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	#define ISCSI_CMD_COMPL_WAIT 5
87
88	inline void iscsi_conn_queue_xmit(struct iscsi_conn *conn)
89	{
90	struct Scsi_Host *shost = conn->session->host;
91	struct iscsi_host *ihost = shost_priv(shost);
92
93	if (ihost->workq)
94	queue_work(wq: ihost->workq, work: &conn->xmitwork);
95	}
96	EXPORT_SYMBOL_GPL(iscsi_conn_queue_xmit);
97
98	inline void iscsi_conn_queue_recv(struct iscsi_conn *conn)
99	{
100	struct Scsi_Host *shost = conn->session->host;
101	struct iscsi_host *ihost = shost_priv(shost);
102
103	if (ihost->workq && !test_bit(ISCSI_CONN_FLAG_SUSPEND_RX, &conn->flags))
104	queue_work(wq: ihost->workq, work: &conn->recvwork);
105	}
106	EXPORT_SYMBOL_GPL(iscsi_conn_queue_recv);
107
108	static void __iscsi_update_cmdsn(struct iscsi_session *session,
109	uint32_t exp_cmdsn, uint32_t max_cmdsn)
110	{
111	/*
112	* standard specifies this check for when to update expected and
113	* max sequence numbers
114	*/
115	if (iscsi_sna_lt(n1: max_cmdsn, n2: exp_cmdsn - 1))
116	return;
117
118	if (exp_cmdsn != session->exp_cmdsn &&
119	!iscsi_sna_lt(n1: exp_cmdsn, n2: session->exp_cmdsn))
120	session->exp_cmdsn = exp_cmdsn;
121
122	if (max_cmdsn != session->max_cmdsn &&
123	!iscsi_sna_lt(n1: max_cmdsn, n2: session->max_cmdsn))
124	session->max_cmdsn = max_cmdsn;
125	}
126
127	void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
128	{
129	__iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
130	be32_to_cpu(hdr->max_cmdsn));
131	}
132	EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
133
134	/**
135	* iscsi_prep_data_out_pdu - initialize Data-Out
136	* @task: scsi command task
137	* @r2t: R2T info
138	* @hdr: iscsi data in pdu
139	*
140	* Notes:
141	* Initialize Data-Out within this R2T sequence and finds
142	* proper data_offset within this SCSI command.
143	*
144	* This function is called with connection lock taken.
145	**/
146	void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
147	struct iscsi_data *hdr)
148	{
149	struct iscsi_conn *conn = task->conn;
150	unsigned int left = r2t->data_length - r2t->sent;
151
152	task->hdr_len = sizeof(struct iscsi_data);
153
154	memset(hdr, 0, sizeof(struct iscsi_data));
155	hdr->ttt = r2t->ttt;
156	hdr->datasn = cpu_to_be32(r2t->datasn);
157	r2t->datasn++;
158	hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
159	hdr->lun = task->lun;
160	hdr->itt = task->hdr_itt;
161	hdr->exp_statsn = r2t->exp_statsn;
162	hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
163	if (left > conn->max_xmit_dlength) {
164	hton24(hdr->dlength, conn->max_xmit_dlength);
165	r2t->data_count = conn->max_xmit_dlength;
166	hdr->flags = 0;
167	} else {
168	hton24(hdr->dlength, left);
169	r2t->data_count = left;
170	hdr->flags = ISCSI_FLAG_CMD_FINAL;
171	}
172	conn->dataout_pdus_cnt++;
173	}
174	EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
175
176	static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
177	{
178	unsigned exp_len = task->hdr_len + len;
179
180	if (exp_len > task->hdr_max) {
181	WARN_ON(1);
182	return -EINVAL;
183	}
184
185	WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
186	task->hdr_len = exp_len;
187	return 0;
188	}
189
190	/*
191	* make an extended cdb AHS
192	*/
193	static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
194	{
195	struct scsi_cmnd *cmd = task->sc;
196	unsigned rlen, pad_len;
197	unsigned short ahslength;
198	struct iscsi_ecdb_ahdr *ecdb_ahdr;
199	int rc;
200
201	ecdb_ahdr = iscsi_next_hdr(task);
202	rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
203
204	BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
205	ahslength = rlen + sizeof(ecdb_ahdr->reserved);
206
207	pad_len = iscsi_padding(len: rlen);
208
209	rc = iscsi_add_hdr(task, len: sizeof(ecdb_ahdr->ahslength) +
210	sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
211	if (rc)
212	return rc;
213
214	if (pad_len)
215	memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
216
217	ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
218	ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
219	ecdb_ahdr->reserved = 0;
220	memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
221
222	ISCSI_DBG_SESSION(task->conn->session,
223	"iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
224	"rlen %d pad_len %d ahs_length %d iscsi_headers_size "
225	"%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
226	task->hdr_len);
227	return 0;
228	}
229
230	/**
231	* iscsi_check_tmf_restrictions - check if a task is affected by TMF
232	* @task: iscsi task
233	* @opcode: opcode to check for
234	*
235	* During TMF a task has to be checked if it's affected.
236	* All unrelated I/O can be passed through, but I/O to the
237	* affected LUN should be restricted.
238	* If 'fast_abort' is set we won't be sending any I/O to the
239	* affected LUN.
240	* Otherwise the target is waiting for all TTTs to be completed,
241	* so we have to send all outstanding Data-Out PDUs to the target.
242	*/
243	static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
244	{
245	struct iscsi_session *session = task->conn->session;
246	struct iscsi_tm *tmf = &session->tmhdr;
247	u64 hdr_lun;
248
249	if (session->tmf_state == TMF_INITIAL)
250	return 0;
251
252	if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
253	return 0;
254
255	switch (ISCSI_TM_FUNC_VALUE(tmf)) {
256	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
257	/*
258	* Allow PDUs for unrelated LUNs
259	*/
260	hdr_lun = scsilun_to_int(&tmf->lun);
261	if (hdr_lun != task->sc->device->lun)
262	return 0;
263	fallthrough;
264	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
265	/*
266	* Fail all SCSI cmd PDUs
267	*/
268	if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
269	iscsi_session_printk(KERN_INFO, session,
270	"task [op %x itt 0x%x/0x%x] rejected.\n",
271	opcode, task->itt, task->hdr_itt);
272	return -EACCES;
273	}
274	/*
275	* And also all data-out PDUs in response to R2T
276	* if fast_abort is set.
277	*/
278	if (session->fast_abort) {
279	iscsi_session_printk(KERN_INFO, session,
280	"task [op %x itt 0x%x/0x%x] fast abort.\n",
281	opcode, task->itt, task->hdr_itt);
282	return -EACCES;
283	}
284	break;
285	case ISCSI_TM_FUNC_ABORT_TASK:
286	/*
287	* the caller has already checked if the task
288	* they want to abort was in the pending queue so if
289	* we are here the cmd pdu has gone out already, and
290	* we will only hit this for data-outs
291	*/
292	if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
293	task->hdr_itt == tmf->rtt) {
294	ISCSI_DBG_SESSION(session,
295	"Preventing task %x/%x from sending "
296	"data-out due to abort task in "
297	"progress\n", task->itt,
298	task->hdr_itt);
299	return -EACCES;
300	}
301	break;
302	}
303
304	return 0;
305	}
306
307	/**
308	* iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
309	* @task: iscsi task
310	*
311	* Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
312	* fields like dlength or final based on how much data it sends
313	*/
314	static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
315	{
316	struct iscsi_conn *conn = task->conn;
317	struct iscsi_session *session = conn->session;
318	struct scsi_cmnd *sc = task->sc;
319	struct iscsi_scsi_req *hdr;
320	unsigned hdrlength, cmd_len, transfer_length;
321	itt_t itt;
322	int rc;
323
324	rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
325	if (rc)
326	return rc;
327
328	if (conn->session->tt->alloc_pdu) {
329	rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
330	if (rc)
331	return rc;
332	}
333	hdr = (struct iscsi_scsi_req *)task->hdr;
334	itt = hdr->itt;
335	memset(hdr, 0, sizeof(*hdr));
336
337	if (session->tt->parse_pdu_itt)
338	hdr->itt = task->hdr_itt = itt;
339	else
340	hdr->itt = task->hdr_itt = build_itt(task->itt,
341	task->conn->session->age);
342	task->hdr_len = 0;
343	rc = iscsi_add_hdr(task, len: sizeof(*hdr));
344	if (rc)
345	return rc;
346	hdr->opcode = ISCSI_OP_SCSI_CMD;
347	hdr->flags = ISCSI_ATTR_SIMPLE;
348	int_to_scsilun(sc->device->lun, &hdr->lun);
349	task->lun = hdr->lun;
350	hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
351	cmd_len = sc->cmd_len;
352	if (cmd_len < ISCSI_CDB_SIZE)
353	memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
354	else if (cmd_len > ISCSI_CDB_SIZE) {
355	rc = iscsi_prep_ecdb_ahs(task);
356	if (rc)
357	return rc;
358	cmd_len = ISCSI_CDB_SIZE;
359	}
360	memcpy(hdr->cdb, sc->cmnd, cmd_len);
361
362	task->imm_count = 0;
363	if (scsi_get_prot_op(scmd: sc) != SCSI_PROT_NORMAL)
364	task->protected = true;
365
366	transfer_length = scsi_transfer_length(scmd: sc);
367	hdr->data_length = cpu_to_be32(transfer_length);
368	if (sc->sc_data_direction == DMA_TO_DEVICE) {
369	struct iscsi_r2t_info *r2t = &task->unsol_r2t;
370
371	hdr->flags |= ISCSI_FLAG_CMD_WRITE;
372	/*
373	* Write counters:
374	*
375	* imm_count bytes to be sent right after
376	* SCSI PDU Header
377	*
378	* unsol_count bytes(as Data-Out) to be sent
379	* without R2T ack right after
380	* immediate data
381	*
382	* r2t data_length bytes to be sent via R2T ack's
383	*
384	* pad_count bytes to be sent as zero-padding
385	*/
386	memset(r2t, 0, sizeof(*r2t));
387
388	if (session->imm_data_en) {
389	if (transfer_length >= session->first_burst)
390	task->imm_count = min(session->first_burst,
391	conn->max_xmit_dlength);
392	else
393	task->imm_count = min(transfer_length,
394	conn->max_xmit_dlength);
395	hton24(hdr->dlength, task->imm_count);
396	} else
397	zero_data(hdr->dlength);
398
399	if (!session->initial_r2t_en) {
400	r2t->data_length = min(session->first_burst,
401	transfer_length) -
402	task->imm_count;
403	r2t->data_offset = task->imm_count;
404	r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
405	r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
406	}
407
408	if (!task->unsol_r2t.data_length)
409	/* No unsolicit Data-Out's */
410	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
411	} else {
412	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
413	zero_data(hdr->dlength);
414
415	if (sc->sc_data_direction == DMA_FROM_DEVICE)
416	hdr->flags |= ISCSI_FLAG_CMD_READ;
417	}
418
419	/* calculate size of additional header segments (AHSs) */
420	hdrlength = task->hdr_len - sizeof(*hdr);
421
422	WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
423	hdrlength /= ISCSI_PAD_LEN;
424
425	WARN_ON(hdrlength >= 256);
426	hdr->hlength = hdrlength & 0xFF;
427	hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
428
429	if (session->tt->init_task && session->tt->init_task(task))
430	return -EIO;
431
432	task->state = ISCSI_TASK_RUNNING;
433	session->cmdsn++;
434
435	conn->scsicmd_pdus_cnt++;
436	ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
437	"itt 0x%x len %d cmdsn %d win %d]\n",
438	sc->sc_data_direction == DMA_TO_DEVICE ?
439	"write" : "read", conn->id, sc, sc->cmnd[0],
440	task->itt, transfer_length,
441	session->cmdsn,
442	session->max_cmdsn - session->exp_cmdsn + 1);
443	return 0;
444	}
445
446	/**
447	* iscsi_free_task - free a task
448	* @task: iscsi cmd task
449	*
450	* Must be called with session back_lock.
451	* This function returns the scsi command to scsi-ml or cleans
452	* up mgmt tasks then returns the task to the pool.
453	*/
454	static void iscsi_free_task(struct iscsi_task *task)
455	{
456	struct iscsi_conn *conn = task->conn;
457	struct iscsi_session *session = conn->session;
458	struct scsi_cmnd *sc = task->sc;
459	int oldstate = task->state;
460
461	ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
462	task->itt, task->state, task->sc);
463
464	session->tt->cleanup_task(task);
465	task->state = ISCSI_TASK_FREE;
466	task->sc = NULL;
467	/*
468	* login task is preallocated so do not free
469	*/
470	if (conn->login_task == task)
471	return;
472
473	kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
474
475	if (sc) {
476	/* SCSI eh reuses commands to verify us */
477	iscsi_cmd(cmd: sc)->task = NULL;
478	/*
479	* queue command may call this to free the task, so
480	* it will decide how to return sc to scsi-ml.
481	*/
482	if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
483	scsi_done(cmd: sc);
484	}
485	}
486
487	bool iscsi_get_task(struct iscsi_task *task)
488	{
489	return refcount_inc_not_zero(r: &task->refcount);
490	}
491	EXPORT_SYMBOL_GPL(iscsi_get_task);
492
493	/**
494	* __iscsi_put_task - drop the refcount on a task
495	* @task: iscsi_task to drop the refcount on
496	*
497	* The back_lock must be held when calling in case it frees the task.
498	*/
499	void __iscsi_put_task(struct iscsi_task *task)
500	{
501	if (refcount_dec_and_test(r: &task->refcount))
502	iscsi_free_task(task);
503	}
504	EXPORT_SYMBOL_GPL(__iscsi_put_task);
505
506	void iscsi_put_task(struct iscsi_task *task)
507	{
508	struct iscsi_session *session = task->conn->session;
509
510	if (refcount_dec_and_test(r: &task->refcount)) {
511	spin_lock_bh(lock: &session->back_lock);
512	iscsi_free_task(task);
513	spin_unlock_bh(lock: &session->back_lock);
514	}
515	}
516	EXPORT_SYMBOL_GPL(iscsi_put_task);
517
518	/**
519	* iscsi_complete_task - finish a task
520	* @task: iscsi cmd task
521	* @state: state to complete task with
522	*
523	* Must be called with session back_lock.
524	*/
525	static void iscsi_complete_task(struct iscsi_task *task, int state)
526	{
527	struct iscsi_conn *conn = task->conn;
528
529	ISCSI_DBG_SESSION(conn->session,
530	"complete task itt 0x%x state %d sc %p\n",
531	task->itt, task->state, task->sc);
532	if (task->state == ISCSI_TASK_COMPLETED ||
533	task->state == ISCSI_TASK_ABRT_TMF ||
534	task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
535	task->state == ISCSI_TASK_REQUEUE_SCSIQ)
536	return;
537	WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
538	task->state = state;
539
540	if (READ_ONCE(conn->ping_task) == task)
541	WRITE_ONCE(conn->ping_task, NULL);
542
543	/* release get from queueing */
544	__iscsi_put_task(task);
545	}
546
547	/**
548	* iscsi_complete_scsi_task - finish scsi task normally
549	* @task: iscsi task for scsi cmd
550	* @exp_cmdsn: expected cmd sn in cpu format
551	* @max_cmdsn: max cmd sn in cpu format
552	*
553	* This is used when drivers do not need or cannot perform
554	* lower level pdu processing.
555	*
556	* Called with session back_lock
557	*/
558	void iscsi_complete_scsi_task(struct iscsi_task *task,
559	uint32_t exp_cmdsn, uint32_t max_cmdsn)
560	{
561	struct iscsi_conn *conn = task->conn;
562
563	ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
564
565	conn->last_recv = jiffies;
566	__iscsi_update_cmdsn(session: conn->session, exp_cmdsn, max_cmdsn);
567	iscsi_complete_task(task, state: ISCSI_TASK_COMPLETED);
568	}
569	EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
570
571	/*
572	* Must be called with back and frwd lock
573	*/
574	static bool cleanup_queued_task(struct iscsi_task *task)
575	{
576	struct iscsi_conn *conn = task->conn;
577	bool early_complete = false;
578
579	/*
580	* We might have raced where we handled a R2T early and got a response
581	* but have not yet taken the task off the requeue list, then a TMF or
582	* recovery happened and so we can still see it here.
583	*/
584	if (task->state == ISCSI_TASK_COMPLETED)
585	early_complete = true;
586
587	if (!list_empty(head: &task->running)) {
588	list_del_init(entry: &task->running);
589	/*
590	* If it's on a list but still running this could be cleanup
591	* from a TMF or session recovery.
