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/target_core_configfs.h>
26 #include <target/iscsi/iscsi_transport.h>
27 
28 #include <target/iscsi/iscsi_target_core.h>
29 #include "iscsi_target_parameters.h"
30 #include "iscsi_target_seq_pdu_list.h"
31 #include "iscsi_target_datain_values.h"
32 #include "iscsi_target_erl0.h"
33 #include "iscsi_target_erl1.h"
34 #include "iscsi_target_erl2.h"
35 #include "iscsi_target_tpg.h"
36 #include "iscsi_target_util.h"
37 #include "iscsi_target.h"
38 
39 #define PRINT_BUFF(buff, len)					\
40 {								\
41 	int zzz;						\
42 								\
43 	pr_debug("%d:\n", __LINE__);				\
44 	for (zzz = 0; zzz < len; zzz++) {			\
45 		if (zzz % 16 == 0) {				\
46 			if (zzz)				\
47 				pr_debug("\n");			\
48 			pr_debug("%4i: ", zzz);			\
49 		}						\
50 		pr_debug("%02x ", (unsigned char) (buff)[zzz]);	\
51 	}							\
52 	if ((len + 1) % 16)					\
53 		pr_debug("\n");					\
54 }
55 
56 extern struct list_head g_tiqn_list;
57 extern spinlock_t tiqn_lock;
58 
59 /*
60  *	Called with cmd->r2t_lock held.
61  */
62 int iscsit_add_r2t_to_list(
63 	struct iscsi_cmd *cmd,
64 	u32 offset,
65 	u32 xfer_len,
66 	int recovery,
67 	u32 r2t_sn)
68 {
69 	struct iscsi_r2t *r2t;
70 
71 	r2t = kmem_cache_zalloc(lio_r2t_cache, GFP_ATOMIC);
72 	if (!r2t) {
73 		pr_err("Unable to allocate memory for struct iscsi_r2t.\n");
74 		return -1;
75 	}
76 	INIT_LIST_HEAD(&r2t->r2t_list);
77 
78 	r2t->recovery_r2t = recovery;
79 	r2t->r2t_sn = (!r2t_sn) ? cmd->r2t_sn++ : r2t_sn;
80 	r2t->offset = offset;
81 	r2t->xfer_len = xfer_len;
82 	list_add_tail(&r2t->r2t_list, &cmd->cmd_r2t_list);
83 	spin_unlock_bh(&cmd->r2t_lock);
84 
85 	iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, ISTATE_SEND_R2T);
86 
87 	spin_lock_bh(&cmd->r2t_lock);
88 	return 0;
89 }
90 
91 struct iscsi_r2t *iscsit_get_r2t_for_eos(
92 	struct iscsi_cmd *cmd,
93 	u32 offset,
94 	u32 length)
95 {
96 	struct iscsi_r2t *r2t;
97 
98 	spin_lock_bh(&cmd->r2t_lock);
99 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
100 		if ((r2t->offset <= offset) &&
101 		    (r2t->offset + r2t->xfer_len) >= (offset + length)) {
102 			spin_unlock_bh(&cmd->r2t_lock);
103 			return r2t;
104 		}
105 	}
106 	spin_unlock_bh(&cmd->r2t_lock);
107 
108 	pr_err("Unable to locate R2T for Offset: %u, Length:"
109 			" %u\n", offset, length);
110 	return NULL;
111 }
112 
113 struct iscsi_r2t *iscsit_get_r2t_from_list(struct iscsi_cmd *cmd)
114 {
115 	struct iscsi_r2t *r2t;
116 
117 	spin_lock_bh(&cmd->r2t_lock);
118 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
119 		if (!r2t->sent_r2t) {
120 			spin_unlock_bh(&cmd->r2t_lock);
121 			return r2t;
122 		}
123 	}
124 	spin_unlock_bh(&cmd->r2t_lock);
125 
126 	pr_err("Unable to locate next R2T to send for ITT:"
127 			" 0x%08x.\n", cmd->init_task_tag);
128 	return NULL;
129 }
130 
131 /*
132  *	Called with cmd->r2t_lock held.
133  */
134 void iscsit_free_r2t(struct iscsi_r2t *r2t, struct iscsi_cmd *cmd)
135 {
136 	list_del(&r2t->r2t_list);
137 	kmem_cache_free(lio_r2t_cache, r2t);
138 }
139 
140 void iscsit_free_r2ts_from_list(struct iscsi_cmd *cmd)
141 {
142 	struct iscsi_r2t *r2t, *r2t_tmp;
143 
144 	spin_lock_bh(&cmd->r2t_lock);
145 	list_for_each_entry_safe(r2t, r2t_tmp, &cmd->cmd_r2t_list, r2t_list)
146 		iscsit_free_r2t(r2t, cmd);
147 	spin_unlock_bh(&cmd->r2t_lock);
148 }
149 
150 /*
151  * May be called from software interrupt (timer) context for allocating
152  * iSCSI NopINs.
