1 /*******************************************************************************
2  * This file contains the iSCSI Target specific utility functions.
3  *
4  * \u00a9 Copyright 2007-2011 RisingTide Systems LLC.
5  *
6  * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
7  *
8  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  ******************************************************************************/
20 
21 #include <linux/list.h>
22 #include <scsi/scsi_tcq.h>
23 #include <scsi/iscsi_proto.h>
24 #include <target/target_core_base.h>
25 #include <target/target_core_fabric.h>
26 #include <target/target_core_configfs.h>
27 #include <target/iscsi/iscsi_transport.h>
28 
29 #include "iscsi_target_core.h"
30 #include "iscsi_target_parameters.h"
31 #include "iscsi_target_seq_pdu_list.h"
32 #include "iscsi_target_datain_values.h"
33 #include "iscsi_target_erl0.h"
34 #include "iscsi_target_erl1.h"
35 #include "iscsi_target_erl2.h"
36 #include "iscsi_target_tpg.h"
37 #include "iscsi_target_tq.h"
38 #include "iscsi_target_util.h"
39 #include "iscsi_target.h"
40 
41 #define PRINT_BUFF(buff, len)					\
42 {								\
43 	int zzz;						\
44 								\
45 	pr_debug("%d:\n", __LINE__);				\
46 	for (zzz = 0; zzz < len; zzz++) {			\
47 		if (zzz % 16 == 0) {				\
48 			if (zzz)				\
49 				pr_debug("\n");			\
50 			pr_debug("%4i: ", zzz);			\
51 		}						\
52 		pr_debug("%02x ", (unsigned char) (buff)[zzz]);	\
53 	}							\
54 	if ((len + 1) % 16)					\
55 		pr_debug("\n");					\
56 }
57 
58 extern struct list_head g_tiqn_list;
59 extern spinlock_t tiqn_lock;
60 
61 /*
62  *	Called with cmd->r2t_lock held.
63  */
64 int iscsit_add_r2t_to_list(
65 	struct iscsi_cmd *cmd,
66 	u32 offset,
67 	u32 xfer_len,
68 	int recovery,
69 	u32 r2t_sn)
70 {
71 	struct iscsi_r2t *r2t;
72 
73 	r2t = kmem_cache_zalloc(lio_r2t_cache, GFP_ATOMIC);
74 	if (!r2t) {
75 		pr_err("Unable to allocate memory for struct iscsi_r2t.\n");
76 		return -1;
77 	}
78 	INIT_LIST_HEAD(&r2t->r2t_list);
79 
80 	r2t->recovery_r2t = recovery;
81 	r2t->r2t_sn = (!r2t_sn) ? cmd->r2t_sn++ : r2t_sn;
82 	r2t->offset = offset;
83 	r2t->xfer_len = xfer_len;
84 	list_add_tail(&r2t->r2t_list, &cmd->cmd_r2t_list);
85 	spin_unlock_bh(&cmd->r2t_lock);
86 
87 	iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, ISTATE_SEND_R2T);
88 
89 	spin_lock_bh(&cmd->r2t_lock);
90 	return 0;
91 }
92 
93 struct iscsi_r2t *iscsit_get_r2t_for_eos(
94 	struct iscsi_cmd *cmd,
95 	u32 offset,
96 	u32 length)
97 {
98 	struct iscsi_r2t *r2t;
99 
100 	spin_lock_bh(&cmd->r2t_lock);
101 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
102 		if ((r2t->offset <= offset) &&
103 		    (r2t->offset + r2t->xfer_len) >= (offset + length)) {
104 			spin_unlock_bh(&cmd->r2t_lock);
105 			return r2t;
106 		}
107 	}
108 	spin_unlock_bh(&cmd->r2t_lock);
109 
110 	pr_err("Unable to locate R2T for Offset: %u, Length:"
111 			" %u\n", offset, length);
112 	return NULL;
113 }
114 
115 struct iscsi_r2t *iscsit_get_r2t_from_list(struct iscsi_cmd *cmd)
116 {
117 	struct iscsi_r2t *r2t;
118 
119 	spin_lock_bh(&cmd->r2t_lock);
120 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
121 		if (!r2t->sent_r2t) {
122 			spin_unlock_bh(&cmd->r2t_lock);
123 			return r2t;
124 		}
125 	}
126 	spin_unlock_bh(&cmd->r2t_lock);
127 
128 	pr_err("Unable to locate next R2T to send for ITT:"
129 			" 0x%08x.\n", cmd->init_task_tag);
130 	return NULL;
131 }
132 
133 /*
134  *	Called with cmd->r2t_lock held.
