1 /*******************************************************************************
2  * This file contains the iSCSI Target specific utility functions.
3  *
4  * (c) Copyright 2007-2013 Datera, Inc.
5  *
6  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  ******************************************************************************/
18 
19 #include <linux/list.h>
20 #include <linux/percpu_ida.h>
21 #include <scsi/scsi_tcq.h>
22 #include <scsi/iscsi_proto.h>
23 #include <target/target_core_base.h>
24 #include <target/target_core_fabric.h>
25 #include <target/iscsi/iscsi_transport.h>
26 
27 #include <target/iscsi/iscsi_target_core.h>
28 #include "iscsi_target_parameters.h"
29 #include "iscsi_target_seq_pdu_list.h"
30 #include "iscsi_target_datain_values.h"
31 #include "iscsi_target_erl0.h"
32 #include "iscsi_target_erl1.h"
33 #include "iscsi_target_erl2.h"
34 #include "iscsi_target_tpg.h"
35 #include "iscsi_target_util.h"
36 #include "iscsi_target.h"
37 
38 #define PRINT_BUFF(buff, len)					\
39 {								\
40 	int zzz;						\
41 								\
42 	pr_debug("%d:\n", __LINE__);				\
43 	for (zzz = 0; zzz < len; zzz++) {			\
44 		if (zzz % 16 == 0) {				\
45 			if (zzz)				\
46 				pr_debug("\n");			\
47 			pr_debug("%4i: ", zzz);			\
48 		}						\
49 		pr_debug("%02x ", (unsigned char) (buff)[zzz]);	\
50 	}							\
51 	if ((len + 1) % 16)					\
52 		pr_debug("\n");					\
53 }
54 
55 extern struct list_head g_tiqn_list;
56 extern spinlock_t tiqn_lock;
57 
58 /*
59  *	Called with cmd->r2t_lock held.
60  */
61 int iscsit_add_r2t_to_list(
62 	struct iscsi_cmd *cmd,
63 	u32 offset,
64 	u32 xfer_len,
65 	int recovery,
66 	u32 r2t_sn)
67 {
68 	struct iscsi_r2t *r2t;
69 
70 	r2t = kmem_cache_zalloc(lio_r2t_cache, GFP_ATOMIC);
71 	if (!r2t) {
72 		pr_err("Unable to allocate memory for struct iscsi_r2t.\n");
73 		return -1;
74 	}
75 	INIT_LIST_HEAD(&r2t->r2t_list);
76 
77 	r2t->recovery_r2t = recovery;
78 	r2t->r2t_sn = (!r2t_sn) ? cmd->r2t_sn++ : r2t_sn;
79 	r2t->offset = offset;
80 	r2t->xfer_len = xfer_len;
81 	list_add_tail(&r2t->r2t_list, &cmd->cmd_r2t_list);
82 	spin_unlock_bh(&cmd->r2t_lock);
83 
84 	iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, ISTATE_SEND_R2T);
85 
86 	spin_lock_bh(&cmd->r2t_lock);
87 	return 0;
88 }
89 
90 struct iscsi_r2t *iscsit_get_r2t_for_eos(
91 	struct iscsi_cmd *cmd,
92 	u32 offset,
93 	u32 length)
94 {
95 	struct iscsi_r2t *r2t;
96 
97 	spin_lock_bh(&cmd->r2t_lock);
98 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
99 		if ((r2t->offset <= offset) &&
100 		    (r2t->offset + r2t->xfer_len) >= (offset + length)) {
101 			spin_unlock_bh(&cmd->r2t_lock);
102 			return r2t;
103 		}
104 	}
105 	spin_unlock_bh(&cmd->r2t_lock);
106 
107 	pr_err("Unable to locate R2T for Offset: %u, Length:"
108 			" %u\n", offset, length);
109 	return NULL;
110 }
111 
112 struct iscsi_r2t *iscsit_get_r2t_from_list(struct iscsi_cmd *cmd)
113 {
114 	struct iscsi_r2t *r2t;
115 
116 	spin_lock_bh(&cmd->r2t_lock);
117 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
118 		if (!r2t->sent_r2t) {
119 			spin_unlock_bh(&cmd->r2t_lock);
120 			return r2t;
121 		}
122 	}
123 	spin_unlock_bh(&cmd->r2t_lock);
124 
125 	pr_err("Unable to locate next R2T to send for ITT:"
126 			" 0x%08x.\n", cmd->init_task_tag);
127 	return NULL;
128 }
129 
130 /*
131  *	Called with cmd->r2t_lock held.
132  */
133 void iscsit_free_r2t(struct iscsi_r2t *r2t, struct iscsi_cmd *cmd)
134 {
135 	list_del(&r2t->r2t_list);
136 	kmem_cache_free(lio_r2t_cache, r2t);
137 }
138 
139 void iscsit_free_r2ts_from_list(struct iscsi_cmd *cmd)
140 {
141 	struct iscsi_r2t *r2t, *r2t_tmp;
142 
143 	spin_lock_bh(&cmd->r2t_lock);
144 	list_for_each_entry_safe(r2t, r2t_tmp, &cmd->cmd_r2t_list, r2t_list)
145 		iscsit_free_r2t(r2t, cmd);
146 	spin_unlock_bh(&cmd->r2t_lock);
147 }
148 
149 /*
150  * May be called from software interrupt (timer) context for allocating
151  * iSCSI NopINs.
152  */
153 struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn *conn, int state)
154 {
155 	struct iscsi_cmd *cmd;
156 	struct se_session *se_sess = conn->sess->se_sess;
157 	int size, tag;
158 
159 	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, state);
160 	if (tag < 0)
161 		return NULL;
162 
163 	size = sizeof(struct iscsi_cmd) + conn->conn_transport->priv_size;
164 	cmd = (struct iscsi_cmd *)(se_sess->sess_cmd_map + (tag * size));
165 	memset(cmd, 0, size);
166 
167 	cmd->se_cmd.map_tag = tag;
168 	cmd->conn = conn;
169 	INIT_LIST_HEAD(&cmd->i_conn_node);
170 	INIT_LIST_HEAD(&cmd->datain_list);
171 	INIT_LIST_HEAD(&cmd->cmd_r2t_list);
172 	spin_lock_init(&cmd->datain_lock);
173 	spin_lock_init(&cmd->dataout_timeout_lock);
174 	spin_lock_init(&cmd->istate_lock);
175 	spin_lock_init(&cmd->error_lock);
176 	spin_lock_init(&cmd->r2t_lock);
177 
178 	return cmd;
179 }
180 EXPORT_SYMBOL(iscsit_allocate_cmd);
181 
182 struct iscsi_seq *iscsit_get_seq_holder_for_datain(
183 	struct iscsi_cmd *cmd,
184 	u32 seq_send_order)
185 {
186 	u32 i;
187 
188 	for (i = 0; i < cmd->seq_count; i++)
189 		if (cmd->seq_list[i].seq_send_order == seq_send_order)
190 			return &cmd->seq_list[i];
191 
192 	return NULL;
193 }
194 
195 struct iscsi_seq *iscsit_get_seq_holder_for_r2t(struct iscsi_cmd *cmd)
196 {
197 	u32 i;
198 
199 	if (!cmd->seq_list) {
200 		pr_err("struct iscsi_cmd->seq_list is NULL!\n");
201 		return NULL;
202 	}
203 
204 	for (i = 0; i < cmd->seq_count; i++) {
205 		if (cmd->seq_list[i].type != SEQTYPE_NORMAL)
206 			continue;
207 		if (cmd->seq_list[i].seq_send_order == cmd->seq_send_order) {
208 			cmd->seq_send_order++;
209 			return &cmd->seq_list[i];
210 		}
211 	}
212 
213 	return NULL;
214 }
215 
216 struct iscsi_r2t *iscsit_get_holder_for_r2tsn(
217 	struct iscsi_cmd *cmd,
218 	u32 r2t_sn)
219 {
220 	struct iscsi_r2t *r2t;
221 
222 	spin_lock_bh(&cmd->r2t_lock);
223 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
224 		if (r2t->r2t_sn == r2t_sn) {
225 			spin_unlock_bh(&cmd->r2t_lock);
226 			return r2t;
227 		}
228 	}
229 	spin_unlock_bh(&cmd->r2t_lock);
230 
231 	return NULL;
232 }
233 
234 static inline int iscsit_check_received_cmdsn(struct iscsi_session *sess, u32 cmdsn)
235 {
236 	u32 max_cmdsn;
237 	int ret;
238 
239 	/*
240 	 * This is the proper method of checking received CmdSN against
241 	 * ExpCmdSN and MaxCmdSN values, as well as accounting for out
242 	 * or order CmdSNs due to multiple connection sessions and/or
243 	 * CRC failures.