153  */
154 struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn *conn, int state)
155 {
156 	struct iscsi_cmd *cmd;
157 	struct se_session *se_sess = conn->sess->se_sess;
158 	int size, tag;
159 
160 	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, state);
161 	if (tag < 0)
162 		return NULL;
163 
164 	size = sizeof(struct iscsi_cmd) + conn->conn_transport->priv_size;
165 	cmd = (struct iscsi_cmd *)(se_sess->sess_cmd_map + (tag * size));
166 	memset(cmd, 0, size);
167 
168 	cmd->se_cmd.map_tag = tag;
169 	cmd->conn = conn;
170 	INIT_LIST_HEAD(&cmd->i_conn_node);
171 	INIT_LIST_HEAD(&cmd->datain_list);
172 	INIT_LIST_HEAD(&cmd->cmd_r2t_list);
173 	spin_lock_init(&cmd->datain_lock);
174 	spin_lock_init(&cmd->dataout_timeout_lock);
175 	spin_lock_init(&cmd->istate_lock);
176 	spin_lock_init(&cmd->error_lock);
177 	spin_lock_init(&cmd->r2t_lock);
178 
179 	return cmd;
180 }
181 EXPORT_SYMBOL(iscsit_allocate_cmd);
182 
183 struct iscsi_seq *iscsit_get_seq_holder_for_datain(
184 	struct iscsi_cmd *cmd,
185 	u32 seq_send_order)
186 {
187 	u32 i;
188 
189 	for (i = 0; i < cmd->seq_count; i++)
190 		if (cmd->seq_list[i].seq_send_order == seq_send_order)
191 			return &cmd->seq_list[i];
192 
193 	return NULL;
194 }
195 
196 struct iscsi_seq *iscsit_get_seq_holder_for_r2t(struct iscsi_cmd *cmd)
197 {
198 	u32 i;
199 
200 	if (!cmd->seq_list) {
201 		pr_err("struct iscsi_cmd->seq_list is NULL!\n");
202 		return NULL;
203 	}
204 
205 	for (i = 0; i < cmd->seq_count; i++) {
206 		if (cmd->seq_list[i].type != SEQTYPE_NORMAL)
207 			continue;
208 		if (cmd->seq_list[i].seq_send_order == cmd->seq_send_order) {
209 			cmd->seq_send_order++;
210 			return &cmd->seq_list[i];
211 		}
212 	}
213 
214 	return NULL;
215 }
216 
217 struct iscsi_r2t *iscsit_get_holder_for_r2tsn(
218 	struct iscsi_cmd *cmd,
219 	u32 r2t_sn)
220 {
221 	struct iscsi_r2t *r2t;
222 
223 	spin_lock_bh(&cmd->r2t_lock);
224 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
225 		if (r2t->r2t_sn == r2t_sn) {
226 			spin_unlock_bh(&cmd->r2t_lock);
227 			return r2t;
228 		}
229 	}
230 	spin_unlock_bh(&cmd->r2t_lock);
231 
232 	return NULL;
233 }
234 
235 static inline int iscsit_check_received_cmdsn(struct iscsi_session *sess, u32 cmdsn)
236 {
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 	if (iscsi_sna_gt(cmdsn, sess->max_cmd_sn)) {
246 		pr_err("Received CmdSN: 0x%08x is greater than"
247 		       " MaxCmdSN: 0x%08x, ignoring.\n", cmdsn,
248 		       sess->max_cmd_sn);
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 
518 struct iscsi_queue_req *iscsit_get_cmd_from_immediate_queue(struct iscsi_conn *conn)
519 {
520 	struct iscsi_queue_req *qr;
521 
522 	spin_lock_bh(&conn->immed_queue_lock);
523 	if (list_empty(&conn->immed_queue_list)) {
524 		spin_unlock_bh(&conn->immed_queue_lock);
525 		return NULL;
526 	}
527 	qr = list_first_entry(&conn->immed_queue_list,
528 			      struct iscsi_queue_req, qr_list);
529 
530 	list_del(&qr->qr_list);
531 	if (qr->cmd)
532 		atomic_dec(&qr->cmd->immed_queue_count);
533 	spin_unlock_bh(&conn->immed_queue_lock);
534 
535 	return qr;
536 }
537 
538 static void iscsit_remove_cmd_from_immediate_queue(
539 	struct iscsi_cmd *cmd,
540 	struct iscsi_conn *conn)
541 {
542 	struct iscsi_queue_req *qr, *qr_tmp;
543 
544 	spin_lock_bh(&conn->immed_queue_lock);
545 	if (!atomic_read(&cmd->immed_queue_count)) {
546 		spin_unlock_bh(&conn->immed_queue_lock);
547 		return;
548 	}
549 
550 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
551 		if (qr->cmd != cmd)
552 			continue;
553 
554 		atomic_dec(&qr->cmd->immed_queue_count);
555 		list_del(&qr->qr_list);
556 		kmem_cache_free(lio_qr_cache, qr);
557 	}
558 	spin_unlock_bh(&conn->immed_queue_lock);
559 
560 	if (atomic_read(&cmd->immed_queue_count)) {
561 		pr_err("ITT: 0x%08x immed_queue_count: %d\n",
562 			cmd->init_task_tag,
563 			atomic_read(&cmd->immed_queue_count));
564 	}
565 }
566 
567 void iscsit_add_cmd_to_response_queue(
568 	struct iscsi_cmd *cmd,
569 	struct iscsi_conn *conn,
570 	u8 state)
571 {
572 	struct iscsi_queue_req *qr;
573 
574 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
575 	if (!qr) {
576 		pr_err("Unable to allocate memory for"
577 			" struct iscsi_queue_req\n");
578 		return;
579 	}
580 	INIT_LIST_HEAD(&qr->qr_list);
581 	qr->cmd = cmd;
582 	qr->state = state;
583 
584 	spin_lock_bh(&conn->response_queue_lock);
585 	list_add_tail(&qr->qr_list, &conn->response_queue_list);
586 	atomic_inc(&cmd->response_queue_count);
587 	spin_unlock_bh(&conn->response_queue_lock);
588 
589 	wake_up(&conn->queues_wq);
590 }
591 
592 struct iscsi_queue_req *iscsit_get_cmd_from_response_queue(struct iscsi_conn *conn)
