xref: /linux/drivers/scsi/libiscsi.c (revision 0d3b051adbb72ed81956447d0d1e54d5943ee6f5)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * iSCSI lib functions
4  *
5  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
6  * Copyright (C) 2004 - 2006 Mike Christie
7  * Copyright (C) 2004 - 2005 Dmitry Yusupov
8  * Copyright (C) 2004 - 2005 Alex Aizman
9  * maintained by open-iscsi@googlegroups.com
10  */
11 #include <linux/types.h>
12 #include <linux/kfifo.h>
13 #include <linux/delay.h>
14 #include <linux/log2.h>
15 #include <linux/slab.h>
16 #include <linux/sched/signal.h>
17 #include <linux/module.h>
18 #include <asm/unaligned.h>
19 #include <net/tcp.h>
20 #include <scsi/scsi_cmnd.h>
21 #include <scsi/scsi_device.h>
22 #include <scsi/scsi_eh.h>
23 #include <scsi/scsi_tcq.h>
24 #include <scsi/scsi_host.h>
25 #include <scsi/scsi.h>
26 #include <scsi/iscsi_proto.h>
27 #include <scsi/scsi_transport.h>
28 #include <scsi/scsi_transport_iscsi.h>
29 #include <scsi/libiscsi.h>
30 #include <trace/events/iscsi.h>
31 
32 static int iscsi_dbg_lib_conn;
33 module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
34 		   S_IRUGO | S_IWUSR);
35 MODULE_PARM_DESC(debug_libiscsi_conn,
36 		 "Turn on debugging for connections in libiscsi module. "
37 		 "Set to 1 to turn on, and zero to turn off. Default is off.");
38 
39 static int iscsi_dbg_lib_session;
40 module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
41 		   S_IRUGO | S_IWUSR);
42 MODULE_PARM_DESC(debug_libiscsi_session,
43 		 "Turn on debugging for sessions in libiscsi module. "
44 		 "Set to 1 to turn on, and zero to turn off. Default is off.");
45 
46 static int iscsi_dbg_lib_eh;
47 module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
48 		   S_IRUGO | S_IWUSR);
49 MODULE_PARM_DESC(debug_libiscsi_eh,
50 		 "Turn on debugging for error handling in libiscsi module. "
51 		 "Set to 1 to turn on, and zero to turn off. Default is off.");
52 
53 #define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)			\
54 	do {							\
55 		if (iscsi_dbg_lib_conn)				\
56 			iscsi_conn_printk(KERN_INFO, _conn,	\
57 					     "%s " dbg_fmt,	\
58 					     __func__, ##arg);	\
59 		iscsi_dbg_trace(trace_iscsi_dbg_conn,		\
60 				&(_conn)->cls_conn->dev,	\
61 				"%s " dbg_fmt, __func__, ##arg);\
62 	} while (0);
63 
64 #define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)			\
65 	do {								\
66 		if (iscsi_dbg_lib_session)				\
67 			iscsi_session_printk(KERN_INFO, _session,	\
68 					     "%s " dbg_fmt,		\
69 					     __func__, ##arg);		\
70 		iscsi_dbg_trace(trace_iscsi_dbg_session, 		\
71 				&(_session)->cls_session->dev,		\
72 				"%s " dbg_fmt, __func__, ##arg);	\
73 	} while (0);
74 
75 #define ISCSI_DBG_EH(_session, dbg_fmt, arg...)				\
76 	do {								\
77 		if (iscsi_dbg_lib_eh)					\
78 			iscsi_session_printk(KERN_INFO, _session,	\
79 					     "%s " dbg_fmt,		\
80 					     __func__, ##arg);		\
81 		iscsi_dbg_trace(trace_iscsi_dbg_eh,			\
82 				&(_session)->cls_session->dev,		\
83 				"%s " dbg_fmt, __func__, ##arg);	\
84 	} while (0);
85 
86 inline void iscsi_conn_queue_work(struct iscsi_conn *conn)
87 {
88 	struct Scsi_Host *shost = conn->session->host;
89 	struct iscsi_host *ihost = shost_priv(shost);
90 
91 	if (ihost->workq)
92 		queue_work(ihost->workq, &conn->xmitwork);
93 }
94 EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
95 
96 static void __iscsi_update_cmdsn(struct iscsi_session *session,
97 				 uint32_t exp_cmdsn, uint32_t max_cmdsn)
98 {
99 	/*
100 	 * standard specifies this check for when to update expected and
101 	 * max sequence numbers
102 	 */
103 	if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
104 		return;
105 
106 	if (exp_cmdsn != session->exp_cmdsn &&
107 	    !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
108 		session->exp_cmdsn = exp_cmdsn;
109 
110 	if (max_cmdsn != session->max_cmdsn &&
111 	    !iscsi_sna_lt(max_cmdsn, session->max_cmdsn))
112 		session->max_cmdsn = max_cmdsn;
113 }
114 
115 void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
116 {
117 	__iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
118 			     be32_to_cpu(hdr->max_cmdsn));
119 }
120 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
121 
122 /**
123  * iscsi_prep_data_out_pdu - initialize Data-Out
124  * @task: scsi command task
125  * @r2t: R2T info
126  * @hdr: iscsi data in pdu
127  *
128  * Notes:
129  *	Initialize Data-Out within this R2T sequence and finds
130  *	proper data_offset within this SCSI command.
131  *
132  *	This function is called with connection lock taken.
133  **/
134 void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
135 			   struct iscsi_data *hdr)
136 {
137 	struct iscsi_conn *conn = task->conn;
138 	unsigned int left = r2t->data_length - r2t->sent;
139 
140 	task->hdr_len = sizeof(struct iscsi_data);
141 
142 	memset(hdr, 0, sizeof(struct iscsi_data));
143 	hdr->ttt = r2t->ttt;
144 	hdr->datasn = cpu_to_be32(r2t->datasn);
145 	r2t->datasn++;
146 	hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
147 	hdr->lun = task->lun;
148 	hdr->itt = task->hdr_itt;
149 	hdr->exp_statsn = r2t->exp_statsn;
150 	hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
151 	if (left > conn->max_xmit_dlength) {
152 		hton24(hdr->dlength, conn->max_xmit_dlength);
153 		r2t->data_count = conn->max_xmit_dlength;
154 		hdr->flags = 0;
155 	} else {
156 		hton24(hdr->dlength, left);
157 		r2t->data_count = left;
158 		hdr->flags = ISCSI_FLAG_CMD_FINAL;
159 	}
160 	conn->dataout_pdus_cnt++;
161 }
162 EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
163 
164 static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
165 {
166 	unsigned exp_len = task->hdr_len + len;
167 
168 	if (exp_len > task->hdr_max) {
169 		WARN_ON(1);
170 		return -EINVAL;
171 	}
172 
173 	WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
174 	task->hdr_len = exp_len;
175 	return 0;
176 }
177 
178 /*
179  * make an extended cdb AHS
180  */
181 static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
182 {
183 	struct scsi_cmnd *cmd = task->sc;
184 	unsigned rlen, pad_len;
185 	unsigned short ahslength;
186 	struct iscsi_ecdb_ahdr *ecdb_ahdr;
187 	int rc;
188 
189 	ecdb_ahdr = iscsi_next_hdr(task);
190 	rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
191 
192 	BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
193 	ahslength = rlen + sizeof(ecdb_ahdr->reserved);
194 
195 	pad_len = iscsi_padding(rlen);
196 
197 	rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
198 	                   sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
199 	if (rc)
200 		return rc;
201 
202 	if (pad_len)
203 		memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
204 
205 	ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
206 	ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
207 	ecdb_ahdr->reserved = 0;
208 	memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
209 
210 	ISCSI_DBG_SESSION(task->conn->session,
211 			  "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
212 		          "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
213 		          "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
214 		          task->hdr_len);
215 	return 0;
216 }
217 
218 /**
219  * iscsi_check_tmf_restrictions - check if a task is affected by TMF
220  * @task: iscsi task
221  * @opcode: opcode to check for
222  *
223  * During TMF a task has to be checked if it's affected.
224  * All unrelated I/O can be passed through, but I/O to the
225  * affected LUN should be restricted.
226  * If 'fast_abort' is set we won't be sending any I/O to the
227  * affected LUN.
228  * Otherwise the target is waiting for all TTTs to be completed,
229  * so we have to send all outstanding Data-Out PDUs to the target.
230  */
231 static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
232 {
233 	struct iscsi_conn *conn = task->conn;
234 	struct iscsi_tm *tmf = &conn->tmhdr;
235 	u64 hdr_lun;
236 
237 	if (conn->tmf_state == TMF_INITIAL)
238 		return 0;
239 
240 	if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
241 		return 0;
242 
243 	switch (ISCSI_TM_FUNC_VALUE(tmf)) {
244 	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
245 		/*
246 		 * Allow PDUs for unrelated LUNs
247 		 */
248 		hdr_lun = scsilun_to_int(&tmf->lun);
249 		if (hdr_lun != task->sc->device->lun)
250 			return 0;
251 		fallthrough;
252 	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
253 		/*
254 		 * Fail all SCSI cmd PDUs
255 		 */
256 		if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
257 			iscsi_conn_printk(KERN_INFO, conn,
258 					  "task [op %x itt "
259 					  "0x%x/0x%x] "
260 					  "rejected.\n",
261 					  opcode, task->itt,
262 					  task->hdr_itt);
263 			return -EACCES;
264 		}
265 		/*
266 		 * And also all data-out PDUs in response to R2T
267 		 * if fast_abort is set.
268 		 */
269 		if (conn->session->fast_abort) {
270 			iscsi_conn_printk(KERN_INFO, conn,
271 					  "task [op %x itt "
272 					  "0x%x/0x%x] fast abort.\n",
273 					  opcode, task->itt,
274 					  task->hdr_itt);
275 			return -EACCES;
276 		}
277 		break;
278 	case ISCSI_TM_FUNC_ABORT_TASK:
279 		/*
280 		 * the caller has already checked if the task
281 		 * they want to abort was in the pending queue so if
282 		 * we are here the cmd pdu has gone out already, and
283 		 * we will only hit this for data-outs
284 		 */
285 		if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
286 		    task->hdr_itt == tmf->rtt) {
287 			ISCSI_DBG_SESSION(conn->session,
288 					  "Preventing task %x/%x from sending "
289 					  "data-out due to abort task in "
290 					  "progress\n", task->itt,
291 					  task->hdr_itt);
292 			return -EACCES;
293 		}
294 		break;
295 	}
296 
297 	return 0;
298 }
299 
300 /**
301  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
302  * @task: iscsi task
303  *
304  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
305  * fields like dlength or final based on how much data it sends
306  */
307 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
308 {
309 	struct iscsi_conn *conn = task->conn;
310 	struct iscsi_session *session = conn->session;
311 	struct scsi_cmnd *sc = task->sc;
312 	struct iscsi_scsi_req *hdr;
313 	unsigned hdrlength, cmd_len, transfer_length;
314 	itt_t itt;
315 	int rc;
316 
317 	rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
318 	if (rc)
319 		return rc;
320 
321 	if (conn->session->tt->alloc_pdu) {
322 		rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
323 		if (rc)
324 			return rc;
325 	}
326 	hdr = (struct iscsi_scsi_req *)task->hdr;
327 	itt = hdr->itt;
328 	memset(hdr, 0, sizeof(*hdr));
329 
330 	if (session->tt->parse_pdu_itt)
331 		hdr->itt = task->hdr_itt = itt;
332 	else
333 		hdr->itt = task->hdr_itt = build_itt(task->itt,
334 						     task->conn->session->age);
335 	task->hdr_len = 0;
336 	rc = iscsi_add_hdr(task, sizeof(*hdr));
337 	if (rc)
338 		return rc;
339 	hdr->opcode = ISCSI_OP_SCSI_CMD;
340 	hdr->flags = ISCSI_ATTR_SIMPLE;
341 	int_to_scsilun(sc->device->lun, &hdr->lun);
342 	task->lun = hdr->lun;
343 	hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
344 	cmd_len = sc->cmd_len;
345 	if (cmd_len < ISCSI_CDB_SIZE)
346 		memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
347 	else if (cmd_len > ISCSI_CDB_SIZE) {
348 		rc = iscsi_prep_ecdb_ahs(task);
349 		if (rc)
350 			return rc;
351 		cmd_len = ISCSI_CDB_SIZE;
352 	}
353 	memcpy(hdr->cdb, sc->cmnd, cmd_len);
354 
355 	task->imm_count = 0;
356 	if (scsi_get_prot_op(sc) != SCSI_PROT_NORMAL)
357 		task->protected = true;
358 
359 	transfer_length = scsi_transfer_length(sc);
360 	hdr->data_length = cpu_to_be32(transfer_length);
361 	if (sc->sc_data_direction == DMA_TO_DEVICE) {
362 		struct iscsi_r2t_info *r2t = &task->unsol_r2t;
363 
364 		hdr->flags |= ISCSI_FLAG_CMD_WRITE;
365 		/*
366 		 * Write counters:
367 		 *
368 		 *	imm_count	bytes to be sent right after
369 		 *			SCSI PDU Header
370 		 *
371 		 *	unsol_count	bytes(as Data-Out) to be sent
372 		 *			without	R2T ack right after
373 		 *			immediate data
374 		 *
375 		 *	r2t data_length bytes to be sent via R2T ack's
376 		 *
377 		 *      pad_count       bytes to be sent as zero-padding
378 		 */
379 		memset(r2t, 0, sizeof(*r2t));
380 
381 		if (session->imm_data_en) {
382 			if (transfer_length >= session->first_burst)
383 				task->imm_count = min(session->first_burst,
384 							conn->max_xmit_dlength);
385 			else
386 				task->imm_count = min(transfer_length,
387 						      conn->max_xmit_dlength);
388 			hton24(hdr->dlength, task->imm_count);
389 		} else
390 			zero_data(hdr->dlength);
391 
392 		if (!session->initial_r2t_en) {
393 			r2t->data_length = min(session->first_burst,
394 					       transfer_length) -
395 					       task->imm_count;
396 			r2t->data_offset = task->imm_count;
397 			r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
398 			r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
399 		}
400 
401 		if (!task->unsol_r2t.data_length)
402 			/* No unsolicit Data-Out's */
403 			hdr->flags |= ISCSI_FLAG_CMD_FINAL;
404 	} else {
405 		hdr->flags |= ISCSI_FLAG_CMD_FINAL;
406 		zero_data(hdr->dlength);
407 
408 		if (sc->sc_data_direction == DMA_FROM_DEVICE)
409 			hdr->flags |= ISCSI_FLAG_CMD_READ;
410 	}
411 
412 	/* calculate size of additional header segments (AHSs) */
413 	hdrlength = task->hdr_len - sizeof(*hdr);
414 
415 	WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
416 	hdrlength /= ISCSI_PAD_LEN;
417 
418 	WARN_ON(hdrlength >= 256);
419 	hdr->hlength = hdrlength & 0xFF;
420 	hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
421 
422 	if (session->tt->init_task && session->tt->init_task(task))
423 		return -EIO;
424 
425 	task->state = ISCSI_TASK_RUNNING;
426 	session->cmdsn++;
427 
428 	conn->scsicmd_pdus_cnt++;
429 	ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
430 			  "itt 0x%x len %d cmdsn %d win %d]\n",
431 			  sc->sc_data_direction == DMA_TO_DEVICE ?
432 			  "write" : "read", conn->id, sc, sc->cmnd[0],
433 			  task->itt, transfer_length,
434 			  session->cmdsn,
435 			  session->max_cmdsn - session->exp_cmdsn + 1);
436 	return 0;
437 }
438 
439 /**
440  * iscsi_free_task - free a task
441  * @task: iscsi cmd task
442  *
443  * Must be called with session back_lock.
444  * This function returns the scsi command to scsi-ml or cleans
445  * up mgmt tasks then returns the task to the pool.