244 	 */
245 	max_cmdsn = atomic_read(&sess->max_cmd_sn);
246 	if (iscsi_sna_gt(cmdsn, max_cmdsn)) {
247 		pr_err("Received CmdSN: 0x%08x is greater than"
248 		       " MaxCmdSN: 0x%08x, ignoring.\n", cmdsn, max_cmdsn);
249 		ret = CMDSN_MAXCMDSN_OVERRUN;
250 
251 	} else if (cmdsn == sess->exp_cmd_sn) {
252 		sess->exp_cmd_sn++;
253 		pr_debug("Received CmdSN matches ExpCmdSN,"
254 		      " incremented ExpCmdSN to: 0x%08x\n",
255 		      sess->exp_cmd_sn);
256 		ret = CMDSN_NORMAL_OPERATION;
257 
258 	} else if (iscsi_sna_gt(cmdsn, sess->exp_cmd_sn)) {
259 		pr_debug("Received CmdSN: 0x%08x is greater"
260 		      " than ExpCmdSN: 0x%08x, not acknowledging.\n",
261 		      cmdsn, sess->exp_cmd_sn);
262 		ret = CMDSN_HIGHER_THAN_EXP;
263 
264 	} else {
265 		pr_err("Received CmdSN: 0x%08x is less than"
266 		       " ExpCmdSN: 0x%08x, ignoring.\n", cmdsn,
267 		       sess->exp_cmd_sn);
268 		ret = CMDSN_LOWER_THAN_EXP;
269 	}
270 
271 	return ret;
272 }
273 
274 /*
275  * Commands may be received out of order if MC/S is in use.
276  * Ensure they are executed in CmdSN order.
277  */
278 int iscsit_sequence_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
279 			unsigned char *buf, __be32 cmdsn)
280 {
281 	int ret, cmdsn_ret;
282 	bool reject = false;
283 	u8 reason = ISCSI_REASON_BOOKMARK_NO_RESOURCES;
284 
285 	mutex_lock(&conn->sess->cmdsn_mutex);
286 
287 	cmdsn_ret = iscsit_check_received_cmdsn(conn->sess, be32_to_cpu(cmdsn));
288 	switch (cmdsn_ret) {
289 	case CMDSN_NORMAL_OPERATION:
290 		ret = iscsit_execute_cmd(cmd, 0);
291 		if ((ret >= 0) && !list_empty(&conn->sess->sess_ooo_cmdsn_list))
292 			iscsit_execute_ooo_cmdsns(conn->sess);
293 		else if (ret < 0) {
294 			reject = true;
295 			ret = CMDSN_ERROR_CANNOT_RECOVER;
296 		}
297 		break;
298 	case CMDSN_HIGHER_THAN_EXP:
299 		ret = iscsit_handle_ooo_cmdsn(conn->sess, cmd, be32_to_cpu(cmdsn));
300 		if (ret < 0) {
301 			reject = true;
302 			ret = CMDSN_ERROR_CANNOT_RECOVER;
303 			break;
304 		}
305 		ret = CMDSN_HIGHER_THAN_EXP;
306 		break;
307 	case CMDSN_LOWER_THAN_EXP:
308 	case CMDSN_MAXCMDSN_OVERRUN:
309 	default:
310 		cmd->i_state = ISTATE_REMOVE;
311 		iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
312 		/*
313 		 * Existing callers for iscsit_sequence_cmd() will silently
314 		 * ignore commands with CMDSN_LOWER_THAN_EXP, so force this
315 		 * return for CMDSN_MAXCMDSN_OVERRUN as well..