593 {
594 	struct iscsi_queue_req *qr;
595 
596 	spin_lock_bh(&conn->response_queue_lock);
597 	if (list_empty(&conn->response_queue_list)) {
598 		spin_unlock_bh(&conn->response_queue_lock);
599 		return NULL;
600 	}
601 
602 	qr = list_first_entry(&conn->response_queue_list,
603 			      struct iscsi_queue_req, qr_list);
604 
605 	list_del(&qr->qr_list);
606 	if (qr->cmd)
607 		atomic_dec(&qr->cmd->response_queue_count);
608 	spin_unlock_bh(&conn->response_queue_lock);
609 
610 	return qr;
611 }
612 
613 static void iscsit_remove_cmd_from_response_queue(
614 	struct iscsi_cmd *cmd,
615 	struct iscsi_conn *conn)
616 {
617 	struct iscsi_queue_req *qr, *qr_tmp;
618 
619 	spin_lock_bh(&conn->response_queue_lock);
620 	if (!atomic_read(&cmd->response_queue_count)) {
621 		spin_unlock_bh(&conn->response_queue_lock);
622 		return;
623 	}
624 
625 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
626 				qr_list) {
627 		if (qr->cmd != cmd)
628 			continue;
629 
630 		atomic_dec(&qr->cmd->response_queue_count);
631 		list_del(&qr->qr_list);
632 		kmem_cache_free(lio_qr_cache, qr);
633 	}
634 	spin_unlock_bh(&conn->response_queue_lock);
635 
636 	if (atomic_read(&cmd->response_queue_count)) {
637 		pr_err("ITT: 0x%08x response_queue_count: %d\n",
638 			cmd->init_task_tag,
639 			atomic_read(&cmd->response_queue_count));
640 	}
641 }
642 
643 bool iscsit_conn_all_queues_empty(struct iscsi_conn *conn)
644 {
645 	bool empty;
646 
647 	spin_lock_bh(&conn->immed_queue_lock);
648 	empty = list_empty(&conn->immed_queue_list);
649 	spin_unlock_bh(&conn->immed_queue_lock);
650 
651 	if (!empty)
652 		return empty;
653 
654 	spin_lock_bh(&conn->response_queue_lock);
655 	empty = list_empty(&conn->response_queue_list);
656 	spin_unlock_bh(&conn->response_queue_lock);
657 
658 	return empty;
659 }
660 
661 void iscsit_free_queue_reqs_for_conn(struct iscsi_conn *conn)
662 {
663 	struct iscsi_queue_req *qr, *qr_tmp;
664 
665 	spin_lock_bh(&conn->immed_queue_lock);
666 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
667 		list_del(&qr->qr_list);
668 		if (qr->cmd)
669 			atomic_dec(&qr->cmd->immed_queue_count);
670 
671 		kmem_cache_free(lio_qr_cache, qr);
672 	}
673 	spin_unlock_bh(&conn->immed_queue_lock);
674 
675 	spin_lock_bh(&conn->response_queue_lock);
676 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
677 			qr_list) {
678 		list_del(&qr->qr_list);
679 		if (qr->cmd)
680 			atomic_dec(&qr->cmd->response_queue_count);
681 
682 		kmem_cache_free(lio_qr_cache, qr);
683 	}
684 	spin_unlock_bh(&conn->response_queue_lock);
685 }
686 
687 void iscsit_release_cmd(struct iscsi_cmd *cmd)
688 {
689 	struct iscsi_session *sess;
690 	struct se_cmd *se_cmd = &cmd->se_cmd;
691 
692 	if (cmd->conn)
693 		sess = cmd->conn->sess;
694 	else
695 		sess = cmd->sess;
696 
697 	BUG_ON(!sess || !sess->se_sess);
698 
699 	kfree(cmd->buf_ptr);
700 	kfree(cmd->pdu_list);
701 	kfree(cmd->seq_list);
702 	kfree(cmd->tmr_req);
703 	kfree(cmd->iov_data);
704 	kfree(cmd->text_in_ptr);
705 
706 	percpu_ida_free(&sess->se_sess->sess_tag_pool, se_cmd->map_tag);
707 }
708 EXPORT_SYMBOL(iscsit_release_cmd);
709 
710 void __iscsit_free_cmd(struct iscsi_cmd *cmd, bool scsi_cmd,
711 		       bool check_queues)
712 {
713 	struct iscsi_conn *conn = cmd->conn;
714 
715 	if (scsi_cmd) {
716 		if (cmd->data_direction == DMA_TO_DEVICE) {
717 			iscsit_stop_dataout_timer(cmd);
718 			iscsit_free_r2ts_from_list(cmd);
719 		}
720 		if (cmd->data_direction == DMA_FROM_DEVICE)
721 			iscsit_free_all_datain_reqs(cmd);
722 	}
723 
724 	if (conn && check_queues) {
725 		iscsit_remove_cmd_from_immediate_queue(cmd, conn);
726 		iscsit_remove_cmd_from_response_queue(cmd, conn);
727 	}
728 }
729 
730 void iscsit_free_cmd(struct iscsi_cmd *cmd, bool shutdown)
731 {
732 	struct se_cmd *se_cmd = NULL;
733 	int rc;
734 	/*
735 	 * Determine if a struct se_cmd is associated with
736 	 * this struct iscsi_cmd.
737 	 */
738 	switch (cmd->iscsi_opcode) {
739 	case ISCSI_OP_SCSI_CMD:
740 		se_cmd = &cmd->se_cmd;
741 		__iscsit_free_cmd(cmd, true, shutdown);
742 		/*
743 		 * Fallthrough
744 		 */
745 	case ISCSI_OP_SCSI_TMFUNC:
746 		rc = transport_generic_free_cmd(&cmd->se_cmd, shutdown);
747 		if (!rc && shutdown && se_cmd && se_cmd->se_sess) {
748 			__iscsit_free_cmd(cmd, true, shutdown);
749 			target_put_sess_cmd(se_cmd->se_sess, se_cmd);
750 		}
751 		break;
752 	case ISCSI_OP_REJECT:
753 		/*
754 		 * Handle special case for REJECT when iscsi_add_reject*() has
755 		 * overwritten the original iscsi_opcode assignment, and the
756 		 * associated cmd->se_cmd needs to be released.