135  */
136 void iscsit_free_r2t(struct iscsi_r2t *r2t, struct iscsi_cmd *cmd)
137 {
138 	list_del(&r2t->r2t_list);
139 	kmem_cache_free(lio_r2t_cache, r2t);
140 }
141 
142 void iscsit_free_r2ts_from_list(struct iscsi_cmd *cmd)
143 {
144 	struct iscsi_r2t *r2t, *r2t_tmp;
145 
146 	spin_lock_bh(&cmd->r2t_lock);
147 	list_for_each_entry_safe(r2t, r2t_tmp, &cmd->cmd_r2t_list, r2t_list)
148 		iscsit_free_r2t(r2t, cmd);
149 	spin_unlock_bh(&cmd->r2t_lock);
150 }
151 
152 struct iscsi_cmd *iscsit_alloc_cmd(struct iscsi_conn *conn, gfp_t gfp_mask)
153 {
154 	struct iscsi_cmd *cmd;
155 
156 	cmd = kmem_cache_zalloc(lio_cmd_cache, gfp_mask);
157 	if (!cmd)
158 		return NULL;
159 
160 	cmd->release_cmd = &iscsit_release_cmd;
161 	return cmd;
162 }
163 
164 /*
165  * May be called from software interrupt (timer) context for allocating
166  * iSCSI NopINs.
167  */
168 struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn *conn, gfp_t gfp_mask)
169 {
170 	struct iscsi_cmd *cmd;
171 
172 	cmd = conn->conn_transport->iscsit_alloc_cmd(conn, gfp_mask);
173 	if (!cmd) {
174 		pr_err("Unable to allocate memory for struct iscsi_cmd.\n");
175 		return NULL;
176 	}
177 	cmd->conn = conn;
178 	INIT_LIST_HEAD(&cmd->i_conn_node);
179 	INIT_LIST_HEAD(&cmd->datain_list);
180 	INIT_LIST_HEAD(&cmd->cmd_r2t_list);
181 	spin_lock_init(&cmd->datain_lock);
182 	spin_lock_init(&cmd->dataout_timeout_lock);
183 	spin_lock_init(&cmd->istate_lock);
184 	spin_lock_init(&cmd->error_lock);
185 	spin_lock_init(&cmd->r2t_lock);
186 
187 	return cmd;
188 }
189 EXPORT_SYMBOL(iscsit_allocate_cmd);
190 
191 struct iscsi_seq *iscsit_get_seq_holder_for_datain(
192 	struct iscsi_cmd *cmd,
193 	u32 seq_send_order)
194 {
195 	u32 i;
196 
197 	for (i = 0; i < cmd->seq_count; i++)
198 		if (cmd->seq_list[i].seq_send_order == seq_send_order)
199 			return &cmd->seq_list[i];
200 
201 	return NULL;
202 }
203 
204 struct iscsi_seq *iscsit_get_seq_holder_for_r2t(struct iscsi_cmd *cmd)
205 {
206 	u32 i;
207 
208 	if (!cmd->seq_list) {
209 		pr_err("struct iscsi_cmd->seq_list is NULL!\n");
210 		return NULL;
211 	}
212 