316 		 */
317 		ret = CMDSN_LOWER_THAN_EXP;
318 		break;
319 	}
320 	mutex_unlock(&conn->sess->cmdsn_mutex);
321 
322 	if (reject)
323 		iscsit_reject_cmd(cmd, reason, buf);
324 
325 	return ret;
326 }
327 EXPORT_SYMBOL(iscsit_sequence_cmd);
328 
329 int iscsit_check_unsolicited_dataout(struct iscsi_cmd *cmd, unsigned char *buf)
330 {
331 	struct iscsi_conn *conn = cmd->conn;
332 	struct se_cmd *se_cmd = &cmd->se_cmd;
333 	struct iscsi_data *hdr = (struct iscsi_data *) buf;
334 	u32 payload_length = ntoh24(hdr->dlength);
335 
336 	if (conn->sess->sess_ops->InitialR2T) {
337 		pr_err("Received unexpected unsolicited data"
338 			" while InitialR2T=Yes, protocol error.\n");
339 		transport_send_check_condition_and_sense(se_cmd,
340 				TCM_UNEXPECTED_UNSOLICITED_DATA, 0);
341 		return -1;
342 	}
343 
344 	if ((cmd->first_burst_len + payload_length) >
345 	     conn->sess->sess_ops->FirstBurstLength) {
346 		pr_err("Total %u bytes exceeds FirstBurstLength: %u"
347 			" for this Unsolicited DataOut Burst.\n",
348 			(cmd->first_burst_len + payload_length),
349 				conn->sess->sess_ops->FirstBurstLength);
350 		transport_send_check_condition_and_sense(se_cmd,
351 				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
352 		return -1;
353 	}
354 
355 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL))
356 		return 0;
357 
358 	if (((cmd->first_burst_len + payload_length) != cmd->se_cmd.data_length) &&
359 	    ((cmd->first_burst_len + payload_length) !=
360 	      conn->sess->sess_ops->FirstBurstLength)) {
361 		pr_err("Unsolicited non-immediate data received %u"
362 			" does not equal FirstBurstLength: %u, and does"
363 			" not equal ExpXferLen %u.\n",
364 			(cmd->first_burst_len + payload_length),
365 			conn->sess->sess_ops->FirstBurstLength, cmd->se_cmd.data_length);
366 		transport_send_check_condition_and_sense(se_cmd,
367 				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
368 		return -1;
369 	}
370 	return 0;
371 }
372 
373 struct iscsi_cmd *iscsit_find_cmd_from_itt(
374 	struct iscsi_conn *conn,
375 	itt_t init_task_tag)
376 {
377 	struct iscsi_cmd *cmd;
378 
379 	spin_lock_bh(&conn->cmd_lock);
380 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
381 		if (cmd->init_task_tag == init_task_tag) {
382 			spin_unlock_bh(&conn->cmd_lock);
383 			return cmd;
384 		}
385 	}
386 	spin_unlock_bh(&conn->cmd_lock);
387 
388 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu",
389 			init_task_tag, conn->cid);
390 	return NULL;
391 }
392 EXPORT_SYMBOL(iscsit_find_cmd_from_itt);
393 
394 struct iscsi_cmd *iscsit_find_cmd_from_itt_or_dump(
395 	struct iscsi_conn *conn,
396 	itt_t init_task_tag,
397 	u32 length)
398 {
399 	struct iscsi_cmd *cmd;
400 
401 	spin_lock_bh(&conn->cmd_lock);
402 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
403 		if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT)
404 			continue;
405 		if (cmd->init_task_tag == init_task_tag) {
406 			spin_unlock_bh(&conn->cmd_lock);
407 			return cmd;
408 		}
409 	}
410 	spin_unlock_bh(&conn->cmd_lock);
411 
412 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu,"
413 			" dumping payload\n", init_task_tag, conn->cid);
414 	if (length)
415 		iscsit_dump_data_payload(conn, length, 1);
416 
417 	return NULL;
418 }
419 
420 struct iscsi_cmd *iscsit_find_cmd_from_ttt(
421 	struct iscsi_conn *conn,
422 	u32 targ_xfer_tag)
423 {
424 	struct iscsi_cmd *cmd = NULL;
425 
426 	spin_lock_bh(&conn->cmd_lock);
427 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
428 		if (cmd->targ_xfer_tag == targ_xfer_tag) {
429 			spin_unlock_bh(&conn->cmd_lock);
430 			return cmd;
431 		}
432 	}
433 	spin_unlock_bh(&conn->cmd_lock);
434 
435 	pr_err("Unable to locate TTT: 0x%08x on CID: %hu\n",
436 			targ_xfer_tag, conn->cid);
437 	return NULL;
438 }
439 
440 int iscsit_find_cmd_for_recovery(
441 	struct iscsi_session *sess,
442 	struct iscsi_cmd **cmd_ptr,
443 	struct iscsi_conn_recovery **cr_ptr,
444 	itt_t init_task_tag)
445 {
446 	struct iscsi_cmd *cmd = NULL;
447 	struct iscsi_conn_recovery *cr;
448 	/*
449 	 * Scan through the inactive connection recovery list's command list.
450 	 * If init_task_tag matches the command is still alligent.
451 	 */
452 	spin_lock(&sess->cr_i_lock);
453 	list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
454 		spin_lock(&cr->conn_recovery_cmd_lock);
455 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
456 			if (cmd->init_task_tag == init_task_tag) {
457 				spin_unlock(&cr->conn_recovery_cmd_lock);
458 				spin_unlock(&sess->cr_i_lock);
459 
460 				*cr_ptr = cr;
461 				*cmd_ptr = cmd;
462 				return -2;
463 			}
464 		}
465 		spin_unlock(&cr->conn_recovery_cmd_lock);
466 	}
467 	spin_unlock(&sess->cr_i_lock);
468 	/*
469 	 * Scan through the active connection recovery list's command list.
470 	 * If init_task_tag matches the command is ready to be reassigned.
471 	 */
472 	spin_lock(&sess->cr_a_lock);
473 	list_for_each_entry(cr, &sess->cr_active_list, cr_list) {
474 		spin_lock(&cr->conn_recovery_cmd_lock);
475 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
476 			if (cmd->init_task_tag == init_task_tag) {
477 				spin_unlock(&cr->conn_recovery_cmd_lock);
478 				spin_unlock(&sess->cr_a_lock);
479 
480 				*cr_ptr = cr;
481 				*cmd_ptr = cmd;
482 				return 0;
483 			}
484 		}
485 		spin_unlock(&cr->conn_recovery_cmd_lock);
486 	}
487 	spin_unlock(&sess->cr_a_lock);
488 
489 	return -1;
490 }
491 
492 void iscsit_add_cmd_to_immediate_queue(
493 	struct iscsi_cmd *cmd,
494 	struct iscsi_conn *conn,
495 	u8 state)
496 {
497 	struct iscsi_queue_req *qr;
498 
499 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
500 	if (!qr) {
501 		pr_err("Unable to allocate memory for"
502 				" struct iscsi_queue_req\n");
503 		return;
504 	}
505 	INIT_LIST_HEAD(&qr->qr_list);
506 	qr->cmd = cmd;
507 	qr->state = state;
508 
509 	spin_lock_bh(&conn->immed_queue_lock);
510 	list_add_tail(&qr->qr_list, &conn->immed_queue_list);
511 	atomic_inc(&cmd->immed_queue_count);
512 	atomic_set(&conn->check_immediate_queue, 1);
513 	spin_unlock_bh(&conn->immed_queue_lock);
514 
515 	wake_up(&conn->queues_wq);
516 }
517 EXPORT_SYMBOL(iscsit_add_cmd_to_immediate_queue);
518 
519 struct iscsi_queue_req *iscsit_get_cmd_from_immediate_queue(struct iscsi_conn *conn)
520 {
521 	struct iscsi_queue_req *qr;
522 
523 	spin_lock_bh(&conn->immed_queue_lock);
524 	if (list_empty(&conn->immed_queue_list)) {
525 		spin_unlock_bh(&conn->immed_queue_lock);
526 		return NULL;
527 	}
528 	qr = list_first_entry(&conn->immed_queue_list,