592	*/
593	if (task->state == ISCSI_TASK_RUNNING ||
594	task->state == ISCSI_TASK_COMPLETED)
595	__iscsi_put_task(task);
596	}
597
598	if (conn->session->running_aborted_task == task) {
599	conn->session->running_aborted_task = NULL;
600	__iscsi_put_task(task);
601	}
602
603	if (conn->task == task) {
604	conn->task = NULL;
605	__iscsi_put_task(task);
606	}
607
608	return early_complete;
609	}
610
611	/*
612	* session back and frwd lock must be held and if not called for a task that
613	* is still pending or from the xmit thread, then xmit thread must be suspended
614	*/
615	static void __fail_scsi_task(struct iscsi_task *task, int err)
616	{
617	struct iscsi_conn *conn = task->conn;
618	struct scsi_cmnd *sc;
619	int state;
620
621	if (cleanup_queued_task(task))
622	return;
623
624	if (task->state == ISCSI_TASK_PENDING) {
625	/*
626	* cmd never made it to the xmit thread, so we should not count
627	* the cmd in the sequencing
628	*/
629	conn->session->queued_cmdsn--;
630	/* it was never sent so just complete like normal */
631	state = ISCSI_TASK_COMPLETED;
632	} else if (err == DID_TRANSPORT_DISRUPTED)
633	state = ISCSI_TASK_ABRT_SESS_RECOV;
634	else
635	state = ISCSI_TASK_ABRT_TMF;
636
637	sc = task->sc;
638	sc->result = err << 16;
639	scsi_set_resid(cmd: sc, resid: scsi_bufflen(cmd: sc));
640	iscsi_complete_task(task, state);
641	}
642
643	static void fail_scsi_task(struct iscsi_task *task, int err)
644	{
645	struct iscsi_session *session = task->conn->session;
646
647	spin_lock_bh(lock: &session->back_lock);
648	__fail_scsi_task(task, err);
649	spin_unlock_bh(lock: &session->back_lock);
650	}
651
652	static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
653	struct iscsi_task *task)
654	{
655	struct iscsi_session *session = conn->session;
656	struct iscsi_hdr *hdr = task->hdr;
657	struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
658	uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
659
660	if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
661	return -ENOTCONN;
662
663	if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
664	nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
665	/*
666	* pre-format CmdSN for outgoing PDU.
667	*/
668	nop->cmdsn = cpu_to_be32(session->cmdsn);
669	if (hdr->itt != RESERVED_ITT) {
670	/*
671	* TODO: We always use immediate for normal session pdus.
672	* If we start to send tmfs or nops as non-immediate then
673	* we should start checking the cmdsn numbers for mgmt tasks.
674	*
675	* During discovery sessions iscsid sends TEXT as non immediate,
676	* but we always only send one PDU at a time.
677	*/
678	if (conn->c_stage == ISCSI_CONN_STARTED &&
679	!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
680	session->queued_cmdsn++;
681	session->cmdsn++;
682	}
683	}
684
685	if (session->tt->init_task && session->tt->init_task(task))
686	return -EIO;
687
688	if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
689	session->state = ISCSI_STATE_LOGGING_OUT;
690
691	task->state = ISCSI_TASK_RUNNING;
692	ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
693	"datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
694	hdr->itt, task->data_count);
695	return 0;
696	}
697
698	/**
699	* iscsi_alloc_mgmt_task - allocate and setup a mgmt task.
700	* @conn: iscsi conn that the task will be sent on.
701	* @hdr: iscsi pdu that will be sent.
702	* @data: buffer for data segment if needed.
703	* @data_size: length of data in bytes.
704	*/
705	static struct iscsi_task *
706	iscsi_alloc_mgmt_task(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
707	char *data, uint32_t data_size)
708	{
709	struct iscsi_session *session = conn->session;
710	uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
711	struct iscsi_task *task;
712	itt_t itt;
713
714	if (session->state == ISCSI_STATE_TERMINATE ||
715	!test_bit(ISCSI_CONN_FLAG_BOUND, &conn->flags))
716	return NULL;
717
718	if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
719	/*
720	* Login and Text are sent serially, in
721	* request-followed-by-response sequence.
722	* Same task can be used. Same ITT must be used.
723	* Note that login_task is preallocated at conn_create().
724	*/
725	if (conn->login_task->state != ISCSI_TASK_FREE) {
726	iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
727	"progress. Cannot start new task.\n");
728	return NULL;
729	}
730
731	if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
732	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);
733	return NULL;
734	}
735
736	task = conn->login_task;
737	} else {
738	if (session->state != ISCSI_STATE_LOGGED_IN)
739	return NULL;
740
741	if (data_size != 0) {
742	iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
743	return NULL;
744	}
745
746	BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
747	BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
748
749	if (!kfifo_out(&session->cmdpool.queue,
750	(void*)&task, sizeof(void*)))
751	return NULL;
752	}
753	/*
754	* released in complete pdu for task we expect a response for, and
755	* released by the lld when it has transmitted the task for
756	* pdus we do not expect a response for.
757	*/
758	refcount_set(r: &task->refcount, n: 1);
759	task->conn = conn;
760	task->sc = NULL;
761	INIT_LIST_HEAD(list: &task->running);
762	task->state = ISCSI_TASK_PENDING;
763
764	if (data_size) {
765	memcpy(task->data, data, data_size);
766	task->data_count = data_size;
767	} else
768	task->data_count = 0;
769
770	if (conn->session->tt->alloc_pdu) {
771	if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
772	iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
773	"pdu for mgmt task.\n");
774	goto free_task;
775	}
776	}
777
778	itt = task->hdr->itt;
779	task->hdr_len = sizeof(struct iscsi_hdr);
780	memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
781
782	if (hdr->itt != RESERVED_ITT) {
783	if (session->tt->parse_pdu_itt)
784	task->hdr->itt = itt;
785	else
786	task->hdr->itt = build_itt(task->itt,
787	task->conn->session->age);
788	}
789
790	return task;
791
792	free_task:
793	iscsi_put_task(task);
794	return NULL;
795	}
796
797	/**
798	* iscsi_send_mgmt_task - Send task created with iscsi_alloc_mgmt_task.
799	* @task: iscsi task to send.
800	*
801	* On failure this returns a non-zero error code, and the driver must free
802	* the task with iscsi_put_task;
803	*/
804	static int iscsi_send_mgmt_task(struct iscsi_task *task)
805	{
806	struct iscsi_conn *conn = task->conn;
807	struct iscsi_session *session = conn->session;
808	struct iscsi_host *ihost = shost_priv(shost: conn->session->host);
809	int rc = 0;
810
811	if (!ihost->workq) {
812	rc = iscsi_prep_mgmt_task(conn, task);
813	if (rc)
814	return rc;
815
816	rc = session->tt->xmit_task(task);
817	if (rc)
818	return rc;
819	} else {
820	list_add_tail(new: &task->running, head: &conn->mgmtqueue);
821	iscsi_conn_queue_xmit(conn);
822	}
823
824	return 0;
825	}
826
827	static int __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
828	char *data, uint32_t data_size)
829	{
830	struct iscsi_task *task;
831	int rc;
832
833	task = iscsi_alloc_mgmt_task(conn, hdr, data, data_size);
834	if (!task)
835	return -ENOMEM;
836
837	rc = iscsi_send_mgmt_task(task);
838	if (rc)
839	iscsi_put_task(task);
840	return rc;
841	}
842
843	int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
844	char *data, uint32_t data_size)
845	{
846	struct iscsi_conn *conn = cls_conn->dd_data;
847	struct iscsi_session *session = conn->session;
848	int err = 0;
849
850	spin_lock_bh(lock: &session->frwd_lock);
851	if (__iscsi_conn_send_pdu(conn, hdr, data, data_size))
852	err = -EPERM;
853	spin_unlock_bh(lock: &session->frwd_lock);
854	return err;
855	}
856	EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
857
858	/**
859	* iscsi_scsi_cmd_rsp - SCSI Command Response processing
860	* @conn: iscsi connection
861	* @hdr: iscsi header
862	* @task: scsi command task
863	* @data: cmd data buffer
864	* @datalen: len of buffer
865	*
866	* iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
867	* then completes the command and task. called under back_lock
868	**/
869	static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
870	struct iscsi_task *task, char *data,
871	int datalen)
872	{
873	struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
874	struct iscsi_session *session = conn->session;
875	struct scsi_cmnd *sc = task->sc;
876
877	iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
878	conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
879
880	sc->result = (DID_OK << 16) | rhdr->cmd_status;
881
882	if (task->protected) {
883	sector_t sector;
884	u8 ascq;
885
886	/**
887	* Transports that didn't implement check_protection
888	* callback but still published T10-PI support to scsi-mid
889	* deserve this BUG_ON.
890	**/
891	BUG_ON(!session->tt->check_protection);
892
893	ascq = session->tt->check_protection(task, &sector);
894	if (ascq) {
895	scsi_build_sense(scmd: sc, desc: 1, ILLEGAL_REQUEST, asc: 0x10, ascq);
896	scsi_set_sense_information(buf: sc->sense_buffer,
897	SCSI_SENSE_BUFFERSIZE,
898	info: sector);
899	goto out;
900	}
901	}
902
903	if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
904	sc->result = DID_ERROR << 16;
905	goto out;
906	}
907
908	if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
909	uint16_t senselen;
910
911	if (datalen < 2) {
912	invalid_datalen:
913	iscsi_conn_printk(KERN_ERR, conn,
914	"Got CHECK_CONDITION but invalid data "
915	"buffer size of %d\n", datalen);
916	sc->result = DID_BAD_TARGET << 16;
917	goto out;
918	}
919
920	senselen = get_unaligned_be16(p: data);
921	if (datalen < senselen)
922	goto invalid_datalen;
923
924	memcpy(sc->sense_buffer, data + 2,
925	min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
926	ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
927	min_t(uint16_t, senselen,
928	SCSI_SENSE_BUFFERSIZE));
929	}
930
931	if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
932	ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
933	sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
934	}
935
936	if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
937	ISCSI_FLAG_CMD_OVERFLOW)) {
938	int res_count = be32_to_cpu(rhdr->residual_count);
939
940	if (res_count > 0 &&
941	(rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
942	res_count <= scsi_bufflen(cmd: sc)))
943	/* write side for bidi or uni-io set_resid */
944	scsi_set_resid(cmd: sc, resid: res_count);
945	else
946	sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
947	}
948	out:
949	ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
950	sc, sc->result, task->itt);
951	conn->scsirsp_pdus_cnt++;
952	iscsi_complete_task(task, state: ISCSI_TASK_COMPLETED);
953	}
954
955	/**
956	* iscsi_data_in_rsp - SCSI Data-In Response processing
957	* @conn: iscsi connection
958	* @hdr: iscsi pdu
959	* @task: scsi command task
960	*
961	* iscsi_data_in_rsp sets up the scsi_cmnd fields based on the data received
962	* then completes the command and task. called under back_lock
963	**/
964	static void
965	iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
966	struct iscsi_task *task)
967	{
968	struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
969	struct scsi_cmnd *sc = task->sc;
970
971	if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
972	return;
973
974	iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
975	sc->result = (DID_OK << 16) | rhdr->cmd_status;
976	conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
977	if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
978	ISCSI_FLAG_DATA_OVERFLOW)) {
979	int res_count = be32_to_cpu(rhdr->residual_count);
980
981	if (res_count > 0 &&
982	(rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
983	res_count <= sc->sdb.length))
984	scsi_set_resid(cmd: sc, resid: res_count);
985	else
986	sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
987	}
988
989	ISCSI_DBG_SESSION(conn->session, "data in with status done "
990	"[sc %p res %d itt 0x%x]\n",
991	sc, sc->result, task->itt);
992	conn->scsirsp_pdus_cnt++;
993	iscsi_complete_task(task, state: ISCSI_TASK_COMPLETED);
994	}
995
996	static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
997	{
998	struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
999	struct iscsi_session *session = conn->session;
1000
1001	conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1002	conn->tmfrsp_pdus_cnt++;
1003
1004	if (session->tmf_state != TMF_QUEUED)
1005	return;
1006
1007	if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
1008	session->tmf_state = TMF_SUCCESS;
1009	else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
1010	session->tmf_state = TMF_NOT_FOUND;
1011	else
1012	session->tmf_state = TMF_FAILED;
1013	wake_up(&session->ehwait);
1014	}
1015
1016	static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
1017	{
1018	struct iscsi_nopout hdr;
1019	struct iscsi_task *task;
1020
1021	if (!rhdr) {
1022	if (READ_ONCE(conn->ping_task))
1023	return -EINVAL;
1024	}
1025
1026	memset(&hdr, 0, sizeof(struct iscsi_nopout));
1027	hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
1028	hdr.flags = ISCSI_FLAG_CMD_FINAL;
1029
1030	if (rhdr) {
1031	hdr.lun = rhdr->lun;
1032	hdr.ttt = rhdr->ttt;
1033	hdr.itt = RESERVED_ITT;
1034	} else
1035	hdr.ttt = RESERVED_ITT;
1036
1037	task = iscsi_alloc_mgmt_task(conn, hdr: (struct iscsi_hdr *)&hdr, NULL, data_size: 0);
1038	if (!task)
1039	return -ENOMEM;
1040
1041	if (!rhdr)
1042	WRITE_ONCE(conn->ping_task, task);
1043
1044	if (iscsi_send_mgmt_task(task)) {
1045	if (!rhdr)
1046	WRITE_ONCE(conn->ping_task, NULL);
1047	iscsi_put_task(task);
1048
1049	iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
1050	return -EIO;
1051	} else if (!rhdr) {
1052	/* only track our nops */
1053	conn->last_ping = jiffies;
1054	}
1055
1056	return 0;
1057	}
1058
1059	/**
1060	* iscsi_nop_out_rsp - SCSI NOP Response processing
1061	* @task: scsi command task
1062	* @nop: the nop structure
1063	* @data: where to put the data
1064	* @datalen: length of data
1065	*
1066	* iscsi_nop_out_rsp handles nop response from use or
1067	* from user space. called under back_lock
1068	**/
1069	static int iscsi_nop_out_rsp(struct iscsi_task *task,
1070	struct iscsi_nopin *nop, char *data, int datalen)
1071	{
1072	struct iscsi_conn *conn = task->conn;
1073	int rc = 0;
1074
1075	if (READ_ONCE(conn->ping_task) != task) {
1076	/*
1077	* If this is not in response to one of our
1078	* nops then it must be from userspace.
1079	*/
1080	if (iscsi_recv_pdu(conn: conn->cls_conn, hdr: (struct iscsi_hdr *)nop,
1081	data, data_size: datalen))
1082	rc = ISCSI_ERR_CONN_FAILED;
1083	} else
1084	mod_timer(timer: &conn->transport_timer, expires: jiffies + conn->recv_timeout);
1085	iscsi_complete_task(task, state: ISCSI_TASK_COMPLETED);
1086	return rc;
1087	}
1088
1089	static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1090	char *data, int datalen)
1091	{
1092	struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1093	struct iscsi_hdr rejected_pdu;
1094	int opcode, rc = 0;
1095
1096	conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1097
1098	if (ntoh24(reject->dlength) > datalen ||
1099	ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1100	iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1101	"pdu. Invalid data length (pdu dlength "
1102	"%u, datalen %d\n", ntoh24(reject->dlength),
1103	datalen);
1104	return ISCSI_ERR_PROTO;
1105	}
1106	memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1107	opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1108
1109	switch (reject->reason) {
1110	case ISCSI_REASON_DATA_DIGEST_ERROR:
1111	iscsi_conn_printk(KERN_ERR, conn,
1112	"pdu (op 0x%x itt 0x%x) rejected "
1113	"due to DataDigest error.\n",
1114	opcode, rejected_pdu.itt);
1115	break;
1116	case ISCSI_REASON_IMM_CMD_REJECT:
1117	iscsi_conn_printk(KERN_ERR, conn,
1118	"pdu (op 0x%x itt 0x%x) rejected. Too many "
1119	"immediate commands.\n",
1120	opcode, rejected_pdu.itt);
1121	/*
1122	* We only send one TMF at a time so if the target could not
1123	* handle it, then it should get fixed (RFC mandates that
1124	* a target can handle one immediate TMF per conn).
1125	*
1126	* For nops-outs, we could have sent more than one if
1127	* the target is sending us lots of nop-ins
1128	*/
1129	if (opcode != ISCSI_OP_NOOP_OUT)
1130	return 0;
1131
1132	if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1133	/*
1134	* nop-out in response to target's nop-out rejected.
1135	* Just resend.
1136	*/
1137	/* In RX path we are under back lock */
1138	spin_unlock(lock: &conn->session->back_lock);
1139	spin_lock(lock: &conn->session->frwd_lock);
1140	iscsi_send_nopout(conn,
1141	rhdr: (struct iscsi_nopin*)&rejected_pdu);
1142	spin_unlock(lock: &conn->session->frwd_lock);
1143	spin_lock(lock: &conn->session->back_lock);
1144	} else {
1145	struct iscsi_task *task;
1146	/*
1147	* Our nop as ping got dropped. We know the target
1148	* and transport are ok so just clean up
1149	*/
1150	task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1151	if (!task) {
1152	iscsi_conn_printk(KERN_ERR, conn,
1153	"Invalid pdu reject. Could "
1154	"not lookup rejected task.\n");
1155	rc = ISCSI_ERR_BAD_ITT;
1156	} else
1157	rc = iscsi_nop_out_rsp(task,
1158	nop: (struct iscsi_nopin*)&rejected_pdu,
1159	NULL, datalen: 0);
1160	}
1161	break;
1162	default:
1163	iscsi_conn_printk(KERN_ERR, conn,
1164	"pdu (op 0x%x itt 0x%x) rejected. Reason "
1165	"code 0x%x\n", rejected_pdu.opcode,
1166	rejected_pdu.itt, reject->reason);
1167	break;
1168	}
1169	return rc;
1170	}
1171
1172	/**
1173	* iscsi_itt_to_task - look up task by itt
1174	* @conn: iscsi connection
1175	* @itt: itt
1176	*
1177	* This should be used for mgmt tasks like login and nops, or if
1178	* the LDD's itt space does not include the session age.
