xref: /linux/drivers/target/iscsi/iscsi_target_util.c (revision 84dc6037390b8607c5551047d3970336cb51ba9a)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*******************************************************************************
3  * This file contains the iSCSI Target specific utility functions.
4  *
5  * (c) Copyright 2007-2013 Datera, Inc.
6  *
7  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
8  *
9  ******************************************************************************/
10 
11 #include <linux/list.h>
12 #include <linux/sched/signal.h>
13 #include <net/ipv6.h>         /* ipv6_addr_equal() */
14 #include <scsi/scsi_tcq.h>
15 #include <scsi/iscsi_proto.h>
16 #include <target/target_core_base.h>
17 #include <target/target_core_fabric.h>
18 #include <target/iscsi/iscsi_transport.h>
19 
20 #include <target/iscsi/iscsi_target_core.h>
21 #include "iscsi_target_parameters.h"
22 #include "iscsi_target_seq_pdu_list.h"
23 #include "iscsi_target_datain_values.h"
24 #include "iscsi_target_erl0.h"
25 #include "iscsi_target_erl1.h"
26 #include "iscsi_target_erl2.h"
27 #include "iscsi_target_tpg.h"
28 #include "iscsi_target_util.h"
29 #include "iscsi_target.h"
30 
31 extern struct list_head g_tiqn_list;
32 extern spinlock_t tiqn_lock;
33 
34 int iscsit_add_r2t_to_list(
35 	struct iscsit_cmd *cmd,
36 	u32 offset,
37 	u32 xfer_len,
38 	int recovery,
39 	u32 r2t_sn)
40 {
41 	struct iscsi_r2t *r2t;
42 
43 	lockdep_assert_held(&cmd->r2t_lock);
44 
45 	WARN_ON_ONCE((s32)xfer_len < 0);
46 
47 	r2t = kmem_cache_zalloc(lio_r2t_cache, GFP_ATOMIC);
48 	if (!r2t) {
49 		pr_err("Unable to allocate memory for struct iscsi_r2t.\n");
50 		return -1;
51 	}
52 	INIT_LIST_HEAD(&r2t->r2t_list);
53 
54 	r2t->recovery_r2t = recovery;
55 	r2t->r2t_sn = (!r2t_sn) ? cmd->r2t_sn++ : r2t_sn;
56 	r2t->offset = offset;
57 	r2t->xfer_len = xfer_len;
58 	list_add_tail(&r2t->r2t_list, &cmd->cmd_r2t_list);
59 	spin_unlock_bh(&cmd->r2t_lock);
60 
61 	iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, ISTATE_SEND_R2T);
62 
63 	spin_lock_bh(&cmd->r2t_lock);
64 	return 0;
65 }
66 
67 struct iscsi_r2t *iscsit_get_r2t_for_eos(
68 	struct iscsit_cmd *cmd,
69 	u32 offset,
70 	u32 length)
71 {
72 	struct iscsi_r2t *r2t;
73 
74 	spin_lock_bh(&cmd->r2t_lock);
75 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
76 		if ((r2t->offset <= offset) &&
77 		    (r2t->offset + r2t->xfer_len) >= (offset + length)) {
78 			spin_unlock_bh(&cmd->r2t_lock);
79 			return r2t;
80 		}
81 	}
82 	spin_unlock_bh(&cmd->r2t_lock);
83 
84 	pr_err("Unable to locate R2T for Offset: %u, Length:"
85 			" %u\n", offset, length);
86 	return NULL;
87 }
88 
89 struct iscsi_r2t *iscsit_get_r2t_from_list(struct iscsit_cmd *cmd)
90 {
91 	struct iscsi_r2t *r2t;
92 
93 	spin_lock_bh(&cmd->r2t_lock);
94 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
95 		if (!r2t->sent_r2t) {
96 			spin_unlock_bh(&cmd->r2t_lock);
97 			return r2t;
98 		}
99 	}
100 	spin_unlock_bh(&cmd->r2t_lock);
101 
102 	pr_err("Unable to locate next R2T to send for ITT:"
103 			" 0x%08x.\n", cmd->init_task_tag);
104 	return NULL;
105 }
106 
107 void iscsit_free_r2t(struct iscsi_r2t *r2t, struct iscsit_cmd *cmd)
108 {
109 	lockdep_assert_held(&cmd->r2t_lock);
110 
111 	list_del(&r2t->r2t_list);
112 	kmem_cache_free(lio_r2t_cache, r2t);
113 }
114 
115 void iscsit_free_r2ts_from_list(struct iscsit_cmd *cmd)
116 {
117 	struct iscsi_r2t *r2t, *r2t_tmp;
118 
119 	spin_lock_bh(&cmd->r2t_lock);
120 	list_for_each_entry_safe(r2t, r2t_tmp, &cmd->cmd_r2t_list, r2t_list)
121 		iscsit_free_r2t(r2t, cmd);
122 	spin_unlock_bh(&cmd->r2t_lock);
123 }
124 
125 static int iscsit_wait_for_tag(struct se_session *se_sess, int state, int *cpup)
126 {
127 	int tag = -1;
128 	DEFINE_SBQ_WAIT(wait);
129 	struct sbq_wait_state *ws;
130 	struct sbitmap_queue *sbq;
131 
132 	if (state == TASK_RUNNING)
133 		return tag;
134 
135 	sbq = &se_sess->sess_tag_pool;
136 	ws = &sbq->ws[0];
137 	for (;;) {
138 		sbitmap_prepare_to_wait(sbq, ws, &wait, state);
139 		if (signal_pending_state(state, current))
140 			break;
141 		tag = sbitmap_queue_get(sbq, cpup);
142 		if (tag >= 0)
143 			break;
144 		schedule();
145 	}
146 
147 	sbitmap_finish_wait(sbq, ws, &wait);
148 	return tag;
149 }
150 
151 /*
152  * May be called from software interrupt (timer) context for allocating
153  * iSCSI NopINs.