529 			      struct iscsi_queue_req, qr_list);
530 
531 	list_del(&qr->qr_list);
532 	if (qr->cmd)
533 		atomic_dec(&qr->cmd->immed_queue_count);
534 	spin_unlock_bh(&conn->immed_queue_lock);
535 
536 	return qr;
537 }
538 
539 static void iscsit_remove_cmd_from_immediate_queue(
540 	struct iscsi_cmd *cmd,
541 	struct iscsi_conn *conn)
542 {
543 	struct iscsi_queue_req *qr, *qr_tmp;
544 
545 	spin_lock_bh(&conn->immed_queue_lock);
546 	if (!atomic_read(&cmd->immed_queue_count)) {
547 		spin_unlock_bh(&conn->immed_queue_lock);
548 		return;
549 	}
550 
551 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
552 		if (qr->cmd != cmd)
553 			continue;
554 
555 		atomic_dec(&qr->cmd->immed_queue_count);
556 		list_del(&qr->qr_list);
557 		kmem_cache_free(lio_qr_cache, qr);
558 	}
559 	spin_unlock_bh(&conn->immed_queue_lock);
560 
561 	if (atomic_read(&cmd->immed_queue_count)) {
562 		pr_err("ITT: 0x%08x immed_queue_count: %d\n",
563 			cmd->init_task_tag,
564 			atomic_read(&cmd->immed_queue_count));
565 	}
566 }
567 
568 void iscsit_add_cmd_to_response_queue(
569 	struct iscsi_cmd *cmd,
570 	struct iscsi_conn *conn,
571 	u8 state)
572 {
573 	struct iscsi_queue_req *qr;
574 
575 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
576 	if (!qr) {
577 		pr_err("Unable to allocate memory for"
578 			" struct iscsi_queue_req\n");
579 		return;
580 	}
581 	INIT_LIST_HEAD(&qr->qr_list);
582 	qr->cmd = cmd;
583 	qr->state = state;
584 
585 	spin_lock_bh(&conn->response_queue_lock);
586 	list_add_tail(&qr->qr_list, &conn->response_queue_list);
587 	atomic_inc(&cmd->response_queue_count);
588 	spin_unlock_bh(&conn->response_queue_lock);
589 
590 	wake_up(&conn->queues_wq);
591 }
592 
593 struct iscsi_queue_req *iscsit_get_cmd_from_response_queue(struct iscsi_conn *conn)
594 {
595 	struct iscsi_queue_req *qr;
596 
597 	spin_lock_bh(&conn->response_queue_lock);
598 	if (list_empty(&conn->response_queue_list)) {
599 		spin_unlock_bh(&conn->response_queue_lock);
600 		return NULL;
601 	}
602 
603 	qr = list_first_entry(&conn->response_queue_list,
604 			      struct iscsi_queue_req, qr_list);
605 
606 	list_del(&qr->qr_list);
607 	if (qr->cmd)
608 		atomic_dec(&qr->cmd->response_queue_count);
609 	spin_unlock_bh(&conn->response_queue_lock);
610 
611 	return qr;
612 }
613 
614 static void iscsit_remove_cmd_from_response_queue(
615 	struct iscsi_cmd *cmd,
616 	struct iscsi_conn *conn)
617 {
618 	struct iscsi_queue_req *qr, *qr_tmp;
619 
620 	spin_lock_bh(&conn->response_queue_lock);
621 	if (!atomic_read(&cmd->response_queue_count)) {
622 		spin_unlock_bh(&conn->response_queue_lock);
623 		return;
624 	}
625 
626 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
627 				qr_list) {
628 		if (qr->cmd != cmd)
629 			continue;
630 
631 		atomic_dec(&qr->cmd->response_queue_count);
632 		list_del(&qr->qr_list);
633 		kmem_cache_free(lio_qr_cache, qr);
634 	}
635 	spin_unlock_bh(&conn->response_queue_lock);
636 
637 	if (atomic_read(&cmd->response_queue_count)) {
638 		pr_err("ITT: 0x%08x response_queue_count: %d\n",
639 			cmd->init_task_tag,
640 			atomic_read(&cmd->response_queue_count));
641 	}
642 }
643 
644 bool iscsit_conn_all_queues_empty(struct iscsi_conn *conn)
645 {
646 	bool empty;
647 
648 	spin_lock_bh(&conn->immed_queue_lock);
649 	empty = list_empty(&conn->immed_queue_list);
650 	spin_unlock_bh(&conn->immed_queue_lock);
651 
652 	if (!empty)
653 		return empty;
654 
655 	spin_lock_bh(&conn->response_queue_lock);
656 	empty = list_empty(&conn->response_queue_list);
657 	spin_unlock_bh(&conn->response_queue_lock);
658 
659 	return empty;
660 }
661 
662 void iscsit_free_queue_reqs_for_conn(struct iscsi_conn *conn)
663 {
664 	struct iscsi_queue_req *qr, *qr_tmp;
665 
666 	spin_lock_bh(&conn->immed_queue_lock);
667 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
668 		list_del(&qr->qr_list);
669 		if (qr->cmd)
670 			atomic_dec(&qr->cmd->immed_queue_count);
671 
672 		kmem_cache_free(lio_qr_cache, qr);
673 	}
674 	spin_unlock_bh(&conn->immed_queue_lock);
675 
676 	spin_lock_bh(&conn->response_queue_lock);
677 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
678 			qr_list) {
679 		list_del(&qr->qr_list);
680 		if (qr->cmd)
681 			atomic_dec(&qr->cmd->response_queue_count);
682 
683 		kmem_cache_free(lio_qr_cache, qr);
684 	}
685 	spin_unlock_bh(&conn->response_queue_lock);
686 }
687 
688 void iscsit_release_cmd(struct iscsi_cmd *cmd)
689 {
690 	struct iscsi_session *sess;
691 	struct se_cmd *se_cmd = &cmd->se_cmd;
692 
693 	if (cmd->conn)
694 		sess = cmd->conn->sess;
695 	else
696 		sess = cmd->sess;
697 
698 	BUG_ON(!sess || !sess->se_sess);
699 
700 	kfree(cmd->buf_ptr);
701 	kfree(cmd->pdu_list);
702 	kfree(cmd->seq_list);
703 	kfree(cmd->tmr_req);
704 	kfree(cmd->iov_data);
705 	kfree(cmd->text_in_ptr);
706 
707 	percpu_ida_free(&sess->se_sess->sess_tag_pool, se_cmd->map_tag);
708 }
709 EXPORT_SYMBOL(iscsit_release_cmd);
710 
711 void __iscsit_free_cmd(struct iscsi_cmd *cmd, bool scsi_cmd,
712 		       bool check_queues)
713 {
714 	struct iscsi_conn *conn = cmd->conn;
715 
716 	if (scsi_cmd) {
717 		if (cmd->data_direction == DMA_TO_DEVICE) {
718 			iscsit_stop_dataout_timer(cmd);
719 			iscsit_free_r2ts_from_list(cmd);
720 		}
721 		if (cmd->data_direction == DMA_FROM_DEVICE)
722 			iscsit_free_all_datain_reqs(cmd);
723 	}
724 
725 	if (conn && check_queues) {
726 		iscsit_remove_cmd_from_immediate_queue(cmd, conn);
727 		iscsit_remove_cmd_from_response_queue(cmd, conn);
728 	}
729 
730 	if (conn && conn->conn_transport->iscsit_release_cmd)
731 		conn->conn_transport->iscsit_release_cmd(conn, cmd);
732 }
733 
734 void iscsit_free_cmd(struct iscsi_cmd *cmd, bool shutdown)
735 {
736 	struct se_cmd *se_cmd = NULL;
737 	int rc;
738 	/*
739 	 * Determine if a struct se_cmd is associated with
740 	 * this struct iscsi_cmd.
741 	 */
742 	switch (cmd->iscsi_opcode) {
743 	case ISCSI_OP_SCSI_CMD:
744 		se_cmd = &cmd->se_cmd;
745 		__iscsit_free_cmd(cmd, true, shutdown);
746 		/*
747 		 * Fallthrough
748 		 */
749 	case ISCSI_OP_SCSI_TMFUNC:
750 		rc = transport_generic_free_cmd(&cmd->se_cmd, shutdown);
751 		if (!rc && shutdown && se_cmd && se_cmd->se_sess) {
752 			__iscsit_free_cmd(cmd, true, shutdown);
753 			target_put_sess_cmd(se_cmd);
754 		}
755 		break;
756 	case ISCSI_OP_REJECT:
757 		/*
758 		 * Handle special case for REJECT when iscsi_add_reject*() has
759 		 * overwritten the original iscsi_opcode assignment, and the
760 		 * associated cmd->se_cmd needs to be released.