1179	*
1180	* The session back_lock must be held.
1181	*/
1182	struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1183	{
1184	struct iscsi_session *session = conn->session;
1185	int i;
1186
1187	if (itt == RESERVED_ITT)
1188	return NULL;
1189
1190	if (session->tt->parse_pdu_itt)
1191	session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1192	else
1193	i = get_itt(itt);
1194	if (i >= session->cmds_max)
1195	return NULL;
1196
1197	return session->cmds[i];
1198	}
1199	EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1200
1201	/**
1202	* __iscsi_complete_pdu - complete pdu
1203	* @conn: iscsi conn
1204	* @hdr: iscsi header
1205	* @data: data buffer
1206	* @datalen: len of data buffer
1207	*
1208	* Completes pdu processing by freeing any resources allocated at
1209	* queuecommand or send generic. session back_lock must be held and verify
1210	* itt must have been called.
1211	*/
1212	int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1213	char *data, int datalen)
1214	{
1215	struct iscsi_session *session = conn->session;
1216	int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1217	struct iscsi_task *task;
1218	uint32_t itt;
1219
1220	conn->last_recv = jiffies;
1221	rc = iscsi_verify_itt(conn, hdr->itt);
1222	if (rc)
1223	return rc;
1224
1225	if (hdr->itt != RESERVED_ITT)
1226	itt = get_itt(hdr->itt);
1227	else
1228	itt = ~0U;
1229
1230	ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1231	opcode, conn->id, itt, datalen);
1232
1233	if (itt == ~0U) {
1234	iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1235
1236	switch(opcode) {
1237	case ISCSI_OP_NOOP_IN:
1238	if (datalen) {
1239	rc = ISCSI_ERR_PROTO;
1240	break;
1241	}
1242
1243	if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1244	break;
1245
1246	/* In RX path we are under back lock */
1247	spin_unlock(lock: &session->back_lock);
1248	spin_lock(lock: &session->frwd_lock);
1249	iscsi_send_nopout(conn, rhdr: (struct iscsi_nopin*)hdr);
1250	spin_unlock(lock: &session->frwd_lock);
1251	spin_lock(lock: &session->back_lock);
1252	break;
1253	case ISCSI_OP_REJECT:
1254	rc = iscsi_handle_reject(conn, hdr, data, datalen);
1255	break;
1256	case ISCSI_OP_ASYNC_EVENT:
1257	conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1258	if (iscsi_recv_pdu(conn: conn->cls_conn, hdr, data, data_size: datalen))
1259	rc = ISCSI_ERR_CONN_FAILED;
1260	break;
1261	default:
1262	rc = ISCSI_ERR_BAD_OPCODE;
1263	break;
1264	}
1265	goto out;
1266	}
1267
1268	switch(opcode) {
1269	case ISCSI_OP_SCSI_CMD_RSP:
1270	case ISCSI_OP_SCSI_DATA_IN:
1271	task = iscsi_itt_to_ctask(conn, hdr->itt);
1272	if (!task)
1273	return ISCSI_ERR_BAD_ITT;
1274	task->last_xfer = jiffies;
1275	break;
1276	case ISCSI_OP_R2T:
1277	/*
1278	* LLD handles R2Ts if they need to.
1279	*/
1280	return 0;
1281	case ISCSI_OP_LOGOUT_RSP:
1282	case ISCSI_OP_LOGIN_RSP:
1283	case ISCSI_OP_TEXT_RSP:
1284	case ISCSI_OP_SCSI_TMFUNC_RSP:
1285	case ISCSI_OP_NOOP_IN:
1286	task = iscsi_itt_to_task(conn, hdr->itt);
1287	if (!task)
1288	return ISCSI_ERR_BAD_ITT;
1289	break;
1290	default:
1291	return ISCSI_ERR_BAD_OPCODE;
1292	}
1293
1294	switch(opcode) {
1295	case ISCSI_OP_SCSI_CMD_RSP:
1296	iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1297	break;
1298	case ISCSI_OP_SCSI_DATA_IN:
1299	iscsi_data_in_rsp(conn, hdr, task);
1300	break;
1301	case ISCSI_OP_LOGOUT_RSP:
1302	iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1303	if (datalen) {
1304	rc = ISCSI_ERR_PROTO;
1305	break;
1306	}
1307	conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1308	goto recv_pdu;
1309	case ISCSI_OP_LOGIN_RSP:
1310	case ISCSI_OP_TEXT_RSP:
1311	iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1312	/*
1313	* login related PDU's exp_statsn is handled in
1314	* userspace
1315	*/
1316	goto recv_pdu;
1317	case ISCSI_OP_SCSI_TMFUNC_RSP:
1318	iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1319	if (datalen) {
1320	rc = ISCSI_ERR_PROTO;
1321	break;
1322	}
1323
1324	iscsi_tmf_rsp(conn, hdr);
1325	iscsi_complete_task(task, state: ISCSI_TASK_COMPLETED);
1326	break;
1327	case ISCSI_OP_NOOP_IN:
1328	iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1329	if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1330	rc = ISCSI_ERR_PROTO;
1331	break;
1332	}
1333	conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1334
1335	rc = iscsi_nop_out_rsp(task, nop: (struct iscsi_nopin*)hdr,
1336	data, datalen);
1337	break;
1338	default:
1339	rc = ISCSI_ERR_BAD_OPCODE;
1340	break;
1341	}
1342
1343	out:
1344	return rc;
1345	recv_pdu:
1346	if (iscsi_recv_pdu(conn: conn->cls_conn, hdr, data, data_size: datalen))
1347	rc = ISCSI_ERR_CONN_FAILED;
1348	iscsi_complete_task(task, state: ISCSI_TASK_COMPLETED);
1349	return rc;
1350	}
1351	EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1352
1353	int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1354	char *data, int datalen)
1355	{
1356	int rc;
1357
1358	spin_lock(lock: &conn->session->back_lock);
1359	rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1360	spin_unlock(lock: &conn->session->back_lock);
1361	return rc;
1362	}
1363	EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1364
1365	int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1366	{
1367	struct iscsi_session *session = conn->session;
1368	int age = 0, i = 0;
1369
1370	if (itt == RESERVED_ITT)
1371	return 0;
1372
1373	if (session->tt->parse_pdu_itt)
1374	session->tt->parse_pdu_itt(conn, itt, &i, &age);
1375	else {
1376	i = get_itt(itt);
1377	age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1378	}
1379
1380	if (age != session->age) {
1381	iscsi_conn_printk(KERN_ERR, conn,
1382	"received itt %x expected session age (%x)\n",
1383	(__force u32)itt, session->age);
1384	return ISCSI_ERR_BAD_ITT;
1385	}
1386
1387	if (i >= session->cmds_max) {
1388	iscsi_conn_printk(KERN_ERR, conn,
1389	"received invalid itt index %u (max cmds "
1390	"%u.\n", i, session->cmds_max);
1391	return ISCSI_ERR_BAD_ITT;
1392	}
1393	return 0;
1394	}
1395	EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1396
1397	/**
1398	* iscsi_itt_to_ctask - look up ctask by itt
1399	* @conn: iscsi connection
1400	* @itt: itt
1401	*
1402	* This should be used for cmd tasks.
1403	*
1404	* The session back_lock must be held.
1405	*/
1406	struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1407	{
1408	struct iscsi_task *task;
1409
1410	if (iscsi_verify_itt(conn, itt))
1411	return NULL;
1412
1413	task = iscsi_itt_to_task(conn, itt);
1414	if (!task || !task->sc)
1415	return NULL;
1416
1417	if (iscsi_cmd(cmd: task->sc)->age != conn->session->age) {
1418	iscsi_session_printk(KERN_ERR, conn->session,
1419	"task's session age %d, expected %d\n",
1420	iscsi_cmd(task->sc)->age, conn->session->age);
1421	return NULL;
1422	}
1423
1424	return task;
1425	}
1426	EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1427
1428	void iscsi_session_failure(struct iscsi_session *session,
1429	enum iscsi_err err)
1430	{
1431	struct iscsi_conn *conn;
1432
1433	spin_lock_bh(lock: &session->frwd_lock);
1434	conn = session->leadconn;
1435	if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1436	spin_unlock_bh(lock: &session->frwd_lock);
1437	return;
1438	}
1439
1440	iscsi_get_conn(conn: conn->cls_conn);
1441	spin_unlock_bh(lock: &session->frwd_lock);
1442	/*
1443	* if the host is being removed bypass the connection
1444	* recovery initialization because we are going to kill
1445	* the session.
1446	*/
1447	if (err == ISCSI_ERR_INVALID_HOST)
1448	iscsi_conn_error_event(conn: conn->cls_conn, error: err);
1449	else
1450	iscsi_conn_failure(conn, err);
1451	iscsi_put_conn(conn: conn->cls_conn);
1452	}
1453	EXPORT_SYMBOL_GPL(iscsi_session_failure);
1454
1455	static bool iscsi_set_conn_failed(struct iscsi_conn *conn)
1456	{
1457	struct iscsi_session *session = conn->session;
1458
1459	if (session->state == ISCSI_STATE_FAILED)
1460	return false;
1461
1462	if (conn->stop_stage == 0)
1463	session->state = ISCSI_STATE_FAILED;
1464
1465	set_bit(ISCSI_CONN_FLAG_SUSPEND_TX, addr: &conn->flags);
1466	set_bit(ISCSI_CONN_FLAG_SUSPEND_RX, addr: &conn->flags);
1467	return true;
1468	}
1469
1470	void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1471	{
1472	struct iscsi_session *session = conn->session;
1473	bool needs_evt;
1474
1475	spin_lock_bh(lock: &session->frwd_lock);
1476	needs_evt = iscsi_set_conn_failed(conn);
1477	spin_unlock_bh(lock: &session->frwd_lock);
1478
1479	if (needs_evt)
1480	iscsi_conn_error_event(conn: conn->cls_conn, error: err);
1481	}
1482	EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1483
1484	static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1485	{
1486	struct iscsi_session *session = conn->session;
1487
1488	/*
1489	* Check for iSCSI window and take care of CmdSN wrap-around
1490	*/
1491	if (!iscsi_sna_lte(n1: session->queued_cmdsn, n2: session->max_cmdsn)) {
1492	ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1493	"%u MaxCmdSN %u CmdSN %u/%u\n",
1494	session->exp_cmdsn, session->max_cmdsn,
1495	session->cmdsn, session->queued_cmdsn);
1496	return -ENOSPC;
1497	}
1498	return 0;
1499	}
1500
1501	static int iscsi_xmit_task(struct iscsi_conn *conn, struct iscsi_task *task,
1502	bool was_requeue)
1503	{
1504	int rc;
1505
1506	if (!conn->task) {
1507	/*
1508	* Take a ref so we can access it after xmit_task().
1509	*
1510	* This should never fail because the failure paths will have
1511	* stopped the xmit thread.
1512	*/
1513	if (!iscsi_get_task(task)) {
1514	WARN_ON_ONCE(1);
1515	return 0;
1516	}
1517	} else {
1518	/* Already have a ref from when we failed to send it last call */
1519	conn->task = NULL;
1520	}
1521
1522	/*
1523	* If this was a requeue for a R2T we have an extra ref on the task in
1524	* case a bad target sends a cmd rsp before we have handled the task.
1525	*/
1526	if (was_requeue)
1527	iscsi_put_task(task);
1528
1529	/*
1530	* Do this after dropping the extra ref because if this was a requeue
1531	* it's removed from that list and cleanup_queued_task would miss it.
1532	*/
1533	if (test_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags)) {
1534	/*
1535	* Save the task and ref in case we weren't cleaning up this
1536	* task and get woken up again.
1537	*/
1538	conn->task = task;
1539	return -ENODATA;
1540	}
1541
1542	spin_unlock_bh(lock: &conn->session->frwd_lock);
1543	rc = conn->session->tt->xmit_task(task);
1544	spin_lock_bh(lock: &conn->session->frwd_lock);
1545	if (!rc) {
1546	/* done with this task */
1547	task->last_xfer = jiffies;
1548	} else {
1549	/*
1550	* get an extra ref that is released next time we access it
1551	* as conn->task above.
1552	*/
1553	iscsi_get_task(task);
1554	conn->task = task;
1555	}
1556
1557	iscsi_put_task(task);
1558	return rc;
1559	}
1560
1561	/**
1562	* iscsi_requeue_task - requeue task to run from session workqueue
1563	* @task: task to requeue
1564	*
1565	* Callers must have taken a ref to the task that is going to be requeued.
1566	*/
1567	void iscsi_requeue_task(struct iscsi_task *task)
1568	{
1569	struct iscsi_conn *conn = task->conn;
1570
1571	/*
1572	* this may be on the requeue list already if the xmit_task callout
1573	* is handling the r2ts while we are adding new ones
1574	*/
1575	spin_lock_bh(lock: &conn->session->frwd_lock);
1576	if (list_empty(head: &task->running)) {
1577	list_add_tail(new: &task->running, head: &conn->requeue);
1578	} else {
1579	/*
1580	* Don't need the extra ref since it's already requeued and
1581	* has a ref.
1582	*/
1583	iscsi_put_task(task);
1584	}
1585	iscsi_conn_queue_xmit(conn);
1586	spin_unlock_bh(lock: &conn->session->frwd_lock);
1587	}
1588	EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1589
1590	/**
1591	* iscsi_data_xmit - xmit any command into the scheduled connection
1592	* @conn: iscsi connection
1593	*
1594	* Notes:
1595	* The function can return -EAGAIN in which case the caller must
1596	* re-schedule it again later or recover. '0' return code means
1597	* successful xmit.
1598	**/
1599	static int iscsi_data_xmit(struct iscsi_conn *conn)
1600	{
1601	struct iscsi_task *task;
1602	int rc = 0;
1603
1604	spin_lock_bh(lock: &conn->session->frwd_lock);
1605	if (test_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags)) {
1606	ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1607	spin_unlock_bh(lock: &conn->session->frwd_lock);
1608	return -ENODATA;
1609	}
1610
1611	if (conn->task) {
1612	rc = iscsi_xmit_task(conn, task: conn->task, was_requeue: false);
1613	if (rc)
1614	goto done;
1615	}
1616
1617	/*
1618	* process mgmt pdus like nops before commands since we should
1619	* only have one nop-out as a ping from us and targets should not
1620	* overflow us with nop-ins
1621	*/
1622	check_mgmt:
1623	while (!list_empty(head: &conn->mgmtqueue)) {
1624	task = list_entry(conn->mgmtqueue.next, struct iscsi_task,
1625	running);
1626	list_del_init(entry: &task->running);
1627	if (iscsi_prep_mgmt_task(conn, task)) {
1628	/* regular RX path uses back_lock */
1629	spin_lock_bh(lock: &conn->session->back_lock);
1630	__iscsi_put_task(task);
1631	spin_unlock_bh(lock: &conn->session->back_lock);
1632	continue;
1633	}
1634	rc = iscsi_xmit_task(conn, task, was_requeue: false);
1635	if (rc)
1636	goto done;
1637	}
1638
1639	check_requeue:
1640	while (!list_empty(head: &conn->requeue)) {
1641	/*
1642	* we always do fastlogout - conn stop code will clean up.
1643	*/
1644	if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1645	break;
1646
1647	task = list_entry(conn->requeue.next, struct iscsi_task,
1648	running);
1649
1650	if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1651	break;
1652
1653	list_del_init(entry: &task->running);
1654	rc = iscsi_xmit_task(conn, task, was_requeue: true);
1655	if (rc)
1656	goto done;
1657	if (!list_empty(head: &conn->mgmtqueue))
1658	goto check_mgmt;
1659	}
1660
1661	/* process pending command queue */
1662	while (!list_empty(head: &conn->cmdqueue)) {
1663	task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1664	running);
1665	list_del_init(entry: &task->running);
1666	if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1667	fail_scsi_task(task, err: DID_IMM_RETRY);
1668	continue;
1669	}
1670	rc = iscsi_prep_scsi_cmd_pdu(task);
1671	if (rc) {
1672	if (rc == -ENOMEM || rc == -EACCES)
1673	fail_scsi_task(task, err: DID_IMM_RETRY);
1674	else
1675	fail_scsi_task(task, err: DID_ABORT);
1676	continue;
1677	}
1678	rc = iscsi_xmit_task(conn, task, was_requeue: false);
1679	if (rc)
1680	goto done;
1681	/*
1682	* we could continuously get new task requests so
1683	* we need to check the mgmt queue for nops that need to
1684	* be sent to aviod starvation
1685	*/
1686	if (!list_empty(head: &conn->mgmtqueue))
1687	goto check_mgmt;
1688	if (!list_empty(head: &conn->requeue))
1689	goto check_requeue;
1690	}
1691
1692	spin_unlock_bh(lock: &conn->session->frwd_lock);
1693	return -ENODATA;
1694
1695	done:
1696	spin_unlock_bh(lock: &conn->session->frwd_lock);
1697	return rc;
1698	}
1699
1700	static void iscsi_xmitworker(struct work_struct *work)
1701	{
1702	struct iscsi_conn *conn =
1703	container_of(work, struct iscsi_conn, xmitwork);
1704	int rc;
1705	/*
1706	* serialize Xmit worker on a per-connection basis.