757 		 */
758 		if (cmd->se_cmd.se_tfo != NULL) {
759 			se_cmd = &cmd->se_cmd;
760 			__iscsit_free_cmd(cmd, true, shutdown);
761 
762 			rc = transport_generic_free_cmd(&cmd->se_cmd, shutdown);
763 			if (!rc && shutdown && se_cmd->se_sess) {
764 				__iscsit_free_cmd(cmd, true, shutdown);
765 				target_put_sess_cmd(se_cmd->se_sess, se_cmd);
766 			}
767 			break;
768 		}
769 		/* Fall-through */
770 	default:
771 		__iscsit_free_cmd(cmd, false, shutdown);
772 		iscsit_release_cmd(cmd);
773 		break;
774 	}
775 }
776 
777 int iscsit_check_session_usage_count(struct iscsi_session *sess)
778 {
779 	spin_lock_bh(&sess->session_usage_lock);
780 	if (sess->session_usage_count != 0) {
781 		sess->session_waiting_on_uc = 1;
782 		spin_unlock_bh(&sess->session_usage_lock);
783 		if (in_interrupt())
784 			return 2;
785 
786 		wait_for_completion(&sess->session_waiting_on_uc_comp);
787 		return 1;
788 	}
789 	spin_unlock_bh(&sess->session_usage_lock);
790 
791 	return 0;
792 }
793 
794 void iscsit_dec_session_usage_count(struct iscsi_session *sess)
795 {
796 	spin_lock_bh(&sess->session_usage_lock);
797 	sess->session_usage_count--;
798 
799 	if (!sess->session_usage_count && sess->session_waiting_on_uc)
800 		complete(&sess->session_waiting_on_uc_comp);
801 
802 	spin_unlock_bh(&sess->session_usage_lock);
803 }
804 
805 void iscsit_inc_session_usage_count(struct iscsi_session *sess)
806 {
807 	spin_lock_bh(&sess->session_usage_lock);
808 	sess->session_usage_count++;
809 	spin_unlock_bh(&sess->session_usage_lock);
810 }
811 
812 /*
813  *	Setup conn->if_marker and conn->of_marker values based upon
814  *	the initial marker-less interval. (see iSCSI v19 A.2)
815  */
816 int iscsit_set_sync_and_steering_values(struct iscsi_conn *conn)
817 {
818 	int login_ifmarker_count = 0, login_ofmarker_count = 0, next_marker = 0;
819 	/*
820 	 * IFMarkInt and OFMarkInt are negotiated as 32-bit words.
821 	 */
822 	u32 IFMarkInt = (conn->conn_ops->IFMarkInt * 4);
823 	u32 OFMarkInt = (conn->conn_ops->OFMarkInt * 4);
824 
825 	if (conn->conn_ops->OFMarker) {
826 		/*
827 		 * Account for the first Login Command received not
828 		 * via iscsi_recv_msg().
829 		 */
830 		conn->of_marker += ISCSI_HDR_LEN;
831 		if (conn->of_marker <= OFMarkInt) {
832 			conn->of_marker = (OFMarkInt - conn->of_marker);
833 		} else {
834 			login_ofmarker_count = (conn->of_marker / OFMarkInt);
835 			next_marker = (OFMarkInt * (login_ofmarker_count + 1)) +
836 					(login_ofmarker_count * MARKER_SIZE);
837 			conn->of_marker = (next_marker - conn->of_marker);
838 		}
839 		conn->of_marker_offset = 0;
840 		pr_debug("Setting OFMarker value to %u based on Initial"
841 			" Markerless Interval.\n", conn->of_marker);
842 	}
843 
844 	if (conn->conn_ops->IFMarker) {
845 		if (conn->if_marker <= IFMarkInt) {
846 			conn->if_marker = (IFMarkInt - conn->if_marker);
847 		} else {
848 			login_ifmarker_count = (conn->if_marker / IFMarkInt);
849 			next_marker = (IFMarkInt * (login_ifmarker_count + 1)) +
850 					(login_ifmarker_count * MARKER_SIZE);
851 			conn->if_marker = (next_marker - conn->if_marker);
852 		}
853 		pr_debug("Setting IFMarker value to %u based on Initial"
854 			" Markerless Interval.\n", conn->if_marker);
855 	}
856 
857 	return 0;
858 }
859 
860 struct iscsi_conn *iscsit_get_conn_from_cid(struct iscsi_session *sess, u16 cid)
861 {
862 	struct iscsi_conn *conn;
863 
864 	spin_lock_bh(&sess->conn_lock);
865 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
866 		if ((conn->cid == cid) &&
867 		    (conn->conn_state == TARG_CONN_STATE_LOGGED_IN)) {
868 			iscsit_inc_conn_usage_count(conn);
869 			spin_unlock_bh(&sess->conn_lock);
870 			return conn;
871 		}
872 	}
873 	spin_unlock_bh(&sess->conn_lock);
874 
875 	return NULL;
876 }
877 
878 struct iscsi_conn *iscsit_get_conn_from_cid_rcfr(struct iscsi_session *sess, u16 cid)
879 {
880 	struct iscsi_conn *conn;
881 
882 	spin_lock_bh(&sess->conn_lock);
883 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
884 		if (conn->cid == cid) {
885 			iscsit_inc_conn_usage_count(conn);
886 			spin_lock(&conn->state_lock);
887 			atomic_set(&conn->connection_wait_rcfr, 1);
888 			spin_unlock(&conn->state_lock);
889 			spin_unlock_bh(&sess->conn_lock);
890 			return conn;
891 		}
892 	}
893 	spin_unlock_bh(&sess->conn_lock);
894 
895 	return NULL;
896 }
897 
898 void iscsit_check_conn_usage_count(struct iscsi_conn *conn)
899 {
900 	spin_lock_bh(&conn->conn_usage_lock);
901 	if (conn->conn_usage_count != 0) {
902 		conn->conn_waiting_on_uc = 1;
903 		spin_unlock_bh(&conn->conn_usage_lock);
904 
905 		wait_for_completion(&conn->conn_waiting_on_uc_comp);
906 		return;
907 	}
908 	spin_unlock_bh(&conn->conn_usage_lock);
909 }
910 
911 void iscsit_dec_conn_usage_count(struct iscsi_conn *conn)
912 {
913 	spin_lock_bh(&conn->conn_usage_lock);
914 	conn->conn_usage_count--;
915 
916 	if (!conn->conn_usage_count && conn->conn_waiting_on_uc)
917 		complete(&conn->conn_waiting_on_uc_comp);
918 
919 	spin_unlock_bh(&conn->conn_usage_lock);
920 }
921 
922 void iscsit_inc_conn_usage_count(struct iscsi_conn *conn)
923 {
924 	spin_lock_bh(&conn->conn_usage_lock);
925 	conn->conn_usage_count++;
926 	spin_unlock_bh(&conn->conn_usage_lock);
927 }
928 
929 static int iscsit_add_nopin(struct iscsi_conn *conn, int want_response)
930 {
931 	u8 state;
932 	struct iscsi_cmd *cmd;
933 
934 	cmd = iscsit_allocate_cmd(conn, TASK_RUNNING);
935 	if (!cmd)
936 		return -1;
937 
938 	cmd->iscsi_opcode = ISCSI_OP_NOOP_IN;
939 	state = (want_response) ? ISTATE_SEND_NOPIN_WANT_RESPONSE :
940 				ISTATE_SEND_NOPIN_NO_RESPONSE;
941 	cmd->init_task_tag = RESERVED_ITT;
942 	cmd->targ_xfer_tag = (want_response) ?