761 		 */
762 		if (cmd->se_cmd.se_tfo != NULL) {
763 			se_cmd = &cmd->se_cmd;
764 			__iscsit_free_cmd(cmd, true, shutdown);
765 
766 			rc = transport_generic_free_cmd(&cmd->se_cmd, shutdown);
767 			if (!rc && shutdown && se_cmd->se_sess) {
768 				__iscsit_free_cmd(cmd, true, shutdown);
769 				target_put_sess_cmd(se_cmd);
770 			}
771 			break;
772 		}
773 		/* Fall-through */
774 	default:
775 		__iscsit_free_cmd(cmd, false, shutdown);
776 		iscsit_release_cmd(cmd);
777 		break;
778 	}
779 }
780 EXPORT_SYMBOL(iscsit_free_cmd);
781 
782 int iscsit_check_session_usage_count(struct iscsi_session *sess)
783 {
784 	spin_lock_bh(&sess->session_usage_lock);
785 	if (sess->session_usage_count != 0) {
786 		sess->session_waiting_on_uc = 1;
787 		spin_unlock_bh(&sess->session_usage_lock);
788 		if (in_interrupt())
789 			return 2;
790 
791 		wait_for_completion(&sess->session_waiting_on_uc_comp);
792 		return 1;
793 	}
794 	spin_unlock_bh(&sess->session_usage_lock);
795 
796 	return 0;
797 }
798 
799 void iscsit_dec_session_usage_count(struct iscsi_session *sess)
800 {
801 	spin_lock_bh(&sess->session_usage_lock);
802 	sess->session_usage_count--;
803 
804 	if (!sess->session_usage_count && sess->session_waiting_on_uc)
805 		complete(&sess->session_waiting_on_uc_comp);
806 
807 	spin_unlock_bh(&sess->session_usage_lock);
808 }
809 
810 void iscsit_inc_session_usage_count(struct iscsi_session *sess)
811 {
812 	spin_lock_bh(&sess->session_usage_lock);
813 	sess->session_usage_count++;
814 	spin_unlock_bh(&sess->session_usage_lock);
815 }
816 
817 struct iscsi_conn *iscsit_get_conn_from_cid(struct iscsi_session *sess, u16 cid)
818 {
819 	struct iscsi_conn *conn;
820 
821 	spin_lock_bh(&sess->conn_lock);
822 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
823 		if ((conn->cid == cid) &&
824 		    (conn->conn_state == TARG_CONN_STATE_LOGGED_IN)) {
825 			iscsit_inc_conn_usage_count(conn);
826 			spin_unlock_bh(&sess->conn_lock);
827 			return conn;
828 		}
829 	}
830 	spin_unlock_bh(&sess->conn_lock);
831 
832 	return NULL;
833 }
834 
835 struct iscsi_conn *iscsit_get_conn_from_cid_rcfr(struct iscsi_session *sess, u16 cid)
836 {
837 	struct iscsi_conn *conn;
838 
839 	spin_lock_bh(&sess->conn_lock);
840 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
841 		if (conn->cid == cid) {
842 			iscsit_inc_conn_usage_count(conn);
843 			spin_lock(&conn->state_lock);
844 			atomic_set(&conn->connection_wait_rcfr, 1);
845 			spin_unlock(&conn->state_lock);
846 			spin_unlock_bh(&sess->conn_lock);
847 			return conn;
848 		}
849 	}
850 	spin_unlock_bh(&sess->conn_lock);
851 
852 	return NULL;
853 }
854 
855 void iscsit_check_conn_usage_count(struct iscsi_conn *conn)
856 {
857 	spin_lock_bh(&conn->conn_usage_lock);
858 	if (conn->conn_usage_count != 0) {
859 		conn->conn_waiting_on_uc = 1;
860 		spin_unlock_bh(&conn->conn_usage_lock);
861 
862 		wait_for_completion(&conn->conn_waiting_on_uc_comp);
863 		return;
864 	}
865 	spin_unlock_bh(&conn->conn_usage_lock);
866 }
867 
868 void iscsit_dec_conn_usage_count(struct iscsi_conn *conn)
869 {
870 	spin_lock_bh(&conn->conn_usage_lock);
871 	conn->conn_usage_count--;
872 
873 	if (!conn->conn_usage_count && conn->conn_waiting_on_uc)
874 		complete(&conn->conn_waiting_on_uc_comp);
875 
876 	spin_unlock_bh(&conn->conn_usage_lock);
877 }
878 
879 void iscsit_inc_conn_usage_count(struct iscsi_conn *conn)
880 {
881 	spin_lock_bh(&conn->conn_usage_lock);
882 	conn->conn_usage_count++;
883 	spin_unlock_bh(&conn->conn_usage_lock);
884 }
885 
886 static int iscsit_add_nopin(struct iscsi_conn *conn, int want_response)
887 {
888 	u8 state;
889 	struct iscsi_cmd *cmd;
890 
891 	cmd = iscsit_allocate_cmd(conn, TASK_RUNNING);
892 	if (!cmd)
893 		return -1;
894 
895 	cmd->iscsi_opcode = ISCSI_OP_NOOP_IN;
896 	state = (want_response) ? ISTATE_SEND_NOPIN_WANT_RESPONSE :
897 				ISTATE_SEND_NOPIN_NO_RESPONSE;
898 	cmd->init_task_tag = RESERVED_ITT;
899 	cmd->targ_xfer_tag = (want_response) ?