1707	*/
1708	do {
1709	rc = iscsi_data_xmit(conn);
1710	} while (rc >= 0 || rc == -EAGAIN);
1711	}
1712
1713	static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1714	struct scsi_cmnd *sc)
1715	{
1716	struct iscsi_task *task;
1717
1718	if (!kfifo_out(&conn->session->cmdpool.queue,
1719	(void *) &task, sizeof(void *)))
1720	return NULL;
1721
1722	iscsi_cmd(cmd: sc)->age = conn->session->age;
1723	iscsi_cmd(cmd: sc)->task = task;
1724
1725	refcount_set(r: &task->refcount, n: 1);
1726	task->state = ISCSI_TASK_PENDING;
1727	task->conn = conn;
1728	task->sc = sc;
1729	task->have_checked_conn = false;
1730	task->last_timeout = jiffies;
1731	task->last_xfer = jiffies;
1732	task->protected = false;
1733	INIT_LIST_HEAD(list: &task->running);
1734	return task;
1735	}
1736
1737	enum {
1738	FAILURE_BAD_HOST = 1,
1739	FAILURE_SESSION_FAILED,
1740	FAILURE_SESSION_FREED,
1741	FAILURE_WINDOW_CLOSED,
1742	FAILURE_OOM,
1743	FAILURE_SESSION_TERMINATE,
1744	FAILURE_SESSION_IN_RECOVERY,
1745	FAILURE_SESSION_RECOVERY_TIMEOUT,
1746	FAILURE_SESSION_LOGGING_OUT,
1747	FAILURE_SESSION_NOT_READY,
1748	};
1749
1750	int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1751	{
1752	struct iscsi_cls_session *cls_session;
1753	struct iscsi_host *ihost;
1754	int reason = 0;
1755	struct iscsi_session *session;
1756	struct iscsi_conn *conn;
1757	struct iscsi_task *task = NULL;
1758
1759	sc->result = 0;
1760	iscsi_cmd(cmd: sc)->task = NULL;
1761
1762	ihost = shost_priv(shost: host);
1763
1764	cls_session = starget_to_session(scsi_target(sc->device));
1765	session = cls_session->dd_data;
1766	spin_lock_bh(lock: &session->frwd_lock);
1767
1768	reason = iscsi_session_chkready(session: cls_session);
1769	if (reason) {
1770	sc->result = reason;
1771	goto fault;
1772	}
1773
1774	if (session->state != ISCSI_STATE_LOGGED_IN) {
1775	/*
1776	* to handle the race between when we set the recovery state
1777	* and block the session we requeue here (commands could
1778	* be entering our queuecommand while a block is starting
1779	* up because the block code is not locked)
1780	*/
1781	switch (session->state) {
1782	case ISCSI_STATE_FAILED:
1783	/*
1784	* cmds should fail during shutdown, if the session
1785	* state is bad, allowing completion to happen
1786	*/
1787	if (unlikely(system_state != SYSTEM_RUNNING)) {
1788	reason = FAILURE_SESSION_FAILED;
1789	sc->result = DID_NO_CONNECT << 16;
1790	break;
1791	}
1792	fallthrough;
1793	case ISCSI_STATE_IN_RECOVERY:
1794	reason = FAILURE_SESSION_IN_RECOVERY;
1795	sc->result = DID_IMM_RETRY << 16;
1796	break;
1797	case ISCSI_STATE_LOGGING_OUT:
1798	reason = FAILURE_SESSION_LOGGING_OUT;
1799	sc->result = DID_IMM_RETRY << 16;
1800	break;
1801	case ISCSI_STATE_RECOVERY_FAILED:
1802	reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1803	sc->result = DID_TRANSPORT_FAILFAST << 16;
1804	break;
1805	case ISCSI_STATE_TERMINATE:
1806	reason = FAILURE_SESSION_TERMINATE;
1807	sc->result = DID_NO_CONNECT << 16;
1808	break;
1809	default:
1810	reason = FAILURE_SESSION_FREED;
1811	sc->result = DID_NO_CONNECT << 16;
1812	}
1813	goto fault;
1814	}
1815
1816	conn = session->leadconn;
1817	if (!conn) {
1818	reason = FAILURE_SESSION_FREED;
1819	sc->result = DID_NO_CONNECT << 16;
1820	goto fault;
1821	}
1822
1823	if (test_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags)) {
1824	reason = FAILURE_SESSION_IN_RECOVERY;
1825	sc->result = DID_REQUEUE << 16;
1826	goto fault;
1827	}
1828
1829	if (iscsi_check_cmdsn_window_closed(conn)) {
1830	reason = FAILURE_WINDOW_CLOSED;
1831	goto reject;
1832	}
1833
1834	task = iscsi_alloc_task(conn, sc);
1835	if (!task) {
1836	reason = FAILURE_OOM;
1837	goto reject;
1838	}
1839
1840	if (!ihost->workq) {
1841	reason = iscsi_prep_scsi_cmd_pdu(task);
1842	if (reason) {
1843	if (reason == -ENOMEM || reason == -EACCES) {
1844	reason = FAILURE_OOM;
1845	goto prepd_reject;
1846	} else {
1847	sc->result = DID_ABORT << 16;
1848	goto prepd_fault;
1849	}
1850	}
1851	if (session->tt->xmit_task(task)) {
1852	session->cmdsn--;
1853	reason = FAILURE_SESSION_NOT_READY;
1854	goto prepd_reject;
1855	}
1856	} else {
1857	list_add_tail(new: &task->running, head: &conn->cmdqueue);
1858	iscsi_conn_queue_xmit(conn);
1859	}
1860
1861	session->queued_cmdsn++;
1862	spin_unlock_bh(lock: &session->frwd_lock);
1863	return 0;
1864
1865	prepd_reject:
1866	spin_lock_bh(lock: &session->back_lock);
1867	iscsi_complete_task(task, state: ISCSI_TASK_REQUEUE_SCSIQ);
1868	spin_unlock_bh(lock: &session->back_lock);
1869	reject:
1870	spin_unlock_bh(lock: &session->frwd_lock);
1871	ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1872	sc->cmnd[0], reason);
1873	return SCSI_MLQUEUE_TARGET_BUSY;
1874
1875	prepd_fault:
1876	spin_lock_bh(lock: &session->back_lock);
1877	iscsi_complete_task(task, state: ISCSI_TASK_REQUEUE_SCSIQ);
1878	spin_unlock_bh(lock: &session->back_lock);
1879	fault:
1880	spin_unlock_bh(lock: &session->frwd_lock);
1881	ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1882	sc->cmnd[0], reason);
1883	scsi_set_resid(cmd: sc, resid: scsi_bufflen(cmd: sc));
1884	scsi_done(cmd: sc);
1885	return 0;
1886	}
1887	EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1888
1889	int iscsi_target_alloc(struct scsi_target *starget)
1890	{
1891	struct iscsi_cls_session *cls_session = starget_to_session(starget);
1892	struct iscsi_session *session = cls_session->dd_data;
1893
1894	starget->can_queue = session->scsi_cmds_max;
1895	return 0;
1896	}
1897	EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1898
1899	static void iscsi_tmf_timedout(struct timer_list *t)
1900	{
1901	struct iscsi_session *session = from_timer(session, t, tmf_timer);
1902
1903	spin_lock(lock: &session->frwd_lock);
1904	if (session->tmf_state == TMF_QUEUED) {
1905	session->tmf_state = TMF_TIMEDOUT;
1906	ISCSI_DBG_EH(session, "tmf timedout\n");
1907	/* unblock eh_abort() */
1908	wake_up(&session->ehwait);
1909	}
1910	spin_unlock(lock: &session->frwd_lock);
1911	}
1912
1913	static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1914	struct iscsi_tm *hdr, int age,
1915	int timeout)
1916	__must_hold(&session->frwd_lock)
1917	{
1918	struct iscsi_session *session = conn->session;
1919
1920	if (__iscsi_conn_send_pdu(conn, hdr: (struct iscsi_hdr *)hdr, NULL, data_size: 0)) {
1921	spin_unlock_bh(lock: &session->frwd_lock);
1922	iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1923	iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1924	spin_lock_bh(lock: &session->frwd_lock);
1925	return -EPERM;
1926	}
1927	conn->tmfcmd_pdus_cnt++;
1928	session->tmf_timer.expires = timeout * HZ + jiffies;
1929	add_timer(timer: &session->tmf_timer);
1930	ISCSI_DBG_EH(session, "tmf set timeout\n");
1931
1932	spin_unlock_bh(lock: &session->frwd_lock);
1933	mutex_unlock(lock: &session->eh_mutex);
1934
1935	/*
1936	* block eh thread until:
1937	*
1938	* 1) tmf response
1939	* 2) tmf timeout
1940	* 3) session is terminated or restarted or userspace has
1941	* given up on recovery
1942	*/
1943	wait_event_interruptible(session->ehwait, age != session->age ||
1944	session->state != ISCSI_STATE_LOGGED_IN ||
1945	session->tmf_state != TMF_QUEUED);
1946	if (signal_pending(current))
1947	flush_signals(current);
1948	del_timer_sync(timer: &session->tmf_timer);
1949
1950	mutex_lock(&session->eh_mutex);
1951	spin_lock_bh(lock: &session->frwd_lock);
1952	/* if the session drops it will clean up the task */
1953	if (age != session->age ||
1954	session->state != ISCSI_STATE_LOGGED_IN)
1955	return -ENOTCONN;
1956	return 0;
1957	}
1958
1959	/*
1960	* Fail commands. session frwd lock held and xmit thread flushed.
1961	*/
1962	static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
1963	{
1964	struct iscsi_session *session = conn->session;
1965	struct iscsi_task *task;
1966	int i;
1967
1968	restart_cmd_loop:
1969	spin_lock_bh(lock: &session->back_lock);
1970	for (i = 0; i < session->cmds_max; i++) {
1971	task = session->cmds[i];
1972	if (!task->sc || task->state == ISCSI_TASK_FREE)
1973	continue;
1974
1975	if (lun != -1 && lun != task->sc->device->lun)
1976	continue;
1977	/*
1978	* The cmd is completing but if this is called from an eh
1979	* callout path then when we return scsi-ml owns the cmd. Wait
1980	* for the completion path to finish freeing the cmd.
1981	*/
1982	if (!iscsi_get_task(task)) {
1983	spin_unlock_bh(lock: &session->back_lock);
1984	spin_unlock_bh(lock: &session->frwd_lock);
1985	udelay(ISCSI_CMD_COMPL_WAIT);
1986	spin_lock_bh(lock: &session->frwd_lock);
1987	goto restart_cmd_loop;
1988	}
1989
1990	ISCSI_DBG_SESSION(session,
1991	"failing sc %p itt 0x%x state %d\n",
1992	task->sc, task->itt, task->state);
1993	__fail_scsi_task(task, err: error);
1994	__iscsi_put_task(task);
1995	}
1996	spin_unlock_bh(lock: &session->back_lock);
1997	}
1998
1999	/**
2000	* iscsi_suspend_queue - suspend iscsi_queuecommand
2001	* @conn: iscsi conn to stop queueing IO on
2002	*
2003	* This grabs the session frwd_lock to make sure no one is in
2004	* xmit_task/queuecommand, and then sets suspend to prevent
2005	* new commands from being queued. This only needs to be called
2006	* by offload drivers that need to sync a path like ep disconnect
2007	* with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
2008	* will call iscsi_start_tx and iscsi_unblock_session when in FFP.
2009	*/
2010	void iscsi_suspend_queue(struct iscsi_conn *conn)
2011	{
2012	spin_lock_bh(lock: &conn->session->frwd_lock);
2013	set_bit(ISCSI_CONN_FLAG_SUSPEND_TX, addr: &conn->flags);
2014	spin_unlock_bh(lock: &conn->session->frwd_lock);
2015	}
2016	EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
2017
2018	/**
2019	* iscsi_suspend_tx - suspend iscsi_data_xmit
2020	* @conn: iscsi conn to stop processing IO on.
2021	*
2022	* This function sets the suspend bit to prevent iscsi_data_xmit
2023	* from sending new IO, and if work is queued on the xmit thread
2024	* it will wait for it to be completed.
2025	*/
2026	void iscsi_suspend_tx(struct iscsi_conn *conn)
2027	{
2028	struct Scsi_Host *shost = conn->session->host;
2029	struct iscsi_host *ihost = shost_priv(shost);
2030
2031	set_bit(ISCSI_CONN_FLAG_SUSPEND_TX, addr: &conn->flags);
2032	if (ihost->workq)
2033	flush_work(work: &conn->xmitwork);
2034	}
2035	EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
2036
2037	static void iscsi_start_tx(struct iscsi_conn *conn)
2038	{
2039	clear_bit(ISCSI_CONN_FLAG_SUSPEND_TX, addr: &conn->flags);
2040	iscsi_conn_queue_xmit(conn);
2041	}
2042
2043	/**
2044	* iscsi_suspend_rx - Prevent recvwork from running again.
2045	* @conn: iscsi conn to stop.
2046	*/
2047	void iscsi_suspend_rx(struct iscsi_conn *conn)
2048	{
2049	struct Scsi_Host *shost = conn->session->host;
2050	struct iscsi_host *ihost = shost_priv(shost);
2051
2052	set_bit(ISCSI_CONN_FLAG_SUSPEND_RX, addr: &conn->flags);
2053	if (ihost->workq)
2054	flush_work(work: &conn->recvwork);
2055	}
2056	EXPORT_SYMBOL_GPL(iscsi_suspend_rx);
2057
2058	/*
2059	* We want to make sure a ping is in flight. It has timed out.
2060	* And we are not busy processing a pdu that is making
2061	* progress but got started before the ping and is taking a while
2062	* to complete so the ping is just stuck behind it in a queue.
2063	*/
2064	static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
2065	{
2066	if (READ_ONCE(conn->ping_task) &&
2067	time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
2068	(conn->ping_timeout * HZ), jiffies))
2069	return 1;
2070	else
2071	return 0;
2072	}
2073
2074	enum scsi_timeout_action iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
2075	{
2076	enum scsi_timeout_action rc = SCSI_EH_NOT_HANDLED;
2077	struct iscsi_task *task = NULL, *running_task;
2078	struct iscsi_cls_session *cls_session;
2079	struct iscsi_session *session;
2080	struct iscsi_conn *conn;
2081	int i;
2082
2083	cls_session = starget_to_session(scsi_target(sc->device));
2084	session = cls_session->dd_data;
2085
2086	ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
2087
2088	spin_lock_bh(lock: &session->frwd_lock);
2089	spin_lock(lock: &session->back_lock);
2090	task = iscsi_cmd(cmd: sc)->task;
2091	if (!task) {
2092	/*
2093	* Raced with completion. Blk layer has taken ownership
2094	* so let timeout code complete it now.
2095	*/
2096	rc = SCSI_EH_NOT_HANDLED;
2097	spin_unlock(lock: &session->back_lock);
2098	goto done;
2099	}
2100	if (!iscsi_get_task(task)) {
2101	/*
2102	* Racing with the completion path right now, so give it more
2103	* time so that path can complete it like normal.
2104	*/
2105	rc = SCSI_EH_RESET_TIMER;
2106	task = NULL;
2107	spin_unlock(lock: &session->back_lock);
2108	goto done;
2109	}
2110	spin_unlock(lock: &session->back_lock);
2111
2112	if (session->state != ISCSI_STATE_LOGGED_IN) {
2113	/*
2114	* During shutdown, if session is prematurely disconnected,
2115	* recovery won't happen and there will be hung cmds. Not
2116	* handling cmds would trigger EH, also bad in this case.
2117	* Instead, handle cmd, allow completion to happen and let
2118	* upper layer to deal with the result.
2119	*/
2120	if (unlikely(system_state != SYSTEM_RUNNING)) {
2121	sc->result = DID_NO_CONNECT << 16;
2122	ISCSI_DBG_EH(session, "sc on shutdown, handled\n");
2123	rc = SCSI_EH_NOT_HANDLED;
2124	goto done;
2125	}
2126	/*
2127	* We are probably in the middle of iscsi recovery so let
2128	* that complete and handle the error.
2129	*/
2130	rc = SCSI_EH_RESET_TIMER;
2131	goto done;
2132	}
2133
2134	conn = session->leadconn;
2135	if (!conn) {
2136	/* In the middle of shuting down */
2137	rc = SCSI_EH_RESET_TIMER;
2138	goto done;
2139	}
2140
2141	/*
2142	* If we have sent (at least queued to the network layer) a pdu or
2143	* recvd one for the task since the last timeout ask for
2144	* more time. If on the next timeout we have not made progress
2145	* we can check if it is the task or connection when we send the
2146	* nop as a ping.
