI_PARAM_PORTAL_TYPE:
3286 		return iscsi_switch_str_param(&session->portal_type, buf);
3287 	case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3288 		return iscsi_switch_str_param(&session->discovery_parent_type,
3289 					      buf);
3290 	case ISCSI_PARAM_DISCOVERY_SESS:
3291 		sscanf(buf, "%d", &val);
3292 		session->discovery_sess = !!val;
3293 		break;
3294 	case ISCSI_PARAM_LOCAL_IPADDR:
3295 		return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3296 	default:
3297 		return -ENOSYS;
3298 	}
3299 
3300 	return 0;
3301 }
3302 EXPORT_SYMBOL_GPL(iscsi_set_param);
3303 
3304 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3305 			    enum iscsi_param param, char *buf)
3306 {
3307 	struct iscsi_session *session = cls_session->dd_data;
3308 	int len;
3309 
3310 	switch(param) {
3311 	case ISCSI_PARAM_FAST_ABORT:
3312 		len = sprintf(buf, "%d\n", session->fast_abort);
3313 		break;
3314 	case ISCSI_PARAM_ABORT_TMO:
3315 		len = sprintf(buf, "%d\n", session->abort_timeout);
3316 		break;
3317 	case ISCSI_PARAM_LU_RESET_TMO:
3318 		len = sprintf(buf, "%d\n", session->lu_reset_timeout);
3319 		break;
3320 	case ISCSI_PARAM_TGT_RESET_TMO:
3321 		len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
3322 		break;
3323 	case ISCSI_PARAM_INITIAL_R2T_EN:
3324 		len = sprintf(buf, "%d\n", session->initial_r2t_en);
3325 		break;
3326 	case ISCSI_PARAM_MAX_R2T:
3327 		len = sprintf(buf, "%hu\n", session->max_r2t);
3328 		break;
3329 	case ISCSI_PARAM_IMM_DATA_EN:
3330 		len = sprintf(buf, "%d\n", session->imm_data_en);
3331 		break;
3332 	case ISCSI_PARAM_FIRST_BURST:
3333 		len = sprintf(buf, "%u\n", session->first_burst);
3334 		break;
3335 	case ISCSI_PARAM_MAX_BURST:
3336 		len = sprintf(buf, "%u\n", session->max_burst);
3337 		break;
3338 	case ISCSI_PARAM_PDU_INORDER_EN:
3339 		len = sprintf(buf, "%d\n", session->pdu_inorder_en);
3340 		break;
3341 	case ISCSI_PARAM_DATASEQ_INORDER_EN:
3342 		len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
3343 		break;
3344 	case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3345 		len = sprintf(buf, "%d\n", session->def_taskmgmt_tmo);
3346 		break;
3347 	case ISCSI_PARAM_ERL:
3348 		len = sprintf(buf, "%d\n", session->erl);
3349 		break;
3350 	case ISCSI_PARAM_TARGET_NAME:
3351 		len = sprintf(buf, "%s\n", session->targetname);
3352 		break;
3353 	case ISCSI_PARAM_TARGET_ALIAS:
3354 		len = sprintf(buf, "%s\n", session->targetalias);
3355 		break;
3356 	case ISCSI_PARAM_TPGT:
3357 		len = sprintf(buf, "%d\n", session->tpgt);
3358 		break;
3359 	case ISCSI_PARAM_USERNAME:
3360 		len = sprintf(buf, "%s\n", session->username);
3361 		break;
3362 	case ISCSI_PARAM_USERNAME_IN:
3363 		len = sprintf(buf, "%s\n", session->username_in);
3364 		break;
3365 	case ISCSI_PARAM_PASSWORD:
3366 		len = sprintf(buf, "%s\n", session->password);
3367 		break;
3368 	case ISCSI_PARAM_PASSWORD_IN:
3369 		len = sprintf(buf, "%s\n", session->password_in);
3370 		break;
3371 	case ISCSI_PARAM_IFACE_NAME:
3372 		len = sprintf(buf, "%s\n", session->ifacename);
3373 		break;
3374 	case ISCSI_PARAM_INITIATOR_NAME:
3375 		len = sprintf(buf, "%s\n", session->initiatorname);
3376 		break;
3377 	case ISCSI_PARAM_BOOT_ROOT:
3378 		len = sprintf(buf, "%s\n", session->boot_root);
3379 		break;
3380 	case ISCSI_PARAM_BOOT_NIC:
3381 		len = sprintf(buf, "%s\n", session->boot_nic);
3382 		break;
3383 	case ISCSI_PARAM_BOOT_TARGET:
3384 		len = sprintf(buf, "%s\n", session->boot_target);
3385 		break;
3386 	case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3387 		len = sprintf(buf, "%u\n", session->auto_snd_tgt_disable);
3388 		break;
3389 	case ISCSI_PARAM_DISCOVERY_SESS:
3390 		len = sprintf(buf, "%u\n", session->discovery_sess);
3391 		break;
3392 	case ISCSI_PARAM_PORTAL_TYPE:
3393 		len = sprintf(buf, "%s\n", session->portal_type);