213 	for (i = 0; i < cmd->seq_count; i++) {
214 		if (cmd->seq_list[i].type != SEQTYPE_NORMAL)
215 			continue;
216 		if (cmd->seq_list[i].seq_send_order == cmd->seq_send_order) {
217 			cmd->seq_send_order++;
218 			return &cmd->seq_list[i];
219 		}
220 	}
221 
222 	return NULL;
223 }
224 
225 struct iscsi_r2t *iscsit_get_holder_for_r2tsn(
226 	struct iscsi_cmd *cmd,
227 	u32 r2t_sn)
228 {
229 	struct iscsi_r2t *r2t;
230 
231 	spin_lock_bh(&cmd->r2t_lock);
232 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
233 		if (r2t->r2t_sn == r2t_sn) {
234 			spin_unlock_bh(&cmd->r2t_lock);
235 			return r2t;
236 		}
237 	}
238 	spin_unlock_bh(&cmd->r2t_lock);
239 
240 	return NULL;
241 }
242 
243 static inline int iscsit_check_received_cmdsn(struct iscsi_session *sess, u32 cmdsn)
244 {
245 	int ret;
246 
247 	/*
248 	 * This is the proper method of checking received CmdSN against
249 	 * ExpCmdSN and MaxCmdSN values, as well as accounting for out
250 	 * or order CmdSNs due to multiple connection sessions and/or
251 	 * CRC failures.
252 	 */
253 	if (iscsi_sna_gt(cmdsn, sess->max_cmd_sn)) {
254 		pr_err("Received CmdSN: 0x%08x is greater than"
255 		       " MaxCmdSN: 0x%08x, protocol error.\n", cmdsn,
256 		       sess->max_cmd_sn);
257 		ret = CMDSN_ERROR_CANNOT_RECOVER;
258 
259 	} else if (cmdsn == sess->exp_cmd_sn) {
260 		sess->exp_cmd_sn++;
261 		pr_debug("Received CmdSN matches ExpCmdSN,"
262 		      " incremented ExpCmdSN to: 0x%08x\n",
263 		      sess->exp_cmd_sn);
264 		ret = CMDSN_NORMAL_OPERATION;
265 
266 	} else if (iscsi_sna_gt(cmdsn, sess->exp_cmd_sn)) {
267 		pr_debug("Received CmdSN: 0x%08x is greater"
268 		      " than ExpCmdSN: 0x%08x, not acknowledging.\n",
269 		      cmdsn, sess->exp_cmd_sn);
270 		ret = CMDSN_HIGHER_THAN_EXP;
271 
272 	} else {
273 		pr_err("Received CmdSN: 0x%08x is less than"
274 		       " ExpCmdSN: 0x%08x, ignoring.\n", cmdsn,
275 		       sess->exp_cmd_sn);
276 		ret = CMDSN_LOWER_THAN_EXP;
277 	}
278 
279 	return ret;
280 }
281 
282 /*
283  * Commands may be received out of order if MC/S is in use.
284  * Ensure they are executed in CmdSN order.