2147	*/
2148	if (time_after(task->last_xfer, task->last_timeout)) {
2149	ISCSI_DBG_EH(session, "Command making progress. Asking "
2150	"scsi-ml for more time to complete. "
2151	"Last data xfer at %lu. Last timeout was at "
2152	"%lu\n.", task->last_xfer, task->last_timeout);
2153	task->have_checked_conn = false;
2154	rc = SCSI_EH_RESET_TIMER;
2155	goto done;
2156	}
2157
2158	if (!conn->recv_timeout && !conn->ping_timeout)
2159	goto done;
2160	/*
2161	* if the ping timedout then we are in the middle of cleaning up
2162	* and can let the iscsi eh handle it
2163	*/
2164	if (iscsi_has_ping_timed_out(conn)) {
2165	rc = SCSI_EH_RESET_TIMER;
2166	goto done;
2167	}
2168
2169	spin_lock(lock: &session->back_lock);
2170	for (i = 0; i < conn->session->cmds_max; i++) {
2171	running_task = conn->session->cmds[i];
2172	if (!running_task->sc || running_task == task ||
2173	running_task->state != ISCSI_TASK_RUNNING)
2174	continue;
2175
2176	/*
2177	* Only check if cmds started before this one have made
2178	* progress, or this could never fail
2179	*/
2180	if (time_after(running_task->sc->jiffies_at_alloc,
2181	task->sc->jiffies_at_alloc))
2182	continue;
2183
2184	if (time_after(running_task->last_xfer, task->last_timeout)) {
2185	/*
2186	* This task has not made progress, but a task
2187	* started before us has transferred data since
2188	* we started/last-checked. We could be queueing
2189	* too many tasks or the LU is bad.
2190	*
2191	* If the device is bad the cmds ahead of us on
2192	* other devs will complete, and this loop will
2193	* eventually fail starting the scsi eh.
2194	*/
2195	ISCSI_DBG_EH(session, "Command has not made progress "
2196	"but commands ahead of it have. "
2197	"Asking scsi-ml for more time to "
2198	"complete. Our last xfer vs running task "
2199	"last xfer %lu/%lu. Last check %lu.\n",
2200	task->last_xfer, running_task->last_xfer,
2201	task->last_timeout);
2202	spin_unlock(lock: &session->back_lock);
2203	rc = SCSI_EH_RESET_TIMER;
2204	goto done;
2205	}
2206	}
2207	spin_unlock(lock: &session->back_lock);
2208
2209	/* Assumes nop timeout is shorter than scsi cmd timeout */
2210	if (task->have_checked_conn)
2211	goto done;
2212
2213	/*
2214	* Checking the transport already or nop from a cmd timeout still
2215	* running
2216	*/
2217	if (READ_ONCE(conn->ping_task)) {
2218	task->have_checked_conn = true;
2219	rc = SCSI_EH_RESET_TIMER;
2220	goto done;
2221	}
2222
2223	/* Make sure there is a transport check done */
2224	iscsi_send_nopout(conn, NULL);
2225	task->have_checked_conn = true;
2226	rc = SCSI_EH_RESET_TIMER;
2227
2228	done:
2229	spin_unlock_bh(lock: &session->frwd_lock);
2230
2231	if (task) {
2232	task->last_timeout = jiffies;
2233	iscsi_put_task(task);
2234	}
2235	ISCSI_DBG_EH(session, "return %s\n", rc == SCSI_EH_RESET_TIMER ?
2236	"timer reset" : "shutdown or nh");
2237	return rc;
2238	}
2239	EXPORT_SYMBOL_GPL(iscsi_eh_cmd_timed_out);
2240
2241	static void iscsi_check_transport_timeouts(struct timer_list *t)
2242	{
2243	struct iscsi_conn *conn = from_timer(conn, t, transport_timer);
2244	struct iscsi_session *session = conn->session;
2245	unsigned long recv_timeout, next_timeout = 0, last_recv;
2246
2247	spin_lock(lock: &session->frwd_lock);
2248	if (session->state != ISCSI_STATE_LOGGED_IN)
2249	goto done;
2250
2251	recv_timeout = conn->recv_timeout;
2252	if (!recv_timeout)
2253	goto done;
2254
2255	recv_timeout *= HZ;
2256	last_recv = conn->last_recv;
2257
2258	if (iscsi_has_ping_timed_out(conn)) {
2259	iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2260	"expired, recv timeout %d, last rx %lu, "
2261	"last ping %lu, now %lu\n",
2262	conn->ping_timeout, conn->recv_timeout,
2263	last_recv, conn->last_ping, jiffies);
2264	spin_unlock(lock: &session->frwd_lock);
2265	iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2266	return;
2267	}
2268
2269	if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2270	/* send a ping to try to provoke some traffic */
2271	ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2272	if (iscsi_send_nopout(conn, NULL))
2273	next_timeout = jiffies + (1 * HZ);
2274	else
2275	next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2276	} else
2277	next_timeout = last_recv + recv_timeout;
2278
2279	ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2280	mod_timer(timer: &conn->transport_timer, expires: next_timeout);
2281	done:
2282	spin_unlock(lock: &session->frwd_lock);
2283	}
2284
2285	/**
2286	* iscsi_conn_unbind - prevent queueing to conn.
2287	* @cls_conn: iscsi conn ep is bound to.
2288	* @is_active: is the conn in use for boot or is this for EH/termination
2289	*
2290	* This must be called by drivers implementing the ep_disconnect callout.
2291	* It disables queueing to the connection from libiscsi in preparation for
2292	* an ep_disconnect call.
2293	*/
2294	void iscsi_conn_unbind(struct iscsi_cls_conn *cls_conn, bool is_active)
2295	{
2296	struct iscsi_session *session;
2297	struct iscsi_conn *conn;
2298
2299	if (!cls_conn)
2300	return;
2301
2302	conn = cls_conn->dd_data;
2303	session = conn->session;
2304	/*
2305	* Wait for iscsi_eh calls to exit. We don't wait for the tmf to
2306	* complete or timeout. The caller just wants to know what's running
2307	* is everything that needs to be cleaned up, and no cmds will be
2308	* queued.
2309	*/
2310	mutex_lock(&session->eh_mutex);
2311
2312	iscsi_suspend_queue(conn);
2313	iscsi_suspend_tx(conn);
2314
2315	spin_lock_bh(lock: &session->frwd_lock);
2316	clear_bit(ISCSI_CONN_FLAG_BOUND, addr: &conn->flags);
2317
2318	if (!is_active) {
2319	/*
2320	* if logout timed out before userspace could even send a PDU
2321	* the state might still be in ISCSI_STATE_LOGGED_IN and
2322	* allowing new cmds and TMFs.
2323	*/
2324	if (session->state == ISCSI_STATE_LOGGED_IN)
2325	iscsi_set_conn_failed(conn);
2326	}
2327	spin_unlock_bh(lock: &session->frwd_lock);
2328	mutex_unlock(lock: &session->eh_mutex);
2329	}
2330	EXPORT_SYMBOL_GPL(iscsi_conn_unbind);
2331
2332	static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2333	struct iscsi_tm *hdr)
2334	{
2335	memset(hdr, 0, sizeof(*hdr));
2336	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2337	hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2338	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2339	hdr->lun = task->lun;
2340	hdr->rtt = task->hdr_itt;
2341	hdr->refcmdsn = task->cmdsn;
2342	}
2343
2344	int iscsi_eh_abort(struct scsi_cmnd *sc)
2345	{
2346	struct iscsi_cls_session *cls_session;
2347	struct iscsi_session *session;
2348	struct iscsi_conn *conn;
2349	struct iscsi_task *task;
2350	struct iscsi_tm *hdr;
2351	int age;
2352
2353	cls_session = starget_to_session(scsi_target(sc->device));
2354	session = cls_session->dd_data;
2355
2356	ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2357
2358	completion_check:
2359	mutex_lock(&session->eh_mutex);
2360	spin_lock_bh(lock: &session->frwd_lock);
2361	/*
2362	* if session was ISCSI_STATE_IN_RECOVERY then we may not have
2363	* got the command.
2364	*/
2365	if (!iscsi_cmd(cmd: sc)->task) {
2366	ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2367	"it completed.\n");
2368	spin_unlock_bh(lock: &session->frwd_lock);
2369	mutex_unlock(lock: &session->eh_mutex);
2370	return SUCCESS;
2371	}
2372
2373	/*
2374	* If we are not logged in or we have started a new session
2375	* then let the host reset code handle this
2376	*/
2377	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2378	iscsi_cmd(cmd: sc)->age != session->age) {
2379	spin_unlock_bh(lock: &session->frwd_lock);
2380	mutex_unlock(lock: &session->eh_mutex);
2381	ISCSI_DBG_EH(session, "failing abort due to dropped "
2382	"session.\n");
2383	return FAILED;
2384	}
2385
2386	spin_lock(lock: &session->back_lock);
2387	task = iscsi_cmd(cmd: sc)->task;
2388	if (!task || !task->sc) {
2389	/* task completed before time out */
2390	ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2391
2392	spin_unlock(lock: &session->back_lock);
2393	spin_unlock_bh(lock: &session->frwd_lock);
2394	mutex_unlock(lock: &session->eh_mutex);
2395	return SUCCESS;
2396	}
2397
2398	if (!iscsi_get_task(task)) {
2399	spin_unlock(lock: &session->back_lock);
2400	spin_unlock_bh(lock: &session->frwd_lock);
2401	mutex_unlock(lock: &session->eh_mutex);
2402	/* We are just about to call iscsi_free_task so wait for it. */
2403	udelay(ISCSI_CMD_COMPL_WAIT);
2404	goto completion_check;
2405	}
2406
2407	ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n", sc, task->itt);
2408	conn = session->leadconn;
2409	iscsi_get_conn(conn: conn->cls_conn);
2410	conn->eh_abort_cnt++;
2411	age = session->age;
2412	spin_unlock(lock: &session->back_lock);
2413
2414	if (task->state == ISCSI_TASK_PENDING) {
2415	fail_scsi_task(task, err: DID_ABORT);
2416	goto success;
2417	}
2418
2419	/* only have one tmf outstanding at a time */
2420	if (session->tmf_state != TMF_INITIAL)
2421	goto failed;
2422	session->tmf_state = TMF_QUEUED;
2423
2424	hdr = &session->tmhdr;
2425	iscsi_prep_abort_task_pdu(task, hdr);
2426
2427	if (iscsi_exec_task_mgmt_fn(conn, hdr, age, timeout: session->abort_timeout))
2428	goto failed;
2429
2430	switch (session->tmf_state) {
2431	case TMF_SUCCESS:
2432	spin_unlock_bh(lock: &session->frwd_lock);
2433	/*
2434	* stop tx side incase the target had sent a abort rsp but
2435	* the initiator was still writing out data.
2436	*/
2437	iscsi_suspend_tx(conn);
2438	/*
2439	* we do not stop the recv side because targets have been
2440	* good and have never sent us a successful tmf response
2441	* then sent more data for the cmd.
2442	*/
2443	spin_lock_bh(lock: &session->frwd_lock);
2444	fail_scsi_task(task, err: DID_ABORT);
2445	session->tmf_state = TMF_INITIAL;
2446	memset(hdr, 0, sizeof(*hdr));
2447	spin_unlock_bh(lock: &session->frwd_lock);
2448	iscsi_start_tx(conn);
2449	goto success_unlocked;
2450	case TMF_TIMEDOUT:
2451	session->running_aborted_task = task;
2452	spin_unlock_bh(lock: &session->frwd_lock);
2453	iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2454	goto failed_unlocked;
2455	case TMF_NOT_FOUND:
2456	if (iscsi_task_is_completed(task)) {
2457	session->tmf_state = TMF_INITIAL;
2458	memset(hdr, 0, sizeof(*hdr));
2459	/* task completed before tmf abort response */
2460	ISCSI_DBG_EH(session, "sc completed while abort in "
2461	"progress\n");
2462	goto success;
2463	}
2464	fallthrough;
2465	default:
2466	session->tmf_state = TMF_INITIAL;
2467	goto failed;
2468	}
2469
2470	success:
2471	spin_unlock_bh(lock: &session->frwd_lock);
2472	success_unlocked:
2473	ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2474	sc, task->itt);
2475	iscsi_put_task(task);
2476	iscsi_put_conn(conn: conn->cls_conn);
2477	mutex_unlock(lock: &session->eh_mutex);
2478	return SUCCESS;
2479
2480	failed:
2481	spin_unlock_bh(lock: &session->frwd_lock);
2482	failed_unlocked:
2483	ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2484	task ? task->itt : 0);
2485	/*
2486	* The driver might be accessing the task so hold the ref. The conn
2487	* stop cleanup will drop the ref after ep_disconnect so we know the
2488	* driver's no longer touching the task.
2489	*/
2490	if (!session->running_aborted_task)
2491	iscsi_put_task(task);
2492
2493	iscsi_put_conn(conn: conn->cls_conn);
2494	mutex_unlock(lock: &session->eh_mutex);
2495	return FAILED;
2496	}
2497	EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2498
2499	static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2500	{
2501	memset(hdr, 0, sizeof(*hdr));
2502	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2503	hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2504	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2505	int_to_scsilun(sc->device->lun, &hdr->lun);
2506	hdr->rtt = RESERVED_ITT;
2507	}
2508
2509	int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2510	{
2511	struct iscsi_cls_session *cls_session;
2512	struct iscsi_session *session;
2513	struct iscsi_conn *conn;
2514	struct iscsi_tm *hdr;
2515	int rc = FAILED;
2516
2517	cls_session = starget_to_session(scsi_target(sc->device));
2518	session = cls_session->dd_data;
2519
2520	ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2521	sc->device->lun);
2522
2523	mutex_lock(&session->eh_mutex);
2524	spin_lock_bh(lock: &session->frwd_lock);
2525	/*
2526	* Just check if we are not logged in. We cannot check for
2527	* the phase because the reset could come from a ioctl.
2528	*/
2529	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2530	goto unlock;
2531	conn = session->leadconn;
2532
2533	/* only have one tmf outstanding at a time */
2534	if (session->tmf_state != TMF_INITIAL)
2535	goto unlock;
2536	session->tmf_state = TMF_QUEUED;
2537
2538	hdr = &session->tmhdr;
2539	iscsi_prep_lun_reset_pdu(sc, hdr);
2540
2541	if (iscsi_exec_task_mgmt_fn(conn, hdr, age: session->age,
2542	timeout: session->lu_reset_timeout)) {
2543	rc = FAILED;
2544	goto unlock;
2545	}
2546
2547	switch (session->tmf_state) {
2548	case TMF_SUCCESS:
2549	break;
2550	case TMF_TIMEDOUT:
2551	spin_unlock_bh(lock: &session->frwd_lock);
2552	iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2553	goto done;
2554	default:
2555	session->tmf_state = TMF_INITIAL;
2556	goto unlock;
2557	}
2558
2559	rc = SUCCESS;
2560	spin_unlock_bh(lock: &session->frwd_lock);
2561
2562	iscsi_suspend_tx(conn);
2563
2564	spin_lock_bh(lock: &session->frwd_lock);
2565	memset(hdr, 0, sizeof(*hdr));
2566	fail_scsi_tasks(conn, lun: sc->device->lun, error: DID_ERROR);
2567	session->tmf_state = TMF_INITIAL;
2568	spin_unlock_bh(lock: &session->frwd_lock);
2569
2570	iscsi_start_tx(conn);
2571	goto done;
2572
2573	unlock:
2574	spin_unlock_bh(lock: &session->frwd_lock);
2575	done:
2576	ISCSI_DBG_EH(session, "dev reset result = %s\n",
2577	rc == SUCCESS ? "SUCCESS" : "FAILED");
2578	mutex_unlock(lock: &session->eh_mutex);
2579	return rc;
2580	}
2581	EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2582
2583	void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2584	{
2585	struct iscsi_session *session = cls_session->dd_data;
2586
2587	spin_lock_bh(lock: &session->frwd_lock);
2588	if (session->state != ISCSI_STATE_LOGGED_IN) {
2589	session->state = ISCSI_STATE_RECOVERY_FAILED;
2590	wake_up(&session->ehwait);
2591	}
2592	spin_unlock_bh(lock: &session->frwd_lock);
2593	}
2594	EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2595
2596	/**
2597	* iscsi_eh_session_reset - drop session and attempt relogin
2598	* @sc: scsi command
2599	*
2600	* This function will wait for a relogin, session termination from
2601	* userspace, or a recovery/replacement timeout.