446  */
447 static void iscsi_free_task(struct iscsi_task *task)
448 {
449 	struct iscsi_conn *conn = task->conn;
450 	struct iscsi_session *session = conn->session;
451 	struct scsi_cmnd *sc = task->sc;
452 	int oldstate = task->state;
453 
454 	ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
455 			  task->itt, task->state, task->sc);
456 
457 	session->tt->cleanup_task(task);
458 	task->state = ISCSI_TASK_FREE;
459 	task->sc = NULL;
460 	/*
461 	 * login task is preallocated so do not free
462 	 */
463 	if (conn->login_task == task)
464 		return;
465 
466 	kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
467 
468 	if (sc) {
469 		/* SCSI eh reuses commands to verify us */
470 		sc->SCp.ptr = NULL;
471 		/*
472 		 * queue command may call this to free the task, so
473 		 * it will decide how to return sc to scsi-ml.
474 		 */
475 		if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
476 			sc->scsi_done(sc);
477 	}
478 }
479 
480 void __iscsi_get_task(struct iscsi_task *task)
481 {
482 	refcount_inc(&task->refcount);
483 }
484 EXPORT_SYMBOL_GPL(__iscsi_get_task);
485 
486 void __iscsi_put_task(struct iscsi_task *task)
487 {
488 	if (refcount_dec_and_test(&task->refcount))
489 		iscsi_free_task(task);
490 }
491 EXPORT_SYMBOL_GPL(__iscsi_put_task);
492 
493 void iscsi_put_task(struct iscsi_task *task)
494 {
495 	struct iscsi_session *session = task->conn->session;
496 
497 	/* regular RX path uses back_lock */
498 	spin_lock_bh(&session->back_lock);
499 	__iscsi_put_task(task);
500 	spin_unlock_bh(&session->back_lock);
501 }
502 EXPORT_SYMBOL_GPL(iscsi_put_task);
503 
504 /**
505  * iscsi_complete_task - finish a task
506  * @task: iscsi cmd task
507  * @state: state to complete task with
508  *
509  * Must be called with session back_lock.
510  */
511 static void iscsi_complete_task(struct iscsi_task *task, int state)
512 {
513 	struct iscsi_conn *conn = task->conn;
514 
515 	ISCSI_DBG_SESSION(conn->session,
516 			  "complete task itt 0x%x state %d sc %p\n",
517 			  task->itt, task->state, task->sc);
518 	if (task->state == ISCSI_TASK_COMPLETED ||
519 	    task->state == ISCSI_TASK_ABRT_TMF ||
520 	    task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
521 	    task->state == ISCSI_TASK_REQUEUE_SCSIQ)
522 		return;
523 	WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
524 	task->state = state;
525 
526 	spin_lock_bh(&conn->taskqueuelock);
527 	if (!list_empty(&task->running)) {
528 		pr_debug_once("%s while task on list", __func__);
529 		list_del_init(&task->running);
530 	}
531 	spin_unlock_bh(&conn->taskqueuelock);
532 
533 	if (conn->task == task)
534 		conn->task = NULL;
535 
536 	if (READ_ONCE(conn->ping_task) == task)
537 		WRITE_ONCE(conn->ping_task, NULL);
538 
539 	/* release get from queueing */
540 	__iscsi_put_task(task);
541 }
542 
543 /**
544  * iscsi_complete_scsi_task - finish scsi task normally
545  * @task: iscsi task for scsi cmd
546  * @exp_cmdsn: expected cmd sn in cpu format
547  * @max_cmdsn: max cmd sn in cpu format
548  *
549  * This is used when drivers do not need or cannot perform
550  * lower level pdu processing.
551  *
552  * Called with session back_lock
553  */
554 void iscsi_complete_scsi_task(struct iscsi_task *task,
555 			      uint32_t exp_cmdsn, uint32_t max_cmdsn)
556 {
557 	struct iscsi_conn *conn = task->conn;
558 
559 	ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
560 
561 	conn->last_recv = jiffies;
562 	__iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
563 	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
564 }
565 EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
566 
567 
568 /*
569  * session back_lock must be held and if not called for a task that is
570  * still pending or from the xmit thread, then xmit thread must
571  * be suspended.
572  */
573 static void fail_scsi_task(struct iscsi_task *task, int err)
574 {
575 	struct iscsi_conn *conn = task->conn;
576 	struct scsi_cmnd *sc;
577 	int state;
578 
579 	/*
580 	 * if a command completes and we get a successful tmf response
581 	 * we will hit this because the scsi eh abort code does not take
582 	 * a ref to the task.
583 	 */
584 	sc = task->sc;
585 	if (!sc)
586 		return;
587 
588 	if (task->state == ISCSI_TASK_PENDING) {
589 		/*
590 		 * cmd never made it to the xmit thread, so we should not count
591 		 * the cmd in the sequencing
592 		 */
593 		conn->session->queued_cmdsn--;
594 		/* it was never sent so just complete like normal */
595 		state = ISCSI_TASK_COMPLETED;
596 	} else if (err == DID_TRANSPORT_DISRUPTED)
597 		state = ISCSI_TASK_ABRT_SESS_RECOV;
598 	else
599 		state = ISCSI_TASK_ABRT_TMF;
600 
601 	sc->result = err << 16;
602 	scsi_set_resid(sc, scsi_bufflen(sc));
603 
604 	/* regular RX path uses back_lock */
605 	spin_lock_bh(&conn->session->back_lock);
606 	iscsi_complete_task(task, state);
607 	spin_unlock_bh(&conn->session->back_lock);
608 }
609 
610 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
611 				struct iscsi_task *task)
612 {
613 	struct iscsi_session *session = conn->session;
614 	struct iscsi_hdr *hdr = task->hdr;
615 	struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
616 	uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
617 
618 	if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
619 		return -ENOTCONN;
620 
621 	if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
622 		nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
623 	/*
624 	 * pre-format CmdSN for outgoing PDU.
625 	 */
626 	nop->cmdsn = cpu_to_be32(session->cmdsn);
627 	if (hdr->itt != RESERVED_ITT) {
628 		/*
629 		 * TODO: We always use immediate for normal session pdus.
630 		 * If we start to send tmfs or nops as non-immediate then
631 		 * we should start checking the cmdsn numbers for mgmt tasks.
632 		 *
633 		 * During discovery sessions iscsid sends TEXT as non immediate,
634 		 * but we always only send one PDU at a time.
635 		 */
636 		if (conn->c_stage == ISCSI_CONN_STARTED &&
637 		    !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
638 			session->queued_cmdsn++;
639 			session->cmdsn++;
640 		}
641 	}
642 
643 	if (session->tt->init_task && session->tt->init_task(task))
644 		return -EIO;
645 
646 	if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
647 		session->state = ISCSI_STATE_LOGGING_OUT;
648 
649 	task->state = ISCSI_TASK_RUNNING;
650 	ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
651 			  "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
652 			  hdr->itt, task->data_count);
653 	return 0;
654 }
655 
656 static struct iscsi_task *
657 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
658 		      char *data, uint32_t data_size)
659 {
660 	struct iscsi_session *session = conn->session;
661 	struct iscsi_host *ihost = shost_priv(session->host);
662 	uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
663 	struct iscsi_task *task;
664 	itt_t itt;
665 
666 	if (session->state == ISCSI_STATE_TERMINATE)
667 		return NULL;
668 
669 	if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
670 		/*
671 		 * Login and Text are sent serially, in
672 		 * request-followed-by-response sequence.
673 		 * Same task can be used. Same ITT must be used.
674 		 * Note that login_task is preallocated at conn_create().
675 		 */
676 		if (conn->login_task->state != ISCSI_TASK_FREE) {
677 			iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
678 					  "progress. Cannot start new task.\n");
679 			return NULL;
680 		}
681 
682 		if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
683 			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);
684 			return NULL;
685 		}
686 
687 		task = conn->login_task;
688 	} else {
689 		if (session->state != ISCSI_STATE_LOGGED_IN)
690 			return NULL;
691 
692 		if (data_size != 0) {
693 			iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
694 			return NULL;
695 		}
696 
697 		BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
698 		BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
699 
700 		if (!kfifo_out(&session->cmdpool.queue,
701 				 (void*)&task, sizeof(void*)))
702 			return NULL;
703 	}
704 	/*
705 	 * released in complete pdu for task we expect a response for, and
706 	 * released by the lld when it has transmitted the task for
707 	 * pdus we do not expect a response for.
708 	 */
709 	refcount_set(&task->refcount, 1);
710 	task->conn = conn;
711 	task->sc = NULL;
712 	INIT_LIST_HEAD(&task->running);
713 	task->state = ISCSI_TASK_PENDING;
714 
715 	if (data_size) {
716 		memcpy(task->data, data, data_size);
717 		task->data_count = data_size;
718 	} else
719 		task->data_count = 0;
720 
721 	if (conn->session->tt->alloc_pdu) {
722 		if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
723 			iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
724 					 "pdu for mgmt task.\n");
725 			goto free_task;
726 		}
727 	}
728 
729 	itt = task->hdr->itt;
730 	task->hdr_len = sizeof(struct iscsi_hdr);
731 	memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
732 
733 	if (hdr->itt != RESERVED_ITT) {
734 		if (session->tt->parse_pdu_itt)
735 			task->hdr->itt = itt;
736 		else
737 			task->hdr->itt = build_itt(task->itt,
738 						   task->conn->session->age);
739 	}
740 
741 	if (unlikely(READ_ONCE(conn->ping_task) == INVALID_SCSI_TASK))
742 		WRITE_ONCE(conn->ping_task, task);
743 
744 	if (!ihost->workq) {
745 		if (iscsi_prep_mgmt_task(conn, task))
746 			goto free_task;
747 
748 		if (session->tt->xmit_task(task))
749 			goto free_task;
750 	} else {
751 		spin_lock_bh(&conn->taskqueuelock);
752 		list_add_tail(&task->running, &conn->mgmtqueue);
753 		spin_unlock_bh(&conn->taskqueuelock);
754 		iscsi_conn_queue_work(conn);
755 	}
756 
757 	return task;
758 
759 free_task:
760 	/* regular RX path uses back_lock */
761 	spin_lock(&session->back_lock);
762 	__iscsi_put_task(task);
763 	spin_unlock(&session->back_lock);
764 	return NULL;
765 }
766 
767 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
768 			char *data, uint32_t data_size)
769 {
770 	struct iscsi_conn *conn = cls_conn->dd_data;
771 	struct iscsi_session *session = conn->session;
772 	int err = 0;
773 
774 	spin_lock_bh(&session->frwd_lock);
775 	if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
776 		err = -EPERM;
777 	spin_unlock_bh(&session->frwd_lock);
778 	return err;
779 }
780 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
781 
782 /**
783  * iscsi_scsi_cmd_rsp - SCSI Command Response processing
784  * @conn: iscsi connection
785  * @hdr: iscsi header
786  * @task: scsi command task
787  * @data: cmd data buffer
788  * @datalen: len of buffer
789  *
790  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
791  * then completes the command and task. called under back_lock
792  **/
793 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
794 			       struct iscsi_task *task, char *data,
795 			       int datalen)
796 {
797 	struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
798 	struct iscsi_session *session = conn->session;
799 	struct scsi_cmnd *sc = task->sc;
800 
801 	iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
802 	conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
803 
804 	sc->result = (DID_OK << 16) | rhdr->cmd_status;
805 
806 	if (task->protected) {
807 		sector_t sector;
808 		u8 ascq;
809 
810 		/**
811 		 * Transports that didn't implement check_protection
812 		 * callback but still published T10-PI support to scsi-mid
813 		 * deserve this BUG_ON.
814 		 **/
815 		BUG_ON(!session->tt->check_protection);
816 
817 		ascq = session->tt->check_protection(task, &sector);
818 		if (ascq) {
819 			sc->result = DRIVER_SENSE << 24 |
820 				     SAM_STAT_CHECK_CONDITION;
821 			scsi_build_sense_buffer(1, sc->sense_buffer,
822 						ILLEGAL_REQUEST, 0x10, ascq);
823 			scsi_set_sense_information(sc->sense_buffer,
824 						   SCSI_SENSE_BUFFERSIZE,
825 						   sector);
826 			goto out;
827 		}
828 	}
829 
830 	if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
831 		sc->result = DID_ERROR << 16;
832 		goto out;
833 	}
834 
835 	if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
836 		uint16_t senselen;
837 
838 		if (datalen < 2) {
839 invalid_datalen:
840 			iscsi_conn_printk(KERN_ERR,  conn,
841 					 "Got CHECK_CONDITION but invalid data "
842 					 "buffer size of %d\n", datalen);
843 			sc->result = DID_BAD_TARGET << 16;
844 			goto out;
845 		}
846 
847 		senselen = get_unaligned_be16(data);
848 		if (datalen < senselen)
849 			goto invalid_datalen;
850 
851 		memcpy(sc->sense_buffer, data + 2,
852 		       min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
853 		ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
854 				  min_t(uint16_t, senselen,
855 				  SCSI_SENSE_BUFFERSIZE));
856 	}
857 
858 	if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
859 			   ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
860 		sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
861 	}
862 
863 	if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
864 	                   ISCSI_FLAG_CMD_OVERFLOW)) {
865 		int res_count = be32_to_cpu(rhdr->residual_count);
866 
867 		if (res_count > 0 &&
868 		    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
869 		     res_count <= scsi_bufflen(sc)))
870 			/* write side for bidi or uni-io set_resid */
871 			scsi_set_resid(sc, res_count);
872 		else
873 			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
874 	}
875 out:
876 	ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
877 			  sc, sc->result, task->itt);
878 	conn->scsirsp_pdus_cnt++;
879 	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
880 }
881 
882 /**
883  * iscsi_data_in_rsp - SCSI Data-In Response processing
884  * @conn: iscsi connection
885  * @hdr:  iscsi pdu
886  * @task: scsi command task
887  *
888  * iscsi_data_in_rsp sets up the scsi_cmnd fields based on the data received
889  * then completes the command and task. called under back_lock
890  **/
891 static void
892 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
893 		  struct iscsi_task *task)
894 {
895 	struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
896 	struct scsi_cmnd *sc = task->sc;
897 
898 	if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
899 		return;
900 
901 	iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
902 	sc->result = (DID_OK << 16) | rhdr->cmd_status;
903 	conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
904 	if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
905 	                   ISCSI_FLAG_DATA_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 <= sc->sdb.length))
911 			scsi_set_resid(sc, res_count);
912 		else
913 			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
914 	}
915 
916 	ISCSI_DBG_SESSION(conn->session, "data in with status done "
917 			  "[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 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
924 {
925 	struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
926 
927 	conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
928 	conn->tmfrsp_pdus_cnt++;
929 
930 	if (conn->tmf_state != TMF_QUEUED)
931 		return;
932 
933 	if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
934 		conn->tmf_state = TMF_SUCCESS;
935 	else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
936 		conn->tmf_state = TMF_NOT_FOUND;
937 	else
938 		conn->tmf_state = TMF_FAILED;
939 	wake_up(&conn->ehwait);
940 }
941 
942 static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
943 {
944         struct iscsi_nopout hdr;
945 	struct iscsi_task *task;
946 
947 	if (!rhdr) {
948 		if (READ_ONCE(conn->ping_task))
949 			return -EINVAL;
950 		WRITE_ONCE(conn->ping_task, INVALID_SCSI_TASK);
951 	}
952 
953 	memset(&hdr, 0, sizeof(struct iscsi_nopout));
954 	hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
955 	hdr.flags = ISCSI_FLAG_CMD_FINAL;
956 
957 	if (rhdr) {
958 		hdr.lun = rhdr->lun;
959 		hdr.ttt = rhdr->ttt;
960 		hdr.itt = RESERVED_ITT;
961 	} else
962 		hdr.ttt = RESERVED_ITT;
963 
964 	task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
965 	if (!task) {
966 		if (!rhdr)
967 			WRITE_ONCE(conn->ping_task, NULL);
968 		iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
969 		return -EIO;
970 	} else if (!rhdr) {
971 		/* only track our nops */
972 		conn->last_ping = jiffies;
973 	}
974 
975 	return 0;
976 }
977 
978 /**
979  * iscsi_nop_out_rsp - SCSI NOP Response processing
980  * @task: scsi command task
981  * @nop: the nop structure
982  * @data: where to put the data
983  * @datalen: length of data
984  *
985  * iscsi_nop_out_rsp handles nop response from use or
986  * from user space. called under back_lock
987  **/
988 static int iscsi_nop_out_rsp(struct iscsi_task *task,
989 			     struct iscsi_nopin *nop, char *data, int datalen)
990 {
991 	struct iscsi_conn *conn = task->conn;
992 	int rc = 0;
993 
994 	if (READ_ONCE(conn->ping_task) != task) {
995 		/*
996 		 * If this is not in response to one of our
997 		 * nops then it must be from userspace.