3394 		break;
3395 	case ISCSI_PARAM_CHAP_AUTH_EN:
3396 		len = sprintf(buf, "%u\n", session->chap_auth_en);
3397 		break;
3398 	case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3399 		len = sprintf(buf, "%u\n", session->discovery_logout_en);
3400 		break;
3401 	case ISCSI_PARAM_BIDI_CHAP_EN:
3402 		len = sprintf(buf, "%u\n", session->bidi_chap_en);
3403 		break;
3404 	case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3405 		len = sprintf(buf, "%u\n", session->discovery_auth_optional);
3406 		break;
3407 	case ISCSI_PARAM_DEF_TIME2WAIT:
3408 		len = sprintf(buf, "%d\n", session->time2wait);
3409 		break;
3410 	case ISCSI_PARAM_DEF_TIME2RETAIN:
3411 		len = sprintf(buf, "%d\n", session->time2retain);
3412 		break;
3413 	case ISCSI_PARAM_TSID:
3414 		len = sprintf(buf, "%u\n", session->tsid);
3415 		break;
3416 	case ISCSI_PARAM_ISID:
3417 		len = sprintf(buf, "%02x%02x%02x%02x%02x%02x\n",
3418 			      session->isid[0], session->isid[1],
3419 			      session->isid[2], session->isid[3],
3420 			      session->isid[4], session->isid[5]);
3421 		break;
3422 	case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3423 		len = sprintf(buf, "%u\n", session->discovery_parent_idx);
3424 		break;
3425 	case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3426 		if (session->discovery_parent_type)
3427 			len = sprintf(buf, "%s\n",
3428 				      session->discovery_parent_type);
3429 		else
3430 			len = sprintf(buf, "\n");
3431 		break;
3432 	default:
3433 		return -ENOSYS;
3434 	}
3435 
3436 	return len;
3437 }
3438 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3439 
3440 int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3441 			      enum iscsi_param param, char *buf)
3442 {
3443 	struct sockaddr_in6 *sin6 = NULL;
3444 	struct sockaddr_in *sin = NULL;
3445 	int len;
3446 
3447 	switch (addr->ss_family) {
3448 	case AF_INET:
3449 		sin = (struct sockaddr_in *)addr;
3450 		break;
3451 	case AF_INET6:
3452 		sin6 = (struct sockaddr_in6 *)addr;
3453 		break;
3454 	default:
3455 		return -EINVAL;
3456 	}
3457 
3458 	switch (param) {
3459 	case ISCSI_PARAM_CONN_ADDRESS:
3460 	case ISCSI_HOST_PARAM_IPADDRESS:
3461 		if (sin)
3462 			len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
3463 		else
3464 			len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
3465 		break;
3466 	case ISCSI_PARAM_CONN_PORT:
3467 	case ISCSI_PARAM_LOCAL_PORT:
3468 		if (sin)
3469 			len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3470 		else
3471 			len = sprintf(buf, "%hu\n",
3472 				      be16_to_cpu(sin6->sin6_port));
3473 		break;
3474 	default:
3475 		return -EINVAL;
3476 	}
3477 
3478 	return len;
3479 }
3480 EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3481 
3482 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3483 			 enum iscsi_param param, char *buf)
3484 {
3485 	struct iscsi_conn *conn = cls_conn->dd_data;
3486 	int len;
3487 
3488 	switch(param) {
3489 	case ISCSI_PARAM_PING_TMO:
3490 		len = sprintf(buf, "%u\n", conn->ping_timeout);
3491 		break;
3492 	case ISCSI_PARAM_RECV_TMO:
3493 		len = sprintf(buf, "%u\n", conn->recv_timeout);
3494 		break;
3495 	case ISCSI_PARAM_MAX_RECV_DLENGTH:
3496 		len = sprintf(buf, "%u\n", conn->max_recv_dlength);
3497 		break;
3498 	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3499 		len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
3500 		break;
3501 	case ISCSI_PARAM_HDRDGST_EN:
3502 		len = sprintf(buf, "%d\n", conn->hdrdgst_en);
3503 		break;
3504 	case ISCSI_PARAM_DATADGST_EN:
3505 		len = sprintf(buf, "%d\n", conn->datadgst_en);
3506 		break;
3507 	case ISCSI_PARAM_IFMARKER_EN:
3508 		len = sprintf(buf, "%d\n", conn->ifmarker_en);
3509 		break;
3510 	case ISCSI_PARAM_OFMARKER_EN:
3511 		len = sprintf(buf, "%d\n", conn->ofmarker_en);
3512 		break;
3513 	case ISCSI_PARAM_EXP_STATSN:
3514 		len = sprintf(buf, "%u\n", conn->exp_statsn);
3515 		break;
3516 	case ISCSI_PARAM_PERSISTENT_PORT:
3517 		len = sprintf(buf, "%d\n", conn->persistent_port);
3518 		break;
3519 	case ISCSI_PARAM_PERSISTENT_ADDRESS:
3520 		len = sprintf(buf, "%s\n", conn->persistent_address);
3521 		break;
3522 	case ISCSI_PARAM_STATSN:
3523 		len = sprintf(buf, "%u\n", conn->statsn);
3524 		break;
3525 	case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3526 		len = sprintf(buf, "%u\n", conn->max_segment_size);
3527 		break;
3528 	case ISCSI_PARAM_KEEPALIVE_TMO:
3529 		len = sprintf(buf, "%u\n", conn->keepalive_tmo);
3530 		break;
3531 	case ISCSI_PARAM_LOCAL_PORT:
3532 		len = sprintf(buf, "%u\n", conn->local_port);
3533 		break;
3534 	case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3535 		len = sprintf(buf, "%u\n", conn->tcp_timestamp_stat);
3536 		break;
3537 	case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3538 		len = sprintf(buf, "%u\n", conn->tcp_nagle_disable);
3539 		break;
3540 	case ISCSI_PARAM_TCP_WSF_DISABLE:
3541 		len = sprintf(buf, "%u\n", conn->tcp_wsf_disable);
3542 		break;
3543 	case ISCSI_PARAM_TCP_TIMER_SCALE:
3544 		len = sprintf(buf, "%u\n", conn->tcp_timer_scale);
3545 		break;
3546 	case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3547 		len = sprintf(buf, "%u\n", conn->tcp_timestamp_en);
3548 		break;
3549 	case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3550 		len = sprintf(buf, "%u\n", conn->fragment_disable);
3551 		break;
3552 	case ISCSI_PARAM_IPV4_TOS:
3553 		len = sprintf(buf, "%u\n", conn->ipv4_tos);
3554 		break;
3555 	case ISCSI_PARAM_IPV6_TC:
3556 		len = sprintf(buf, "%u\n", conn->ipv6_traffic_class);
3557 		break;
3558 	case ISCSI_PARAM_IPV6_FLOW_LABEL:
3559 		len = sprintf(buf, "%u\n", conn->ipv6_flow_label);
3560 		break;
3561 	case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3562 		len = sprintf(buf, "%u\n", conn->is_fw_assigned_ipv6);
3563 		break;
3564 	case ISCSI_PARAM_TCP_XMIT_WSF:
3565 		len = sprintf(buf, "%u\n", conn->tcp_xmit_wsf);
3566 		break;
3567 	case ISCSI_PARAM_TCP_RECV_WSF:
3568 		len = sprintf(buf, "%u\n", conn->tcp_recv_wsf);
3569 		break;
3570 	case ISCSI_PARAM_LOCAL_IPADDR:
3571 		len = sprintf(buf, "%s\n", conn->local_ipaddr);
3572 		break;
3573 	default:
3574 		return -ENOSYS;
3575 	}
3576 
3577 	return len;
3578 }
3579 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3580 
3581 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3582 			 char *buf)
3583 {
3584 	struct iscsi_host *ihost = shost_priv(shost);
3585 	int len;
3586 
3587 	switch (param) {
3588 	case ISCSI_HOST_PARAM_NETDEV_NAME:
3589 		len = sprintf(buf, "%s\n", ihost->netdev);
3590 		break;
3591 	case ISCSI_HOST_PARAM_HWADDRESS:
3592 		len = sprintf(buf, "%s\n", ihost->hwaddress);
3593 		break;
3594 	case ISCSI_HOST_PARAM_INITIATOR_NAME:
3595 		len = sprintf(buf, "%s\n", ihost->initiatorname);
3596 		break;
3597 	default:
3598 		return -ENOSYS;
3599 	}
3600 
3601 	return len;
3602 }
3603 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3604 
3605 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3606 			 char *buf, int buflen)
3607 {
3608 	struct iscsi_host *ihost = shost_priv(shost);
3609 
3610 	switch (param) {
3611 	case ISCSI_HOST_PARAM_NETDEV_NAME:
3612 		return iscsi_switch_str_param(&ihost->netdev, buf);
3613 	case ISCSI_HOST_PARAM_HWADDRESS:
3614 		return iscsi_switch_str_param(&ihost->hwaddress, buf);
3615 	case ISCSI_HOST_PARAM_INITIATOR_NAME:
3616 		return iscsi_switch_str_param(&ihost->initiatorname, buf);
3617 	default:
3618 		return -ENOSYS;
3619 	}
3620 
3621 	return 0;
3622 }
3623 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3624 
3625 MODULE_AUTHOR("Mike Christie");
3626 MODULE_DESCRIPTION("iSCSI library functions");
3627 MODULE_LICENSE("GPL");
3628