154  */
155 struct iscsit_cmd *iscsit_allocate_cmd(struct iscsit_conn *conn, int state)
156 {
157 	struct iscsit_cmd *cmd;
158 	struct se_session *se_sess = conn->sess->se_sess;
159 	int size, tag, cpu;
160 
161 	tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
162 	if (tag < 0)
163 		tag = iscsit_wait_for_tag(se_sess, state, &cpu);
164 	if (tag < 0)
165 		return NULL;
166 
167 	size = sizeof(struct iscsit_cmd) + conn->conn_transport->priv_size;
168 	cmd = (struct iscsit_cmd *)(se_sess->sess_cmd_map + (tag * size));
169 	memset(cmd, 0, size);
170 
171 	cmd->se_cmd.map_tag = tag;
172 	cmd->se_cmd.map_cpu = cpu;
173 	cmd->conn = conn;
174 	cmd->data_direction = DMA_NONE;
175 	INIT_LIST_HEAD(&cmd->i_conn_node);
176 	INIT_LIST_HEAD(&cmd->datain_list);
177 	INIT_LIST_HEAD(&cmd->cmd_r2t_list);
178 	spin_lock_init(&cmd->datain_lock);
179 	spin_lock_init(&cmd->dataout_timeout_lock);
180 	spin_lock_init(&cmd->istate_lock);
181 	spin_lock_init(&cmd->error_lock);
182 	spin_lock_init(&cmd->r2t_lock);
183 	timer_setup(&cmd->dataout_timer, iscsit_handle_dataout_timeout, 0);
184 
185 	return cmd;
186 }
187 EXPORT_SYMBOL(iscsit_allocate_cmd);
188 
189 struct iscsi_seq *iscsit_get_seq_holder_for_datain(
190 	struct iscsit_cmd *cmd,
191 	u32 seq_send_order)
192 {
193 	u32 i;
194 
195 	for (i = 0; i < cmd->seq_count; i++)
196 		if (cmd->seq_list[i].seq_send_order == seq_send_order)
197 			return &cmd->seq_list[i];
198 
199 	return NULL;
200 }
201 
202 struct iscsi_seq *iscsit_get_seq_holder_for_r2t(struct iscsit_cmd *cmd)
203 {
204 	u32 i;
205 
206 	if (!cmd->seq_list) {
207 		pr_err("struct iscsit_cmd->seq_list is NULL!\n");
208 		return NULL;
209 	}
210 
211 	for (i = 0; i < cmd->seq_count; i++) {
212 		if (cmd->seq_list[i].type != SEQTYPE_NORMAL)
213 			continue;
214 		if (cmd->seq_list[i].seq_send_order == cmd->seq_send_order) {
215 			cmd->seq_send_order++;
216 			return &cmd->seq_list[i];
217 		}
218 	}
219 
220 	return NULL;
221 }
222 
223 struct iscsi_r2t *iscsit_get_holder_for_r2tsn(
224 	struct iscsit_cmd *cmd,
225 	u32 r2t_sn)
226 {
227 	struct iscsi_r2t *r2t;
228 
229 	spin_lock_bh(&cmd->r2t_lock);
230 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
231 		if (r2t->r2t_sn == r2t_sn) {
232 			spin_unlock_bh(&cmd->r2t_lock);
233 			return r2t;
234 		}
235 	}
236 	spin_unlock_bh(&cmd->r2t_lock);
237 
238 	return NULL;
239 }
240 
241 static inline int iscsit_check_received_cmdsn(struct iscsit_session *sess, u32 cmdsn)
242 {
243 	u32 max_cmdsn;
244 	int ret;
245 
246 	/*
247 	 * This is the proper method of checking received CmdSN against
248 	 * ExpCmdSN and MaxCmdSN values, as well as accounting for out
249 	 * or order CmdSNs due to multiple connection sessions and/or
250 	 * CRC failures.
251 	 */
252 	max_cmdsn = atomic_read(&sess->max_cmd_sn);
253 	if (iscsi_sna_gt(cmdsn, max_cmdsn)) {
254 		pr_err("Received CmdSN: 0x%08x is greater than"
255 		       " MaxCmdSN: 0x%08x, ignoring.\n", cmdsn, max_cmdsn);
256 		ret = CMDSN_MAXCMDSN_OVERRUN;
257 
258 	} else if (cmdsn == sess->exp_cmd_sn) {
259 		sess->exp_cmd_sn++;
260 		pr_debug("Received CmdSN matches ExpCmdSN,"
261 		      " incremented ExpCmdSN to: 0x%08x\n",
262 		      sess->exp_cmd_sn);
263 		ret = CMDSN_NORMAL_OPERATION;
264 
265 	} else if (iscsi_sna_gt(cmdsn, sess->exp_cmd_sn)) {
266 		pr_debug("Received CmdSN: 0x%08x is greater"
267 		      " than ExpCmdSN: 0x%08x, not acknowledging.\n",
268 		      cmdsn, sess->exp_cmd_sn);
269 		ret = CMDSN_HIGHER_THAN_EXP;
270 
271 	} else {
272 		pr_err("Received CmdSN: 0x%08x is less than"
273 		       " ExpCmdSN: 0x%08x, ignoring.\n", cmdsn,
274 		       sess->exp_cmd_sn);
275 		ret = CMDSN_LOWER_THAN_EXP;
276 	}
277 
278 	return ret;
279 }
280 
281 /*
282  * Commands may be received out of order if MC/S is in use.
283  * Ensure they are executed in CmdSN order.
284  */
285 int iscsit_sequence_cmd(struct iscsit_conn *conn, struct iscsit_cmd *cmd,
286 			unsigned char *buf, __be32 cmdsn)
287 {
288 	int ret, cmdsn_ret;
289 	bool reject = false;
290 	u8 reason = ISCSI_REASON_BOOKMARK_NO_RESOURCES;
291 
292 	mutex_lock(&conn->sess->cmdsn_mutex);
293 
294 	cmdsn_ret = iscsit_check_received_cmdsn(conn->sess, be32_to_cpu(cmdsn));
295 	switch (cmdsn_ret) {
296 	case CMDSN_NORMAL_OPERATION:
297 		ret = iscsit_execute_cmd(cmd, 0);
298 		if ((ret >= 0) && !list_empty(&conn->sess->sess_ooo_cmdsn_list))
299 			iscsit_execute_ooo_cmdsns(conn->sess);
300 		else if (ret < 0) {
301 			reject = true;
302 			ret = CMDSN_ERROR_CANNOT_RECOVER;
303 		}
304 		break;
305 	case CMDSN_HIGHER_THAN_EXP:
306 		ret = iscsit_handle_ooo_cmdsn(conn->sess, cmd, be32_to_cpu(cmdsn));
307 		if (ret < 0) {
308 			reject = true;
309 			ret = CMDSN_ERROR_CANNOT_RECOVER;
310 			break;
311 		}
312 		ret = CMDSN_HIGHER_THAN_EXP;
313 		break;
314 	case CMDSN_LOWER_THAN_EXP:
315 	case CMDSN_MAXCMDSN_OVERRUN:
316 	default:
317 		cmd->i_state = ISTATE_REMOVE;
318 		iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
319 		/*
320 		 * Existing callers for iscsit_sequence_cmd() will silently
321 		 * ignore commands with CMDSN_LOWER_THAN_EXP, so force this
322 		 * return for CMDSN_MAXCMDSN_OVERRUN as well..