943 			     session_get_next_ttt(conn->sess) : 0xFFFFFFFF;
944 	spin_lock_bh(&conn->cmd_lock);
945 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
946 	spin_unlock_bh(&conn->cmd_lock);
947 
948 	if (want_response)
949 		iscsit_start_nopin_response_timer(conn);
950 	iscsit_add_cmd_to_immediate_queue(cmd, conn, state);
951 
952 	return 0;
953 }
954 
955 static void iscsit_handle_nopin_response_timeout(unsigned long data)
956 {
957 	struct iscsi_conn *conn = (struct iscsi_conn *) data;
958 
959 	iscsit_inc_conn_usage_count(conn);
960 
961 	spin_lock_bh(&conn->nopin_timer_lock);
962 	if (conn->nopin_response_timer_flags & ISCSI_TF_STOP) {
963 		spin_unlock_bh(&conn->nopin_timer_lock);
964 		iscsit_dec_conn_usage_count(conn);
965 		return;
966 	}
967 
968 	pr_debug("Did not receive response to NOPIN on CID: %hu on"
969 		" SID: %u, failing connection.\n", conn->cid,
970 			conn->sess->sid);
971 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
972 	spin_unlock_bh(&conn->nopin_timer_lock);
973 
974 	{
975 	struct iscsi_portal_group *tpg = conn->sess->tpg;
976 	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
977 
978 	if (tiqn) {
979 		spin_lock_bh(&tiqn->sess_err_stats.lock);
980 		strcpy(tiqn->sess_err_stats.last_sess_fail_rem_name,
981 				conn->sess->sess_ops->InitiatorName);
982 		tiqn->sess_err_stats.last_sess_failure_type =
983 				ISCSI_SESS_ERR_CXN_TIMEOUT;
984 		tiqn->sess_err_stats.cxn_timeout_errors++;
985 		atomic_long_inc(&conn->sess->conn_timeout_errors);
986 		spin_unlock_bh(&tiqn->sess_err_stats.lock);
987 	}
988 	}
989 
990 	iscsit_cause_connection_reinstatement(conn, 0);
991 	iscsit_dec_conn_usage_count(conn);
992 }
993 
994 void iscsit_mod_nopin_response_timer(struct iscsi_conn *conn)
995 {
996 	struct iscsi_session *sess = conn->sess;
997 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
998 
999 	spin_lock_bh(&conn->nopin_timer_lock);
1000 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
1001 		spin_unlock_bh(&conn->nopin_timer_lock);
1002 		return;
1003 	}
1004 
1005 	mod_timer(&conn->nopin_response_timer,
1006 		(get_jiffies_64() + na->nopin_response_timeout * HZ));
1007 	spin_unlock_bh(&conn->nopin_timer_lock);
1008 }
1009 
1010 /*
1011  *	Called with conn->nopin_timer_lock held.
1012  */
1013 void iscsit_start_nopin_response_timer(struct iscsi_conn *conn)
1014 {
1015 	struct iscsi_session *sess = conn->sess;
1016 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1017 
1018 	spin_lock_bh(&conn->nopin_timer_lock);
1019 	if (conn->nopin_response_timer_flags & ISCSI_TF_RUNNING) {
1020 		spin_unlock_bh(&conn->nopin_timer_lock);
1021 		return;
1022 	}
1023 
1024 	init_timer(&conn->nopin_response_timer);
1025 	conn->nopin_response_timer.expires =
1026 		(get_jiffies_64() + na->nopin_response_timeout * HZ);
1027 	conn->nopin_response_timer.data = (unsigned long)conn;
1028 	conn->nopin_response_timer.function = iscsit_handle_nopin_response_timeout;
1029 	conn->nopin_response_timer_flags &= ~ISCSI_TF_STOP;
1030 	conn->nopin_response_timer_flags |= ISCSI_TF_RUNNING;
1031 	add_timer(&conn->nopin_response_timer);
1032 
1033 	pr_debug("Started NOPIN Response Timer on CID: %d to %u"
1034 		" seconds\n", conn->cid, na->nopin_response_timeout);
1035 	spin_unlock_bh(&conn->nopin_timer_lock);
1036 }
1037 
1038 void iscsit_stop_nopin_response_timer(struct iscsi_conn *conn)
1039 {
1040 	spin_lock_bh(&conn->nopin_timer_lock);
1041 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
1042 		spin_unlock_bh(&conn->nopin_timer_lock);
1043 		return;
1044 	}
1045 	conn->nopin_response_timer_flags |= ISCSI_TF_STOP;
1046 	spin_unlock_bh(&conn->nopin_timer_lock);
1047 
1048 	del_timer_sync(&conn->nopin_response_timer);
1049 
1050 	spin_lock_bh(&conn->nopin_timer_lock);
1051 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
1052 	spin_unlock_bh(&conn->nopin_timer_lock);
1053 }
1054 
1055 static void iscsit_handle_nopin_timeout(unsigned long data)
1056 {
1057 	struct iscsi_conn *conn = (struct iscsi_conn *) data;
1058 
1059 	iscsit_inc_conn_usage_count(conn);
1060 
1061 	spin_lock_bh(&conn->nopin_timer_lock);
1062 	if (conn->nopin_timer_flags & ISCSI_TF_STOP) {
1063 		spin_unlock_bh(&conn->nopin_timer_lock);
1064 		iscsit_dec_conn_usage_count(conn);
1065 		return;
1066 	}
1067 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1068 	spin_unlock_bh(&conn->nopin_timer_lock);
1069 
1070 	iscsit_add_nopin(conn, 1);
1071 	iscsit_dec_conn_usage_count(conn);
1072 }
1073 
1074 /*
1075  * Called with conn->nopin_timer_lock held.