2602	*/
2603	int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2604	{
2605	struct iscsi_cls_session *cls_session;
2606	struct iscsi_session *session;
2607	struct iscsi_conn *conn;
2608
2609	cls_session = starget_to_session(scsi_target(sc->device));
2610	session = cls_session->dd_data;
2611
2612	mutex_lock(&session->eh_mutex);
2613	spin_lock_bh(lock: &session->frwd_lock);
2614	if (session->state == ISCSI_STATE_TERMINATE) {
2615	failed:
2616	ISCSI_DBG_EH(session,
2617	"failing session reset: Could not log back into "
2618	"%s [age %d]\n", session->targetname,
2619	session->age);
2620	spin_unlock_bh(lock: &session->frwd_lock);
2621	mutex_unlock(lock: &session->eh_mutex);
2622	return FAILED;
2623	}
2624
2625	conn = session->leadconn;
2626	iscsi_get_conn(conn: conn->cls_conn);
2627
2628	spin_unlock_bh(lock: &session->frwd_lock);
2629	mutex_unlock(lock: &session->eh_mutex);
2630
2631	iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2632	iscsi_put_conn(conn: conn->cls_conn);
2633
2634	ISCSI_DBG_EH(session, "wait for relogin\n");
2635	wait_event_interruptible(session->ehwait,
2636	session->state == ISCSI_STATE_TERMINATE ||
2637	session->state == ISCSI_STATE_LOGGED_IN ||
2638	session->state == ISCSI_STATE_RECOVERY_FAILED);
2639	if (signal_pending(current))
2640	flush_signals(current);
2641
2642	mutex_lock(&session->eh_mutex);
2643	spin_lock_bh(lock: &session->frwd_lock);
2644	if (session->state == ISCSI_STATE_LOGGED_IN) {
2645	ISCSI_DBG_EH(session,
2646	"session reset succeeded for %s,%s\n",
2647	session->targetname, conn->persistent_address);
2648	} else
2649	goto failed;
2650	spin_unlock_bh(lock: &session->frwd_lock);
2651	mutex_unlock(lock: &session->eh_mutex);
2652	return SUCCESS;
2653	}
2654	EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2655
2656	static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2657	{
2658	memset(hdr, 0, sizeof(*hdr));
2659	hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2660	hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2661	hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2662	hdr->rtt = RESERVED_ITT;
2663	}
2664
2665	/**
2666	* iscsi_eh_target_reset - reset target
2667	* @sc: scsi command
2668	*
2669	* This will attempt to send a warm target reset.
2670	*/
2671	static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2672	{
2673	struct iscsi_cls_session *cls_session;
2674	struct iscsi_session *session;
2675	struct iscsi_conn *conn;
2676	struct iscsi_tm *hdr;
2677	int rc = FAILED;
2678
2679	cls_session = starget_to_session(scsi_target(sc->device));
2680	session = cls_session->dd_data;
2681
2682	ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2683	session->targetname);
2684
2685	mutex_lock(&session->eh_mutex);
2686	spin_lock_bh(lock: &session->frwd_lock);
2687	/*
2688	* Just check if we are not logged in. We cannot check for
2689	* the phase because the reset could come from a ioctl.
2690	*/
2691	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2692	goto unlock;
2693	conn = session->leadconn;
2694
2695	/* only have one tmf outstanding at a time */
2696	if (session->tmf_state != TMF_INITIAL)
2697	goto unlock;
2698	session->tmf_state = TMF_QUEUED;
2699
2700	hdr = &session->tmhdr;
2701	iscsi_prep_tgt_reset_pdu(sc, hdr);
2702
2703	if (iscsi_exec_task_mgmt_fn(conn, hdr, age: session->age,
2704	timeout: session->tgt_reset_timeout)) {
2705	rc = FAILED;
2706	goto unlock;
2707	}
2708
2709	switch (session->tmf_state) {
2710	case TMF_SUCCESS:
2711	break;
2712	case TMF_TIMEDOUT:
2713	spin_unlock_bh(lock: &session->frwd_lock);
2714	iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2715	goto done;
2716	default:
2717	session->tmf_state = TMF_INITIAL;
2718	goto unlock;
2719	}
2720
2721	rc = SUCCESS;
2722	spin_unlock_bh(lock: &session->frwd_lock);
2723
2724	iscsi_suspend_tx(conn);
2725
2726	spin_lock_bh(lock: &session->frwd_lock);
2727	memset(hdr, 0, sizeof(*hdr));
2728	fail_scsi_tasks(conn, lun: -1, error: DID_ERROR);
2729	session->tmf_state = TMF_INITIAL;
2730	spin_unlock_bh(lock: &session->frwd_lock);
2731
2732	iscsi_start_tx(conn);
2733	goto done;
2734
2735	unlock:
2736	spin_unlock_bh(lock: &session->frwd_lock);
2737	done:
2738	ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2739	rc == SUCCESS ? "SUCCESS" : "FAILED");
2740	mutex_unlock(lock: &session->eh_mutex);
2741	return rc;
2742	}
2743
2744	/**
2745	* iscsi_eh_recover_target - reset target and possibly the session
2746	* @sc: scsi command
2747	*
2748	* This will attempt to send a warm target reset. If that fails,
2749	* we will escalate to ERL0 session recovery.
2750	*/
2751	int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2752	{
2753	int rc;
2754
2755	rc = iscsi_eh_target_reset(sc);
2756	if (rc == FAILED)
2757	rc = iscsi_eh_session_reset(sc);
2758	return rc;
2759	}
2760	EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2761
2762	/*
2763	* Pre-allocate a pool of @max items of @item_size. By default, the pool
2764	* should be accessed via kfifo_{get,put} on q->queue.
2765	* Optionally, the caller can obtain the array of object pointers
2766	* by passing in a non-NULL @items pointer
2767	*/
2768	int
2769	iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2770	{
2771	int i, num_arrays = 1;
2772
2773	memset(q, 0, sizeof(*q));
2774
2775	q->max = max;
2776
2777	/* If the user passed an items pointer, he wants a copy of
2778	* the array. */
2779	if (items)
2780	num_arrays++;
2781	q->pool = kvcalloc(n: num_arrays * max, size: sizeof(void *), GFP_KERNEL);
2782	if (q->pool == NULL)
2783	return -ENOMEM;
2784
2785	kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2786
2787	for (i = 0; i < max; i++) {
2788	q->pool[i] = kzalloc(size: item_size, GFP_KERNEL);
2789	if (q->pool[i] == NULL) {
2790	q->max = i;
2791	goto enomem;
2792	}
2793	kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2794	}
2795
2796	if (items) {
2797	*items = q->pool + max;
2798	memcpy(*items, q->pool, max * sizeof(void *));
2799	}
2800
2801	return 0;
2802
2803	enomem:
2804	iscsi_pool_free(q);
2805	return -ENOMEM;
2806	}
2807	EXPORT_SYMBOL_GPL(iscsi_pool_init);
2808
2809	void iscsi_pool_free(struct iscsi_pool *q)
2810	{
2811	int i;
2812
2813	for (i = 0; i < q->max; i++)
2814	kfree(objp: q->pool[i]);
2815	kvfree(addr: q->pool);
2816	}
2817	EXPORT_SYMBOL_GPL(iscsi_pool_free);
2818
2819	int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
2820	uint16_t requested_cmds_max)
2821	{
2822	int scsi_cmds, total_cmds = requested_cmds_max;
2823
2824	check:
2825	if (!total_cmds)
2826	total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2827	/*
2828	* The iscsi layer needs some tasks for nop handling and tmfs,
2829	* so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2830	* + 1 command for scsi IO.
2831	*/
2832	if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2833	printk(KERN_ERR "iscsi: invalid max cmds of %d. Must be a power of two that is at least %d.\n",
2834	total_cmds, ISCSI_TOTAL_CMDS_MIN);
2835	return -EINVAL;
2836	}
2837
2838	if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2839	printk(KERN_INFO "iscsi: invalid max cmds of %d. Must be a power of 2 less than or equal to %d. Using %d.\n",
2840	requested_cmds_max, ISCSI_TOTAL_CMDS_MAX,
2841	ISCSI_TOTAL_CMDS_MAX);
2842	total_cmds = ISCSI_TOTAL_CMDS_MAX;
2843	}
2844
2845	if (!is_power_of_2(n: total_cmds)) {
2846	total_cmds = rounddown_pow_of_two(total_cmds);
2847	if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2848	printk(KERN_ERR "iscsi: invalid max cmds of %d. Must be a power of 2 greater than %d.\n", requested_cmds_max, ISCSI_TOTAL_CMDS_MIN);
2849	return -EINVAL;
2850	}
2851
2852	printk(KERN_INFO "iscsi: invalid max cmds %d. Must be a power of 2. Rounding max cmds down to %d.\n",
2853	requested_cmds_max, total_cmds);
2854	}
2855
2856	scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2857	if (shost->can_queue && scsi_cmds > shost->can_queue) {
2858	total_cmds = shost->can_queue;
2859
2860	printk(KERN_INFO "iscsi: requested max cmds %u is higher than driver limit. Using driver limit %u\n",
2861	requested_cmds_max, shost->can_queue);
2862	goto check;
2863	}
2864
2865	return scsi_cmds;
2866	}
2867	EXPORT_SYMBOL_GPL(iscsi_host_get_max_scsi_cmds);
2868
2869	/**
2870	* iscsi_host_add - add host to system
2871	* @shost: scsi host
2872	* @pdev: parent device
2873	*
2874	* This should be called by partial offload and software iscsi drivers
2875	* to add a host to the system.
2876	*/
2877	int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2878	{
2879	if (!shost->can_queue)
2880	shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2881
2882	if (!shost->cmd_per_lun)
2883	shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2884
2885	return scsi_add_host(host: shost, dev: pdev);
2886	}
2887	EXPORT_SYMBOL_GPL(iscsi_host_add);
2888
2889	/**
2890	* iscsi_host_alloc - allocate a host and driver data
2891	* @sht: scsi host template
2892	* @dd_data_size: driver host data size
2893	* @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2894	*
2895	* This should be called by partial offload and software iscsi drivers.
2896	* To access the driver specific memory use the iscsi_host_priv() macro.
2897	*/
2898	struct Scsi_Host *iscsi_host_alloc(const struct scsi_host_template *sht,
2899	int dd_data_size, bool xmit_can_sleep)
2900	{
2901	struct Scsi_Host *shost;
2902	struct iscsi_host *ihost;
2903
2904	shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2905	if (!shost)
2906	return NULL;
2907	ihost = shost_priv(shost);
2908
2909	if (xmit_can_sleep) {
2910	ihost->workq = alloc_workqueue(fmt: "iscsi_q_%d",
2911	flags: WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
2912	max_active: 1, shost->host_no);
2913	if (!ihost->workq)
2914	goto free_host;
2915	}
2916
2917	spin_lock_init(&ihost->lock);
2918	ihost->state = ISCSI_HOST_SETUP;
2919	ihost->num_sessions = 0;
2920	init_waitqueue_head(&ihost->session_removal_wq);
2921	return shost;
2922
2923	free_host:
2924	scsi_host_put(t: shost);
2925	return NULL;
2926	}
2927	EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2928
2929	static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2930	{
2931	iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2932	}
2933
2934	/**
2935	* iscsi_host_remove - remove host and sessions
2936	* @shost: scsi host
2937	* @is_shutdown: true if called from a driver shutdown callout
2938	*
2939	* If there are any sessions left, this will initiate the removal and wait
2940	* for the completion.
2941	*/
2942	void iscsi_host_remove(struct Scsi_Host *shost, bool is_shutdown)
2943	{
2944	struct iscsi_host *ihost = shost_priv(shost);
2945	unsigned long flags;
2946
2947	spin_lock_irqsave(&ihost->lock, flags);
2948	ihost->state = ISCSI_HOST_REMOVED;
2949	spin_unlock_irqrestore(lock: &ihost->lock, flags);
2950
2951	if (!is_shutdown)
2952	iscsi_host_for_each_session(shost, fn: iscsi_notify_host_removed);
2953	else
2954	iscsi_host_for_each_session(shost, fn: iscsi_force_destroy_session);
2955
2956	wait_event_interruptible(ihost->session_removal_wq,
2957	ihost->num_sessions == 0);
2958	if (signal_pending(current))
2959	flush_signals(current);
2960
2961	scsi_remove_host(shost);
2962	}
2963	EXPORT_SYMBOL_GPL(iscsi_host_remove);
2964
2965	void iscsi_host_free(struct Scsi_Host *shost)
2966	{
2967	struct iscsi_host *ihost = shost_priv(shost);
2968
2969	if (ihost->workq)
2970	destroy_workqueue(wq: ihost->workq);
2971
2972	kfree(objp: ihost->netdev);
2973	kfree(objp: ihost->hwaddress);
2974	kfree(objp: ihost->initiatorname);
2975	scsi_host_put(t: shost);
2976	}
2977	EXPORT_SYMBOL_GPL(iscsi_host_free);
2978
2979	static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2980	{
2981	struct iscsi_host *ihost = shost_priv(shost);
2982	unsigned long flags;
2983
2984	shost = scsi_host_get(shost);
2985	if (!shost) {
2986	printk(KERN_ERR "Invalid state. Cannot notify host removal "
2987	"of session teardown event because host already "
2988	"removed.\n");
2989	return;
2990	}
2991
2992	spin_lock_irqsave(&ihost->lock, flags);
2993	ihost->num_sessions--;
2994	if (ihost->num_sessions == 0)
2995	wake_up(&ihost->session_removal_wq);
2996	spin_unlock_irqrestore(lock: &ihost->lock, flags);
2997	scsi_host_put(t: shost);
2998	}
2999
3000	/**
3001	* iscsi_session_setup - create iscsi cls session and host and session
3002	* @iscsit: iscsi transport template
3003	* @shost: scsi host
3004	* @cmds_max: session can queue
3005	* @dd_size: private driver data size, added to session allocation size
3006	* @cmd_task_size: LLD task private data size
3007	* @initial_cmdsn: initial CmdSN
3008	* @id: target ID to add to this session
3009	*
3010	* This can be used by software iscsi_transports that allocate
3011	* a session per scsi host.
3012	*
3013	* Callers should set cmds_max to the largest total numer (mgmt + scsi) of
3014	* tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
3015	* for nop handling and login/logout requests.
3016	*/
3017	struct iscsi_cls_session *
3018	iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
3019	uint16_t cmds_max, int dd_size, int cmd_task_size,
3020	uint32_t initial_cmdsn, unsigned int id)
3021	{
3022	struct iscsi_host *ihost = shost_priv(shost);
3023	struct iscsi_session *session;
3024	struct iscsi_cls_session *cls_session;
3025	int cmd_i, scsi_cmds;
3026	unsigned long flags;
3027
3028	spin_lock_irqsave(&ihost->lock, flags);
3029	if (ihost->state == ISCSI_HOST_REMOVED) {
3030	spin_unlock_irqrestore(lock: &ihost->lock, flags);
3031	return NULL;
3032	}
3033	ihost->num_sessions++;
3034	spin_unlock_irqrestore(lock: &ihost->lock, flags);
3035
3036	scsi_cmds = iscsi_host_get_max_scsi_cmds(shost, cmds_max);
3037	if (scsi_cmds < 0)
3038	goto dec_session_count;
3039
3040	cls_session = iscsi_alloc_session(shost, transport: iscsit,
3041	dd_size: sizeof(struct iscsi_session) +
3042	dd_size);
3043	if (!cls_session)
3044	goto dec_session_count;
3045	session = cls_session->dd_data;
3046	session->cls_session = cls_session;
3047	session->host = shost;
3048	session->state = ISCSI_STATE_FREE;
3049	session->fast_abort = 1;
3050	session->tgt_reset_timeout = 30;
3051	session->lu_reset_timeout = 15;
3052	session->abort_timeout = 10;
3053	session->scsi_cmds_max = scsi_cmds;
3054	session->cmds_max = scsi_cmds + ISCSI_MGMT_CMDS_MAX;
3055	session->queued_cmdsn = session->cmdsn = initial_cmdsn;
3056	session->exp_cmdsn = initial_cmdsn + 1;
3057	session->max_cmdsn = initial_cmdsn + 1;
3058	session->max_r2t = 1;
3059	session->tt = iscsit;
3060	session->dd_data = cls_session->dd_data + sizeof(*session);
3061
3062	session->tmf_state = TMF_INITIAL;
3063	timer_setup(&session->tmf_timer, iscsi_tmf_timedout, 0);
3064	mutex_init(&session->eh_mutex);
3065	init_waitqueue_head(&session->ehwait);
3066
3067	spin_lock_init(&session->frwd_lock);
3068	spin_lock_init(&session->back_lock);
3069
3070	/* initialize SCSI PDU commands pool */
3071	if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
3072	(void***)&session->cmds,
3073	cmd_task_size + sizeof(struct iscsi_task)))
3074	goto cmdpool_alloc_fail;
3075
3076	/* pre-format cmds pool with ITT */
3077	for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
3078	struct iscsi_task *task = session->cmds[cmd_i];
3079
3080	if (cmd_task_size)
3081	task->dd_data = &task[1];
3082	task->itt = cmd_i;
3083	task->state = ISCSI_TASK_FREE;
3084	INIT_LIST_HEAD(list: &task->running);
3085	}
3086
3087	if (!try_module_get(module: iscsit->owner))
3088	goto module_get_fail;
3089
3090	if (iscsi_add_session(session: cls_session, target_id: id))
3091	goto cls_session_fail;
3092
3093	return cls_session;
3094
3095	cls_session_fail:
3096	module_put(module: iscsit->owner);
3097	module_get_fail:
3098	iscsi_pool_free(&session->cmdpool);
3099	cmdpool_alloc_fail:
3100	iscsi_free_session(session: cls_session);
3101	dec_session_count:
3102	iscsi_host_dec_session_cnt(shost);
3103	return NULL;
3104	}
3105	EXPORT_SYMBOL_GPL(iscsi_session_setup);
3106
3107	/*
3108	* issi_session_remove - Remove session from iSCSI class.