285  */
286 int iscsit_sequence_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
287 			unsigned char *buf, __be32 cmdsn)
288 {
289 	int ret, cmdsn_ret;
290 	bool reject = false;
291 	u8 reason = ISCSI_REASON_BOOKMARK_NO_RESOURCES;
292 
293 	mutex_lock(&conn->sess->cmdsn_mutex);
294 
295 	cmdsn_ret = iscsit_check_received_cmdsn(conn->sess, be32_to_cpu(cmdsn));
296 	switch (cmdsn_ret) {
297 	case CMDSN_NORMAL_OPERATION:
298 		ret = iscsit_execute_cmd(cmd, 0);
299 		if ((ret >= 0) && !list_empty(&conn->sess->sess_ooo_cmdsn_list))
300 			iscsit_execute_ooo_cmdsns(conn->sess);
301 		else if (ret < 0) {
302 			reject = true;
303 			ret = CMDSN_ERROR_CANNOT_RECOVER;
304 		}
305 		break;
306 	case CMDSN_HIGHER_THAN_EXP:
307 		ret = iscsit_handle_ooo_cmdsn(conn->sess, cmd, be32_to_cpu(cmdsn));
308 		if (ret < 0) {
309 			reject = true;
310 			ret = CMDSN_ERROR_CANNOT_RECOVER;
311 			break;
312 		}
313 		ret = CMDSN_HIGHER_THAN_EXP;
314 		break;
315 	case CMDSN_LOWER_THAN_EXP:
316 		cmd->i_state = ISTATE_REMOVE;
317 		iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
318 		ret = cmdsn_ret;
319 		break;
320 	default:
321 		reason = ISCSI_REASON_PROTOCOL_ERROR;
322 		reject = true;
323 		ret = cmdsn_ret;
324 		break;
325 	}
326 	mutex_unlock(&conn->sess->cmdsn_mutex);
327 
328 	if (reject)
329 		iscsit_reject_cmd(cmd, reason, buf);
330 
331 	return ret;
332 }
333 EXPORT_SYMBOL(iscsit_sequence_cmd);
334 
335 int iscsit_check_unsolicited_dataout(struct iscsi_cmd *cmd, unsigned char *buf)
336 {
337 	struct iscsi_conn *conn = cmd->conn;
338 	struct se_cmd *se_cmd = &cmd->se_cmd;
339 	struct iscsi_data *hdr = (struct iscsi_data *) buf;
340 	u32 payload_length = ntoh24(hdr->dlength);
341 
342 	if (conn->sess->sess_ops->InitialR2T) {
343 		pr_err("Received unexpected unsolicited data"
344 			" while InitialR2T=Yes, protocol error.\n");
345 		transport_send_check_condition_and_sense(se_cmd,
346 				TCM_UNEXPECTED_UNSOLICITED_DATA, 0);
347 		return -1;
348 	}
349 
350 	if ((cmd->first_burst_len + payload_length) >
351 	     conn->sess->sess_ops->FirstBurstLength) {
352 		pr_err("Total %u bytes exceeds FirstBurstLength: %u"
353 			" for this Unsolicited DataOut Burst.\n",
354 			(cmd->first_burst_len + payload_length),
355 				conn->sess->sess_ops->FirstBurstLength);
356 		transport_send_check_condition_and_sense(se_cmd,
357 				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
358 		return -1;
359 	}
360 
361 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL))
362 		return 0;
363 
364 	if (((cmd->first_burst_len + payload_length) != cmd->se_cmd.data_length) &&
365 	    ((cmd->first_burst_len + payload_length) !=
366 	      conn->sess->sess_ops->FirstBurstLength)) {
367 		pr_err("Unsolicited non-immediate data received %u"
368 			" does not equal FirstBurstLength: %u, and does"
369 			" not equal ExpXferLen %u.\n",
370 			(cmd->first_burst_len + payload_length),
371 			conn->sess->sess_ops->FirstBurstLength, cmd->se_cmd.data_length);
372 		transport_send_check_condition_and_sense(se_cmd,
373 				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
374 		return -1;
375 	}
376 	return 0;
377 }
378 
379 struct iscsi_cmd *iscsit_find_cmd_from_itt(
380 	struct iscsi_conn *conn,
381 	itt_t init_task_tag)
382 {
383 	struct iscsi_cmd *cmd;
384 
385 	spin_lock_bh(&conn->cmd_lock);
386 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
387 		if (cmd->init_task_tag == init_task_tag) {