900 			     session_get_next_ttt(conn->sess) : 0xFFFFFFFF;
901 	spin_lock_bh(&conn->cmd_lock);
902 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
903 	spin_unlock_bh(&conn->cmd_lock);
904 
905 	if (want_response)
906 		iscsit_start_nopin_response_timer(conn);
907 	iscsit_add_cmd_to_immediate_queue(cmd, conn, state);
908 
909 	return 0;
910 }
911 
912 static void iscsit_handle_nopin_response_timeout(unsigned long data)
913 {
914 	struct iscsi_conn *conn = (struct iscsi_conn *) data;
915 
916 	iscsit_inc_conn_usage_count(conn);
917 
918 	spin_lock_bh(&conn->nopin_timer_lock);
919 	if (conn->nopin_response_timer_flags & ISCSI_TF_STOP) {
920 		spin_unlock_bh(&conn->nopin_timer_lock);
921 		iscsit_dec_conn_usage_count(conn);
922 		return;
923 	}
924 
925 	pr_debug("Did not receive response to NOPIN on CID: %hu on"
926 		" SID: %u, failing connection.\n", conn->cid,
927 			conn->sess->sid);
928 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
929 	spin_unlock_bh(&conn->nopin_timer_lock);
930 
931 	{
932 	struct iscsi_portal_group *tpg = conn->sess->tpg;
933 	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
934 
935 	if (tiqn) {
936 		spin_lock_bh(&tiqn->sess_err_stats.lock);
937 		strcpy(tiqn->sess_err_stats.last_sess_fail_rem_name,
938 				conn->sess->sess_ops->InitiatorName);
939 		tiqn->sess_err_stats.last_sess_failure_type =
940 				ISCSI_SESS_ERR_CXN_TIMEOUT;
941 		tiqn->sess_err_stats.cxn_timeout_errors++;
942 		atomic_long_inc(&conn->sess->conn_timeout_errors);
943 		spin_unlock_bh(&tiqn->sess_err_stats.lock);
944 	}
945 	}
946 
947 	iscsit_cause_connection_reinstatement(conn, 0);
948 	iscsit_dec_conn_usage_count(conn);
949 }
950 
951 void iscsit_mod_nopin_response_timer(struct iscsi_conn *conn)
952 {
953 	struct iscsi_session *sess = conn->sess;
954 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
955 
956 	spin_lock_bh(&conn->nopin_timer_lock);
957 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
958 		spin_unlock_bh(&conn->nopin_timer_lock);
959 		return;
960 	}
961 
962 	mod_timer(&conn->nopin_response_timer,
963 		(get_jiffies_64() + na->nopin_response_timeout * HZ));
964 	spin_unlock_bh(&conn->nopin_timer_lock);
965 }
966 
967 /*
968  *	Called with conn->nopin_timer_lock held.
969  */
970 void iscsit_start_nopin_response_timer(struct iscsi_conn *conn)
971 {
972 	struct iscsi_session *sess = conn->sess;
973 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
974 
975 	spin_lock_bh(&conn->nopin_timer_lock);
976 	if (conn->nopin_response_timer_flags & ISCSI_TF_RUNNING) {
977 		spin_unlock_bh(&conn->nopin_timer_lock);
978 		return;
979 	}
980 
981 	init_timer(&conn->nopin_response_timer);
982 	conn->nopin_response_timer.expires =
983 		(get_jiffies_64() + na->nopin_response_timeout * HZ);
984 	conn->nopin_response_timer.data = (unsigned long)conn;
985 	conn->nopin_response_timer.function = iscsit_handle_nopin_response_timeout;
986 	conn->nopin_response_timer_flags &= ~ISCSI_TF_STOP;
987 	conn->nopin_response_timer_flags |= ISCSI_TF_RUNNING;
988 	add_timer(&conn->nopin_response_timer);
989 
990 	pr_debug("Started NOPIN Response Timer on CID: %d to %u"
991 		" seconds\n", conn->cid, na->nopin_response_timeout);
992 	spin_unlock_bh(&conn->nopin_timer_lock);
993 }
994 
995 void iscsit_stop_nopin_response_timer(struct iscsi_conn *conn)
996 {
997 	spin_lock_bh(&conn->nopin_timer_lock);
998 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
999 		spin_unlock_bh(&conn->nopin_timer_lock);
1000 		return;
1001 	}
1002 	conn->nopin_response_timer_flags |= ISCSI_TF_STOP;
1003 	spin_unlock_bh(&conn->nopin_timer_lock);
1004 
1005 	del_timer_sync(&conn->nopin_response_timer);
1006 
1007 	spin_lock_bh(&conn->nopin_timer_lock);
1008 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
1009 	spin_unlock_bh(&conn->nopin_timer_lock);
1010 }
1011 
1012 static void iscsit_handle_nopin_timeout(unsigned long data)
1013 {
1014 	struct iscsi_conn *conn = (struct iscsi_conn *) data;
1015 
1016 	iscsit_inc_conn_usage_count(conn);
1017 
1018 	spin_lock_bh(&conn->nopin_timer_lock);
1019 	if (conn->nopin_timer_flags & ISCSI_TF_STOP) {
1020 		spin_unlock_bh(&conn->nopin_timer_lock);
1021 		iscsit_dec_conn_usage_count(conn);
1022 		return;
1023 	}
1024 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1025 	spin_unlock_bh(&conn->nopin_timer_lock);
1026 
1027 	iscsit_add_nopin(conn, 1);
1028 	iscsit_dec_conn_usage_count(conn);
1029 }
1030 
1031 /*
1032  * Called with conn->nopin_timer_lock held.
1033  */
1034 void __iscsit_start_nopin_timer(struct iscsi_conn *conn)
1035 {
1036 	struct iscsi_session *sess = conn->sess;
1037 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1038 	/*
1039 	* NOPIN timeout is disabled.
1040 	 */
1041 	if (!na->nopin_timeout)
1042 		return;
1043 
1044 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING)
1045 		return;
1046 
1047 	init_timer(&conn->nopin_timer);
1048 	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1049 	conn->nopin_timer.data = (unsigned long)conn;
1050 	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1051 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1052 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1053 	add_timer(&conn->nopin_timer);
1054 
1055 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1056 		" interval\n", conn->cid, na->nopin_timeout);
1057 }
1058 
1059 void iscsit_start_nopin_timer(struct iscsi_conn *conn)
1060 {
1061 	struct iscsi_session *sess = conn->sess;
1062 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1063 	/*
1064 	 * NOPIN timeout is disabled..