998 		 */
999 		if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
1000 				   data, datalen))
1001 			rc = ISCSI_ERR_CONN_FAILED;
1002 	} else
1003 		mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1004 	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1005 	return rc;
1006 }
1007 
1008 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1009 			       char *data, int datalen)
1010 {
1011 	struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1012 	struct iscsi_hdr rejected_pdu;
1013 	int opcode, rc = 0;
1014 
1015 	conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1016 
1017 	if (ntoh24(reject->dlength) > datalen ||
1018 	    ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1019 		iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1020 				  "pdu. Invalid data length (pdu dlength "
1021 				  "%u, datalen %d\n", ntoh24(reject->dlength),
1022 				  datalen);
1023 		return ISCSI_ERR_PROTO;
1024 	}
1025 	memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1026 	opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1027 
1028 	switch (reject->reason) {
1029 	case ISCSI_REASON_DATA_DIGEST_ERROR:
1030 		iscsi_conn_printk(KERN_ERR, conn,
1031 				  "pdu (op 0x%x itt 0x%x) rejected "
1032 				  "due to DataDigest error.\n",
1033 				  opcode, rejected_pdu.itt);
1034 		break;
1035 	case ISCSI_REASON_IMM_CMD_REJECT:
1036 		iscsi_conn_printk(KERN_ERR, conn,
1037 				  "pdu (op 0x%x itt 0x%x) rejected. Too many "
1038 				  "immediate commands.\n",
1039 				  opcode, rejected_pdu.itt);
1040 		/*
1041 		 * We only send one TMF at a time so if the target could not
1042 		 * handle it, then it should get fixed (RFC mandates that
1043 		 * a target can handle one immediate TMF per conn).
1044 		 *
1045 		 * For nops-outs, we could have sent more than one if
1046 		 * the target is sending us lots of nop-ins
1047 		 */
1048 		if (opcode != ISCSI_OP_NOOP_OUT)
1049 			return 0;
1050 
1051 		if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1052 			/*
1053 			 * nop-out in response to target's nop-out rejected.
1054 			 * Just resend.
1055 			 */
1056 			/* In RX path we are under back lock */
1057 			spin_unlock(&conn->session->back_lock);
1058 			spin_lock(&conn->session->frwd_lock);
1059 			iscsi_send_nopout(conn,
1060 					  (struct iscsi_nopin*)&rejected_pdu);
1061 			spin_unlock(&conn->session->frwd_lock);
1062 			spin_lock(&conn->session->back_lock);
1063 		} else {
1064 			struct iscsi_task *task;
1065 			/*
1066 			 * Our nop as ping got dropped. We know the target
1067 			 * and transport are ok so just clean up
1068 			 */
1069 			task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1070 			if (!task) {
1071 				iscsi_conn_printk(KERN_ERR, conn,
1072 						 "Invalid pdu reject. Could "
1073 						 "not lookup rejected task.\n");
1074 				rc = ISCSI_ERR_BAD_ITT;
1075 			} else
1076 				rc = iscsi_nop_out_rsp(task,
1077 					(struct iscsi_nopin*)&rejected_pdu,
1078 					NULL, 0);
1079 		}
1080 		break;
1081 	default:
1082 		iscsi_conn_printk(KERN_ERR, conn,
1083 				  "pdu (op 0x%x itt 0x%x) rejected. Reason "
1084 				  "code 0x%x\n", rejected_pdu.opcode,
1085 				  rejected_pdu.itt, reject->reason);
1086 		break;
1087 	}
1088 	return rc;
1089 }
1090 
1091 /**
1092  * iscsi_itt_to_task - look up task by itt
1093  * @conn: iscsi connection
1094  * @itt: itt
1095  *
1096  * This should be used for mgmt tasks like login and nops, or if
1097  * the LDD's itt space does not include the session age.
1098  *
1099  * The session back_lock must be held.
1100  */
1101 struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1102 {
1103 	struct iscsi_session *session = conn->session;
1104 	int i;
1105 
1106 	if (itt == RESERVED_ITT)
1107 		return NULL;
1108 
1109 	if (session->tt->parse_pdu_itt)
1110 		session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1111 	else
1112 		i = get_itt(itt);
1113 	if (i >= session->cmds_max)
1114 		return NULL;
1115 
1116 	return session->cmds[i];
1117 }
1118 EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1119 
1120 /**
1121  * __iscsi_complete_pdu - complete pdu
1122  * @conn: iscsi conn
1123  * @hdr: iscsi header
1124  * @data: data buffer
1125  * @datalen: len of data buffer
1126  *
1127  * Completes pdu processing by freeing any resources allocated at
1128  * queuecommand or send generic. session back_lock must be held and verify
1129  * itt must have been called.
1130  */
1131 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1132 			 char *data, int datalen)
1133 {
1134 	struct iscsi_session *session = conn->session;
1135 	int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1136 	struct iscsi_task *task;
1137 	uint32_t itt;
1138 
1139 	conn->last_recv = jiffies;
1140 	rc = iscsi_verify_itt(conn, hdr->itt);
1141 	if (rc)
1142 		return rc;
1143 
1144 	if (hdr->itt != RESERVED_ITT)
1145 		itt = get_itt(hdr->itt);
1146 	else
1147 		itt = ~0U;
1148 
1149 	ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1150 			  opcode, conn->id, itt, datalen);
1151 
1152 	if (itt == ~0U) {
1153 		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1154 
1155 		switch(opcode) {
1156 		case ISCSI_OP_NOOP_IN:
1157 			if (datalen) {
1158 				rc = ISCSI_ERR_PROTO;
1159 				break;
1160 			}
1161 
1162 			if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1163 				break;
1164 
1165 			/* In RX path we are under back lock */
1166 			spin_unlock(&session->back_lock);
1167 			spin_lock(&session->frwd_lock);
1168 			iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1169 			spin_unlock(&session->frwd_lock);
1170 			spin_lock(&session->back_lock);
1171 			break;
1172 		case ISCSI_OP_REJECT:
1173 			rc = iscsi_handle_reject(conn, hdr, data, datalen);
1174 			break;
1175 		case ISCSI_OP_ASYNC_EVENT:
1176 			conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1177 			if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1178 				rc = ISCSI_ERR_CONN_FAILED;
1179 			break;
1180 		default:
1181 			rc = ISCSI_ERR_BAD_OPCODE;
1182 			break;
1183 		}
1184 		goto out;
1185 	}
1186 
1187 	switch(opcode) {
1188 	case ISCSI_OP_SCSI_CMD_RSP:
1189 	case ISCSI_OP_SCSI_DATA_IN:
1190 		task = iscsi_itt_to_ctask(conn, hdr->itt);
1191 		if (!task)
1192 			return ISCSI_ERR_BAD_ITT;
1193 		task->last_xfer = jiffies;
1194 		break;
1195 	case ISCSI_OP_R2T:
1196 		/*
1197 		 * LLD handles R2Ts if they need to.
1198 		 */
1199 		return 0;
1200 	case ISCSI_OP_LOGOUT_RSP:
1201 	case ISCSI_OP_LOGIN_RSP:
1202 	case ISCSI_OP_TEXT_RSP:
1203 	case ISCSI_OP_SCSI_TMFUNC_RSP:
1204 	case ISCSI_OP_NOOP_IN:
1205 		task = iscsi_itt_to_task(conn, hdr->itt);
1206 		if (!task)
1207 			return ISCSI_ERR_BAD_ITT;
1208 		break;
1209 	default:
1210 		return ISCSI_ERR_BAD_OPCODE;
1211 	}
1212 
1213 	switch(opcode) {
1214 	case ISCSI_OP_SCSI_CMD_RSP:
1215 		iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1216 		break;
1217 	case ISCSI_OP_SCSI_DATA_IN:
1218 		iscsi_data_in_rsp(conn, hdr, task);
1219 		break;
1220 	case ISCSI_OP_LOGOUT_RSP:
1221 		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1222 		if (datalen) {
1223 			rc = ISCSI_ERR_PROTO;
1224 			break;
1225 		}
1226 		conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1227 		goto recv_pdu;
1228 	case ISCSI_OP_LOGIN_RSP:
1229 	case ISCSI_OP_TEXT_RSP:
1230 		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1231 		/*
1232 		 * login related PDU's exp_statsn is handled in
1233 		 * userspace
1234 		 */
1235 		goto recv_pdu;
1236 	case ISCSI_OP_SCSI_TMFUNC_RSP:
1237 		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1238 		if (datalen) {
1239 			rc = ISCSI_ERR_PROTO;
1240 			break;
1241 		}
1242 
1243 		iscsi_tmf_rsp(conn, hdr);
1244 		iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1245 		break;
1246 	case ISCSI_OP_NOOP_IN:
1247 		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1248 		if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1249 			rc = ISCSI_ERR_PROTO;
1250 			break;
1251 		}
1252 		conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1253 
1254 		rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1255 				       data, datalen);
1256 		break;
1257 	default:
1258 		rc = ISCSI_ERR_BAD_OPCODE;
1259 		break;
1260 	}
1261 
1262 out:
1263 	return rc;
1264 recv_pdu:
1265 	if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1266 		rc = ISCSI_ERR_CONN_FAILED;
1267 	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1268 	return rc;
1269 }
1270 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1271 
1272 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1273 		       char *data, int datalen)
1274 {
1275 	int rc;
1276 
1277 	spin_lock(&conn->session->back_lock);
1278 	rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1279 	spin_unlock(&conn->session->back_lock);
1280 	return rc;
1281 }
1282 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1283 
1284 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1285 {
1286 	struct iscsi_session *session = conn->session;
1287 	int age = 0, i = 0;
1288 
1289 	if (itt == RESERVED_ITT)
1290 		return 0;
1291 
1292 	if (session->tt->parse_pdu_itt)
1293 		session->tt->parse_pdu_itt(conn, itt, &i, &age);
1294 	else {
1295 		i = get_itt(itt);
1296 		age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1297 	}
1298 
1299 	if (age != session->age) {
1300 		iscsi_conn_printk(KERN_ERR, conn,
1301 				  "received itt %x expected session age (%x)\n",
1302 				  (__force u32)itt, session->age);
1303 		return ISCSI_ERR_BAD_ITT;
1304 	}
1305 
1306 	if (i >= session->cmds_max) {
1307 		iscsi_conn_printk(KERN_ERR, conn,
1308 				  "received invalid itt index %u (max cmds "
1309 				   "%u.\n", i, session->cmds_max);
1310 		return ISCSI_ERR_BAD_ITT;
1311 	}
1312 	return 0;
1313 }
1314 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1315 
1316 /**
1317  * iscsi_itt_to_ctask - look up ctask by itt
1318  * @conn: iscsi connection
1319  * @itt: itt
1320  *
1321  * This should be used for cmd tasks.
1322  *
1323  * The session back_lock must be held.
1324  */
1325 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1326 {
1327 	struct iscsi_task *task;
1328 
1329 	if (iscsi_verify_itt(conn, itt))
1330 		return NULL;
1331 
1332 	task = iscsi_itt_to_task(conn, itt);
1333 	if (!task || !task->sc)
1334 		return NULL;
1335 
1336 	if (task->sc->SCp.phase != conn->session->age) {
1337 		iscsi_session_printk(KERN_ERR, conn->session,
1338 				  "task's session age %d, expected %d\n",
1339 				  task->sc->SCp.phase, conn->session->age);
1340 		return NULL;
1341 	}
1342 
1343 	return task;
1344 }
1345 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1346 
1347 void iscsi_session_failure(struct iscsi_session *session,
1348 			   enum iscsi_err err)
1349 {
1350 	struct iscsi_conn *conn;
1351 	struct device *dev;
1352 
1353 	spin_lock_bh(&session->frwd_lock);
1354 	conn = session->leadconn;
1355 	if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1356 		spin_unlock_bh(&session->frwd_lock);
1357 		return;
1358 	}
1359 
1360 	dev = get_device(&conn->cls_conn->dev);
1361 	spin_unlock_bh(&session->frwd_lock);
1362 	if (!dev)
1363 	        return;
1364 	/*
1365 	 * if the host is being removed bypass the connection
1366 	 * recovery initialization because we are going to kill
1367 	 * the session.
1368 	 */
1369 	if (err == ISCSI_ERR_INVALID_HOST)
1370 		iscsi_conn_error_event(conn->cls_conn, err);
1371 	else
1372 		iscsi_conn_failure(conn, err);
1373 	put_device(dev);
1374 }
1375 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1376 
1377 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1378 {
1379 	struct iscsi_session *session = conn->session;
1380 
1381 	spin_lock_bh(&session->frwd_lock);
1382 	if (session->state == ISCSI_STATE_FAILED) {
1383 		spin_unlock_bh(&session->frwd_lock);
1384 		return;
1385 	}
1386 
1387 	if (conn->stop_stage == 0)
1388 		session->state = ISCSI_STATE_FAILED;
1389 	spin_unlock_bh(&session->frwd_lock);
1390 
1391 	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1392 	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1393 	iscsi_conn_error_event(conn->cls_conn, err);
1394 }
1395 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1396 
1397 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1398 {
1399 	struct iscsi_session *session = conn->session;
1400 
1401 	/*
1402 	 * Check for iSCSI window and take care of CmdSN wrap-around
1403 	 */
1404 	if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1405 		ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1406 				  "%u MaxCmdSN %u CmdSN %u/%u\n",
1407 				  session->exp_cmdsn, session->max_cmdsn,
1408 				  session->cmdsn, session->queued_cmdsn);
1409 		return -ENOSPC;
1410 	}
1411 	return 0;
1412 }
1413 
1414 static int iscsi_xmit_task(struct iscsi_conn *conn)
1415 {
1416 	struct iscsi_task *task = conn->task;
1417 	int rc;
1418 
1419 	if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
1420 		return -ENODATA;
1421 
1422 	spin_lock_bh(&conn->session->back_lock);
1423 	if (conn->task == NULL) {
1424 		spin_unlock_bh(&conn->session->back_lock);
1425 		return -ENODATA;
1426 	}
1427 	__iscsi_get_task(task);
1428 	spin_unlock_bh(&conn->session->back_lock);
1429 	spin_unlock_bh(&conn->session->frwd_lock);
1430 	rc = conn->session->tt->xmit_task(task);
1431 	spin_lock_bh(&conn->session->frwd_lock);
1432 	if (!rc) {
1433 		/* done with this task */
1434 		task->last_xfer = jiffies;
1435 		conn->task = NULL;
1436 	}
1437 	/* regular RX path uses back_lock */
1438 	spin_lock(&conn->session->back_lock);
1439 	__iscsi_put_task(task);
1440 	spin_unlock(&conn->session->back_lock);
1441 	return rc;
1442 }
1443 
1444 /**
1445  * iscsi_requeue_task - requeue task to run from session workqueue
1446  * @task: task to requeue
1447  *
1448  * LLDs that need to run a task from the session workqueue should call
1449  * this. The session frwd_lock must be held. This should only be called
1450  * by software drivers.
1451  */
1452 void iscsi_requeue_task(struct iscsi_task *task)
1453 {
1454 	struct iscsi_conn *conn = task->conn;
1455 
1456 	/*
1457 	 * this may be on the requeue list already if the xmit_task callout
1458 	 * is handling the r2ts while we are adding new ones
1459 	 */
1460 	spin_lock_bh(&conn->taskqueuelock);
1461 	if (list_empty(&task->running))
1462 		list_add_tail(&task->running, &conn->requeue);
1463 	spin_unlock_bh(&conn->taskqueuelock);
1464 	iscsi_conn_queue_work(conn);
1465 }
1466 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1467 
1468 /**
1469  * iscsi_data_xmit - xmit any command into the scheduled connection
1470  * @conn: iscsi connection
1471  *
1472  * Notes:
1473  *	The function can return -EAGAIN in which case the caller must
1474  *	re-schedule it again later or recover. '0' return code means
1475  *	successful xmit.