323 		 */
324 		ret = CMDSN_LOWER_THAN_EXP;
325 		break;
326 	}
327 	mutex_unlock(&conn->sess->cmdsn_mutex);
328 
329 	if (reject)
330 		iscsit_reject_cmd(cmd, reason, buf);
331 
332 	return ret;
333 }
334 EXPORT_SYMBOL(iscsit_sequence_cmd);
335 
336 struct iscsit_cmd *iscsit_find_cmd_from_itt(
337 	struct iscsit_conn *conn,
338 	itt_t init_task_tag)
339 {
340 	struct iscsit_cmd *cmd;
341 
342 	spin_lock_bh(&conn->cmd_lock);
343 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
344 		if (cmd->init_task_tag == init_task_tag) {
345 			spin_unlock_bh(&conn->cmd_lock);
346 			return cmd;
347 		}
348 	}
349 	spin_unlock_bh(&conn->cmd_lock);
350 
351 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu",
352 			init_task_tag, conn->cid);
353 	return NULL;
354 }
355 EXPORT_SYMBOL(iscsit_find_cmd_from_itt);
356 
357 struct iscsit_cmd *iscsit_find_cmd_from_itt_or_dump(
358 	struct iscsit_conn *conn,
359 	itt_t init_task_tag,
360 	u32 length)
361 {
362 	struct iscsit_cmd *cmd;
363 
364 	spin_lock_bh(&conn->cmd_lock);
365 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
366 		if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT)
367 			continue;
368 		if (cmd->init_task_tag == init_task_tag) {
369 			spin_unlock_bh(&conn->cmd_lock);
370 			return cmd;
371 		}
372 	}
373 	spin_unlock_bh(&conn->cmd_lock);
374 
375 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu,"
376 			" dumping payload\n", init_task_tag, conn->cid);
377 	if (length)
378 		iscsit_dump_data_payload(conn, length, 1);
379 
380 	return NULL;
381 }
382 EXPORT_SYMBOL(iscsit_find_cmd_from_itt_or_dump);
383 
384 struct iscsit_cmd *iscsit_find_cmd_from_ttt(
385 	struct iscsit_conn *conn,
386 	u32 targ_xfer_tag)
387 {
388 	struct iscsit_cmd *cmd = NULL;
389 
390 	spin_lock_bh(&conn->cmd_lock);
391 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
392 		if (cmd->targ_xfer_tag == targ_xfer_tag) {
393 			spin_unlock_bh(&conn->cmd_lock);
394 			return cmd;
395 		}
396 	}
397 	spin_unlock_bh(&conn->cmd_lock);
398 
399 	pr_err("Unable to locate TTT: 0x%08x on CID: %hu\n",
400 			targ_xfer_tag, conn->cid);
401 	return NULL;
402 }
403 
404 int iscsit_find_cmd_for_recovery(
405 	struct iscsit_session *sess,
406 	struct iscsit_cmd **cmd_ptr,
407 	struct iscsi_conn_recovery **cr_ptr,
408 	itt_t init_task_tag)
409 {
410 	struct iscsit_cmd *cmd = NULL;
411 	struct iscsi_conn_recovery *cr;
412 	/*
413 	 * Scan through the inactive connection recovery list's command list.
414 	 * If init_task_tag matches the command is still alligent.
415 	 */
416 	spin_lock(&sess->cr_i_lock);
417 	list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
418 		spin_lock(&cr->conn_recovery_cmd_lock);
419 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
420 			if (cmd->init_task_tag == init_task_tag) {
421 				spin_unlock(&cr->conn_recovery_cmd_lock);
422 				spin_unlock(&sess->cr_i_lock);
423 
424 				*cr_ptr = cr;
425 				*cmd_ptr = cmd;
426 				return -2;
427 			}
428 		}
429 		spin_unlock(&cr->conn_recovery_cmd_lock);
430 	}
431 	spin_unlock(&sess->cr_i_lock);
432 	/*
433 	 * Scan through the active connection recovery list's command list.
434 	 * If init_task_tag matches the command is ready to be reassigned.
435 	 */
436 	spin_lock(&sess->cr_a_lock);
437 	list_for_each_entry(cr, &sess->cr_active_list, cr_list) {
438 		spin_lock(&cr->conn_recovery_cmd_lock);
439 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
440 			if (cmd->init_task_tag == init_task_tag) {
441 				spin_unlock(&cr->conn_recovery_cmd_lock);
442 				spin_unlock(&sess->cr_a_lock);
443 
444 				*cr_ptr = cr;
445 				*cmd_ptr = cmd;
446 				return 0;
447 			}
448 		}
449 		spin_unlock(&cr->conn_recovery_cmd_lock);
450 	}
451 	spin_unlock(&sess->cr_a_lock);
452 
453 	return -1;
454 }
455 
456 void iscsit_add_cmd_to_immediate_queue(
457 	struct iscsit_cmd *cmd,
458 	struct iscsit_conn *conn,
459 	u8 state)
460 {
461 	struct iscsi_queue_req *qr;
462 
463 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
464 	if (!qr) {
465 		pr_err("Unable to allocate memory for"
466 				" struct iscsi_queue_req\n");
467 		return;
468 	}
469 	INIT_LIST_HEAD(&qr->qr_list);
470 	qr->cmd = cmd;
471 	qr->state = state;
472 
473 	spin_lock_bh(&conn->immed_queue_lock);
474 	list_add_tail(&qr->qr_list, &conn->immed_queue_list);
475 	atomic_inc(&cmd->immed_queue_count);
476 	atomic_set(&conn->check_immediate_queue, 1);
477 	spin_unlock_bh(&conn->immed_queue_lock);
478 
479 	wake_up(&conn->queues_wq);
480 }
481 EXPORT_SYMBOL(iscsit_add_cmd_to_immediate_queue);
482 
483 struct iscsi_queue_req *iscsit_get_cmd_from_immediate_queue(struct iscsit_conn *conn)
484 {
485 	struct iscsi_queue_req *qr;
486 
487 	spin_lock_bh(&conn->immed_queue_lock);
488 	if (list_empty(&conn->immed_queue_list)) {
489 		spin_unlock_bh(&conn->immed_queue_lock);
490 		return NULL;
491 	}
492 	qr = list_first_entry(&conn->immed_queue_list,
493 			      struct iscsi_queue_req, qr_list);