1065 	 */
1066 	if (!na->nopin_timeout)
1067 		return;
1068 
1069 	spin_lock_bh(&conn->nopin_timer_lock);
1070 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING) {
1071 		spin_unlock_bh(&conn->nopin_timer_lock);
1072 		return;
1073 	}
1074 
1075 	init_timer(&conn->nopin_timer);
1076 	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1077 	conn->nopin_timer.data = (unsigned long)conn;
1078 	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1079 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1080 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1081 	add_timer(&conn->nopin_timer);
1082 
1083 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1084 			" interval\n", conn->cid, na->nopin_timeout);
1085 	spin_unlock_bh(&conn->nopin_timer_lock);
1086 }
1087 
1088 void iscsit_stop_nopin_timer(struct iscsi_conn *conn)
1089 {
1090 	spin_lock_bh(&conn->nopin_timer_lock);
1091 	if (!(conn->nopin_timer_flags & ISCSI_TF_RUNNING)) {
1092 		spin_unlock_bh(&conn->nopin_timer_lock);
1093 		return;
1094 	}
1095 	conn->nopin_timer_flags |= ISCSI_TF_STOP;
1096 	spin_unlock_bh(&conn->nopin_timer_lock);
1097 
1098 	del_timer_sync(&conn->nopin_timer);
1099 
1100 	spin_lock_bh(&conn->nopin_timer_lock);
1101 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1102 	spin_unlock_bh(&conn->nopin_timer_lock);
1103 }
1104 
1105 int iscsit_send_tx_data(
1106 	struct iscsi_cmd *cmd,
1107 	struct iscsi_conn *conn,
1108 	int use_misc)
1109 {
1110 	int tx_sent, tx_size;
1111 	u32 iov_count;
1112 	struct kvec *iov;
1113 
1114 send_data:
1115 	tx_size = cmd->tx_size;
1116 
1117 	if (!use_misc) {
1118 		iov = &cmd->iov_data[0];
1119 		iov_count = cmd->iov_data_count;
1120 	} else {
1121 		iov = &cmd->iov_misc[0];
1122 		iov_count = cmd->iov_misc_count;
1123 	}
1124 
1125 	tx_sent = tx_data(conn, &iov[0], iov_count, tx_size);
1126 	if (tx_size != tx_sent) {
1127 		if (tx_sent == -EAGAIN) {
1128 			pr_err("tx_data() returned -EAGAIN\n");
1129 			goto send_data;
1130 		} else
1131 			return -1;
1132 	}
1133 	cmd->tx_size = 0;
1134 
1135 	return 0;
1136 }
1137 
1138 int iscsit_fe_sendpage_sg(
1139 	struct iscsi_cmd *cmd,
1140 	struct iscsi_conn *conn)
1141 {
1142 	struct scatterlist *sg = cmd->first_data_sg;
1143 	struct kvec iov;
1144 	u32 tx_hdr_size, data_len;
1145 	u32 offset = cmd->first_data_sg_off;
1146 	int tx_sent, iov_off;
1147 
1148 send_hdr:
1149 	tx_hdr_size = ISCSI_HDR_LEN;
1150 	if (conn->conn_ops->HeaderDigest)
1151 		tx_hdr_size += ISCSI_CRC_LEN;
1152 
1153 	iov.iov_base = cmd->pdu;
1154 	iov.iov_len = tx_hdr_size;
1155 
1156 	tx_sent = tx_data(conn, &iov, 1, tx_hdr_size);
1157 	if (tx_hdr_size != tx_sent) {
1158 		if (tx_sent == -EAGAIN) {
1159 			pr_err("tx_data() returned -EAGAIN\n");
1160 			goto send_hdr;
1161 		}
1162 		return -1;
1163 	}
1164 
1165 	data_len = cmd->tx_size - tx_hdr_size - cmd->padding;
1166 	/*
1167 	 * Set iov_off used by padding and data digest tx_data() calls below
1168 	 * in order to determine proper offset into cmd->iov_data[]
1169 	 */
1170 	if (conn->conn_ops->DataDigest) {
1171 		data_len -= ISCSI_CRC_LEN;
1172 		if (cmd->padding)
1173 			iov_off = (cmd->iov_data_count - 2);
1174 		else
1175 			iov_off = (cmd->iov_data_count - 1);
1176 	} else {
1177 		iov_off = (cmd->iov_data_count - 1);
1178 	}
1179 	/*
1180 	 * Perform sendpage() for each page in the scatterlist
1181 	 */
1182 	while (data_len) {
1183 		u32 space = (sg->length - offset);
1184 		u32 sub_len = min_t(u32, data_len, space);
1185 send_pg:
1186 		tx_sent = conn->sock->ops->sendpage(conn->sock,
1187 					sg_page(sg), sg->offset + offset, sub_len, 0);
1188 		if (tx_sent != sub_len) {
1189 			if (tx_sent == -EAGAIN) {
1190 				pr_err("tcp_sendpage() returned"
1191 						" -EAGAIN\n");
1192 				goto send_pg;
1193 			}
1194 
1195 			pr_err("tcp_sendpage() failure: %d\n",
1196 					tx_sent);
1197 			return -1;
1198 		}
1199 
1200 		data_len -= sub_len;
1201 		offset = 0;
1202 		sg = sg_next(sg);
1203 	}
1204 
1205 send_padding:
1206 	if (cmd->padding) {
1207 		struct kvec *iov_p = &cmd->iov_data[iov_off++];
1208 
1209 		tx_sent = tx_data(conn, iov_p, 1, cmd->padding);
1210 		if (cmd->padding != tx_sent) {
1211 			if (tx_sent == -EAGAIN) {
1212 				pr_err("tx_data() returned -EAGAIN\n");
1213 				goto send_padding;
1214 			}
1215 			return -1;
1216 		}
1217 	}
1218 
1219 send_datacrc:
1220 	if (conn->conn_ops->DataDigest) {
1221 		struct kvec *iov_d = &cmd->iov_data[iov_off];
1222 
1223 		tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN);
1224 		if (ISCSI_CRC_LEN != tx_sent) {
1225 			if (tx_sent == -EAGAIN) {
1226 				pr_err("tx_data() returned -EAGAIN\n");
1227 				goto send_datacrc;
1228 			}
1229 			return -1;
1230 		}
1231 	}
1232 
1233 	return 0;
1234 }
1235 
1236 /*
1237  *      This function is used for mainly sending a ISCSI_TARG_LOGIN_RSP PDU
1238  *      back to the Initiator when an expection condition occurs with the
1239  *      errors set in status_class and status_detail.
1240  *
1241  *      Parameters:     iSCSI Connection, Status Class, Status Detail.
1242  *      Returns:        0 on success, -1 on error.
1243  */
1244 int iscsit_tx_login_rsp(struct iscsi_conn *conn, u8 status_class, u8 status_detail)
1245 {
1246 	struct iscsi_login_rsp *hdr;
1247 	struct iscsi_login *login = conn->conn_login;
1248 
1249 	login->login_failed = 1;
1250 	iscsit_collect_login_stats(conn, status_class, status_detail);
1251 
1252 	memset(&login->rsp[0], 0, ISCSI_HDR_LEN);
1253 
1254 	hdr	= (struct iscsi_login_rsp *)&login->rsp[0];
1255 	hdr->opcode		= ISCSI_OP_LOGIN_RSP;
1256 	hdr->status_class	= status_class;
1257 	hdr->status_detail	= status_detail;
1258 	hdr->itt		= conn->login_itt;
1259 
1260 	return conn->conn_transport->iscsit_put_login_tx(conn, login, 0);
1261 }
1262 
1263 void iscsit_print_session_params(struct iscsi_session *sess)
1264 {
1265 	struct iscsi_conn *conn;
1266 
1267 	pr_debug("-----------------------------[Session Params for"
1268 		" SID: %u]-----------------------------\n", sess->sid);
1269 	spin_lock_bh(&sess->conn_lock);
1270 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
1271 		iscsi_dump_conn_ops(conn->conn_ops);