1476  **/
1477 static int iscsi_data_xmit(struct iscsi_conn *conn)
1478 {
1479 	struct iscsi_task *task;
1480 	int rc = 0;
1481 
1482 	spin_lock_bh(&conn->session->frwd_lock);
1483 	if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1484 		ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1485 		spin_unlock_bh(&conn->session->frwd_lock);
1486 		return -ENODATA;
1487 	}
1488 
1489 	if (conn->task) {
1490 		rc = iscsi_xmit_task(conn);
1491 	        if (rc)
1492 		        goto done;
1493 	}
1494 
1495 	/*
1496 	 * process mgmt pdus like nops before commands since we should
1497 	 * only have one nop-out as a ping from us and targets should not
1498 	 * overflow us with nop-ins
1499 	 */
1500 	spin_lock_bh(&conn->taskqueuelock);
1501 check_mgmt:
1502 	while (!list_empty(&conn->mgmtqueue)) {
1503 		conn->task = list_entry(conn->mgmtqueue.next,
1504 					 struct iscsi_task, running);
1505 		list_del_init(&conn->task->running);
1506 		spin_unlock_bh(&conn->taskqueuelock);
1507 		if (iscsi_prep_mgmt_task(conn, conn->task)) {
1508 			/* regular RX path uses back_lock */
1509 			spin_lock_bh(&conn->session->back_lock);
1510 			__iscsi_put_task(conn->task);
1511 			spin_unlock_bh(&conn->session->back_lock);
1512 			conn->task = NULL;
1513 			spin_lock_bh(&conn->taskqueuelock);
1514 			continue;
1515 		}
1516 		rc = iscsi_xmit_task(conn);
1517 		if (rc)
1518 			goto done;
1519 		spin_lock_bh(&conn->taskqueuelock);
1520 	}
1521 
1522 	/* process pending command queue */
1523 	while (!list_empty(&conn->cmdqueue)) {
1524 		conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1525 					running);
1526 		list_del_init(&conn->task->running);
1527 		spin_unlock_bh(&conn->taskqueuelock);
1528 		if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1529 			fail_scsi_task(conn->task, DID_IMM_RETRY);
1530 			spin_lock_bh(&conn->taskqueuelock);
1531 			continue;
1532 		}
1533 		rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1534 		if (rc) {
1535 			if (rc == -ENOMEM || rc == -EACCES) {
1536 				spin_lock_bh(&conn->taskqueuelock);
1537 				list_add_tail(&conn->task->running,
1538 					      &conn->cmdqueue);
1539 				conn->task = NULL;
1540 				spin_unlock_bh(&conn->taskqueuelock);
1541 				goto done;
1542 			} else
1543 				fail_scsi_task(conn->task, DID_ABORT);
1544 			spin_lock_bh(&conn->taskqueuelock);
1545 			continue;
1546 		}
1547 		rc = iscsi_xmit_task(conn);
1548 		if (rc)
1549 			goto done;
1550 		/*
1551 		 * we could continuously get new task requests so
1552 		 * we need to check the mgmt queue for nops that need to
1553 		 * be sent to aviod starvation
1554 		 */
1555 		spin_lock_bh(&conn->taskqueuelock);
1556 		if (!list_empty(&conn->mgmtqueue))
1557 			goto check_mgmt;
1558 	}
1559 
1560 	while (!list_empty(&conn->requeue)) {
1561 		/*
1562 		 * we always do fastlogout - conn stop code will clean up.
1563 		 */
1564 		if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1565 			break;
1566 
1567 		task = list_entry(conn->requeue.next, struct iscsi_task,
1568 				  running);
1569 		if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1570 			break;
1571 
1572 		conn->task = task;
1573 		list_del_init(&conn->task->running);
1574 		conn->task->state = ISCSI_TASK_RUNNING;
1575 		spin_unlock_bh(&conn->taskqueuelock);
1576 		rc = iscsi_xmit_task(conn);
1577 		if (rc)
1578 			goto done;
1579 		spin_lock_bh(&conn->taskqueuelock);
1580 		if (!list_empty(&conn->mgmtqueue))
1581 			goto check_mgmt;
1582 	}
1583 	spin_unlock_bh(&conn->taskqueuelock);
1584 	spin_unlock_bh(&conn->session->frwd_lock);
1585 	return -ENODATA;
1586 
1587 done:
1588 	spin_unlock_bh(&conn->session->frwd_lock);
1589 	return rc;
1590 }
1591 
1592 static void iscsi_xmitworker(struct work_struct *work)
1593 {
1594 	struct iscsi_conn *conn =
1595 		container_of(work, struct iscsi_conn, xmitwork);
1596 	int rc;
1597 	/*
1598 	 * serialize Xmit worker on a per-connection basis.
1599 	 */
1600 	do {
1601 		rc = iscsi_data_xmit(conn);
1602 	} while (rc >= 0 || rc == -EAGAIN);
1603 }
1604 
1605 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1606 						  struct scsi_cmnd *sc)
1607 {
1608 	struct iscsi_task *task;
1609 
1610 	if (!kfifo_out(&conn->session->cmdpool.queue,
1611 			 (void *) &task, sizeof(void *)))
1612 		return NULL;
1613 
1614 	sc->SCp.phase = conn->session->age;
1615 	sc->SCp.ptr = (char *) task;
1616 
1617 	refcount_set(&task->refcount, 1);
1618 	task->state = ISCSI_TASK_PENDING;
1619 	task->conn = conn;
1620 	task->sc = sc;
1621 	task->have_checked_conn = false;
1622 	task->last_timeout = jiffies;
1623 	task->last_xfer = jiffies;
1624 	task->protected = false;
1625 	INIT_LIST_HEAD(&task->running);
1626 	return task;
1627 }
1628 
1629 enum {
1630 	FAILURE_BAD_HOST = 1,
1631 	FAILURE_SESSION_FAILED,
1632 	FAILURE_SESSION_FREED,
1633 	FAILURE_WINDOW_CLOSED,
1634 	FAILURE_OOM,
1635 	FAILURE_SESSION_TERMINATE,
1636 	FAILURE_SESSION_IN_RECOVERY,
1637 	FAILURE_SESSION_RECOVERY_TIMEOUT,
1638 	FAILURE_SESSION_LOGGING_OUT,
1639 	FAILURE_SESSION_NOT_READY,
1640 };
1641 
1642 int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1643 {
1644 	struct iscsi_cls_session *cls_session;
1645 	struct iscsi_host *ihost;
1646 	int reason = 0;
1647 	struct iscsi_session *session;
1648 	struct iscsi_conn *conn;
1649 	struct iscsi_task *task = NULL;
1650 
1651 	sc->result = 0;
1652 	sc->SCp.ptr = NULL;
1653 
1654 	ihost = shost_priv(host);
1655 
1656 	cls_session = starget_to_session(scsi_target(sc->device));
1657 	session = cls_session->dd_data;
1658 	spin_lock_bh(&session->frwd_lock);
1659 
1660 	reason = iscsi_session_chkready(cls_session);
1661 	if (reason) {
1662 		sc->result = reason;
1663 		goto fault;
1664 	}
1665 
1666 	if (session->state != ISCSI_STATE_LOGGED_IN) {
1667 		/*
1668 		 * to handle the race between when we set the recovery state
1669 		 * and block the session we requeue here (commands could
1670 		 * be entering our queuecommand while a block is starting
1671 		 * up because the block code is not locked)
1672 		 */
1673 		switch (session->state) {
1674 		case ISCSI_STATE_FAILED:
1675 			/*
1676 			 * cmds should fail during shutdown, if the session
1677 			 * state is bad, allowing completion to happen
1678 			 */
1679 			if (unlikely(system_state != SYSTEM_RUNNING)) {
1680 				reason = FAILURE_SESSION_FAILED;
1681 				sc->result = DID_NO_CONNECT << 16;
1682 				break;
1683 			}
1684 			fallthrough;
1685 		case ISCSI_STATE_IN_RECOVERY:
1686 			reason = FAILURE_SESSION_IN_RECOVERY;
1687 			sc->result = DID_IMM_RETRY << 16;
1688 			break;
1689 		case ISCSI_STATE_LOGGING_OUT:
1690 			reason = FAILURE_SESSION_LOGGING_OUT;
1691 			sc->result = DID_IMM_RETRY << 16;
1692 			break;
1693 		case ISCSI_STATE_RECOVERY_FAILED:
1694 			reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1695 			sc->result = DID_TRANSPORT_FAILFAST << 16;
1696 			break;
1697 		case ISCSI_STATE_TERMINATE:
1698 			reason = FAILURE_SESSION_TERMINATE;
1699 			sc->result = DID_NO_CONNECT << 16;
1700 			break;
1701 		default:
1702 			reason = FAILURE_SESSION_FREED;
1703 			sc->result = DID_NO_CONNECT << 16;
1704 		}
1705 		goto fault;
1706 	}
1707 
1708 	conn = session->leadconn;
1709 	if (!conn) {
1710 		reason = FAILURE_SESSION_FREED;
1711 		sc->result = DID_NO_CONNECT << 16;
1712 		goto fault;
1713 	}
1714 
1715 	if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1716 		reason = FAILURE_SESSION_IN_RECOVERY;
1717 		sc->result = DID_REQUEUE << 16;
1718 		goto fault;
1719 	}
1720 
1721 	if (iscsi_check_cmdsn_window_closed(conn)) {
1722 		reason = FAILURE_WINDOW_CLOSED;
1723 		goto reject;
1724 	}
1725 
1726 	task = iscsi_alloc_task(conn, sc);
1727 	if (!task) {
1728 		reason = FAILURE_OOM;
1729 		goto reject;
1730 	}
1731 
1732 	if (!ihost->workq) {
1733 		reason = iscsi_prep_scsi_cmd_pdu(task);
1734 		if (reason) {
1735 			if (reason == -ENOMEM ||  reason == -EACCES) {
1736 				reason = FAILURE_OOM;
1737 				goto prepd_reject;
1738 			} else {
1739 				sc->result = DID_ABORT << 16;
1740 				goto prepd_fault;
1741 			}
1742 		}
1743 		if (session->tt->xmit_task(task)) {
1744 			session->cmdsn--;
1745 			reason = FAILURE_SESSION_NOT_READY;
1746 			goto prepd_reject;
1747 		}
1748 	} else {
1749 		spin_lock_bh(&conn->taskqueuelock);
1750 		list_add_tail(&task->running, &conn->cmdqueue);
1751 		spin_unlock_bh(&conn->taskqueuelock);
1752 		iscsi_conn_queue_work(conn);
1753 	}
1754 
1755 	session->queued_cmdsn++;
1756 	spin_unlock_bh(&session->frwd_lock);
1757 	return 0;
1758 
1759 prepd_reject:
1760 	spin_lock_bh(&session->back_lock);
1761 	iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1762 	spin_unlock_bh(&session->back_lock);
1763 reject:
1764 	spin_unlock_bh(&session->frwd_lock);
1765 	ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1766 			  sc->cmnd[0], reason);
1767 	return SCSI_MLQUEUE_TARGET_BUSY;
1768 
1769 prepd_fault:
1770 	spin_lock_bh(&session->back_lock);
1771 	iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1772 	spin_unlock_bh(&session->back_lock);
1773 fault:
1774 	spin_unlock_bh(&session->frwd_lock);
1775 	ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1776 			  sc->cmnd[0], reason);
1777 	scsi_set_resid(sc, scsi_bufflen(sc));
1778 	sc->scsi_done(sc);
1779 	return 0;
1780 }
1781 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1782 
1783 int iscsi_target_alloc(struct scsi_target *starget)
1784 {
1785 	struct iscsi_cls_session *cls_session = starget_to_session(starget);
1786 	struct iscsi_session *session = cls_session->dd_data;
1787 
1788 	starget->can_queue = session->scsi_cmds_max;
1789 	return 0;
1790 }
1791 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1792 
1793 static void iscsi_tmf_timedout(struct timer_list *t)
1794 {
1795 	struct iscsi_conn *conn = from_timer(conn, t, tmf_timer);
1796 	struct iscsi_session *session = conn->session;
1797 
1798 	spin_lock(&session->frwd_lock);
1799 	if (conn->tmf_state == TMF_QUEUED) {
1800 		conn->tmf_state = TMF_TIMEDOUT;
1801 		ISCSI_DBG_EH(session, "tmf timedout\n");
1802 		/* unblock eh_abort() */
1803 		wake_up(&conn->ehwait);
1804 	}
1805 	spin_unlock(&session->frwd_lock);
1806 }
1807 
1808 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1809 				   struct iscsi_tm *hdr, int age,
1810 				   int timeout)
1811 	__must_hold(&session->frwd_lock)
1812 {
1813 	struct iscsi_session *session = conn->session;
1814 	struct iscsi_task *task;
1815 
1816 	task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1817 				      NULL, 0);
1818 	if (!task) {
1819 		spin_unlock_bh(&session->frwd_lock);
1820 		iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1821 		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1822 		spin_lock_bh(&session->frwd_lock);
1823 		return -EPERM;
1824 	}
1825 	conn->tmfcmd_pdus_cnt++;
1826 	conn->tmf_timer.expires = timeout * HZ + jiffies;
1827 	add_timer(&conn->tmf_timer);
1828 	ISCSI_DBG_EH(session, "tmf set timeout\n");
1829 
1830 	spin_unlock_bh(&session->frwd_lock);
1831 	mutex_unlock(&session->eh_mutex);
1832 
1833 	/*
1834 	 * block eh thread until:
1835 	 *
1836 	 * 1) tmf response
1837 	 * 2) tmf timeout
1838 	 * 3) session is terminated or restarted or userspace has
1839 	 * given up on recovery
1840 	 */
1841 	wait_event_interruptible(conn->ehwait, age != session->age ||
1842 				 session->state != ISCSI_STATE_LOGGED_IN ||
1843 				 conn->tmf_state != TMF_QUEUED);
1844 	if (signal_pending(current))
1845 		flush_signals(current);
1846 	del_timer_sync(&conn->tmf_timer);
1847 
1848 	mutex_lock(&session->eh_mutex);
1849 	spin_lock_bh(&session->frwd_lock);
1850 	/* if the session drops it will clean up the task */
1851 	if (age != session->age ||
1852 	    session->state != ISCSI_STATE_LOGGED_IN)
1853 		return -ENOTCONN;
1854 	return 0;
1855 }
1856 
1857 /*
1858  * Fail commands. session lock held and recv side suspended and xmit
1859  * thread flushed
1860  */
1861 static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
1862 {
1863 	struct iscsi_task *task;
1864 	int i;
1865 
1866 	for (i = 0; i < conn->session->cmds_max; i++) {
1867 		task = conn->session->cmds[i];
1868 		if (!task->sc || task->state == ISCSI_TASK_FREE)
1869 			continue;
1870 
1871 		if (lun != -1 && lun != task->sc->device->lun)
1872 			continue;
1873 
1874 		ISCSI_DBG_SESSION(conn->session,
1875 				  "failing sc %p itt 0x%x state %d\n",
1876 				  task->sc, task->itt, task->state);
1877 		fail_scsi_task(task, error);
1878 	}
1879 }
1880 
1881 /**
1882  * iscsi_suspend_queue - suspend iscsi_queuecommand
1883  * @conn: iscsi conn to stop queueing IO on
1884  *
1885  * This grabs the session frwd_lock to make sure no one is in
1886  * xmit_task/queuecommand, and then sets suspend to prevent
1887  * new commands from being queued. This only needs to be called
1888  * by offload drivers that need to sync a path like ep disconnect
1889  * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1890  * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1891  */
1892 void iscsi_suspend_queue(struct iscsi_conn *conn)
1893 {
1894 	spin_lock_bh(&conn->session->frwd_lock);
1895 	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1896 	spin_unlock_bh(&conn->session->frwd_lock);
1897 }
1898 EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1899 
1900 /**
1901  * iscsi_suspend_tx - suspend iscsi_data_xmit
1902  * @conn: iscsi conn tp stop processing IO on.
1903  *
1904  * This function sets the suspend bit to prevent iscsi_data_xmit
1905  * from sending new IO, and if work is queued on the xmit thread
1906  * it will wait for it to be completed.
1907  */
1908 void iscsi_suspend_tx(struct iscsi_conn *conn)
1909 {
1910 	struct Scsi_Host *shost = conn->session->host;
1911 	struct iscsi_host *ihost = shost_priv(shost);
1912 
1913 	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1914 	if (ihost->workq)
1915 		flush_workqueue(ihost->workq);
1916 }
1917 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1918 
1919 static void iscsi_start_tx(struct iscsi_conn *conn)
1920 {
1921 	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1922 	iscsi_conn_queue_work(conn);
1923 }
1924 
1925 /*
1926  * We want to make sure a ping is in flight. It has timed out.