494 
495 	list_del(&qr->qr_list);
496 	if (qr->cmd)
497 		atomic_dec(&qr->cmd->immed_queue_count);
498 	spin_unlock_bh(&conn->immed_queue_lock);
499 
500 	return qr;
501 }
502 
503 static void iscsit_remove_cmd_from_immediate_queue(
504 	struct iscsit_cmd *cmd,
505 	struct iscsit_conn *conn)
506 {
507 	struct iscsi_queue_req *qr, *qr_tmp;
508 
509 	spin_lock_bh(&conn->immed_queue_lock);
510 	if (!atomic_read(&cmd->immed_queue_count)) {
511 		spin_unlock_bh(&conn->immed_queue_lock);
512 		return;
513 	}
514 
515 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
516 		if (qr->cmd != cmd)
517 			continue;
518 
519 		atomic_dec(&qr->cmd->immed_queue_count);
520 		list_del(&qr->qr_list);
521 		kmem_cache_free(lio_qr_cache, qr);
522 	}
523 	spin_unlock_bh(&conn->immed_queue_lock);
524 
525 	if (atomic_read(&cmd->immed_queue_count)) {
526 		pr_err("ITT: 0x%08x immed_queue_count: %d\n",
527 			cmd->init_task_tag,
528 			atomic_read(&cmd->immed_queue_count));
529 	}
530 }
531 
532 int iscsit_add_cmd_to_response_queue(
533 	struct iscsit_cmd *cmd,
534 	struct iscsit_conn *conn,
535 	u8 state)
536 {
537 	struct iscsi_queue_req *qr;
538 
539 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
540 	if (!qr) {
541 		pr_err("Unable to allocate memory for"
542 			" struct iscsi_queue_req\n");
543 		return -ENOMEM;
544 	}
545 	INIT_LIST_HEAD(&qr->qr_list);
546 	qr->cmd = cmd;
547 	qr->state = state;
548 
549 	spin_lock_bh(&conn->response_queue_lock);
550 	list_add_tail(&qr->qr_list, &conn->response_queue_list);
551 	atomic_inc(&cmd->response_queue_count);
552 	spin_unlock_bh(&conn->response_queue_lock);
553 
554 	wake_up(&conn->queues_wq);
555 	return 0;
556 }
557 
558 struct iscsi_queue_req *iscsit_get_cmd_from_response_queue(struct iscsit_conn *conn)
559 {
560 	struct iscsi_queue_req *qr;
561 
562 	spin_lock_bh(&conn->response_queue_lock);
563 	if (list_empty(&conn->response_queue_list)) {
564 		spin_unlock_bh(&conn->response_queue_lock);
565 		return NULL;
566 	}
567 
568 	qr = list_first_entry(&conn->response_queue_list,
569 			      struct iscsi_queue_req, qr_list);
570 
571 	list_del(&qr->qr_list);
572 	if (qr->cmd)
573 		atomic_dec(&qr->cmd->response_queue_count);
574 	spin_unlock_bh(&conn->response_queue_lock);
575 
576 	return qr;
577 }
578 
579 static void iscsit_remove_cmd_from_response_queue(
580 	struct iscsit_cmd *cmd,
581 	struct iscsit_conn *conn)
582 {
583 	struct iscsi_queue_req *qr, *qr_tmp;
584 
585 	spin_lock_bh(&conn->response_queue_lock);
586 	if (!atomic_read(&cmd->response_queue_count)) {
587 		spin_unlock_bh(&conn->response_queue_lock);
588 		return;
589 	}
590 
591 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
592 				qr_list) {
593 		if (qr->cmd != cmd)
594 			continue;
595 
596 		atomic_dec(&qr->cmd->response_queue_count);
597 		list_del(&qr->qr_list);
598 		kmem_cache_free(lio_qr_cache, qr);
599 	}
600 	spin_unlock_bh(&conn->response_queue_lock);
601 
602 	if (atomic_read(&cmd->response_queue_count)) {
603 		pr_err("ITT: 0x%08x response_queue_count: %d\n",
604 			cmd->init_task_tag,
605 			atomic_read(&cmd->response_queue_count));
606 	}
607 }
608 
609 bool iscsit_conn_all_queues_empty(struct iscsit_conn *conn)
610 {
611 	bool empty;
612 
613 	spin_lock_bh(&conn->immed_queue_lock);
614 	empty = list_empty(&conn->immed_queue_list);
615 	spin_unlock_bh(&conn->immed_queue_lock);
616 
617 	if (!empty)
618 		return empty;
619 
620 	spin_lock_bh(&conn->response_queue_lock);
621 	empty = list_empty(&conn->response_queue_list);
622 	spin_unlock_bh(&conn->response_queue_lock);
623 
624 	return empty;
625 }
626 
627 void iscsit_free_queue_reqs_for_conn(struct iscsit_conn *conn)
628 {
629 	struct iscsi_queue_req *qr, *qr_tmp;
630 
631 	spin_lock_bh(&conn->immed_queue_lock);
632 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
633 		list_del(&qr->qr_list);
634 		if (qr->cmd)
635 			atomic_dec(&qr->cmd->immed_queue_count);
636 
637 		kmem_cache_free(lio_qr_cache, qr);
638 	}
639 	spin_unlock_bh(&conn->immed_queue_lock);
640 
641 	spin_lock_bh(&conn->response_queue_lock);
642 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
643 			qr_list) {
644 		list_del(&qr->qr_list);
645 		if (qr->cmd)
646 			atomic_dec(&qr->cmd->response_queue_count);
647 
648 		kmem_cache_free(lio_qr_cache, qr);
649 	}
650 	spin_unlock_bh(&conn->response_queue_lock);
651 }
652 
653 void iscsit_release_cmd(struct iscsit_cmd *cmd)
654 {
655 	struct iscsit_session *sess;
656 	struct se_cmd *se_cmd = &cmd->se_cmd;
657 
658 	WARN_ON(!list_empty(&cmd->i_conn_node));
659 
660 	if (cmd->conn)
661 		sess = cmd->conn->sess;
662 	else
663 		sess = cmd->sess;
664 
665 	BUG_ON(!sess || !sess->se_sess);
666 
667 	kfree(cmd->buf_ptr);
668 	kfree(cmd->pdu_list);
669 	kfree(cmd->seq_list);
670 	kfree(cmd->tmr_req);
671 	kfree(cmd->overflow_buf);
672 	kfree(cmd->iov_data);
673 	kfree(cmd->text_in_ptr);
674 
675 	target_free_tag(sess->se_sess, se_cmd);