1076  */
1077 void __iscsit_start_nopin_timer(struct iscsi_conn *conn)
1078 {
1079 	struct iscsi_session *sess = conn->sess;
1080 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1081 	/*
1082 	* NOPIN timeout is disabled.
1083 	 */
1084 	if (!na->nopin_timeout)
1085 		return;
1086 
1087 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING)
1088 		return;
1089 
1090 	init_timer(&conn->nopin_timer);
1091 	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1092 	conn->nopin_timer.data = (unsigned long)conn;
1093 	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1094 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1095 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1096 	add_timer(&conn->nopin_timer);
1097 
1098 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1099 		" interval\n", conn->cid, na->nopin_timeout);
1100 }
1101 
1102 void iscsit_start_nopin_timer(struct iscsi_conn *conn)
1103 {
1104 	struct iscsi_session *sess = conn->sess;
1105 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1106 	/*
1107 	 * NOPIN timeout is disabled..
1108 	 */
1109 	if (!na->nopin_timeout)
1110 		return;
1111 
1112 	spin_lock_bh(&conn->nopin_timer_lock);
1113 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING) {
1114 		spin_unlock_bh(&conn->nopin_timer_lock);
1115 		return;
1116 	}
1117 
1118 	init_timer(&conn->nopin_timer);
1119 	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1120 	conn->nopin_timer.data = (unsigned long)conn;
1121 	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1122 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1123 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1124 	add_timer(&conn->nopin_timer);
1125 
1126 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1127 			" interval\n", conn->cid, na->nopin_timeout);
1128 	spin_unlock_bh(&conn->nopin_timer_lock);
1129 }
1130 
1131 void iscsit_stop_nopin_timer(struct iscsi_conn *conn)
1132 {
1133 	spin_lock_bh(&conn->nopin_timer_lock);
1134 	if (!(conn->nopin_timer_flags & ISCSI_TF_RUNNING)) {
1135 		spin_unlock_bh(&conn->nopin_timer_lock);
1136 		return;
1137 	}
1138 	conn->nopin_timer_flags |= ISCSI_TF_STOP;
1139 	spin_unlock_bh(&conn->nopin_timer_lock);
1140 
1141 	del_timer_sync(&conn->nopin_timer);
1142 
1143 	spin_lock_bh(&conn->nopin_timer_lock);
1144 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1145 	spin_unlock_bh(&conn->nopin_timer_lock);
1146 }
1147 
1148 int iscsit_send_tx_data(
1149 	struct iscsi_cmd *cmd,
1150 	struct iscsi_conn *conn,
1151 	int use_misc)
1152 {
1153 	int tx_sent, tx_size;
1154 	u32 iov_count;
1155 	struct kvec *iov;
1156 
1157 send_data:
1158 	tx_size = cmd->tx_size;
1159 
1160 	if (!use_misc) {
1161 		iov = &cmd->iov_data[0];
1162 		iov_count = cmd->iov_data_count;
1163 	} else {
1164 		iov = &cmd->iov_misc[0];
1165 		iov_count = cmd->iov_misc_count;
1166 	}
1167 
1168 	tx_sent = tx_data(conn, &iov[0], iov_count, tx_size);
1169 	if (tx_size != tx_sent) {
1170 		if (tx_sent == -EAGAIN) {
1171 			pr_err("tx_data() returned -EAGAIN\n");
1172 			goto send_data;
1173 		} else
1174 			return -1;
1175 	}
1176 	cmd->tx_size = 0;
1177 
1178 	return 0;
1179 }
1180 
1181 int iscsit_fe_sendpage_sg(
1182 	struct iscsi_cmd *cmd,
1183 	struct iscsi_conn *conn)
1184 {
1185 	struct scatterlist *sg = cmd->first_data_sg;
1186 	struct kvec iov;
1187 	u32 tx_hdr_size, data_len;
1188 	u32 offset = cmd->first_data_sg_off;
1189 	int tx_sent, iov_off;
1190 
1191 send_hdr:
1192 	tx_hdr_size = ISCSI_HDR_LEN;
1193 	if (conn->conn_ops->HeaderDigest)
1194 		tx_hdr_size += ISCSI_CRC_LEN;
1195 
1196 	iov.iov_base = cmd->pdu;
1197 	iov.iov_len = tx_hdr_size;
1198 
1199 	tx_sent = tx_data(conn, &iov, 1, tx_hdr_size);
1200 	if (tx_hdr_size != tx_sent) {
1201 		if (tx_sent == -EAGAIN) {
1202 			pr_err("tx_data() returned -EAGAIN\n");
1203 			goto send_hdr;
1204 		}
1205 		return -1;
1206 	}
1207 
1208 	data_len = cmd->tx_size - tx_hdr_size - cmd->padding;
1209 	/*
1210 	 * Set iov_off used by padding and data digest tx_data() calls below
1211 	 * in order to determine proper offset into cmd->iov_data[]
1212 	 */
1213 	if (conn->conn_ops->DataDigest) {
1214 		data_len -= ISCSI_CRC_LEN;
1215 		if (cmd->padding)