1927  * And we are not busy processing a pdu that is making
1928  * progress but got started before the ping and is taking a while
1929  * to complete so the ping is just stuck behind it in a queue.
1930  */
1931 static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1932 {
1933 	if (READ_ONCE(conn->ping_task) &&
1934 	    time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1935 			   (conn->ping_timeout * HZ), jiffies))
1936 		return 1;
1937 	else
1938 		return 0;
1939 }
1940 
1941 enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1942 {
1943 	enum blk_eh_timer_return rc = BLK_EH_DONE;
1944 	struct iscsi_task *task = NULL, *running_task;
1945 	struct iscsi_cls_session *cls_session;
1946 	struct iscsi_session *session;
1947 	struct iscsi_conn *conn;
1948 	int i;
1949 
1950 	cls_session = starget_to_session(scsi_target(sc->device));
1951 	session = cls_session->dd_data;
1952 
1953 	ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1954 
1955 	spin_lock_bh(&session->frwd_lock);
1956 	task = (struct iscsi_task *)sc->SCp.ptr;
1957 	if (!task) {
1958 		/*
1959 		 * Raced with completion. Blk layer has taken ownership
1960 		 * so let timeout code complete it now.
1961 		 */
1962 		rc = BLK_EH_DONE;
1963 		goto done;
1964 	}
1965 
1966 	if (session->state != ISCSI_STATE_LOGGED_IN) {
1967 		/*
1968 		 * During shutdown, if session is prematurely disconnected,
1969 		 * recovery won't happen and there will be hung cmds. Not
1970 		 * handling cmds would trigger EH, also bad in this case.
1971 		 * Instead, handle cmd, allow completion to happen and let
1972 		 * upper layer to deal with the result.
1973 		 */
1974 		if (unlikely(system_state != SYSTEM_RUNNING)) {
1975 			sc->result = DID_NO_CONNECT << 16;
1976 			ISCSI_DBG_EH(session, "sc on shutdown, handled\n");
1977 			rc = BLK_EH_DONE;
1978 			goto done;
1979 		}
1980 		/*
1981 		 * We are probably in the middle of iscsi recovery so let
1982 		 * that complete and handle the error.
1983 		 */
1984 		rc = BLK_EH_RESET_TIMER;
1985 		goto done;
1986 	}
1987 
1988 	conn = session->leadconn;
1989 	if (!conn) {
1990 		/* In the middle of shuting down */
1991 		rc = BLK_EH_RESET_TIMER;
1992 		goto done;
1993 	}
1994 
1995 	/*
1996 	 * If we have sent (at least queued to the network layer) a pdu or
1997 	 * recvd one for the task since the last timeout ask for
1998 	 * more time. If on the next timeout we have not made progress
1999 	 * we can check if it is the task or connection when we send the
2000 	 * nop as a ping.
2001 	 */
2002 	if (time_after(task->last_xfer, task->last_timeout)) {
2003 		ISCSI_DBG_EH(session, "Command making progress. Asking "
2004 			     "scsi-ml for more time to complete. "
2005 			     "Last data xfer at %lu. Last timeout was at "
2006 			     "%lu\n.", task->last_xfer, task->last_timeout);
2007 		task->have_checked_conn = false;
2008 		rc = BLK_EH_RESET_TIMER;
2009 		goto done;
2010 	}
2011 
2012 	if (!conn->recv_timeout && !conn->ping_timeout)
2013 		goto done;
2014 	/*
2015 	 * if the ping timedout then we are in the middle of cleaning up
2016 	 * and can let the iscsi eh handle it
2017 	 */
2018 	if (iscsi_has_ping_timed_out(conn)) {
2019 		rc = BLK_EH_RESET_TIMER;
2020 		goto done;
2021 	}
2022 
2023 	for (i = 0; i < conn->session->cmds_max; i++) {
2024 		running_task = conn->session->cmds[i];
2025 		if (!running_task->sc || running_task == task ||
2026 		     running_task->state != ISCSI_TASK_RUNNING)
2027 			continue;
2028 
2029 		/*
2030 		 * Only check if cmds started before this one have made
2031 		 * progress, or this could never fail
2032 		 */
2033 		if (time_after(running_task->sc->jiffies_at_alloc,
2034 			       task->sc->jiffies_at_alloc))
2035 			continue;
2036 
2037 		if (time_after(running_task->last_xfer, task->last_timeout)) {
2038 			/*
2039 			 * This task has not made progress, but a task
2040 			 * started before us has transferred data since
2041 			 * we started/last-checked. We could be queueing
2042 			 * too many tasks or the LU is bad.
2043 			 *
2044 			 * If the device is bad the cmds ahead of us on
2045 			 * other devs will complete, and this loop will
2046 			 * eventually fail starting the scsi eh.
2047 			 */
2048 			ISCSI_DBG_EH(session, "Command has not made progress "
2049 				     "but commands ahead of it have. "
2050 				     "Asking scsi-ml for more time to "
2051 				     "complete. Our last xfer vs running task "
2052 				     "last xfer %lu/%lu. Last check %lu.\n",
2053 				     task->last_xfer, running_task->last_xfer,
2054 				     task->last_timeout);
2055 			rc = BLK_EH_RESET_TIMER;
2056 			goto done;
2057 		}
2058 	}
2059 
2060 	/* Assumes nop timeout is shorter than scsi cmd timeout */
2061 	if (task->have_checked_conn)
2062 		goto done;
2063 
2064 	/*
2065 	 * Checking the transport already or nop from a cmd timeout still
2066 	 * running
2067 	 */
2068 	if (READ_ONCE(conn->ping_task)) {
2069 		task->have_checked_conn = true;
2070 		rc = BLK_EH_RESET_TIMER;
2071 		goto done;
2072 	}
2073 
2074 	/* Make sure there is a transport check done */
2075 	iscsi_send_nopout(conn, NULL);
2076 	task->have_checked_conn = true;
2077 	rc = BLK_EH_RESET_TIMER;
2078 
2079 done:
2080 	if (task)
2081 		task->last_timeout = jiffies;
2082 	spin_unlock_bh(&session->frwd_lock);
2083 	ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2084 		     "timer reset" : "shutdown or nh");
2085 	return rc;
2086 }
2087 EXPORT_SYMBOL_GPL(iscsi_eh_cmd_timed_out);
2088 
2089 static void iscsi_check_transport_timeouts(struct timer_list *t)
2090 {
2091 	struct iscsi_conn *conn = from_timer(conn, t, transport_timer);
2092 	struct iscsi_session *session = conn->session;
2093 	unsigned long recv_timeout, next_timeout = 0, last_recv;
2094 
2095 	spin_lock(&session->frwd_lock);
2096 	if (session->state != ISCSI_STATE_LOGGED_IN)
2097 		goto done;
2098 
2099 	recv_timeout = conn->recv_timeout;
2100 	if (!recv_timeout)
2101 		goto done;
2102 
2103 	recv_timeout *= HZ;
2104 	last_recv = conn->last_recv;
2105 
2106 	if (iscsi_has_ping_timed_out(conn)) {
2107 		iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2108 				  "expired, recv timeout %d, last rx %lu, "
2109 				  "last ping %lu, now %lu\n",
2110 				  conn->ping_timeout, conn->recv_timeout,
2111 				  last_recv, conn->last_ping, jiffies);
2112 		spin_unlock(&session->frwd_lock);
2113 		iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2114 		return;
2115 	}
2116 
2117 	if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2118 		/* send a ping to try to provoke some traffic */
2119 		ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2120 		if (iscsi_send_nopout(conn, NULL))
2121 			next_timeout = jiffies + (1 * HZ);
2122 		else
2123 			next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2124 	} else
2125 		next_timeout = last_recv + recv_timeout;
2126 
2127 	ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2128 	mod_timer(&conn->transport_timer, next_timeout);
2129 done:
2130 	spin_unlock(&session->frwd_lock);
2131 }
2132 
2133 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2134 				      struct iscsi_tm *hdr)
2135 {
2136 	memset(hdr, 0, sizeof(*hdr));
2137 	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2138 	hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2139 	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2140 	hdr->lun = task->lun;
2141 	hdr->rtt = task->hdr_itt;
2142 	hdr->refcmdsn = task->cmdsn;
2143 }
2144 
2145 int iscsi_eh_abort(struct scsi_cmnd *sc)
2146 {
2147 	struct iscsi_cls_session *cls_session;
2148 	struct iscsi_session *session;
2149 	struct iscsi_conn *conn;
2150 	struct iscsi_task *task;
2151 	struct iscsi_tm *hdr;
2152 	int age;
2153 
2154 	cls_session = starget_to_session(scsi_target(sc->device));
2155 	session = cls_session->dd_data;
2156 
2157 	ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2158 
2159 	mutex_lock(&session->eh_mutex);
2160 	spin_lock_bh(&session->frwd_lock);
2161 	/*
2162 	 * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2163 	 * got the command.
2164 	 */
2165 	if (!sc->SCp.ptr) {
2166 		ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2167 				      "it completed.\n");
2168 		spin_unlock_bh(&session->frwd_lock);
2169 		mutex_unlock(&session->eh_mutex);
2170 		return SUCCESS;
2171 	}
2172 
2173 	/*
2174 	 * If we are not logged in or we have started a new session
2175 	 * then let the host reset code handle this
2176 	 */
2177 	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2178 	    sc->SCp.phase != session->age) {
2179 		spin_unlock_bh(&session->frwd_lock);
2180 		mutex_unlock(&session->eh_mutex);
2181 		ISCSI_DBG_EH(session, "failing abort due to dropped "
2182 				  "session.\n");
2183 		return FAILED;
2184 	}
2185 
2186 	conn = session->leadconn;
2187 	conn->eh_abort_cnt++;
2188 	age = session->age;
2189 
2190 	task = (struct iscsi_task *)sc->SCp.ptr;
2191 	ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2192 		     sc, task->itt);
2193 
2194 	/* task completed before time out */
2195 	if (!task->sc) {
2196 		ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2197 		goto success;
2198 	}
2199 
2200 	if (task->state == ISCSI_TASK_PENDING) {
2201 		fail_scsi_task(task, DID_ABORT);
2202 		goto success;
2203 	}
2204 
2205 	/* only have one tmf outstanding at a time */
2206 	if (conn->tmf_state != TMF_INITIAL)
2207 		goto failed;
2208 	conn->tmf_state = TMF_QUEUED;
2209 
2210 	hdr = &conn->tmhdr;
2211 	iscsi_prep_abort_task_pdu(task, hdr);
2212 
2213 	if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout))
2214 		goto failed;
2215 
2216 	switch (conn->tmf_state) {
2217 	case TMF_SUCCESS:
2218 		spin_unlock_bh(&session->frwd_lock);
2219 		/*
2220 		 * stop tx side incase the target had sent a abort rsp but
2221 		 * the initiator was still writing out data.
2222 		 */
2223 		iscsi_suspend_tx(conn);
2224 		/*
2225 		 * we do not stop the recv side because targets have been
2226 		 * good and have never sent us a successful tmf response
2227 		 * then sent more data for the cmd.
2228 		 */
2229 		spin_lock_bh(&session->frwd_lock);
2230 		fail_scsi_task(task, DID_ABORT);
2231 		conn->tmf_state = TMF_INITIAL;
2232 		memset(hdr, 0, sizeof(*hdr));
2233 		spin_unlock_bh(&session->frwd_lock);
2234 		iscsi_start_tx(conn);
2235 		goto success_unlocked;
2236 	case TMF_TIMEDOUT:
2237 		spin_unlock_bh(&session->frwd_lock);
2238 		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2239 		goto failed_unlocked;
2240 	case TMF_NOT_FOUND:
2241 		if (!sc->SCp.ptr) {
2242 			conn->tmf_state = TMF_INITIAL;
2243 			memset(hdr, 0, sizeof(*hdr));
2244 			/* task completed before tmf abort response */
2245 			ISCSI_DBG_EH(session, "sc completed while abort	in "
2246 					      "progress\n");
2247 			goto success;
2248 		}
2249 		fallthrough;
2250 	default:
2251 		conn->tmf_state = TMF_INITIAL;
2252 		goto failed;
2253 	}
2254 
2255 success:
2256 	spin_unlock_bh(&session->frwd_lock);
2257 success_unlocked:
2258 	ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2259 		     sc, task->itt);
2260 	mutex_unlock(&session->eh_mutex);
2261 	return SUCCESS;
2262 
2263 failed:
2264 	spin_unlock_bh(&session->frwd_lock);
2265 failed_unlocked:
2266 	ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2267 		     task ? task->itt : 0);
2268 	mutex_unlock(&session->eh_mutex);
2269 	return FAILED;
2270 }
2271 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2272 
2273 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2274 {
2275 	memset(hdr, 0, sizeof(*hdr));
2276 	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2277 	hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2278 	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2279 	int_to_scsilun(sc->device->lun, &hdr->lun);
2280 	hdr->rtt = RESERVED_ITT;
2281 }
2282 
2283 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2284 {
2285 	struct iscsi_cls_session *cls_session;
2286 	struct iscsi_session *session;
2287 	struct iscsi_conn *conn;
2288 	struct iscsi_tm *hdr;
2289 	int rc = FAILED;
2290 
2291 	cls_session = starget_to_session(scsi_target(sc->device));
2292 	session = cls_session->dd_data;
2293 
2294 	ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2295 		     sc->device->lun);
2296 
2297 	mutex_lock(&session->eh_mutex);
2298 	spin_lock_bh(&session->frwd_lock);
2299 	/*
2300 	 * Just check if we are not logged in. We cannot check for
2301 	 * the phase because the reset could come from a ioctl.
2302 	 */
2303 	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2304 		goto unlock;
2305 	conn = session->leadconn;
2306 
2307 	/* only have one tmf outstanding at a time */
2308 	if (conn->tmf_state != TMF_INITIAL)
2309 		goto unlock;
2310 	conn->tmf_state = TMF_QUEUED;
2311 
2312 	hdr = &conn->tmhdr;
2313 	iscsi_prep_lun_reset_pdu(sc, hdr);
2314 
2315 	if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2316 				    session->lu_reset_timeout)) {
2317 		rc = FAILED;
2318 		goto unlock;
2319 	}
2320 
2321 	switch (conn->tmf_state) {
2322 	case TMF_SUCCESS:
2323 		break;
2324 	case TMF_TIMEDOUT:
2325 		spin_unlock_bh(&session->frwd_lock);
2326 		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2327 		goto done;
2328 	default:
2329 		conn->tmf_state = TMF_INITIAL;
2330 		goto unlock;
2331 	}
2332 
2333 	rc = SUCCESS;
2334 	spin_unlock_bh(&session->frwd_lock);
2335 
2336 	iscsi_suspend_tx(conn);
2337 
2338 	spin_lock_bh(&session->frwd_lock);
2339 	memset(hdr, 0, sizeof(*hdr));
2340 	fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2341 	conn->tmf_state = TMF_INITIAL;
2342 	spin_unlock_bh(&session->frwd_lock);
2343 
2344 	iscsi_start_tx(conn);
2345 	goto done;
2346 
2347 unlock:
2348 	spin_unlock_bh(&session->frwd_lock);
2349 done:
2350 	ISCSI_DBG_EH(session, "dev reset result = %s\n",
2351 		     rc == SUCCESS ? "SUCCESS" : "FAILED");
2352 	mutex_unlock(&session->eh_mutex);
2353 	return rc;
2354 }
2355 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2356 
2357 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2358 {
2359 	struct iscsi_session *session = cls_session->dd_data;
2360 
2361 	spin_lock_bh(&session->frwd_lock);
2362 	if (session->state != ISCSI_STATE_LOGGED_IN) {
2363 		session->state = ISCSI_STATE_RECOVERY_FAILED;
2364 		if (session->leadconn)
2365 			wake_up(&session->leadconn->ehwait);
2366 	}
2367 	spin_unlock_bh(&session->frwd_lock);
2368 }
2369 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2370 
2371 /**
2372  * iscsi_eh_session_reset - drop session and attempt relogin
2373  * @sc: scsi command
2374  *
2375  * This function will wait for a relogin, session termination from
2376  * userspace, or a recovery/replacement timeout.