676 }
677 EXPORT_SYMBOL(iscsit_release_cmd);
678 
679 void __iscsit_free_cmd(struct iscsit_cmd *cmd, bool check_queues)
680 {
681 	struct iscsit_conn *conn = cmd->conn;
682 
683 	WARN_ON(!list_empty(&cmd->i_conn_node));
684 
685 	if (cmd->data_direction == DMA_TO_DEVICE) {
686 		iscsit_stop_dataout_timer(cmd);
687 		iscsit_free_r2ts_from_list(cmd);
688 	}
689 	if (cmd->data_direction == DMA_FROM_DEVICE)
690 		iscsit_free_all_datain_reqs(cmd);
691 
692 	if (conn && check_queues) {
693 		iscsit_remove_cmd_from_immediate_queue(cmd, conn);
694 		iscsit_remove_cmd_from_response_queue(cmd, conn);
695 	}
696 
697 	if (conn && conn->conn_transport->iscsit_unmap_cmd)
698 		conn->conn_transport->iscsit_unmap_cmd(conn, cmd);
699 }
700 
701 void iscsit_free_cmd(struct iscsit_cmd *cmd, bool shutdown)
702 {
703 	struct se_cmd *se_cmd = cmd->se_cmd.se_tfo ? &cmd->se_cmd : NULL;
704 	int rc;
705 
706 	WARN_ON(!list_empty(&cmd->i_conn_node));
707 
708 	__iscsit_free_cmd(cmd, shutdown);
709 	if (se_cmd) {
710 		rc = transport_generic_free_cmd(se_cmd, shutdown);
711 		if (!rc && shutdown && se_cmd->se_sess) {
712 			__iscsit_free_cmd(cmd, shutdown);
713 			target_put_sess_cmd(se_cmd);
714 		}
715 	} else {
716 		iscsit_release_cmd(cmd);
717 	}
718 }
719 EXPORT_SYMBOL(iscsit_free_cmd);
720 
721 bool iscsit_check_session_usage_count(struct iscsit_session *sess,
722 				      bool can_sleep)
723 {
724 	spin_lock_bh(&sess->session_usage_lock);
725 	if (sess->session_usage_count != 0) {
726 		sess->session_waiting_on_uc = 1;
727 		spin_unlock_bh(&sess->session_usage_lock);
728 		if (!can_sleep)
729 			return true;
730 
731 		wait_for_completion(&sess->session_waiting_on_uc_comp);
732 		return false;
733 	}
734 	spin_unlock_bh(&sess->session_usage_lock);
735 
736 	return false;
737 }
738 
739 void iscsit_dec_session_usage_count(struct iscsit_session *sess)
740 {
741 	spin_lock_bh(&sess->session_usage_lock);
742 	sess->session_usage_count--;
743 
744 	if (!sess->session_usage_count && sess->session_waiting_on_uc) {
745 		spin_unlock_bh(&sess->session_usage_lock);
746 		complete(&sess->session_waiting_on_uc_comp);
747 		return;
748 	}
749 
750 	spin_unlock_bh(&sess->session_usage_lock);
751 }
752 
753 void iscsit_inc_session_usage_count(struct iscsit_session *sess)
754 {
755 	spin_lock_bh(&sess->session_usage_lock);
756 	sess->session_usage_count++;
757 	spin_unlock_bh(&sess->session_usage_lock);
758 }
759 
760 struct iscsit_conn *iscsit_get_conn_from_cid(struct iscsit_session *sess, u16 cid)
761 {
762 	struct iscsit_conn *conn;
763 
764 	spin_lock_bh(&sess->conn_lock);
765 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
766 		if ((conn->cid == cid) &&
767 		    (conn->conn_state == TARG_CONN_STATE_LOGGED_IN)) {
768 			iscsit_inc_conn_usage_count(conn);
769 			spin_unlock_bh(&sess->conn_lock);
770 			return conn;
771 		}
772 	}
773 	spin_unlock_bh(&sess->conn_lock);
774 
775 	return NULL;
776 }
777 
778 struct iscsit_conn *iscsit_get_conn_from_cid_rcfr(struct iscsit_session *sess, u16 cid)
779 {
780 	struct iscsit_conn *conn;
781 
782 	spin_lock_bh(&sess->conn_lock);
783 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
784 		if (conn->cid == cid) {
785 			iscsit_inc_conn_usage_count(conn);
786 			spin_lock(&conn->state_lock);
787 			atomic_set(&conn->connection_wait_rcfr, 1);
788 			spin_unlock(&conn->state_lock);
789 			spin_unlock_bh(&sess->conn_lock);
790 			return conn;
791 		}
792 	}
793 	spin_unlock_bh(&sess->conn_lock);
794 
795 	return NULL;
796 }
797 
798 void iscsit_check_conn_usage_count(struct iscsit_conn *conn)
799 {
800 	spin_lock_bh(&conn->conn_usage_lock);
801 	if (conn->conn_usage_count != 0) {
802 		conn->conn_waiting_on_uc = 1;
803 		spin_unlock_bh(&conn->conn_usage_lock);
804 
805 		wait_for_completion(&conn->conn_waiting_on_uc_comp);
806 		return;
807 	}
808 	spin_unlock_bh(&conn->conn_usage_lock);
809 }
810 
811 void iscsit_dec_conn_usage_count(struct iscsit_conn *conn)
812 {
813 	spin_lock_bh(&conn->conn_usage_lock);
814 	conn->conn_usage_count--;
815 
816 	if (!conn->conn_usage_count && conn->conn_waiting_on_uc) {
817 		spin_unlock_bh(&conn->conn_usage_lock);
818 		complete(&conn->conn_waiting_on_uc_comp);
819 		return;
820 	}
821 
822 	spin_unlock_bh(&conn->conn_usage_lock);
823 }
824 
825 void iscsit_inc_conn_usage_count(struct iscsit_conn *conn)
826 {
827 	spin_lock_bh(&conn->conn_usage_lock);
828 	conn->conn_usage_count++;
829 	spin_unlock_bh(&conn->conn_usage_lock);
830 }
831 
832 static int iscsit_add_nopin(struct iscsit_conn *conn, int want_response)
833 {
834 	u8 state;
835 	struct iscsit_cmd *cmd;
836 
837 	cmd = iscsit_allocate_cmd(conn, TASK_RUNNING);
838 	if (!cmd)
839 		return -1;
840 
841 	cmd->iscsi_opcode = ISCSI_OP_NOOP_IN;
842 	state = (want_response) ? ISTATE_SEND_NOPIN_WANT_RESPONSE :
843 				ISTATE_SEND_NOPIN_NO_RESPONSE;
844 	cmd->init_task_tag = RESERVED_ITT;
845 	cmd->targ_xfer_tag = (want_response) ?