3109	*/
3110	void iscsi_session_remove(struct iscsi_cls_session *cls_session)
3111	{
3112	struct iscsi_session *session = cls_session->dd_data;
3113	struct Scsi_Host *shost = session->host;
3114
3115	iscsi_remove_session(session: cls_session);
3116	/*
3117	* host removal only has to wait for its children to be removed from
3118	* sysfs, and iscsi_tcp needs to do iscsi_host_remove before freeing
3119	* the session, so drop the session count here.
3120	*/
3121	iscsi_host_dec_session_cnt(shost);
3122	}
3123	EXPORT_SYMBOL_GPL(iscsi_session_remove);
3124
3125	/**
3126	* iscsi_session_free - Free iscsi session and it's resources
3127	* @cls_session: iscsi session
3128	*/
3129	void iscsi_session_free(struct iscsi_cls_session *cls_session)
3130	{
3131	struct iscsi_session *session = cls_session->dd_data;
3132	struct module *owner = cls_session->transport->owner;
3133
3134	iscsi_pool_free(&session->cmdpool);
3135	kfree(objp: session->password);
3136	kfree(objp: session->password_in);
3137	kfree(objp: session->username);
3138	kfree(objp: session->username_in);
3139	kfree(objp: session->targetname);
3140	kfree(objp: session->targetalias);
3141	kfree(objp: session->initiatorname);
3142	kfree(objp: session->boot_root);
3143	kfree(objp: session->boot_nic);
3144	kfree(objp: session->boot_target);
3145	kfree(objp: session->ifacename);
3146	kfree(objp: session->portal_type);
3147	kfree(objp: session->discovery_parent_type);
3148
3149	iscsi_free_session(session: cls_session);
3150	module_put(module: owner);
3151	}
3152	EXPORT_SYMBOL_GPL(iscsi_session_free);
3153
3154	/**
3155	* iscsi_session_teardown - destroy session and cls_session
3156	* @cls_session: iscsi session
3157	*/
3158	void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
3159	{
3160	iscsi_session_remove(cls_session);
3161	iscsi_session_free(cls_session);
3162	}
3163	EXPORT_SYMBOL_GPL(iscsi_session_teardown);
3164
3165	/**
3166	* iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
3167	* @cls_session: iscsi_cls_session
3168	* @dd_size: private driver data size
3169	* @conn_idx: cid
3170	*/
3171	struct iscsi_cls_conn *
3172	iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
3173	uint32_t conn_idx)
3174	{
3175	struct iscsi_session *session = cls_session->dd_data;
3176	struct iscsi_conn *conn;
3177	struct iscsi_cls_conn *cls_conn;
3178	char *data;
3179	int err;
3180
3181	cls_conn = iscsi_alloc_conn(sess: cls_session, dd_size: sizeof(*conn) + dd_size,
3182	cid: conn_idx);
3183	if (!cls_conn)
3184	return NULL;
3185	conn = cls_conn->dd_data;
3186
3187	conn->dd_data = cls_conn->dd_data + sizeof(*conn);
3188	conn->session = session;
3189	conn->cls_conn = cls_conn;
3190	conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
3191	conn->id = conn_idx;
3192	conn->exp_statsn = 0;
3193
3194	timer_setup(&conn->transport_timer, iscsi_check_transport_timeouts, 0);
3195
3196	INIT_LIST_HEAD(list: &conn->mgmtqueue);
3197	INIT_LIST_HEAD(list: &conn->cmdqueue);
3198	INIT_LIST_HEAD(list: &conn->requeue);
3199	INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
3200
3201	/* allocate login_task used for the login/text sequences */
3202	spin_lock_bh(lock: &session->frwd_lock);
3203	if (!kfifo_out(&session->cmdpool.queue,
3204	(void*)&conn->login_task,
3205	sizeof(void*))) {
3206	spin_unlock_bh(lock: &session->frwd_lock);
3207	goto login_task_alloc_fail;
3208	}
3209	spin_unlock_bh(lock: &session->frwd_lock);
3210
3211	data = (char *) __get_free_pages(GFP_KERNEL,
3212	order: get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3213	if (!data)
3214	goto login_task_data_alloc_fail;
3215	conn->login_task->data = conn->data = data;
3216
3217	err = iscsi_add_conn(conn: cls_conn);
3218	if (err)
3219	goto login_task_add_dev_fail;
3220
3221	return cls_conn;
3222
3223	login_task_add_dev_fail:
3224	free_pages(addr: (unsigned long) conn->data,
3225	order: get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3226
3227	login_task_data_alloc_fail:
3228	kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3229	sizeof(void*));
3230	login_task_alloc_fail:
3231	iscsi_put_conn(conn: cls_conn);
3232	return NULL;
3233	}
3234	EXPORT_SYMBOL_GPL(iscsi_conn_setup);
3235
3236	/**
3237	* iscsi_conn_teardown - teardown iscsi connection
3238	* @cls_conn: iscsi class connection
3239	*
3240	* TODO: we may need to make this into a two step process
3241	* like scsi-mls remove + put host
3242	*/
3243	void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
3244	{
3245	struct iscsi_conn *conn = cls_conn->dd_data;
3246	struct iscsi_session *session = conn->session;
3247
3248	iscsi_remove_conn(conn: cls_conn);
3249
3250	del_timer_sync(timer: &conn->transport_timer);
3251
3252	mutex_lock(&session->eh_mutex);
3253	spin_lock_bh(lock: &session->frwd_lock);
3254	conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
3255	if (session->leadconn == conn) {
3256	/*
3257	* leading connection? then give up on recovery.
3258	*/
3259	session->state = ISCSI_STATE_TERMINATE;
3260	wake_up(&session->ehwait);
3261	}
3262	spin_unlock_bh(lock: &session->frwd_lock);
3263
3264	/* flush queued up work because we free the connection below */
3265	iscsi_suspend_tx(conn);
3266
3267	spin_lock_bh(lock: &session->frwd_lock);
3268	free_pages(addr: (unsigned long) conn->data,
3269	order: get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3270	kfree(objp: conn->persistent_address);
3271	kfree(objp: conn->local_ipaddr);
3272	/* regular RX path uses back_lock */
3273	spin_lock_bh(lock: &session->back_lock);
3274	kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3275	sizeof(void*));
3276	spin_unlock_bh(lock: &session->back_lock);
3277	if (session->leadconn == conn)
3278	session->leadconn = NULL;
3279	spin_unlock_bh(lock: &session->frwd_lock);
3280	mutex_unlock(lock: &session->eh_mutex);
3281
3282	iscsi_put_conn(conn: cls_conn);
3283	}
3284	EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
3285
3286	int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
3287	{
3288	struct iscsi_conn *conn = cls_conn->dd_data;
3289	struct iscsi_session *session = conn->session;
3290
3291	if (!session) {
3292	iscsi_conn_printk(KERN_ERR, conn,
3293	"can't start unbound connection\n");
3294	return -EPERM;
3295	}
3296
3297	if ((session->imm_data_en || !session->initial_r2t_en) &&
3298	session->first_burst > session->max_burst) {
3299	iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
3300	"first_burst %d max_burst %d\n",
3301	session->first_burst, session->max_burst);
3302	return -EINVAL;
3303	}
3304
3305	if (conn->ping_timeout && !conn->recv_timeout) {
3306	iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3307	"zero. Using 5 seconds\n.");
3308	conn->recv_timeout = 5;
3309	}
3310
3311	if (conn->recv_timeout && !conn->ping_timeout) {
3312	iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3313	"zero. Using 5 seconds.\n");
3314	conn->ping_timeout = 5;
3315	}
3316
3317	spin_lock_bh(lock: &session->frwd_lock);
3318	conn->c_stage = ISCSI_CONN_STARTED;
3319	session->state = ISCSI_STATE_LOGGED_IN;
3320	session->queued_cmdsn = session->cmdsn;
3321
3322	conn->last_recv = jiffies;
3323	conn->last_ping = jiffies;
3324	if (conn->recv_timeout && conn->ping_timeout)
3325	mod_timer(timer: &conn->transport_timer,
3326	expires: jiffies + (conn->recv_timeout * HZ));
3327
3328	switch(conn->stop_stage) {
3329	case STOP_CONN_RECOVER:
3330	/*
3331	* unblock eh_abort() if it is blocked. re-try all
3332	* commands after successful recovery
3333	*/
3334	conn->stop_stage = 0;
3335	session->tmf_state = TMF_INITIAL;
3336	session->age++;
3337	if (session->age == 16)
3338	session->age = 0;
3339	break;
3340	case STOP_CONN_TERM:
3341	conn->stop_stage = 0;
3342	break;
3343	default:
3344	break;
3345	}
3346	spin_unlock_bh(lock: &session->frwd_lock);
3347
3348	iscsi_unblock_session(session: session->cls_session);
3349	wake_up(&session->ehwait);
3350	return 0;
3351	}
3352	EXPORT_SYMBOL_GPL(iscsi_conn_start);
3353
3354	static void
3355	fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3356	{
3357	struct iscsi_task *task;
3358	int i, state;
3359
3360	for (i = 0; i < conn->session->cmds_max; i++) {
3361	task = conn->session->cmds[i];
3362	if (task->sc)
3363	continue;
3364
3365	if (task->state == ISCSI_TASK_FREE)
3366	continue;
3367
3368	ISCSI_DBG_SESSION(conn->session,
3369	"failing mgmt itt 0x%x state %d\n",
3370	task->itt, task->state);
3371
3372	spin_lock_bh(lock: &session->back_lock);
3373	if (cleanup_queued_task(task)) {
3374	spin_unlock_bh(lock: &session->back_lock);
3375	continue;
3376	}
3377
3378	state = ISCSI_TASK_ABRT_SESS_RECOV;
3379	if (task->state == ISCSI_TASK_PENDING)
3380	state = ISCSI_TASK_COMPLETED;
3381	iscsi_complete_task(task, state);
3382	spin_unlock_bh(lock: &session->back_lock);
3383	}
3384	}
3385
3386	void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3387	{
3388	struct iscsi_conn *conn = cls_conn->dd_data;
3389	struct iscsi_session *session = conn->session;
3390	int old_stop_stage;
3391
3392	mutex_lock(&session->eh_mutex);
3393	spin_lock_bh(lock: &session->frwd_lock);
3394	if (conn->stop_stage == STOP_CONN_TERM) {
3395	spin_unlock_bh(lock: &session->frwd_lock);
3396	mutex_unlock(lock: &session->eh_mutex);
3397	return;
3398	}
3399
3400	/*
3401	* When this is called for the in_login state, we only want to clean
3402	* up the login task and connection. We do not need to block and set
3403	* the recovery state again
3404	*/
3405	if (flag == STOP_CONN_TERM)
3406	session->state = ISCSI_STATE_TERMINATE;
3407	else if (conn->stop_stage != STOP_CONN_RECOVER)
3408	session->state = ISCSI_STATE_IN_RECOVERY;
3409
3410	old_stop_stage = conn->stop_stage;
3411	conn->stop_stage = flag;
3412	spin_unlock_bh(lock: &session->frwd_lock);
3413
3414	del_timer_sync(timer: &conn->transport_timer);
3415	iscsi_suspend_tx(conn);
3416
3417	spin_lock_bh(lock: &session->frwd_lock);
3418	conn->c_stage = ISCSI_CONN_STOPPED;
3419	spin_unlock_bh(lock: &session->frwd_lock);
3420
3421	/*
3422	* for connection level recovery we should not calculate
3423	* header digest. conn->hdr_size used for optimization
3424	* in hdr_extract() and will be re-negotiated at
3425	* set_param() time.
3426	*/
3427	if (flag == STOP_CONN_RECOVER) {
3428	conn->hdrdgst_en = 0;
3429	conn->datadgst_en = 0;
3430	if (session->state == ISCSI_STATE_IN_RECOVERY &&
3431	old_stop_stage != STOP_CONN_RECOVER) {
3432	ISCSI_DBG_SESSION(session, "blocking session\n");
3433	iscsi_block_session(session: session->cls_session);
3434	}
3435	}
3436
3437	/*
3438	* flush queues.
3439	*/
3440	spin_lock_bh(lock: &session->frwd_lock);
3441	fail_scsi_tasks(conn, lun: -1, error: DID_TRANSPORT_DISRUPTED);
3442	fail_mgmt_tasks(session, conn);
3443	memset(&session->tmhdr, 0, sizeof(session->tmhdr));
3444	spin_unlock_bh(lock: &session->frwd_lock);
3445	mutex_unlock(lock: &session->eh_mutex);
3446	}
3447	EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3448
3449	int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3450	struct iscsi_cls_conn *cls_conn, int is_leading)
3451	{
3452	struct iscsi_session *session = cls_session->dd_data;
3453	struct iscsi_conn *conn = cls_conn->dd_data;
3454
3455	spin_lock_bh(lock: &session->frwd_lock);
3456	if (is_leading)
3457	session->leadconn = conn;
3458
3459	set_bit(ISCSI_CONN_FLAG_BOUND, addr: &conn->flags);
3460	spin_unlock_bh(lock: &session->frwd_lock);
3461
3462	/*
3463	* The target could have reduced it's window size between logins, so
3464	* we have to reset max/exp cmdsn so we can see the new values.
3465	*/
3466	spin_lock_bh(lock: &session->back_lock);
3467	session->max_cmdsn = session->exp_cmdsn = session->cmdsn + 1;
3468	spin_unlock_bh(lock: &session->back_lock);
3469	/*
3470	* Unblock xmitworker(), Login Phase will pass through.