2377  */
2378 int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2379 {
2380 	struct iscsi_cls_session *cls_session;
2381 	struct iscsi_session *session;
2382 	struct iscsi_conn *conn;
2383 
2384 	cls_session = starget_to_session(scsi_target(sc->device));
2385 	session = cls_session->dd_data;
2386 	conn = session->leadconn;
2387 
2388 	mutex_lock(&session->eh_mutex);
2389 	spin_lock_bh(&session->frwd_lock);
2390 	if (session->state == ISCSI_STATE_TERMINATE) {
2391 failed:
2392 		ISCSI_DBG_EH(session,
2393 			     "failing session reset: Could not log back into "
2394 			     "%s [age %d]\n", session->targetname,
2395 			     session->age);
2396 		spin_unlock_bh(&session->frwd_lock);
2397 		mutex_unlock(&session->eh_mutex);
2398 		return FAILED;
2399 	}
2400 
2401 	spin_unlock_bh(&session->frwd_lock);
2402 	mutex_unlock(&session->eh_mutex);
2403 	/*
2404 	 * we drop the lock here but the leadconn cannot be destoyed while
2405 	 * we are in the scsi eh
2406 	 */
2407 	iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2408 
2409 	ISCSI_DBG_EH(session, "wait for relogin\n");
2410 	wait_event_interruptible(conn->ehwait,
2411 				 session->state == ISCSI_STATE_TERMINATE ||
2412 				 session->state == ISCSI_STATE_LOGGED_IN ||
2413 				 session->state == ISCSI_STATE_RECOVERY_FAILED);
2414 	if (signal_pending(current))
2415 		flush_signals(current);
2416 
2417 	mutex_lock(&session->eh_mutex);
2418 	spin_lock_bh(&session->frwd_lock);
2419 	if (session->state == ISCSI_STATE_LOGGED_IN) {
2420 		ISCSI_DBG_EH(session,
2421 			     "session reset succeeded for %s,%s\n",
2422 			     session->targetname, conn->persistent_address);
2423 	} else
2424 		goto failed;
2425 	spin_unlock_bh(&session->frwd_lock);
2426 	mutex_unlock(&session->eh_mutex);
2427 	return SUCCESS;
2428 }
2429 EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2430 
2431 static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2432 {
2433 	memset(hdr, 0, sizeof(*hdr));
2434 	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2435 	hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2436 	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2437 	hdr->rtt = RESERVED_ITT;
2438 }
2439 
2440 /**
2441  * iscsi_eh_target_reset - reset target
2442  * @sc: scsi command
2443  *
2444  * This will attempt to send a warm target reset.
2445  */
2446 static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2447 {
2448 	struct iscsi_cls_session *cls_session;
2449 	struct iscsi_session *session;
2450 	struct iscsi_conn *conn;
2451 	struct iscsi_tm *hdr;
2452 	int rc = FAILED;
2453 
2454 	cls_session = starget_to_session(scsi_target(sc->device));
2455 	session = cls_session->dd_data;
2456 
2457 	ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2458 		     session->targetname);
2459 
2460 	mutex_lock(&session->eh_mutex);
2461 	spin_lock_bh(&session->frwd_lock);
2462 	/*
2463 	 * Just check if we are not logged in. We cannot check for
2464 	 * the phase because the reset could come from a ioctl.
2465 	 */
2466 	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2467 		goto unlock;
2468 	conn = session->leadconn;
2469 
2470 	/* only have one tmf outstanding at a time */
2471 	if (conn->tmf_state != TMF_INITIAL)
2472 		goto unlock;
2473 	conn->tmf_state = TMF_QUEUED;
2474 
2475 	hdr = &conn->tmhdr;
2476 	iscsi_prep_tgt_reset_pdu(sc, hdr);
2477 
2478 	if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2479 				    session->tgt_reset_timeout)) {
2480 		rc = FAILED;
2481 		goto unlock;
2482 	}
2483 
2484 	switch (conn->tmf_state) {
2485 	case TMF_SUCCESS:
2486 		break;
2487 	case TMF_TIMEDOUT:
2488 		spin_unlock_bh(&session->frwd_lock);
2489 		iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2490 		goto done;
2491 	default:
2492 		conn->tmf_state = TMF_INITIAL;
2493 		goto unlock;
2494 	}
2495 
2496 	rc = SUCCESS;
2497 	spin_unlock_bh(&session->frwd_lock);
2498 
2499 	iscsi_suspend_tx(conn);
2500 
2501 	spin_lock_bh(&session->frwd_lock);
2502 	memset(hdr, 0, sizeof(*hdr));
2503 	fail_scsi_tasks(conn, -1, DID_ERROR);
2504 	conn->tmf_state = TMF_INITIAL;
2505 	spin_unlock_bh(&session->frwd_lock);
2506 
2507 	iscsi_start_tx(conn);
2508 	goto done;
2509 
2510 unlock:
2511 	spin_unlock_bh(&session->frwd_lock);
2512 done:
2513 	ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2514 		     rc == SUCCESS ? "SUCCESS" : "FAILED");
2515 	mutex_unlock(&session->eh_mutex);
2516 	return rc;
2517 }
2518 
2519 /**
2520  * iscsi_eh_recover_target - reset target and possibly the session
2521  * @sc: scsi command
2522  *
2523  * This will attempt to send a warm target reset. If that fails,
2524  * we will escalate to ERL0 session recovery.
2525  */
2526 int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2527 {
2528 	int rc;
2529 
2530 	rc = iscsi_eh_target_reset(sc);
2531 	if (rc == FAILED)
2532 		rc = iscsi_eh_session_reset(sc);
2533 	return rc;
2534 }
2535 EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2536 
2537 /*
2538  * Pre-allocate a pool of @max items of @item_size. By default, the pool
2539  * should be accessed via kfifo_{get,put} on q->queue.
2540  * Optionally, the caller can obtain the array of object pointers
2541  * by passing in a non-NULL @items pointer
2542  */
2543 int
2544 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2545 {
2546 	int i, num_arrays = 1;
2547 
2548 	memset(q, 0, sizeof(*q));
2549 
2550 	q->max = max;
2551 
2552 	/* If the user passed an items pointer, he wants a copy of
2553 	 * the array. */
2554 	if (items)
2555 		num_arrays++;
2556 	q->pool = kvcalloc(num_arrays * max, sizeof(void *), GFP_KERNEL);
2557 	if (q->pool == NULL)
2558 		return -ENOMEM;
2559 
2560 	kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2561 
2562 	for (i = 0; i < max; i++) {
2563 		q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2564 		if (q->pool[i] == NULL) {
2565 			q->max = i;
2566 			goto enomem;
2567 		}
2568 		kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2569 	}
2570 
2571 	if (items) {
2572 		*items = q->pool + max;
2573 		memcpy(*items, q->pool, max * sizeof(void *));
2574 	}
2575 
2576 	return 0;
2577 
2578 enomem:
2579 	iscsi_pool_free(q);
2580 	return -ENOMEM;
2581 }
2582 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2583 
2584 void iscsi_pool_free(struct iscsi_pool *q)
2585 {
2586 	int i;
2587 
2588 	for (i = 0; i < q->max; i++)
2589 		kfree(q->pool[i]);
2590 	kvfree(q->pool);
2591 }
2592 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2593 
2594 /**
2595  * iscsi_host_add - add host to system
2596  * @shost: scsi host
2597  * @pdev: parent device
2598  *
2599  * This should be called by partial offload and software iscsi drivers
2600  * to add a host to the system.
2601  */
2602 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2603 {
2604 	if (!shost->can_queue)
2605 		shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2606 
2607 	if (!shost->cmd_per_lun)
2608 		shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2609 
2610 	return scsi_add_host(shost, pdev);
2611 }
2612 EXPORT_SYMBOL_GPL(iscsi_host_add);
2613 
2614 /**
2615  * iscsi_host_alloc - allocate a host and driver data
2616  * @sht: scsi host template
2617  * @dd_data_size: driver host data size
2618  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2619  *
2620  * This should be called by partial offload and software iscsi drivers.
2621  * To access the driver specific memory use the iscsi_host_priv() macro.
2622  */
2623 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2624 				   int dd_data_size, bool xmit_can_sleep)
2625 {
2626 	struct Scsi_Host *shost;
2627 	struct iscsi_host *ihost;
2628 
2629 	shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2630 	if (!shost)
2631 		return NULL;
2632 	ihost = shost_priv(shost);
2633 
2634 	if (xmit_can_sleep) {
2635 		snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2636 			"iscsi_q_%d", shost->host_no);
2637 		ihost->workq = alloc_workqueue("%s",
2638 			WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
2639 			1, ihost->workq_name);
2640 		if (!ihost->workq)
2641 			goto free_host;
2642 	}
2643 
2644 	spin_lock_init(&ihost->lock);
2645 	ihost->state = ISCSI_HOST_SETUP;
2646 	ihost->num_sessions = 0;
2647 	init_waitqueue_head(&ihost->session_removal_wq);
2648 	return shost;
2649 
2650 free_host:
2651 	scsi_host_put(shost);
2652 	return NULL;
2653 }
2654 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2655 
2656 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2657 {
2658 	iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2659 }
2660 
2661 /**
2662  * iscsi_host_remove - remove host and sessions
2663  * @shost: scsi host
2664  *
2665  * If there are any sessions left, this will initiate the removal and wait
2666  * for the completion.
2667  */
2668 void iscsi_host_remove(struct Scsi_Host *shost)
2669 {
2670 	struct iscsi_host *ihost = shost_priv(shost);
2671 	unsigned long flags;
2672 
2673 	spin_lock_irqsave(&ihost->lock, flags);
2674 	ihost->state = ISCSI_HOST_REMOVED;
2675 	spin_unlock_irqrestore(&ihost->lock, flags);
2676 
2677 	iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2678 	wait_event_interruptible(ihost->session_removal_wq,
2679 				 ihost->num_sessions == 0);
2680 	if (signal_pending(current))
2681 		flush_signals(current);
2682 
2683 	scsi_remove_host(shost);
2684 	if (ihost->workq)
2685 		destroy_workqueue(ihost->workq);
2686 }
2687 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2688 
2689 void iscsi_host_free(struct Scsi_Host *shost)
2690 {
2691 	struct iscsi_host *ihost = shost_priv(shost);
2692 
2693 	kfree(ihost->netdev);
2694 	kfree(ihost->hwaddress);
2695 	kfree(ihost->initiatorname);
2696 	scsi_host_put(shost);
2697 }
2698 EXPORT_SYMBOL_GPL(iscsi_host_free);
2699 
2700 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2701 {
2702 	struct iscsi_host *ihost = shost_priv(shost);
2703 	unsigned long flags;
2704 
2705 	shost = scsi_host_get(shost);
2706 	if (!shost) {
2707 		printk(KERN_ERR "Invalid state. Cannot notify host removal "
2708 		      "of session teardown event because host already "
2709 		      "removed.\n");
2710 		return;
2711 	}
2712 
2713 	spin_lock_irqsave(&ihost->lock, flags);
2714 	ihost->num_sessions--;
2715 	if (ihost->num_sessions == 0)
2716 		wake_up(&ihost->session_removal_wq);
2717 	spin_unlock_irqrestore(&ihost->lock, flags);
2718 	scsi_host_put(shost);
2719 }
2720 
2721 /**
2722  * iscsi_session_setup - create iscsi cls session and host and session
2723  * @iscsit: iscsi transport template
2724  * @shost: scsi host
2725  * @cmds_max: session can queue
2726  * @dd_size: private driver data size, added to session allocation size
2727  * @cmd_task_size: LLD task private data size
2728  * @initial_cmdsn: initial CmdSN
2729  * @id: target ID to add to this session
2730  *
2731  * This can be used by software iscsi_transports that allocate
2732  * a session per scsi host.
2733  *
2734  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2735  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2736  * for nop handling and login/logout requests.
2737  */
2738 struct iscsi_cls_session *
2739 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2740 		    uint16_t cmds_max, int dd_size, int cmd_task_size,
2741 		    uint32_t initial_cmdsn, unsigned int id)
2742 {
2743 	struct iscsi_host *ihost = shost_priv(shost);
2744 	struct iscsi_session *session;
2745 	struct iscsi_cls_session *cls_session;
2746 	int cmd_i, scsi_cmds, total_cmds = cmds_max;
2747 	unsigned long flags;
2748 
2749 	spin_lock_irqsave(&ihost->lock, flags);
2750 	if (ihost->state == ISCSI_HOST_REMOVED) {
2751 		spin_unlock_irqrestore(&ihost->lock, flags);
2752 		return NULL;
2753 	}
2754 	ihost->num_sessions++;
2755 	spin_unlock_irqrestore(&ihost->lock, flags);
2756 
2757 	if (!total_cmds)
2758 		total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2759 	/*
2760 	 * The iscsi layer needs some tasks for nop handling and tmfs,
2761 	 * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2762 	 * + 1 command for scsi IO.