1216 			iov_off = (cmd->iov_data_count - 2);
1217 		else
1218 			iov_off = (cmd->iov_data_count - 1);
1219 	} else {
1220 		iov_off = (cmd->iov_data_count - 1);
1221 	}
1222 	/*
1223 	 * Perform sendpage() for each page in the scatterlist
1224 	 */
1225 	while (data_len) {
1226 		u32 space = (sg->length - offset);
1227 		u32 sub_len = min_t(u32, data_len, space);
1228 send_pg:
1229 		tx_sent = conn->sock->ops->sendpage(conn->sock,
1230 					sg_page(sg), sg->offset + offset, sub_len, 0);
1231 		if (tx_sent != sub_len) {
1232 			if (tx_sent == -EAGAIN) {
1233 				pr_err("tcp_sendpage() returned"
1234 						" -EAGAIN\n");
1235 				goto send_pg;
1236 			}
1237 
1238 			pr_err("tcp_sendpage() failure: %d\n",
1239 					tx_sent);
1240 			return -1;
1241 		}
1242 
1243 		data_len -= sub_len;
1244 		offset = 0;
1245 		sg = sg_next(sg);
1246 	}
1247 
1248 send_padding:
1249 	if (cmd->padding) {
1250 		struct kvec *iov_p = &cmd->iov_data[iov_off++];
1251 
1252 		tx_sent = tx_data(conn, iov_p, 1, cmd->padding);
1253 		if (cmd->padding != tx_sent) {
1254 			if (tx_sent == -EAGAIN) {
1255 				pr_err("tx_data() returned -EAGAIN\n");
1256 				goto send_padding;
1257 			}
1258 			return -1;
1259 		}
1260 	}
1261 
1262 send_datacrc:
1263 	if (conn->conn_ops->DataDigest) {
1264 		struct kvec *iov_d = &cmd->iov_data[iov_off];
1265 
1266 		tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN);
1267 		if (ISCSI_CRC_LEN != tx_sent) {
1268 			if (tx_sent == -EAGAIN) {
1269 				pr_err("tx_data() returned -EAGAIN\n");
1270 				goto send_datacrc;
1271 			}
1272 			return -1;
1273 		}
1274 	}
1275 
1276 	return 0;
1277 }
1278 
1279 /*
1280  *      This function is used for mainly sending a ISCSI_TARG_LOGIN_RSP PDU
1281  *      back to the Initiator when an expection condition occurs with the
1282  *      errors set in status_class and status_detail.
1283  *
1284  *      Parameters:     iSCSI Connection, Status Class, Status Detail.
1285  *      Returns:        0 on success, -1 on error.
1286  */
1287 int iscsit_tx_login_rsp(struct iscsi_conn *conn, u8 status_class, u8 status_detail)
1288 {
1289 	struct iscsi_login_rsp *hdr;
1290 	struct iscsi_login *login = conn->conn_login;
1291 
1292 	login->login_failed = 1;
1293 	iscsit_collect_login_stats(conn, status_class, status_detail);
1294 
1295 	memset(&login->rsp[0], 0, ISCSI_HDR_LEN);
1296 
1297 	hdr	= (struct iscsi_login_rsp *)&login->rsp[0];
1298 	hdr->opcode		= ISCSI_OP_LOGIN_RSP;
1299 	hdr->status_class	= status_class;
1300 	hdr->status_detail	= status_detail;
1301 	hdr->itt		= conn->login_itt;
1302 
1303 	return conn->conn_transport->iscsit_put_login_tx(conn, login, 0);
1304 }
1305 
1306 void iscsit_print_session_params(struct iscsi_session *sess)
1307 {
1308 	struct iscsi_conn *conn;
1309 
1310 	pr_debug("-----------------------------[Session Params for"
1311 		" SID: %u]-----------------------------\n", sess->sid);
1312 	spin_lock_bh(&sess->conn_lock);
1313 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
1314 		iscsi_dump_conn_ops(conn->conn_ops);
1315 	spin_unlock_bh(&sess->conn_lock);
1316 
1317 	iscsi_dump_sess_ops(sess->sess_ops);
1318 }
1319 
1320 static int iscsit_do_rx_data(
1321 	struct iscsi_conn *conn,
1322 	struct iscsi_data_count *count)
1323 {
1324 	int data = count->data_length, rx_loop = 0, total_rx = 0;
1325 	struct msghdr msg;
1326 
1327 	if (!conn || !conn->sock || !conn->conn_ops)
1328 		return -1;
1329 
1330 	memset(&msg, 0, sizeof(struct msghdr));
1331 	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC,
1332 		      count->iov, count->iov_count, data);
1333 
1334 	while (total_rx < data) {
1335 		rx_loop = sock_recvmsg(conn->sock, &msg,
1336 				      (data - total_rx), MSG_WAITALL);
1337 		if (rx_loop <= 0) {
1338 			pr_debug("rx_loop: %d total_rx: %d\n",
1339 				rx_loop, total_rx);
1340 			return rx_loop;
1341 		}
1342 		total_rx += rx_loop;
1343 		pr_debug("rx_loop: %d, total_rx: %d, data: %d\n",
1344 				rx_loop, total_rx, data);
1345 	}
1346 
1347 	return total_rx;
1348 }
1349 
1350 static int iscsit_do_tx_data(
1351 	struct iscsi_conn *conn,
1352 	struct iscsi_data_count *count)
1353 {
1354 	int ret, iov_len;
1355 	struct kvec *iov_p;