846 			     session_get_next_ttt(conn->sess) : 0xFFFFFFFF;
847 	spin_lock_bh(&conn->cmd_lock);
848 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
849 	spin_unlock_bh(&conn->cmd_lock);
850 
851 	if (want_response)
852 		iscsit_start_nopin_response_timer(conn);
853 	iscsit_add_cmd_to_immediate_queue(cmd, conn, state);
854 
855 	return 0;
856 }
857 
858 void iscsit_handle_nopin_response_timeout(struct timer_list *t)
859 {
860 	struct iscsit_conn *conn = timer_container_of(conn, t,
861 						      nopin_response_timer);
862 	struct iscsit_session *sess = conn->sess;
863 
864 	iscsit_inc_conn_usage_count(conn);
865 
866 	spin_lock_bh(&conn->nopin_timer_lock);
867 	if (conn->nopin_response_timer_flags & ISCSI_TF_STOP) {
868 		spin_unlock_bh(&conn->nopin_timer_lock);
869 		iscsit_dec_conn_usage_count(conn);
870 		return;
871 	}
872 
873 	pr_err("Did not receive response to NOPIN on CID: %hu, failing"
874 		" connection for I_T Nexus %s,i,0x%6phN,%s,t,0x%02x\n",
875 		conn->cid, sess->sess_ops->InitiatorName, sess->isid,
876 		sess->tpg->tpg_tiqn->tiqn, (u32)sess->tpg->tpgt);
877 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
878 	spin_unlock_bh(&conn->nopin_timer_lock);
879 
880 	iscsit_fill_cxn_timeout_err_stats(sess);
881 	iscsit_cause_connection_reinstatement(conn, 0);
882 	iscsit_dec_conn_usage_count(conn);
883 }
884 
885 void iscsit_mod_nopin_response_timer(struct iscsit_conn *conn)
886 {
887 	struct iscsit_session *sess = conn->sess;
888 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
889 
890 	spin_lock_bh(&conn->nopin_timer_lock);
891 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
892 		spin_unlock_bh(&conn->nopin_timer_lock);
893 		return;
894 	}
895 
896 	mod_timer(&conn->nopin_response_timer,
897 		(get_jiffies_64() + na->nopin_response_timeout * HZ));
898 	spin_unlock_bh(&conn->nopin_timer_lock);
899 }
900 
901 void iscsit_start_nopin_response_timer(struct iscsit_conn *conn)
902 {
903 	struct iscsit_session *sess = conn->sess;
904 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
905 
906 	spin_lock_bh(&conn->nopin_timer_lock);
907 	if (conn->nopin_response_timer_flags & ISCSI_TF_RUNNING) {
908 		spin_unlock_bh(&conn->nopin_timer_lock);
909 		return;
910 	}
911 
912 	conn->nopin_response_timer_flags &= ~ISCSI_TF_STOP;
913 	conn->nopin_response_timer_flags |= ISCSI_TF_RUNNING;
914 	mod_timer(&conn->nopin_response_timer,
915 		  jiffies + na->nopin_response_timeout * HZ);
916 
917 	pr_debug("Started NOPIN Response Timer on CID: %d to %u"
918 		" seconds\n", conn->cid, na->nopin_response_timeout);
919 	spin_unlock_bh(&conn->nopin_timer_lock);
920 }
921 
922 void iscsit_stop_nopin_response_timer(struct iscsit_conn *conn)
923 {
924 	spin_lock_bh(&conn->nopin_timer_lock);
925 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
926 		spin_unlock_bh(&conn->nopin_timer_lock);
927 		return;
928 	}
929 	conn->nopin_response_timer_flags |= ISCSI_TF_STOP;
930 	spin_unlock_bh(&conn->nopin_timer_lock);
931 
932 	timer_delete_sync(&conn->nopin_response_timer);
933 
934 	spin_lock_bh(&conn->nopin_timer_lock);
935 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
936 	spin_unlock_bh(&conn->nopin_timer_lock);
937 }
938 
939 void iscsit_handle_nopin_timeout(struct timer_list *t)
940 {
941 	struct iscsit_conn *conn = timer_container_of(conn, t, nopin_timer);
942 
943 	iscsit_inc_conn_usage_count(conn);
944 
945 	spin_lock_bh(&conn->nopin_timer_lock);
946 	if (conn->nopin_timer_flags & ISCSI_TF_STOP) {
947 		spin_unlock_bh(&conn->nopin_timer_lock);
948 		iscsit_dec_conn_usage_count(conn);
949 		return;
950 	}
951 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
952 	spin_unlock_bh(&conn->nopin_timer_lock);
953 
954 	iscsit_add_nopin(conn, 1);
955 	iscsit_dec_conn_usage_count(conn);
956 }
957 
958 void __iscsit_start_nopin_timer(struct iscsit_conn *conn)
959 {
960 	struct iscsit_session *sess = conn->sess;
961 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
962 
963 	lockdep_assert_held(&conn->nopin_timer_lock);
964 
965 	/*
966 	* NOPIN timeout is disabled.
967 	 */
968 	if (!na->nopin_timeout)
969 		return;
970 
971 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING)
972 		return;
973 
974 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
975 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
976 	mod_timer(&conn->nopin_timer, jiffies + na->nopin_timeout * HZ);
977 
978 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
979 		" interval\n", conn->cid, na->nopin_timeout);
980 }
981 
982 void iscsit_start_nopin_timer(struct iscsit_conn *conn)
983 {
984 	spin_lock_bh(&conn->nopin_timer_lock);
985 	__iscsit_start_nopin_timer(conn);
986 	spin_unlock_bh(&conn->nopin_timer_lock);
987 }
988 
989 void iscsit_stop_nopin_timer(struct iscsit_conn *conn)
990 {
991 	spin_lock_bh(&conn->nopin_timer_lock);
992 	if (!(conn->nopin_timer_flags & ISCSI_TF_RUNNING)) {
993 		spin_unlock_bh(&conn->nopin_timer_lock);
994 		return;
995 	}
996 	conn->nopin_timer_flags |= ISCSI_TF_STOP;
997 	spin_unlock_bh(&conn->nopin_timer_lock);
998 
999 	timer_delete_sync(&conn->nopin_timer);
1000 
1001 	spin_lock_bh(&conn->nopin_timer_lock);
1002 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1003 	spin_unlock_bh(&conn->nopin_timer_lock);
1004 }
1005 
1006 void iscsit_login_timeout(struct timer_list *t)
1007 {
1008 	struct iscsit_conn *conn = timer_container_of(conn, t, login_timer);