2763 	 */
2764 	if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2765 		printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2766 		       "must be a power of two that is at least %d.\n",
2767 		       total_cmds, ISCSI_TOTAL_CMDS_MIN);
2768 		goto dec_session_count;
2769 	}
2770 
2771 	if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2772 		printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2773 		       "must be a power of 2 less than or equal to %d.\n",
2774 		       cmds_max, ISCSI_TOTAL_CMDS_MAX);
2775 		total_cmds = ISCSI_TOTAL_CMDS_MAX;
2776 	}
2777 
2778 	if (!is_power_of_2(total_cmds)) {
2779 		printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2780 		       "must be a power of 2.\n", total_cmds);
2781 		total_cmds = rounddown_pow_of_two(total_cmds);
2782 		if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2783 			goto dec_session_count;
2784 		printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2785 		       total_cmds);
2786 	}
2787 	scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2788 
2789 	cls_session = iscsi_alloc_session(shost, iscsit,
2790 					  sizeof(struct iscsi_session) +
2791 					  dd_size);
2792 	if (!cls_session)
2793 		goto dec_session_count;
2794 	session = cls_session->dd_data;
2795 	session->cls_session = cls_session;
2796 	session->host = shost;
2797 	session->state = ISCSI_STATE_FREE;
2798 	session->fast_abort = 1;
2799 	session->tgt_reset_timeout = 30;
2800 	session->lu_reset_timeout = 15;
2801 	session->abort_timeout = 10;
2802 	session->scsi_cmds_max = scsi_cmds;
2803 	session->cmds_max = total_cmds;
2804 	session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2805 	session->exp_cmdsn = initial_cmdsn + 1;
2806 	session->max_cmdsn = initial_cmdsn + 1;
2807 	session->max_r2t = 1;
2808 	session->tt = iscsit;
2809 	session->dd_data = cls_session->dd_data + sizeof(*session);
2810 
2811 	mutex_init(&session->eh_mutex);
2812 	spin_lock_init(&session->frwd_lock);
2813 	spin_lock_init(&session->back_lock);
2814 
2815 	/* initialize SCSI PDU commands pool */
2816 	if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2817 			    (void***)&session->cmds,
2818 			    cmd_task_size + sizeof(struct iscsi_task)))
2819 		goto cmdpool_alloc_fail;
2820 
2821 	/* pre-format cmds pool with ITT */
2822 	for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2823 		struct iscsi_task *task = session->cmds[cmd_i];
2824 
2825 		if (cmd_task_size)
2826 			task->dd_data = &task[1];
2827 		task->itt = cmd_i;
2828 		task->state = ISCSI_TASK_FREE;
2829 		INIT_LIST_HEAD(&task->running);
2830 	}
2831 
2832 	if (!try_module_get(iscsit->owner))
2833 		goto module_get_fail;
2834 
2835 	if (iscsi_add_session(cls_session, id))
2836 		goto cls_session_fail;
2837 
2838 	return cls_session;
2839 
2840 cls_session_fail:
2841 	module_put(iscsit->owner);
2842 module_get_fail:
2843 	iscsi_pool_free(&session->cmdpool);
2844 cmdpool_alloc_fail:
2845 	iscsi_free_session(cls_session);
2846 dec_session_count:
2847 	iscsi_host_dec_session_cnt(shost);
2848 	return NULL;
2849 }
2850 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2851 
2852 /**
2853  * iscsi_session_teardown - destroy session, host, and cls_session
2854  * @cls_session: iscsi session
2855  */
2856 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2857 {
2858 	struct iscsi_session *session = cls_session->dd_data;
2859 	struct module *owner = cls_session->transport->owner;
2860 	struct Scsi_Host *shost = session->host;
2861 
2862 	iscsi_pool_free(&session->cmdpool);
2863 
2864 	iscsi_remove_session(cls_session);
2865 
2866 	kfree(session->password);
2867 	kfree(session->password_in);
2868 	kfree(session->username);
2869 	kfree(session->username_in);
2870 	kfree(session->targetname);
2871 	kfree(session->targetalias);
2872 	kfree(session->initiatorname);
2873 	kfree(session->boot_root);
2874 	kfree(session->boot_nic);
2875 	kfree(session->boot_target);
2876 	kfree(session->ifacename);
2877 	kfree(session->portal_type);
2878 	kfree(session->discovery_parent_type);
2879 
2880 	iscsi_free_session(cls_session);
2881 
2882 	iscsi_host_dec_session_cnt(shost);
2883 	module_put(owner);
2884 }
2885 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2886 
2887 /**
2888  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2889  * @cls_session: iscsi_cls_session
2890  * @dd_size: private driver data size
2891  * @conn_idx: cid
2892  */
2893 struct iscsi_cls_conn *
2894 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2895 		 uint32_t conn_idx)
2896 {
2897 	struct iscsi_session *session = cls_session->dd_data;
2898 	struct iscsi_conn *conn;
2899 	struct iscsi_cls_conn *cls_conn;
2900 	char *data;
2901 
2902 	cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2903 				     conn_idx);
2904 	if (!cls_conn)
2905 		return NULL;
2906 	conn = cls_conn->dd_data;
2907 	memset(conn, 0, sizeof(*conn) + dd_size);
2908 
2909 	conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2910 	conn->session = session;
2911 	conn->cls_conn = cls_conn;
2912 	conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2913 	conn->id = conn_idx;
2914 	conn->exp_statsn = 0;
2915 	conn->tmf_state = TMF_INITIAL;
2916 
2917 	timer_setup(&conn->transport_timer, iscsi_check_transport_timeouts, 0);
2918 
2919 	INIT_LIST_HEAD(&conn->mgmtqueue);
2920 	INIT_LIST_HEAD(&conn->cmdqueue);
2921 	INIT_LIST_HEAD(&conn->requeue);
2922 	spin_lock_init(&conn->taskqueuelock);
2923 	INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2924 
2925 	/* allocate login_task used for the login/text sequences */
2926 	spin_lock_bh(&session->frwd_lock);
2927 	if (!kfifo_out(&session->cmdpool.queue,
2928                          (void*)&conn->login_task,
2929 			 sizeof(void*))) {
2930 		spin_unlock_bh(&session->frwd_lock);
2931 		goto login_task_alloc_fail;
2932 	}
2933 	spin_unlock_bh(&session->frwd_lock);
2934 
2935 	data = (char *) __get_free_pages(GFP_KERNEL,
2936 					 get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2937 	if (!data)
2938 		goto login_task_data_alloc_fail;
2939 	conn->login_task->data = conn->data = data;
2940 
2941 	timer_setup(&conn->tmf_timer, iscsi_tmf_timedout, 0);
2942 	init_waitqueue_head(&conn->ehwait);
2943 
2944 	return cls_conn;
2945 
2946 login_task_data_alloc_fail:
2947 	kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2948 		    sizeof(void*));
2949 login_task_alloc_fail:
2950 	iscsi_destroy_conn(cls_conn);
2951 	return NULL;
2952 }
2953 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2954 
2955 /**
2956  * iscsi_conn_teardown - teardown iscsi connection
2957  * @cls_conn: iscsi class connection
2958  *
2959  * TODO: we may need to make this into a two step process
2960  * like scsi-mls remove + put host
2961  */
2962 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2963 {
2964 	struct iscsi_conn *conn = cls_conn->dd_data;
2965 	struct iscsi_session *session = conn->session;
2966 
2967 	del_timer_sync(&conn->transport_timer);
2968 
2969 	mutex_lock(&session->eh_mutex);
2970 	spin_lock_bh(&session->frwd_lock);
2971 	conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2972 	if (session->leadconn == conn) {
2973 		/*
2974 		 * leading connection? then give up on recovery.
2975 		 */
2976 		session->state = ISCSI_STATE_TERMINATE;
2977 		wake_up(&conn->ehwait);
2978 	}
2979 	spin_unlock_bh(&session->frwd_lock);
2980 
2981 	/* flush queued up work because we free the connection below */
2982 	iscsi_suspend_tx(conn);
2983 
2984 	spin_lock_bh(&session->frwd_lock);
2985 	free_pages((unsigned long) conn->data,
2986 		   get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2987 	kfree(conn->persistent_address);
2988 	kfree(conn->local_ipaddr);
2989 	/* regular RX path uses back_lock */
2990 	spin_lock_bh(&session->back_lock);
2991 	kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2992 		    sizeof(void*));
2993 	spin_unlock_bh(&session->back_lock);
2994 	if (session->leadconn == conn)
2995 		session->leadconn = NULL;
2996 	spin_unlock_bh(&session->frwd_lock);
2997 	mutex_unlock(&session->eh_mutex);
2998 
2999 	iscsi_destroy_conn(cls_conn);
3000 }
3001 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
3002 
3003 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
3004 {
3005 	struct iscsi_conn *conn = cls_conn->dd_data;
3006 	struct iscsi_session *session = conn->session;
3007 
3008 	if (!session) {
3009 		iscsi_conn_printk(KERN_ERR, conn,
3010 				  "can't start unbound connection\n");
3011 		return -EPERM;
3012 	}
3013 
3014 	if ((session->imm_data_en || !session->initial_r2t_en) &&
3015 	     session->first_burst > session->max_burst) {
3016 		iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
3017 				  "first_burst %d max_burst %d\n",
3018 				  session->first_burst, session->max_burst);
3019 		return -EINVAL;
3020 	}
3021 
3022 	if (conn->ping_timeout && !conn->recv_timeout) {
3023 		iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3024 				  "zero. Using 5 seconds\n.");
3025 		conn->recv_timeout = 5;
3026 	}
3027 
3028 	if (conn->recv_timeout && !conn->ping_timeout) {
3029 		iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3030 				  "zero. Using 5 seconds.\n");
3031 		conn->ping_timeout = 5;
3032 	}
3033 
3034 	spin_lock_bh(&session->frwd_lock);
3035 	conn->c_stage = ISCSI_CONN_STARTED;
3036 	session->state = ISCSI_STATE_LOGGED_IN;
3037 	session->queued_cmdsn = session->cmdsn;
3038 
3039 	conn->last_recv = jiffies;
3040 	conn->last_ping = jiffies;
3041 	if (conn->recv_timeout && conn->ping_timeout)
3042 		mod_timer(&conn->transport_timer,
3043 			  jiffies + (conn->recv_timeout * HZ));
3044 
3045 	switch(conn->stop_stage) {
3046 	case STOP_CONN_RECOVER:
3047 		/*
3048 		 * unblock eh_abort() if it is blocked. re-try all
3049 		 * commands after successful recovery
3050 		 */
3051 		conn->stop_stage = 0;
3052 		conn->tmf_state = TMF_INITIAL;
3053 		session->age++;
3054 		if (session->age == 16)
3055 			session->age = 0;
3056 		break;
3057 	case STOP_CONN_TERM:
3058 		conn->stop_stage = 0;
3059 		break;
3060 	default:
3061 		break;
3062 	}
3063 	spin_unlock_bh(&session->frwd_lock);
3064 
3065 	iscsi_unblock_session(session->cls_session);
3066 	wake_up(&conn->ehwait);
3067 	return 0;
3068 }
3069 EXPORT_SYMBOL_GPL(iscsi_conn_start);
3070 
3071 static void
3072 fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3073 {
3074 	struct iscsi_task *task;
3075 	int i, state;
3076 
3077 	for (i = 0; i < conn->session->cmds_max; i++) {
3078 		task = conn->session->cmds[i];
3079 		if (task->sc)
3080 			continue;
3081 
3082 		if (task->state == ISCSI_TASK_FREE)
3083 			continue;
3084 
3085 		ISCSI_DBG_SESSION(conn->session,
3086 				  "failing mgmt itt 0x%x state %d\n",
3087 				  task->itt, task->state);
3088 		state = ISCSI_TASK_ABRT_SESS_RECOV;
3089 		if (task->state == ISCSI_TASK_PENDING)
3090 			state = ISCSI_TASK_COMPLETED;
3091 		spin_lock_bh(&session->back_lock);
3092 		iscsi_complete_task(task, state);
3093 		spin_unlock_bh(&session->back_lock);
3094 	}
3095 }
3096 
3097 static void iscsi_start_session_recovery(struct iscsi_session *session,
3098 					 struct iscsi_conn *conn, int flag)
3099 {
3100 	int old_stop_stage;
3101 
3102 	mutex_lock(&session->eh_mutex);
3103 	spin_lock_bh(&session->frwd_lock);
3104 	if (conn->stop_stage == STOP_CONN_TERM) {
3105 		spin_unlock_bh(&session->frwd_lock);
3106 		mutex_unlock(&session->eh_mutex);
3107 		return;
3108 	}
3109 
3110 	/*
3111 	 * When this is called for the in_login state, we only want to clean
3112 	 * up the login task and connection. We do not need to block and set
3113 	 * the recovery state again
3114 	 */
3115 	if (flag == STOP_CONN_TERM)
3116 		session->state = ISCSI_STATE_TERMINATE;
3117 	else if (conn->stop_stage != STOP_CONN_RECOVER)
3118 		session->state = ISCSI_STATE_IN_RECOVERY;
3119 
3120 	old_stop_stage = conn->stop_stage;
3121 	conn->stop_stage = flag;
3122 	spin_unlock_bh(&session->frwd_lock);
3123 
3124 	del_timer_sync(&conn->transport_timer);
3125 	iscsi_suspend_tx(conn);
3126 
3127 	spin_lock_bh(&session->frwd_lock);
3128 	conn->c_stage = ISCSI_CONN_STOPPED;
3129 	spin_unlock_bh(&session->frwd_lock);
3130 
3131 	/*
3132 	 * for connection level recovery we should not calculate
3133 	 * header digest. conn->hdr_size used for optimization
3134 	 * in hdr_extract() and will be re-negotiated at
3135 	 * set_param() time.
3136 	 */
3137 	if (flag == STOP_CONN_RECOVER) {
3138 		conn->hdrdgst_en = 0;
3139 		conn->datadgst_en = 0;
3140 		if (session->state == ISCSI_STATE_IN_RECOVERY &&
3141 		    old_stop_stage != STOP_CONN_RECOVER) {
3142 			ISCSI_DBG_SESSION(session, "blocking session\n");
3143 			iscsi_block_session(session->cls_session);
3144 		}
3145 	}
3146 
3147 	/*
3148 	 * flush queues.
3149 	 */
3150 	spin_lock_bh(&session->frwd_lock);
3151 	fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3152 	fail_mgmt_tasks(session, conn);
3153 	memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3154 	spin_unlock_bh(&session->frwd_lock);
3155 	mutex_unlock(&session->eh_mutex);
3156 }
3157 
3158 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3159 {
3160 	struct iscsi_conn *conn = cls_conn->dd_data;
3161 	struct iscsi_session *session = conn->session;
3162 
3163 	switch (flag) {
3164 	case STOP_CONN_RECOVER:
3165 		cls_conn->state = ISCSI_CONN_FAILED;
3166 		break;
3167 	case STOP_CONN_TERM:
3168 		cls_conn->state = ISCSI_CONN_DOWN;
3169 		break;
3170 	default:
3171 		iscsi_conn_printk(KERN_ERR, conn,
3172 				  "invalid stop flag %d\n", flag);
3173 		return;
3174 	}
3175 
3176 	iscsi_start_session_recovery(session, conn, flag);
3177 }
3178 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3179 
3180 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3181 		    struct iscsi_cls_conn *cls_conn, int is_leading)
3182 {
3183 	struct iscsi_session *session = cls_session->dd_data;
3184 	struct iscsi_conn *conn = cls_conn->dd_data;
3185 
3186 	spin_lock_bh(&session->frwd_lock);
3187 	if (is_leading)
3188 		session->leadconn = conn;
3189 	spin_unlock_bh(&session->frwd_lock);
3190 
3191 	/*
3192 	 * Unblock xmitworker(), Login Phase will pass through.