1356 	struct msghdr msg;
1357 
1358 	if (!conn || !conn->sock || !conn->conn_ops)
1359 		return -1;
1360 
1361 	if (count->data_length <= 0) {
1362 		pr_err("Data length is: %d\n", count->data_length);
1363 		return -1;
1364 	}
1365 
1366 	memset(&msg, 0, sizeof(struct msghdr));
1367 
1368 	iov_p = count->iov;
1369 	iov_len = count->iov_count;
1370 
1371 	ret = kernel_sendmsg(conn->sock, &msg, iov_p, iov_len,
1372 			     count->data_length);
1373 	if (ret != count->data_length) {
1374 		pr_err("Unexpected ret: %d send data %d\n",
1375 		       ret, count->data_length);
1376 		return -EPIPE;
1377 	}
1378 	pr_debug("ret: %d, sent data: %d\n", ret, count->data_length);
1379 
1380 	return ret;
1381 }
1382 
1383 int rx_data(
1384 	struct iscsi_conn *conn,
1385 	struct kvec *iov,
1386 	int iov_count,
1387 	int data)
1388 {
1389 	struct iscsi_data_count c;
1390 
1391 	if (!conn || !conn->sock || !conn->conn_ops)
1392 		return -1;
1393 
1394 	memset(&c, 0, sizeof(struct iscsi_data_count));
1395 	c.iov = iov;
1396 	c.iov_count = iov_count;
1397 	c.data_length = data;
1398 	c.type = ISCSI_RX_DATA;
1399 
1400 	return iscsit_do_rx_data(conn, &c);
1401 }
1402 
1403 int tx_data(
1404 	struct iscsi_conn *conn,
1405 	struct kvec *iov,
1406 	int iov_count,
1407 	int data)
1408 {
1409 	struct iscsi_data_count c;
1410 
1411 	if (!conn || !conn->sock || !conn->conn_ops)
1412 		return -1;
1413 
1414 	memset(&c, 0, sizeof(struct iscsi_data_count));
1415 	c.iov = iov;
1416 	c.iov_count = iov_count;
1417 	c.data_length = data;
1418 	c.type = ISCSI_TX_DATA;
1419 
1420 	return iscsit_do_tx_data(conn, &c);
1421 }
1422 
1423 void iscsit_collect_login_stats(
1424 	struct iscsi_conn *conn,
1425 	u8 status_class,
1426 	u8 status_detail)
1427 {
1428 	struct iscsi_param *intrname = NULL;
1429 	struct iscsi_tiqn *tiqn;
1430 	struct iscsi_login_stats *ls;
1431 
1432 	tiqn = iscsit_snmp_get_tiqn(conn);
1433 	if (!tiqn)
1434 		return;
1435 
1436 	ls = &tiqn->login_stats;
1437 
1438 	spin_lock(&ls->lock);
1439 	if (!strcmp(conn->login_ip, ls->last_intr_fail_ip_addr) &&
1440 	    ((get_jiffies_64() - ls->last_fail_time) < 10)) {
1441 		/* We already have the failure info for this login */
1442 		spin_unlock(&ls->lock);
1443 		return;
1444 	}
1445 
1446 	if (status_class == ISCSI_STATUS_CLS_SUCCESS)
1447 		ls->accepts++;
1448 	else if (status_class == ISCSI_STATUS_CLS_REDIRECT) {
1449 		ls->redirects++;
1450 		ls->last_fail_type = ISCSI_LOGIN_FAIL_REDIRECT;
1451 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1452 		 (status_detail == ISCSI_LOGIN_STATUS_AUTH_FAILED)) {
1453 		ls->authenticate_fails++;
1454 		ls->last_fail_type =  ISCSI_LOGIN_FAIL_AUTHENTICATE;
1455 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1456 		 (status_detail == ISCSI_LOGIN_STATUS_TGT_FORBIDDEN)) {
1457 		ls->authorize_fails++;
1458 		ls->last_fail_type = ISCSI_LOGIN_FAIL_AUTHORIZE;
1459 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR) &&
1460 		 (status_detail == ISCSI_LOGIN_STATUS_INIT_ERR)) {
1461 		ls->negotiate_fails++;
1462 		ls->last_fail_type = ISCSI_LOGIN_FAIL_NEGOTIATE;
1463 	} else {
1464 		ls->other_fails++;
1465 		ls->last_fail_type = ISCSI_LOGIN_FAIL_OTHER;
1466 	}
1467 
1468 	/* Save initiator name, ip address and time, if it is a failed login */
1469 	if (status_class != ISCSI_STATUS_CLS_SUCCESS) {
1470 		if (conn->param_list)
1471 			intrname = iscsi_find_param_from_key(INITIATORNAME,
1472 							     conn->param_list);
1473 		strlcpy(ls->last_intr_fail_name,
1474 		       (intrname ? intrname->value : "Unknown"),
1475 		       sizeof(ls->last_intr_fail_name));
1476 
1477 		ls->last_intr_fail_ip_family = conn->login_family;
1478 
1479 		snprintf(ls->last_intr_fail_ip_addr, IPV6_ADDRESS_SPACE,
1480 				"%s", conn->login_ip);
1481 		ls->last_fail_time = get_jiffies_64();
1482 	}
1483 
1484 	spin_unlock(&ls->lock);
1485 }
1486 
1487 struct iscsi_tiqn *iscsit_snmp_get_tiqn(struct iscsi_conn *conn)
1488 {
1489 	struct iscsi_portal_group *tpg;
1490 
1491 	if (!conn || !conn->sess)
1492 		return NULL;
1493 
1494 	tpg = conn->sess->tpg;
1495 	if (!tpg)
1496 		return NULL;
1497 
1498 	if (!tpg->tpg_tiqn)
1499 		return NULL;
1500 
1501 	return tpg->tpg_tiqn;
1502 }
1503