1009 	struct iscsi_login *login = conn->login;
1010 
1011 	pr_debug("Entering iscsi_target_login_timeout >>>>>>>>>>>>>>>>>>>\n");
1012 
1013 	spin_lock_bh(&conn->login_timer_lock);
1014 	login->login_failed = 1;
1015 
1016 	if (conn->login_kworker) {
1017 		pr_debug("Sending SIGINT to conn->login_kworker %s/%d\n",
1018 			 conn->login_kworker->comm, conn->login_kworker->pid);
1019 		send_sig(SIGINT, conn->login_kworker, 1);
1020 	} else {
1021 		schedule_delayed_work(&conn->login_work, 0);
1022 	}
1023 	spin_unlock_bh(&conn->login_timer_lock);
1024 }
1025 
1026 void iscsit_start_login_timer(struct iscsit_conn *conn, struct task_struct *kthr)
1027 {
1028 	pr_debug("Login timer started\n");
1029 
1030 	conn->login_kworker = kthr;
1031 	mod_timer(&conn->login_timer, jiffies + TA_LOGIN_TIMEOUT * HZ);
1032 }
1033 
1034 int iscsit_set_login_timer_kworker(struct iscsit_conn *conn, struct task_struct *kthr)
1035 {
1036 	struct iscsi_login *login = conn->login;
1037 	int ret = 0;
1038 
1039 	spin_lock_bh(&conn->login_timer_lock);
1040 	if (login->login_failed) {
1041 		/* The timer has already expired */
1042 		ret = -1;
1043 	} else {
1044 		conn->login_kworker = kthr;
1045 	}
1046 	spin_unlock_bh(&conn->login_timer_lock);
1047 
1048 	return ret;
1049 }
1050 
1051 void iscsit_stop_login_timer(struct iscsit_conn *conn)
1052 {
1053 	pr_debug("Login timer stopped\n");
1054 	timer_delete_sync(&conn->login_timer);
1055 }
1056 
1057 int iscsit_send_tx_data(
1058 	struct iscsit_cmd *cmd,
1059 	struct iscsit_conn *conn,
1060 	int use_misc)
1061 {
1062 	int tx_sent, tx_size;
1063 	u32 iov_count;
1064 	struct kvec *iov;
1065 
1066 send_data:
1067 	tx_size = cmd->tx_size;
1068 
1069 	if (!use_misc) {
1070 		iov = &cmd->iov_data[0];
1071 		iov_count = cmd->iov_data_count;
1072 	} else {
1073 		iov = &cmd->iov_misc[0];
1074 		iov_count = cmd->iov_misc_count;
1075 	}
1076 
1077 	tx_sent = tx_data(conn, &iov[0], iov_count, tx_size);
1078 	if (tx_size != tx_sent) {
1079 		if (tx_sent == -EAGAIN) {
1080 			pr_err("tx_data() returned -EAGAIN\n");
1081 			goto send_data;
1082 		} else
1083 			return -1;
1084 	}
1085 	cmd->tx_size = 0;
1086 
1087 	return 0;
1088 }
1089 
1090 int iscsit_fe_sendpage_sg(
1091 	struct iscsit_cmd *cmd,
1092 	struct iscsit_conn *conn)
1093 {
1094 	struct scatterlist *sg = cmd->first_data_sg;
1095 	struct bio_vec bvec;
1096 	struct msghdr msghdr = { .msg_flags = MSG_SPLICE_PAGES,	};
1097 	struct kvec iov;
1098 	u32 tx_hdr_size, data_len;
1099 	u32 offset = cmd->first_data_sg_off;
1100 	int tx_sent, iov_off;
1101 
1102 send_hdr:
1103 	tx_hdr_size = ISCSI_HDR_LEN;
1104 	if (conn->conn_ops->HeaderDigest)
1105 		tx_hdr_size += ISCSI_CRC_LEN;
1106 
1107 	iov.iov_base = cmd->pdu;
1108 	iov.iov_len = tx_hdr_size;
1109 
1110 	tx_sent = tx_data(conn, &iov, 1, tx_hdr_size);
1111 	if (tx_hdr_size != tx_sent) {
1112 		if (tx_sent == -EAGAIN) {
1113 			pr_err("tx_data() returned -EAGAIN\n");
1114 			goto send_hdr;
1115 		}
1116 		return -1;
1117 	}
1118 
1119 	data_len = cmd->tx_size - tx_hdr_size - cmd->padding;
1120 	/*
1121 	 * Set iov_off used by padding and data digest tx_data() calls below
1122 	 * in order to determine proper offset into cmd->iov_data[]
1123 	 */
1124 	if (conn->conn_ops->DataDigest) {
1125 		data_len -= ISCSI_CRC_LEN;
1126 		if (cmd->padding)
1127 			iov_off = (cmd->iov_data_count - 2);
1128 		else
1129 			iov_off = (cmd->iov_data_count - 1);
1130 	} else {
1131 		iov_off = (cmd->iov_data_count - 1);
1132 	}
1133 	/*
1134 	 * Perform sendpage() for each page in the scatterlist
1135 	 */
1136 	while (data_len) {
1137 		u32 space = (sg->length - offset);
1138 		u32 sub_len = min_t(u32, data_len, space);
1139 send_pg:
1140 		bvec_set_page(&bvec, sg_page(sg), sub_len, sg->offset + offset);
1141 		iov_iter_bvec(&msghdr.msg_iter, ITER_SOURCE, &bvec, 1, sub_len);
1142 
1143 		tx_sent = conn->sock->ops->sendmsg(conn->sock, &msghdr,
1144 						   sub_len);
1145 		if (tx_sent != sub_len) {
1146 			if (tx_sent == -EAGAIN) {
1147 				pr_err("sendmsg/splice returned -EAGAIN\n");
1148 				goto send_pg;
1149 			}
1150 
1151 			pr_err("sendmsg/splice failure: %d\n", tx_sent);
1152 			return -1;
1153 		}
1154 
1155 		data_len -= sub_len;
1156 		offset = 0;
1157 		sg = sg_next(sg);
1158 	}
1159 
1160 send_padding:
1161 	if (cmd->padding) {
1162 		struct kvec *iov_p = &cmd->iov_data[iov_off++];
1163 
1164 		tx_sent = tx_data(conn, iov_p, 1, cmd->padding);
1165 		if (cmd->padding != tx_sent) {
1166 			if (tx_sent == -EAGAIN) {
1167 				pr_err("tx_data() returned -EAGAIN\n");
1168 				goto send_padding;
1169 			}
1170 			return -1;
1171 		}
1172 	}
1173 
1174 send_datacrc:
1175 	if (conn->conn_ops->DataDigest) {
1176 		struct kvec *iov_d = &cmd->iov_data[iov_off];
1177 
1178 		tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN);
1179 		if (ISCSI_CRC_LEN != tx_sent) {
1180 			if (tx_sent == -EAGAIN) {
1181 				pr_err("tx_data() returned -EAGAIN\n");
1182 				goto send_datacrc;
1183 			}
1184 			return -1;
1185 		}
1186 	}
1187 
1188 	return 0;
1189 }
1190 
1191 /*
1192  *      This function is used for mainly sending a ISCSI_TARG_LOGIN_RSP PDU
1193  *      back to the Initiator when an expection condition occurs with the
1194  *      errors set in status_class and status_detail.
1195  *
1196  *      Parameters:     iSCSI Connection, Status Class, Status Detail.
1197  *      Returns:        0 on success, -1 on error.