3193 	 */
3194 	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3195 	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3196 	return 0;
3197 }
3198 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3199 
3200 int iscsi_switch_str_param(char **param, char *new_val_buf)
3201 {
3202 	char *new_val;
3203 
3204 	if (*param) {
3205 		if (!strcmp(*param, new_val_buf))
3206 			return 0;
3207 	}
3208 
3209 	new_val = kstrdup(new_val_buf, GFP_NOIO);
3210 	if (!new_val)
3211 		return -ENOMEM;
3212 
3213 	kfree(*param);
3214 	*param = new_val;
3215 	return 0;
3216 }
3217 EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3218 
3219 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3220 		    enum iscsi_param param, char *buf, int buflen)
3221 {
3222 	struct iscsi_conn *conn = cls_conn->dd_data;
3223 	struct iscsi_session *session = conn->session;
3224 	int val;
3225 
3226 	switch(param) {
3227 	case ISCSI_PARAM_FAST_ABORT:
3228 		sscanf(buf, "%d", &session->fast_abort);
3229 		break;
3230 	case ISCSI_PARAM_ABORT_TMO:
3231 		sscanf(buf, "%d", &session->abort_timeout);
3232 		break;
3233 	case ISCSI_PARAM_LU_RESET_TMO:
3234 		sscanf(buf, "%d", &session->lu_reset_timeout);
3235 		break;
3236 	case ISCSI_PARAM_TGT_RESET_TMO:
3237 		sscanf(buf, "%d", &session->tgt_reset_timeout);
3238 		break;
3239 	case ISCSI_PARAM_PING_TMO:
3240 		sscanf(buf, "%d", &conn->ping_timeout);
3241 		break;
3242 	case ISCSI_PARAM_RECV_TMO:
3243 		sscanf(buf, "%d", &conn->recv_timeout);
3244 		break;
3245 	case ISCSI_PARAM_MAX_RECV_DLENGTH:
3246 		sscanf(buf, "%d", &conn->max_recv_dlength);
3247 		break;
3248 	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3249 		sscanf(buf, "%d", &conn->max_xmit_dlength);
3250 		break;
3251 	case ISCSI_PARAM_HDRDGST_EN:
3252 		sscanf(buf, "%d", &conn->hdrdgst_en);
3253 		break;
3254 	case ISCSI_PARAM_DATADGST_EN:
3255 		sscanf(buf, "%d", &conn->datadgst_en);
3256 		break;
3257 	case ISCSI_PARAM_INITIAL_R2T_EN:
3258 		sscanf(buf, "%d", &session->initial_r2t_en);
3259 		break;
3260 	case ISCSI_PARAM_MAX_R2T:
3261 		sscanf(buf, "%hu", &session->max_r2t);
3262 		break;
3263 	case ISCSI_PARAM_IMM_DATA_EN:
3264 		sscanf(buf, "%d", &session->imm_data_en);
3265 		break;
3266 	case ISCSI_PARAM_FIRST_BURST:
3267 		sscanf(buf, "%d", &session->first_burst);
3268 		break;
3269 	case ISCSI_PARAM_MAX_BURST:
3270 		sscanf(buf, "%d", &session->max_burst);
3271 		break;
3272 	case ISCSI_PARAM_PDU_INORDER_EN:
3273 		sscanf(buf, "%d", &session->pdu_inorder_en);
3274 		break;
3275 	case ISCSI_PARAM_DATASEQ_INORDER_EN:
3276 		sscanf(buf, "%d", &session->dataseq_inorder_en);
3277 		break;
3278 	case ISCSI_PARAM_ERL:
3279 		sscanf(buf, "%d", &session->erl);
3280 		break;
3281 	case ISCSI_PARAM_EXP_STATSN:
3282 		sscanf(buf, "%u", &conn->exp_statsn);
3283 		break;
3284 	case ISCSI_PARAM_USERNAME:
3285 		return iscsi_switch_str_param(&session->username, buf);
3286 	case ISCSI_PARAM_USERNAME_IN:
3287 		return iscsi_switch_str_param(&session->username_in, buf);
3288 	case ISCSI_PARAM_PASSWORD:
3289 		return iscsi_switch_str_param(&session->password, buf);
3290 	case ISCSI_PARAM_PASSWORD_IN:
3291 		return iscsi_switch_str_param(&session->password_in, buf);
3292 	case ISCSI_PARAM_TARGET_NAME:
3293 		return iscsi_switch_str_param(&session->targetname, buf);
3294 	case ISCSI_PARAM_TARGET_ALIAS:
3295 		return iscsi_switch_str_param(&session->targetalias, buf);
3296 	case ISCSI_PARAM_TPGT:
3297 		sscanf(buf, "%d", &session->tpgt);
3298 		break;
3299 	case ISCSI_PARAM_PERSISTENT_PORT:
3300 		sscanf(buf, "%d", &conn->persistent_port);
3301 		break;
3302 	case ISCSI_PARAM_PERSISTENT_ADDRESS:
3303 		return iscsi_switch_str_param(&conn->persistent_address, buf);
3304 	case ISCSI_PARAM_IFACE_NAME:
3305 		return iscsi_switch_str_param(&session->ifacename, buf);
3306 	case ISCSI_PARAM_INITIATOR_NAME:
3307 		return iscsi_switch_str_param(&session->initiatorname, buf);
3308 	case ISCSI_PARAM_BOOT_ROOT:
3309 		return iscsi_switch_str_param(&session->boot_root, buf);
3310 	case ISCSI_PARAM_BOOT_NIC:
3311 		return iscsi_switch_str_param(&session->boot_nic, buf);
3312 	case ISCSI_PARAM_BOOT_TARGET:
3313 		return iscsi_switch_str_param(&session->boot_target, buf);
3314 	case ISCSI_PARAM_PORTAL_TYPE:
3315 		return iscsi_switch_str_param(&session->portal_type, buf);
3316 	case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3317 		return iscsi_switch_str_param(&session->discovery_parent_type,
3318 					      buf);
3319 	case ISCSI_PARAM_DISCOVERY_SESS:
3320 		sscanf(buf, "%d", &val);
3321 		session->discovery_sess = !!val;
3322 		break;
3323 	case ISCSI_PARAM_LOCAL_IPADDR:
3324 		return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3325 	default:
3326 		return -ENOSYS;
3327 	}
3328 
3329 	return 0;
3330 }
3331 EXPORT_SYMBOL_GPL(iscsi_set_param);
3332 
3333 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3334 			    enum iscsi_param param, char *buf)
3335 {
3336 	struct iscsi_session *session = cls_session->dd_data;
3337 	int len;
3338 
3339 	switch(param) {
3340 	case ISCSI_PARAM_FAST_ABORT:
3341 		len = sprintf(buf, "%d\n", session->fast_abort);
3342 		break;
3343 	case ISCSI_PARAM_ABORT_TMO:
3344 		len = sprintf(buf, "%d\n", session->abort_timeout);
3345 		break;
3346 	case ISCSI_PARAM_LU_RESET_TMO:
3347 		len = sprintf(buf, "%d\n", session->lu_reset_timeout);
3348 		break;
3349 	case ISCSI_PARAM_TGT_RESET_TMO:
3350 		len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
3351 		break;
3352 	case ISCSI_PARAM_INITIAL_R2T_EN:
3353 		len = sprintf(buf, "%d\n", session->initial_r2t_en);
3354 		break;
3355 	case ISCSI_PARAM_MAX_R2T:
3356 		len = sprintf(buf, "%hu\n", session->max_r2t);
3357 		break;
3358 	case ISCSI_PARAM_IMM_DATA_EN:
3359 		len = sprintf(buf, "%d\n", session->imm_data_en);
3360 		break;
3361 	case ISCSI_PARAM_FIRST_BURST:
3362 		len = sprintf(buf, "%u\n", session->first_burst);
3363 		break;
3364 	case ISCSI_PARAM_MAX_BURST:
3365 		len = sprintf(buf, "%u\n", session->max_burst);
3366 		break;
3367 	case ISCSI_PARAM_PDU_INORDER_EN:
3368 		len = sprintf(buf, "%d\n", session->pdu_inorder_en);
3369 		break;
3370 	case ISCSI_PARAM_DATASEQ_INORDER_EN:
3371 		len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
3372 		break;
3373 	case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3374 		len = sprintf(buf, "%d\n", session->def_taskmgmt_tmo);
3375 		break;
3376 	case ISCSI_PARAM_ERL:
3377 		len = sprintf(buf, "%d\n", session->erl);
3378 		break;
3379 	case ISCSI_PARAM_TARGET_NAME:
3380 		len = sprintf(buf, "%s\n", session->targetname);
3381 		break;
3382 	case ISCSI_PARAM_TARGET_ALIAS:
3383 		len = sprintf(buf, "%s\n", session->targetalias);
3384 		break;
3385 	case ISCSI_PARAM_TPGT:
3386 		len = sprintf(buf, "%d\n", session->tpgt);
3387 		break;
3388 	case ISCSI_PARAM_USERNAME:
3389 		len = sprintf(buf, "%s\n", session->username);
3390 		break;
3391 	case ISCSI_PARAM_USERNAME_IN:
3392 		len = sprintf(buf, "%s\n", session->username_in);
3393 		break;
3394 	case ISCSI_PARAM_PASSWORD:
3395 		len = sprintf(buf, "%s\n", session->password);
3396 		break;
3397 	case ISCSI_PARAM_PASSWORD_IN:
3398 		len = sprintf(buf, "%s\n", session->password_in);
3399 		break;
3400 	case ISCSI_PARAM_IFACE_NAME:
3401 		len = sprintf(buf, "%s\n", session->ifacename);
3402 		break;
3403 	case ISCSI_PARAM_INITIATOR_NAME:
3404 		len = sprintf(buf, "%s\n", session->initiatorname);
3405 		break;
3406 	case ISCSI_PARAM_BOOT_ROOT:
3407 		len = sprintf(buf, "%s\n", session->boot_root);
3408 		break;
3409 	case ISCSI_PARAM_BOOT_NIC:
3410 		len = sprintf(buf, "%s\n", session->boot_nic);
3411 		break;
3412 	case ISCSI_PARAM_BOOT_TARGET:
3413 		len = sprintf(buf, "%s\n", session->boot_target);
3414 		break;
3415 	case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3416 		len = sprintf(buf, "%u\n", session->auto_snd_tgt_disable);
3417 		break;
3418 	case ISCSI_PARAM_DISCOVERY_SESS:
3419 		len = sprintf(buf, "%u\n", session->discovery_sess);
3420 		break;
3421 	case ISCSI_PARAM_PORTAL_TYPE:
3422 		len = sprintf(buf, "%s\n", session->portal_type);
3423 		break;
3424 	case ISCSI_PARAM_CHAP_AUTH_EN:
3425 		len = sprintf(buf, "%u\n", session->chap_auth_en);
3426 		break;
3427 	case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3428 		len = sprintf(buf, "%u\n", session->discovery_logout_en);
3429 		break;
3430 	case ISCSI_PARAM_BIDI_CHAP_EN:
3431 		len = sprintf(buf, "%u\n", session->bidi_chap_en);
3432 		break;
3433 	case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3434 		len = sprintf(buf, "%u\n", session->discovery_auth_optional);
3435 		break;
3436 	case ISCSI_PARAM_DEF_TIME2WAIT:
3437 		len = sprintf(buf, "%d\n", session->time2wait);
3438 		break;
3439 	case ISCSI_PARAM_DEF_TIME2RETAIN:
3440 		len = sprintf(buf, "%d\n", session->time2retain);
3441 		break;
3442 	case ISCSI_PARAM_TSID:
3443 		len = sprintf(buf, "%u\n", session->tsid);
3444 		break;
3445 	case ISCSI_PARAM_ISID:
3446 		len = sprintf(buf, "%02x%02x%02x%02x%02x%02x\n",
3447 			      session->isid[0], session->isid[1],
3448 			      session->isid[2], session->isid[3],
3449 			      session->isid[4], session->isid[5]);
3450 		break;
3451 	case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3452 		len = sprintf(buf, "%u\n", session->discovery_parent_idx);
3453 		break;
3454 	case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3455 		if (session->discovery_parent_type)
3456 			len = sprintf(buf, "%s\n",
3457 				      session->discovery_parent_type);
3458 		else
3459 			len = sprintf(buf, "\n");
3460 		break;
3461 	default:
3462 		return -ENOSYS;
3463 	}
3464 
3465 	return len;
3466 }
3467 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3468 
3469 int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3470 			      enum iscsi_param param, char *buf)
3471 {
3472 	struct sockaddr_in6 *sin6 = NULL;
3473 	struct sockaddr_in *sin = NULL;
3474 	int len;
3475 
3476 	switch (addr->ss_family) {
3477 	case AF_INET:
3478 		sin = (struct sockaddr_in *)addr;
3479 		break;
3480 	case AF_INET6:
3481 		sin6 = (struct sockaddr_in6 *)addr;
3482 		break;
3483 	default:
3484 		return -EINVAL;
3485 	}
3486 
3487 	switch (param) {
3488 	case ISCSI_PARAM_CONN_ADDRESS:
3489 	case ISCSI_HOST_PARAM_IPADDRESS:
3490 		if (sin)
3491 			len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
3492 		else
3493 			len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
3494 		break;
3495 	case ISCSI_PARAM_CONN_PORT:
3496 	case ISCSI_PARAM_LOCAL_PORT:
3497 		if (sin)
3498 			len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3499 		else
3500 			len = sprintf(buf, "%hu\n",
3501 				      be16_to_cpu(sin6->sin6_port));
3502 		break;
3503 	default:
3504 		return -EINVAL;
3505 	}
3506 
3507 	return len;
3508 }
3509 EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3510 
3511 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3512 			 enum iscsi_param param, char *buf)
3513 {
3514 	struct iscsi_conn *conn = cls_conn->dd_data;
3515 	int len;
3516 
3517 	switch(param) {
3518 	case ISCSI_PARAM_PING_TMO:
3519 		len = sprintf(buf, "%u\n", conn->ping_timeout);
3520 		break;
3521 	case ISCSI_PARAM_RECV_TMO:
3522 		len = sprintf(buf, "%u\n", conn->recv_timeout);
3523 		break;
3524 	case ISCSI_PARAM_MAX_RECV_DLENGTH:
3525 		len = sprintf(buf, "%u\n", conn->max_recv_dlength);
3526 		break;
3527 	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3528 		len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
3529 		break;
3530 	case ISCSI_PARAM_HDRDGST_EN:
3531 		len = sprintf(buf, "%d\n", conn->hdrdgst_en);
3532 		break;
3533 	case ISCSI_PARAM_DATADGST_EN:
3534 		len = sprintf(buf, "%d\n", conn->datadgst_en);
3535 		break;
3536 	case ISCSI_PARAM_IFMARKER_EN:
3537 		len = sprintf(buf, "%d\n", conn->ifmarker_en);
3538 		break;
3539 	case ISCSI_PARAM_OFMARKER_EN:
3540 		len = sprintf(buf, "%d\n", conn->ofmarker_en);
3541 		break;
3542 	case ISCSI_PARAM_EXP_STATSN:
3543 		len = sprintf(buf, "%u\n", conn->exp_statsn);
3544 		break;
3545 	case ISCSI_PARAM_PERSISTENT_PORT:
3546 		len = sprintf(buf, "%d\n", conn->persistent_port);
3547 		break;
3548 	case ISCSI_PARAM_PERSISTENT_ADDRESS:
3549 		len = sprintf(buf, "%s\n", conn->persistent_address);
3550 		break;
3551 	case ISCSI_PARAM_STATSN:
3552 		len = sprintf(buf, "%u\n", conn->statsn);
3553 		break;
3554 	case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3555 		len = sprintf(buf, "%u\n", conn->max_segment_size);
3556 		break;
3557 	case ISCSI_PARAM_KEEPALIVE_TMO:
3558 		len = sprintf(buf, "%u\n", conn->keepalive_tmo);
3559 		break;
3560 	case ISCSI_PARAM_LOCAL_PORT:
3561 		len = sprintf(buf, "%u\n", conn->local_port);
3562 		break;
3563 	case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3564 		len = sprintf(buf, "%u\n", conn->tcp_timestamp_stat);
3565 		break;
3566 	case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3567 		len = sprintf(buf, "%u\n", conn->tcp_nagle_disable);
3568 		break;
3569 	case ISCSI_PARAM_TCP_WSF_DISABLE:
3570 		len = sprintf(buf, "%u\n", conn->tcp_wsf_disable);
3571 		break;
3572 	case ISCSI_PARAM_TCP_TIMER_SCALE:
3573 		len = sprintf(buf, "%u\n", conn->tcp_timer_scale);
3574 		break;
3575 	case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3576 		len = sprintf(buf, "%u\n", conn->tcp_timestamp_en);
3577 		break;
3578 	case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3579 		len = sprintf(buf, "%u\n", conn->fragment_disable);
3580 		break;
3581 	case ISCSI_PARAM_IPV4_TOS:
3582 		len = sprintf(buf, "%u\n", conn->ipv4_tos);
3583 		break;
3584 	case ISCSI_PARAM_IPV6_TC:
3585 		len = sprintf(buf, "%u\n", conn->ipv6_traffic_class);
3586 		break;
3587 	case ISCSI_PARAM_IPV6_FLOW_LABEL:
3588 		len = sprintf(buf, "%u\n", conn->ipv6_flow_label);
3589 		break;
3590 	case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3591 		len = sprintf(buf, "%u\n", conn->is_fw_assigned_ipv6);
3592 		break;
3593 	case ISCSI_PARAM_TCP_XMIT_WSF:
3594 		len = sprintf(buf, "%u\n", conn->tcp_xmit_wsf);
3595 		break;
3596 	case ISCSI_PARAM_TCP_RECV_WSF:
3597 		len = sprintf(buf, "%u\n", conn->tcp_recv_wsf);
3598 		break;
3599 	case ISCSI_PARAM_LOCAL_IPADDR:
3600 		len = sprintf(buf, "%s\n", conn->local_ipaddr);
3601 		break;
3602 	default:
3603 		return -ENOSYS;
3604 	}
3605 
3606 	return len;
3607 }
3608 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3609 
3610 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3611 			 char *buf)
3612 {
3613 	struct iscsi_host *ihost = shost_priv(shost);
3614 	int len;
3615 
3616 	switch (param) {
3617 	case ISCSI_HOST_PARAM_NETDEV_NAME:
3618 		len = sprintf(buf, "%s\n", ihost->netdev);
3619 		break;
3620 	case ISCSI_HOST_PARAM_HWADDRESS:
3621 		len = sprintf(buf, "%s\n", ihost->hwaddress);
3622 		break;
3623 	case ISCSI_HOST_PARAM_INITIATOR_NAME:
3624 		len = sprintf(buf, "%s\n", ihost->initiatorname);
3625 		break;
3626 	default:
3627 		return -ENOSYS;
3628 	}
3629 
3630 	return len;
3631 }
3632 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3633 
3634 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3635 			 char *buf, int buflen)
3636 {
3637 	struct iscsi_host *ihost = shost_priv(shost);
3638 
3639 	switch (param) {
3640 	case ISCSI_HOST_PARAM_NETDEV_NAME:
3641 		return iscsi_switch_str_param(&ihost->netdev, buf);
3642 	case ISCSI_HOST_PARAM_HWADDRESS:
3643 		return iscsi_switch_str_param(&ihost->hwaddress, buf);
3644 	case ISCSI_HOST_PARAM_INITIATOR_NAME:
3645 		return iscsi_switch_str_param(&ihost->initiatorname, buf);
3646 	default:
3647 		return -ENOSYS;
3648 	}
3649 
3650 	return 0;
3651 }
3652 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3653 
3654 MODULE_AUTHOR("Mike Christie");
3655 MODULE_DESCRIPTION("iSCSI library functions");
3656 MODULE_LICENSE("GPL");
3657