1272 	spin_unlock_bh(&sess->conn_lock);
1273 
1274 	iscsi_dump_sess_ops(sess->sess_ops);
1275 }
1276 
1277 static int iscsit_do_rx_data(
1278 	struct iscsi_conn *conn,
1279 	struct iscsi_data_count *count)
1280 {
1281 	int data = count->data_length, rx_loop = 0, total_rx = 0;
1282 	struct msghdr msg;
1283 
1284 	if (!conn || !conn->sock || !conn->conn_ops)
1285 		return -1;
1286 
1287 	memset(&msg, 0, sizeof(struct msghdr));
1288 	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC,
1289 		      count->iov, count->iov_count, data);
1290 
1291 	while (msg_data_left(&msg)) {
1292 		rx_loop = sock_recvmsg(conn->sock, &msg, MSG_WAITALL);
1293 		if (rx_loop <= 0) {
1294 			pr_debug("rx_loop: %d total_rx: %d\n",
1295 				rx_loop, total_rx);
1296 			return rx_loop;
1297 		}
1298 		total_rx += rx_loop;
1299 		pr_debug("rx_loop: %d, total_rx: %d, data: %d\n",
1300 				rx_loop, total_rx, data);
1301 	}
1302 
1303 	return total_rx;
1304 }
1305 
1306 static int iscsit_do_tx_data(
1307 	struct iscsi_conn *conn,
1308 	struct iscsi_data_count *count)
1309 {
1310 	int ret, iov_len;
1311 	struct kvec *iov_p;
1312 	struct msghdr msg;
1313 
1314 	if (!conn || !conn->sock || !conn->conn_ops)
1315 		return -1;
1316 
1317 	if (count->data_length <= 0) {
1318 		pr_err("Data length is: %d\n", count->data_length);
1319 		return -1;
1320 	}
1321 
1322 	memset(&msg, 0, sizeof(struct msghdr));
1323 
1324 	iov_p = count->iov;
1325 	iov_len = count->iov_count;
1326 
1327 	ret = kernel_sendmsg(conn->sock, &msg, iov_p, iov_len,
1328 			     count->data_length);
1329 	if (ret != count->data_length) {
1330 		pr_err("Unexpected ret: %d send data %d\n",
1331 		       ret, count->data_length);
1332 		return -EPIPE;
1333 	}
1334 	pr_debug("ret: %d, sent data: %d\n", ret, count->data_length);
1335 
1336 	return ret;
1337 }
1338 
1339 int rx_data(
1340 	struct iscsi_conn *conn,
1341 	struct kvec *iov,
1342 	int iov_count,
1343 	int data)
1344 {
1345 	struct iscsi_data_count c;
1346 
1347 	if (!conn || !conn->sock || !conn->conn_ops)
1348 		return -1;
1349 
1350 	memset(&c, 0, sizeof(struct iscsi_data_count));
1351 	c.iov = iov;
1352 	c.iov_count = iov_count;
1353 	c.data_length = data;
1354 	c.type = ISCSI_RX_DATA;
1355 
1356 	return iscsit_do_rx_data(conn, &c);
1357 }
1358 
1359 int tx_data(
1360 	struct iscsi_conn *conn,
1361 	struct kvec *iov,
1362 	int iov_count,
1363 	int data)
1364 {
1365 	struct iscsi_data_count c;
1366 
1367 	if (!conn || !conn->sock || !conn->conn_ops)
1368 		return -1;
1369 
1370 	memset(&c, 0, sizeof(struct iscsi_data_count));
1371 	c.iov = iov;
1372 	c.iov_count = iov_count;
1373 	c.data_length = data;
1374 	c.type = ISCSI_TX_DATA;
1375 
1376 	return iscsit_do_tx_data(conn, &c);
1377 }
1378 
1379 static bool sockaddr_equal(struct sockaddr_storage *x, struct sockaddr_storage *y)
1380 {
1381 	switch (x->ss_family) {
1382 	case AF_INET: {
1383 		struct sockaddr_in *sinx = (struct sockaddr_in *)x;
1384 		struct sockaddr_in *siny = (struct sockaddr_in *)y;
1385 		if (sinx->sin_addr.s_addr != siny->sin_addr.s_addr)
1386 			return false;
1387 		if (sinx->sin_port != siny->sin_port)
1388 			return false;
1389 		break;
1390 	}
1391 	case AF_INET6: {
1392 		struct sockaddr_in6 *sinx = (struct sockaddr_in6 *)x;
1393 		struct sockaddr_in6 *siny = (struct sockaddr_in6 *)y;
1394 		if (!ipv6_addr_equal(&sinx->sin6_addr, &siny->sin6_addr))
1395 			return false;
1396 		if (sinx->sin6_port != siny->sin6_port)
1397 			return false;
1398 		break;
1399 	}
1400 	default:
1401 		return false;
1402 	}
1403 	return true;
1404 }
1405 
1406 void iscsit_collect_login_stats(
1407 	struct iscsi_conn *conn,
1408 	u8 status_class,
1409 	u8 status_detail)
1410 {
1411 	struct iscsi_param *intrname = NULL;
1412 	struct iscsi_tiqn *tiqn;
1413 	struct iscsi_login_stats *ls;
1414 
1415 	tiqn = iscsit_snmp_get_tiqn(conn);
1416 	if (!tiqn)
1417 		return;
1418 
1419 	ls = &tiqn->login_stats;
1420 
1421 	spin_lock(&ls->lock);
1422 	if (sockaddr_equal(&conn->login_sockaddr, &ls->last_intr_fail_sockaddr) &&
1423 	    ((get_jiffies_64() - ls->last_fail_time) < 10)) {
1424 		/* We already have the failure info for this login */
1425 		spin_unlock(&ls->lock);
1426 		return;
1427 	}
1428 
1429 	if (status_class == ISCSI_STATUS_CLS_SUCCESS)
1430 		ls->accepts++;
1431 	else if (status_class == ISCSI_STATUS_CLS_REDIRECT) {
1432 		ls->redirects++;
1433 		ls->last_fail_type = ISCSI_LOGIN_FAIL_REDIRECT;
1434 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1435 		 (status_detail == ISCSI_LOGIN_STATUS_AUTH_FAILED)) {
1436 		ls->authenticate_fails++;
1437 		ls->last_fail_type =  ISCSI_LOGIN_FAIL_AUTHENTICATE;
1438 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1439 		 (status_detail == ISCSI_LOGIN_STATUS_TGT_FORBIDDEN)) {
1440 		ls->authorize_fails++;
1441 		ls->last_fail_type = ISCSI_LOGIN_FAIL_AUTHORIZE;
1442 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR) &&
1443 		 (status_detail == ISCSI_LOGIN_STATUS_INIT_ERR)) {
1444 		ls->negotiate_fails++;
1445 		ls->last_fail_type = ISCSI_LOGIN_FAIL_NEGOTIATE;
1446 	} else {
1447 		ls->other_fails++;
1448 		ls->last_fail_type = ISCSI_LOGIN_FAIL_OTHER;
1449 	}
1450 
1451 	/* Save initiator name, ip address and time, if it is a failed login */
1452 	if (status_class != ISCSI_STATUS_CLS_SUCCESS) {
1453 		if (conn->param_list)
1454 			intrname = iscsi_find_param_from_key(INITIATORNAME,
1455 							     conn->param_list);
1456 		strlcpy(ls->last_intr_fail_name,
1457 		       (intrname ? intrname->value : "Unknown"),
1458 		       sizeof(ls->last_intr_fail_name));
1459 
1460 		ls->last_intr_fail_ip_family = conn->login_family;
1461 
1462 		ls->last_intr_fail_sockaddr = conn->login_sockaddr;
1463 		ls->last_fail_time = get_jiffies_64();
1464 	}
1465 
1466 	spin_unlock(&ls->lock);
1467 }
1468 
1469 struct iscsi_tiqn *iscsit_snmp_get_tiqn(struct iscsi_conn *conn)
1470 {
1471 	struct iscsi_portal_group *tpg;
1472 
1473 	if (!conn || !conn->sess)
1474 		return NULL;
1475 
1476 	tpg = conn->sess->tpg;
1477 	if (!tpg)
1478 		return NULL;
1479 
1480 	if (!tpg->tpg_tiqn)
1481 		return NULL;
1482 
1483 	return tpg->tpg_tiqn;
1484 }
1485