3471	*/
3472	clear_bit(ISCSI_CONN_FLAG_SUSPEND_RX, addr: &conn->flags);
3473	clear_bit(ISCSI_CONN_FLAG_SUSPEND_TX, addr: &conn->flags);
3474	return 0;
3475	}
3476	EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3477
3478	int iscsi_switch_str_param(char **param, char *new_val_buf)
3479	{
3480	char *new_val;
3481
3482	if (*param) {
3483	if (!strcmp(*param, new_val_buf))
3484	return 0;
3485	}
3486
3487	new_val = kstrdup(s: new_val_buf, GFP_NOIO);
3488	if (!new_val)
3489	return -ENOMEM;
3490
3491	kfree(objp: *param);
3492	*param = new_val;
3493	return 0;
3494	}
3495	EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3496
3497	int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3498	enum iscsi_param param, char *buf, int buflen)
3499	{
3500	struct iscsi_conn *conn = cls_conn->dd_data;
3501	struct iscsi_session *session = conn->session;
3502	int val;
3503
3504	switch(param) {
3505	case ISCSI_PARAM_FAST_ABORT:
3506	sscanf(buf, "%d", &session->fast_abort);
3507	break;
3508	case ISCSI_PARAM_ABORT_TMO:
3509	sscanf(buf, "%d", &session->abort_timeout);
3510	break;
3511	case ISCSI_PARAM_LU_RESET_TMO:
3512	sscanf(buf, "%d", &session->lu_reset_timeout);
3513	break;
3514	case ISCSI_PARAM_TGT_RESET_TMO:
3515	sscanf(buf, "%d", &session->tgt_reset_timeout);
3516	break;
3517	case ISCSI_PARAM_PING_TMO:
3518	sscanf(buf, "%d", &conn->ping_timeout);
3519	break;
3520	case ISCSI_PARAM_RECV_TMO:
3521	sscanf(buf, "%d", &conn->recv_timeout);
3522	break;
3523	case ISCSI_PARAM_MAX_RECV_DLENGTH:
3524	sscanf(buf, "%d", &conn->max_recv_dlength);
3525	break;
3526	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3527	sscanf(buf, "%d", &conn->max_xmit_dlength);
3528	break;
3529	case ISCSI_PARAM_HDRDGST_EN:
3530	sscanf(buf, "%d", &conn->hdrdgst_en);
3531	break;
3532	case ISCSI_PARAM_DATADGST_EN:
3533	sscanf(buf, "%d", &conn->datadgst_en);
3534	break;
3535	case ISCSI_PARAM_INITIAL_R2T_EN:
3536	sscanf(buf, "%d", &session->initial_r2t_en);
3537	break;
3538	case ISCSI_PARAM_MAX_R2T:
3539	sscanf(buf, "%hu", &session->max_r2t);
3540	break;
3541	case ISCSI_PARAM_IMM_DATA_EN:
3542	sscanf(buf, "%d", &session->imm_data_en);
3543	break;
3544	case ISCSI_PARAM_FIRST_BURST:
3545	sscanf(buf, "%d", &session->first_burst);
3546	break;
3547	case ISCSI_PARAM_MAX_BURST:
3548	sscanf(buf, "%d", &session->max_burst);
3549	break;
3550	case ISCSI_PARAM_PDU_INORDER_EN:
3551	sscanf(buf, "%d", &session->pdu_inorder_en);
3552	break;
3553	case ISCSI_PARAM_DATASEQ_INORDER_EN:
3554	sscanf(buf, "%d", &session->dataseq_inorder_en);
3555	break;
3556	case ISCSI_PARAM_ERL:
3557	sscanf(buf, "%d", &session->erl);
3558	break;
3559	case ISCSI_PARAM_EXP_STATSN:
3560	sscanf(buf, "%u", &conn->exp_statsn);
3561	break;
3562	case ISCSI_PARAM_USERNAME:
3563	return iscsi_switch_str_param(&session->username, buf);
3564	case ISCSI_PARAM_USERNAME_IN:
3565	return iscsi_switch_str_param(&session->username_in, buf);
3566	case ISCSI_PARAM_PASSWORD:
3567	return iscsi_switch_str_param(&session->password, buf);
3568	case ISCSI_PARAM_PASSWORD_IN:
3569	return iscsi_switch_str_param(&session->password_in, buf);
3570	case ISCSI_PARAM_TARGET_NAME:
3571	return iscsi_switch_str_param(&session->targetname, buf);
3572	case ISCSI_PARAM_TARGET_ALIAS:
3573	return iscsi_switch_str_param(&session->targetalias, buf);
3574	case ISCSI_PARAM_TPGT:
3575	sscanf(buf, "%d", &session->tpgt);
3576	break;
3577	case ISCSI_PARAM_PERSISTENT_PORT:
3578	sscanf(buf, "%d", &conn->persistent_port);
3579	break;
3580	case ISCSI_PARAM_PERSISTENT_ADDRESS:
3581	return iscsi_switch_str_param(&conn->persistent_address, buf);
3582	case ISCSI_PARAM_IFACE_NAME:
3583	return iscsi_switch_str_param(&session->ifacename, buf);
3584	case ISCSI_PARAM_INITIATOR_NAME:
3585	return iscsi_switch_str_param(&session->initiatorname, buf);
3586	case ISCSI_PARAM_BOOT_ROOT:
3587	return iscsi_switch_str_param(&session->boot_root, buf);
3588	case ISCSI_PARAM_BOOT_NIC:
3589	return iscsi_switch_str_param(&session->boot_nic, buf);
3590	case ISCSI_PARAM_BOOT_TARGET:
3591	return iscsi_switch_str_param(&session->boot_target, buf);
3592	case ISCSI_PARAM_PORTAL_TYPE:
3593	return iscsi_switch_str_param(&session->portal_type, buf);
3594	case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3595	return iscsi_switch_str_param(&session->discovery_parent_type,
3596	buf);
3597	case ISCSI_PARAM_DISCOVERY_SESS:
3598	sscanf(buf, "%d", &val);
3599	session->discovery_sess = !!val;
3600	break;
3601	case ISCSI_PARAM_LOCAL_IPADDR:
3602	return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3603	default:
3604	return -ENOSYS;
3605	}
3606
3607	return 0;
3608	}
3609	EXPORT_SYMBOL_GPL(iscsi_set_param);
3610
3611	int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3612	enum iscsi_param param, char *buf)
3613	{
3614	struct iscsi_session *session = cls_session->dd_data;
3615	int len;
3616
3617	switch(param) {
3618	case ISCSI_PARAM_FAST_ABORT:
3619	len = sysfs_emit(buf, fmt: "%d\n", session->fast_abort);
3620	break;
3621	case ISCSI_PARAM_ABORT_TMO:
3622	len = sysfs_emit(buf, fmt: "%d\n", session->abort_timeout);
3623	break;
3624	case ISCSI_PARAM_LU_RESET_TMO:
3625	len = sysfs_emit(buf, fmt: "%d\n", session->lu_reset_timeout);
3626	break;
3627	case ISCSI_PARAM_TGT_RESET_TMO:
3628	len = sysfs_emit(buf, fmt: "%d\n", session->tgt_reset_timeout);
3629	break;
3630	case ISCSI_PARAM_INITIAL_R2T_EN:
3631	len = sysfs_emit(buf, fmt: "%d\n", session->initial_r2t_en);
3632	break;
3633	case ISCSI_PARAM_MAX_R2T:
3634	len = sysfs_emit(buf, fmt: "%hu\n", session->max_r2t);
3635	break;
3636	case ISCSI_PARAM_IMM_DATA_EN:
3637	len = sysfs_emit(buf, fmt: "%d\n", session->imm_data_en);
3638	break;
3639	case ISCSI_PARAM_FIRST_BURST:
3640	len = sysfs_emit(buf, fmt: "%u\n", session->first_burst);
3641	break;
3642	case ISCSI_PARAM_MAX_BURST:
3643	len = sysfs_emit(buf, fmt: "%u\n", session->max_burst);
3644	break;
3645	case ISCSI_PARAM_PDU_INORDER_EN:
3646	len = sysfs_emit(buf, fmt: "%d\n", session->pdu_inorder_en);
3647	break;
3648	case ISCSI_PARAM_DATASEQ_INORDER_EN:
3649	len = sysfs_emit(buf, fmt: "%d\n", session->dataseq_inorder_en);
3650	break;
3651	case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3652	len = sysfs_emit(buf, fmt: "%d\n", session->def_taskmgmt_tmo);
3653	break;
3654	case ISCSI_PARAM_ERL:
3655	len = sysfs_emit(buf, fmt: "%d\n", session->erl);
3656	break;
3657	case ISCSI_PARAM_TARGET_NAME:
3658	len = sysfs_emit(buf, fmt: "%s\n", session->targetname);
3659	break;
3660	case ISCSI_PARAM_TARGET_ALIAS:
3661	len = sysfs_emit(buf, fmt: "%s\n", session->targetalias);
3662	break;
3663	case ISCSI_PARAM_TPGT:
3664	len = sysfs_emit(buf, fmt: "%d\n", session->tpgt);
3665	break;
3666	case ISCSI_PARAM_USERNAME:
3667	len = sysfs_emit(buf, fmt: "%s\n", session->username);
3668	break;
3669	case ISCSI_PARAM_USERNAME_IN:
3670	len = sysfs_emit(buf, fmt: "%s\n", session->username_in);
3671	break;
3672	case ISCSI_PARAM_PASSWORD:
3673	len = sysfs_emit(buf, fmt: "%s\n", session->password);
3674	break;
3675	case ISCSI_PARAM_PASSWORD_IN:
3676	len = sysfs_emit(buf, fmt: "%s\n", session->password_in);
3677	break;
3678	case ISCSI_PARAM_IFACE_NAME:
3679	len = sysfs_emit(buf, fmt: "%s\n", session->ifacename);
3680	break;
3681	case ISCSI_PARAM_INITIATOR_NAME:
3682	len = sysfs_emit(buf, fmt: "%s\n", session->initiatorname);
3683	break;
3684	case ISCSI_PARAM_BOOT_ROOT:
3685	len = sysfs_emit(buf, fmt: "%s\n", session->boot_root);
3686	break;
3687	case ISCSI_PARAM_BOOT_NIC:
3688	len = sysfs_emit(buf, fmt: "%s\n", session->boot_nic);
3689	break;
3690	case ISCSI_PARAM_BOOT_TARGET:
3691	len = sysfs_emit(buf, fmt: "%s\n", session->boot_target);
3692	break;
3693	case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3694	len = sysfs_emit(buf, fmt: "%u\n", session->auto_snd_tgt_disable);
3695	break;
3696	case ISCSI_PARAM_DISCOVERY_SESS:
3697	len = sysfs_emit(buf, fmt: "%u\n", session->discovery_sess);
3698	break;
3699	case ISCSI_PARAM_PORTAL_TYPE:
3700	len = sysfs_emit(buf, fmt: "%s\n", session->portal_type);
3701	break;
3702	case ISCSI_PARAM_CHAP_AUTH_EN:
3703	len = sysfs_emit(buf, fmt: "%u\n", session->chap_auth_en);
3704	break;
3705	case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3706	len = sysfs_emit(buf, fmt: "%u\n", session->discovery_logout_en);
3707	break;
3708	case ISCSI_PARAM_BIDI_CHAP_EN:
3709	len = sysfs_emit(buf, fmt: "%u\n", session->bidi_chap_en);
3710	break;
3711	case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3712	len = sysfs_emit(buf, fmt: "%u\n", session->discovery_auth_optional);
3713	break;
3714	case ISCSI_PARAM_DEF_TIME2WAIT:
3715	len = sysfs_emit(buf, fmt: "%d\n", session->time2wait);
3716	break;
3717	case ISCSI_PARAM_DEF_TIME2RETAIN:
3718	len = sysfs_emit(buf, fmt: "%d\n", session->time2retain);
3719	break;
3720	case ISCSI_PARAM_TSID:
3721	len = sysfs_emit(buf, fmt: "%u\n", session->tsid);
3722	break;
3723	case ISCSI_PARAM_ISID:
3724	len = sysfs_emit(buf, fmt: "%02x%02x%02x%02x%02x%02x\n",
3725	session->isid[0], session->isid[1],
3726	session->isid[2], session->isid[3],
3727	session->isid[4], session->isid[5]);
3728	break;
3729	case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3730	len = sysfs_emit(buf, fmt: "%u\n", session->discovery_parent_idx);
3731	break;
3732	case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3733	if (session->discovery_parent_type)
3734	len = sysfs_emit(buf, fmt: "%s\n",
3735	session->discovery_parent_type);
3736	else
3737	len = sysfs_emit(buf, fmt: "\n");
3738	break;
3739	default:
3740	return -ENOSYS;
3741	}
3742
3743	return len;
3744	}
3745	EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3746
3747	int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3748	enum iscsi_param param, char *buf)
3749	{
3750	struct sockaddr_in6 *sin6 = NULL;
3751	struct sockaddr_in *sin = NULL;
3752	int len;
3753
3754	switch (addr->ss_family) {
3755	case AF_INET:
3756	sin = (struct sockaddr_in *)addr;
3757	break;
3758	case AF_INET6:
3759	sin6 = (struct sockaddr_in6 *)addr;
3760	break;
3761	default:
3762	return -EINVAL;
3763	}
3764
3765	switch (param) {
3766	case ISCSI_PARAM_CONN_ADDRESS:
3767	case ISCSI_HOST_PARAM_IPADDRESS:
3768	if (sin)
3769	len = sysfs_emit(buf, fmt: "%pI4\n", &sin->sin_addr.s_addr);
3770	else
3771	len = sysfs_emit(buf, fmt: "%pI6\n", &sin6->sin6_addr);
3772	break;
3773	case ISCSI_PARAM_CONN_PORT:
3774	case ISCSI_PARAM_LOCAL_PORT:
3775	if (sin)
3776	len = sysfs_emit(buf, fmt: "%hu\n", be16_to_cpu(sin->sin_port));
3777	else
3778	len = sysfs_emit(buf, fmt: "%hu\n",
3779	be16_to_cpu(sin6->sin6_port));
3780	break;
3781	default:
3782	return -EINVAL;
3783	}
3784
3785	return len;
3786	}
3787	EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3788
3789	int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3790	enum iscsi_param param, char *buf)
3791	{
3792	struct iscsi_conn *conn = cls_conn->dd_data;
3793	int len;
3794
3795	switch(param) {
3796	case ISCSI_PARAM_PING_TMO:
3797	len = sysfs_emit(buf, fmt: "%u\n", conn->ping_timeout);
3798	break;
3799	case ISCSI_PARAM_RECV_TMO:
3800	len = sysfs_emit(buf, fmt: "%u\n", conn->recv_timeout);
3801	break;
3802	case ISCSI_PARAM_MAX_RECV_DLENGTH:
3803	len = sysfs_emit(buf, fmt: "%u\n", conn->max_recv_dlength);
3804	break;
3805	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3806	len = sysfs_emit(buf, fmt: "%u\n", conn->max_xmit_dlength);
3807	break;
3808	case ISCSI_PARAM_HDRDGST_EN:
3809	len = sysfs_emit(buf, fmt: "%d\n", conn->hdrdgst_en);
3810	break;
3811	case ISCSI_PARAM_DATADGST_EN:
3812	len = sysfs_emit(buf, fmt: "%d\n", conn->datadgst_en);
3813	break;
3814	case ISCSI_PARAM_IFMARKER_EN:
3815	len = sysfs_emit(buf, fmt: "%d\n", conn->ifmarker_en);
3816	break;
3817	case ISCSI_PARAM_OFMARKER_EN:
3818	len = sysfs_emit(buf, fmt: "%d\n", conn->ofmarker_en);
3819	break;
3820	case ISCSI_PARAM_EXP_STATSN:
3821	len = sysfs_emit(buf, fmt: "%u\n", conn->exp_statsn);
3822	break;
3823	case ISCSI_PARAM_PERSISTENT_PORT:
3824	len = sysfs_emit(buf, fmt: "%d\n", conn->persistent_port);
3825	break;
3826	case ISCSI_PARAM_PERSISTENT_ADDRESS:
3827	len = sysfs_emit(buf, fmt: "%s\n", conn->persistent_address);
3828	break;
3829	case ISCSI_PARAM_STATSN:
3830	len = sysfs_emit(buf, fmt: "%u\n", conn->statsn);
3831	break;
3832	case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3833	len = sysfs_emit(buf, fmt: "%u\n", conn->max_segment_size);
3834	break;
3835	case ISCSI_PARAM_KEEPALIVE_TMO:
3836	len = sysfs_emit(buf, fmt: "%u\n", conn->keepalive_tmo);
3837	break;
3838	case ISCSI_PARAM_LOCAL_PORT:
3839	len = sysfs_emit(buf, fmt: "%u\n", conn->local_port);
3840	break;
3841	case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3842	len = sysfs_emit(buf, fmt: "%u\n", conn->tcp_timestamp_stat);
3843	break;
3844	case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3845	len = sysfs_emit(buf, fmt: "%u\n", conn->tcp_nagle_disable);
3846	break;
3847	case ISCSI_PARAM_TCP_WSF_DISABLE:
3848	len = sysfs_emit(buf, fmt: "%u\n", conn->tcp_wsf_disable);
3849	break;
3850	case ISCSI_PARAM_TCP_TIMER_SCALE:
3851	len = sysfs_emit(buf, fmt: "%u\n", conn->tcp_timer_scale);
3852	break;
3853	case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3854	len = sysfs_emit(buf, fmt: "%u\n", conn->tcp_timestamp_en);
3855	break;
3856	case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3857	len = sysfs_emit(buf, fmt: "%u\n", conn->fragment_disable);
3858	break;
3859	case ISCSI_PARAM_IPV4_TOS:
3860	len = sysfs_emit(buf, fmt: "%u\n", conn->ipv4_tos);
3861	break;
3862	case ISCSI_PARAM_IPV6_TC:
3863	len = sysfs_emit(buf, fmt: "%u\n", conn->ipv6_traffic_class);
3864	break;
3865	case ISCSI_PARAM_IPV6_FLOW_LABEL:
3866	len = sysfs_emit(buf, fmt: "%u\n", conn->ipv6_flow_label);
3867	break;
3868	case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3869	len = sysfs_emit(buf, fmt: "%u\n", conn->is_fw_assigned_ipv6);
3870	break;
3871	case ISCSI_PARAM_TCP_XMIT_WSF:
3872	len = sysfs_emit(buf, fmt: "%u\n", conn->tcp_xmit_wsf);
3873	break;
3874	case ISCSI_PARAM_TCP_RECV_WSF:
3875	len = sysfs_emit(buf, fmt: "%u\n", conn->tcp_recv_wsf);
3876	break;
3877	case ISCSI_PARAM_LOCAL_IPADDR:
3878	len = sysfs_emit(buf, fmt: "%s\n", conn->local_ipaddr);
3879	break;
3880	default:
3881	return -ENOSYS;
3882	}
3883
3884	return len;
3885	}
3886	EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3887
3888	int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3889	char *buf)
3890	{
3891	struct iscsi_host *ihost = shost_priv(shost);
3892	int len;
3893
3894	switch (param) {
3895	case ISCSI_HOST_PARAM_NETDEV_NAME:
3896	len = sysfs_emit(buf, fmt: "%s\n", ihost->netdev);
3897	break;
3898	case ISCSI_HOST_PARAM_HWADDRESS:
3899	len = sysfs_emit(buf, fmt: "%s\n", ihost->hwaddress);
3900	break;
3901	case ISCSI_HOST_PARAM_INITIATOR_NAME:
3902	len = sysfs_emit(buf, fmt: "%s\n", ihost->initiatorname);
3903	break;
3904	default:
3905	return -ENOSYS;
3906	}
3907
3908	return len;
3909	}
3910	EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3911
3912	int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3913	char *buf, int buflen)
3914	{
3915	struct iscsi_host *ihost = shost_priv(shost);
3916
3917	switch (param) {
3918	case ISCSI_HOST_PARAM_NETDEV_NAME:
3919	return iscsi_switch_str_param(&ihost->netdev, buf);
3920	case ISCSI_HOST_PARAM_HWADDRESS:
3921	return iscsi_switch_str_param(&ihost->hwaddress, buf);
3922	case ISCSI_HOST_PARAM_INITIATOR_NAME:
3923	return iscsi_switch_str_param(&ihost->initiatorname, buf);
3924	default:
3925	return -ENOSYS;
3926	}
3927
3928	return 0;
3929	}
3930	EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3931
3932	MODULE_AUTHOR("Mike Christie");
3933	MODULE_DESCRIPTION("iSCSI library functions");
3934	MODULE_LICENSE("GPL");
3935