1198  */
1199 int iscsit_tx_login_rsp(struct iscsit_conn *conn, u8 status_class, u8 status_detail)
1200 {
1201 	struct iscsi_login_rsp *hdr;
1202 	struct iscsi_login *login = conn->conn_login;
1203 
1204 	login->login_failed = 1;
1205 	iscsit_collect_login_stats(conn, status_class, status_detail);
1206 
1207 	memset(&login->rsp[0], 0, ISCSI_HDR_LEN);
1208 
1209 	hdr	= (struct iscsi_login_rsp *)&login->rsp[0];
1210 	hdr->opcode		= ISCSI_OP_LOGIN_RSP;
1211 	hdr->status_class	= status_class;
1212 	hdr->status_detail	= status_detail;
1213 	hdr->itt		= conn->login_itt;
1214 
1215 	return conn->conn_transport->iscsit_put_login_tx(conn, login, 0);
1216 }
1217 
1218 int rx_data(
1219 	struct iscsit_conn *conn,
1220 	struct kvec *iov,
1221 	int iov_count,
1222 	int data)
1223 {
1224 	int rx_loop = 0, total_rx = 0;
1225 	struct msghdr msg;
1226 
1227 	if (!conn || !conn->sock || !conn->conn_ops)
1228 		return -1;
1229 
1230 	memset(&msg, 0, sizeof(struct msghdr));
1231 	iov_iter_kvec(&msg.msg_iter, ITER_DEST, iov, iov_count, data);
1232 
1233 	while (msg_data_left(&msg)) {
1234 		rx_loop = sock_recvmsg(conn->sock, &msg, MSG_WAITALL);
1235 		if (rx_loop <= 0) {
1236 			pr_debug("rx_loop: %d total_rx: %d\n",
1237 				rx_loop, total_rx);
1238 			return rx_loop;
1239 		}
1240 		total_rx += rx_loop;
1241 		pr_debug("rx_loop: %d, total_rx: %d, data: %d\n",
1242 				rx_loop, total_rx, data);
1243 	}
1244 
1245 	return total_rx;
1246 }
1247 
1248 int tx_data(
1249 	struct iscsit_conn *conn,
1250 	struct kvec *iov,
1251 	int iov_count,
1252 	int data)
1253 {
1254 	struct msghdr msg;
1255 	int total_tx = 0;
1256 
1257 	if (!conn || !conn->sock || !conn->conn_ops)
1258 		return -1;
1259 
1260 	if (data <= 0) {
1261 		pr_err("Data length is: %d\n", data);
1262 		return -1;
1263 	}
1264 
1265 	memset(&msg, 0, sizeof(struct msghdr));
1266 
1267 	iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iov, iov_count, data);
1268 
1269 	while (msg_data_left(&msg)) {
1270 		int tx_loop = sock_sendmsg(conn->sock, &msg);
1271 		if (tx_loop <= 0) {
1272 			pr_debug("tx_loop: %d total_tx %d\n",
1273 				tx_loop, total_tx);
1274 			return tx_loop;
1275 		}
1276 		total_tx += tx_loop;
1277 		pr_debug("tx_loop: %d, total_tx: %d, data: %d\n",
1278 					tx_loop, total_tx, data);
1279 	}
1280 
1281 	return total_tx;
1282 }
1283 
1284 void iscsit_collect_login_stats(
1285 	struct iscsit_conn *conn,
1286 	u8 status_class,
1287 	u8 status_detail)
1288 {
1289 	struct iscsi_param *intrname = NULL;
1290 	struct iscsi_tiqn *tiqn;
1291 	struct iscsi_login_stats *ls;
1292 
1293 	tiqn = iscsit_snmp_get_tiqn(conn);
1294 	if (!tiqn)
1295 		return;
1296 
1297 	ls = &tiqn->login_stats;
1298 
1299 	spin_lock(&ls->lock);
1300 	if (status_class == ISCSI_STATUS_CLS_SUCCESS)
1301 		ls->accepts++;
1302 	else if (status_class == ISCSI_STATUS_CLS_REDIRECT) {
1303 		ls->redirects++;
1304 		ls->last_fail_type = ISCSI_LOGIN_FAIL_REDIRECT;
1305 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1306 		 (status_detail == ISCSI_LOGIN_STATUS_AUTH_FAILED)) {
1307 		ls->authenticate_fails++;
1308 		ls->last_fail_type =  ISCSI_LOGIN_FAIL_AUTHENTICATE;
1309 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1310 		 (status_detail == ISCSI_LOGIN_STATUS_TGT_FORBIDDEN)) {
1311 		ls->authorize_fails++;
1312 		ls->last_fail_type = ISCSI_LOGIN_FAIL_AUTHORIZE;
1313 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR) &&
1314 		 (status_detail == ISCSI_LOGIN_STATUS_INIT_ERR)) {
1315 		ls->negotiate_fails++;
1316 		ls->last_fail_type = ISCSI_LOGIN_FAIL_NEGOTIATE;
1317 	} else {
1318 		ls->other_fails++;
1319 		ls->last_fail_type = ISCSI_LOGIN_FAIL_OTHER;
1320 	}
1321 
1322 	/* Save initiator name, ip address and time, if it is a failed login */
1323 	if (status_class != ISCSI_STATUS_CLS_SUCCESS) {
1324 		if (conn->param_list)
1325 			intrname = iscsi_find_param_from_key(INITIATORNAME,
1326 							     conn->param_list);
1327 		strscpy(ls->last_intr_fail_name,
1328 		       (intrname ? intrname->value : "Unknown"),
1329 		       sizeof(ls->last_intr_fail_name));
1330 
1331 		ls->last_intr_fail_ip_family = conn->login_family;
1332 
1333 		ls->last_intr_fail_sockaddr = conn->login_sockaddr;
1334 		ls->last_fail_time = get_jiffies_64();
1335 	}
1336 
1337 	spin_unlock(&ls->lock);
1338 }
1339 
1340 struct iscsi_tiqn *iscsit_snmp_get_tiqn(struct iscsit_conn *conn)
1341 {
1342 	struct iscsi_portal_group *tpg;
1343 
1344 	if (!conn)
1345 		return NULL;
1346 
1347 	tpg = conn->tpg;
1348 	if (!tpg)
1349 		return NULL;
1350 
1351 	if (!tpg->tpg_tiqn)
1352 		return NULL;
1353 
1354 	return tpg->tpg_tiqn;
1355 }
1356 
1357 void iscsit_fill_cxn_timeout_err_stats(struct iscsit_session *sess)
1358 {
1359 	struct iscsi_portal_group *tpg = sess->tpg;
1360 	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
1361 
1362 	if (!tiqn)
1363 		return;
1364 
1365 	spin_lock_bh(&tiqn->sess_err_stats.lock);
1366 	strscpy(tiqn->sess_err_stats.last_sess_fail_rem_name,
1367 			sess->sess_ops->InitiatorName,
1368 			sizeof(tiqn->sess_err_stats.last_sess_fail_rem_name));
1369 	tiqn->sess_err_stats.last_sess_failure_type =
1370 			ISCSI_SESS_ERR_CXN_TIMEOUT;
1371 	tiqn->sess_err_stats.cxn_timeout_errors++;
1372 	atomic_long_inc(&sess->conn_timeout_errors);
1373 	spin_unlock_bh(&tiqn->sess_err_stats.lock);
1374 }
1375