388 			spin_unlock_bh(&conn->cmd_lock);
389 			return cmd;
390 		}
391 	}
392 	spin_unlock_bh(&conn->cmd_lock);
393 
394 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu",
395 			init_task_tag, conn->cid);
396 	return NULL;
397 }
398 
399 struct iscsi_cmd *iscsit_find_cmd_from_itt_or_dump(
400 	struct iscsi_conn *conn,
401 	itt_t init_task_tag,
402 	u32 length)
403 {
404 	struct iscsi_cmd *cmd;
405 
406 	spin_lock_bh(&conn->cmd_lock);
407 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
408 		if (cmd->init_task_tag == init_task_tag) {
409 			spin_unlock_bh(&conn->cmd_lock);
410 			return cmd;
411 		}
412 	}
413 	spin_unlock_bh(&conn->cmd_lock);
414 
415 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu,"
416 			" dumping payload\n", init_task_tag, conn->cid);
417 	if (length)
418 		iscsit_dump_data_payload(conn, length, 1);
419 
420 	return NULL;
421 }
422 
423 struct iscsi_cmd *iscsit_find_cmd_from_ttt(
424 	struct iscsi_conn *conn,
425 	u32 targ_xfer_tag)
426 {
427 	struct iscsi_cmd *cmd = NULL;
428 
429 	spin_lock_bh(&conn->cmd_lock);
430 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
431 		if (cmd->targ_xfer_tag == targ_xfer_tag) {
432 			spin_unlock_bh(&conn->cmd_lock);
433 			return cmd;
434 		}
435 	}
436 	spin_unlock_bh(&conn->cmd_lock);
437 
438 	pr_err("Unable to locate TTT: 0x%08x on CID: %hu\n",
439 			targ_xfer_tag, conn->cid);
440 	return NULL;
441 }
442 
443 int iscsit_find_cmd_for_recovery(
444 	struct iscsi_session *sess,
445 	struct iscsi_cmd **cmd_ptr,
446 	struct iscsi_conn_recovery **cr_ptr,
447 	itt_t init_task_tag)
448 {
449 	struct iscsi_cmd *cmd = NULL;
450 	struct iscsi_conn_recovery *cr;
451 	/*
452 	 * Scan through the inactive connection recovery list's command list.
453 	 * If init_task_tag matches the command is still alligent.
454 	 */
455 	spin_lock(&sess->cr_i_lock);
456 	list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
457 		spin_lock(&cr->conn_recovery_cmd_lock);
458 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
459 			if (cmd->init_task_tag == init_task_tag) {
460 				spin_unlock(&cr->conn_recovery_cmd_lock);
461 				spin_unlock(&sess->cr_i_lock);
462 
463 				*cr_ptr = cr;
464 				*cmd_ptr = cmd;
465 				return -2;
466 			}
467 		}
468 		spin_unlock(&cr->conn_recovery_cmd_lock);
469 	}
470 	spin_unlock(&sess->cr_i_lock);
471 	/*
472 	 * Scan through the active connection recovery list's command list.
473 	 * If init_task_tag matches the command is ready to be reassigned.
474 	 */
475 	spin_lock(&sess->cr_a_lock);
476 	list_for_each_entry(cr, &sess->cr_active_list, cr_list) {
477 		spin_lock(&cr->conn_recovery_cmd_lock);
478 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
479 			if (cmd->init_task_tag == init_task_tag) {
480 				spin_unlock(&cr->conn_recovery_cmd_lock);
481 				spin_unlock(&sess->cr_a_lock);
482 
483 				*cr_ptr = cr;
484 				*cmd_ptr = cmd;
485 				return 0;
486 			}
487 		}
488 		spin_unlock(&cr->conn_recovery_cmd_lock);
489 	}
490 	spin_unlock(&sess->cr_a_lock);
491 
492 	return -1;
493 }
494 
495 void iscsit_add_cmd_to_immediate_queue(
496 	struct iscsi_cmd *cmd,
497 	struct iscsi_conn *conn,
498 	u8 state)
499 {
500 	struct iscsi_queue_req *qr;
501 
502 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
503 	if (!qr) {
504 		pr_err("Unable to allocate memory for"
505 				" struct iscsi_queue_req\n");
506 		return;
507 	}
508 	INIT_LIST_HEAD(&qr->qr_list);
509 	qr->cmd = cmd;
510 	qr->state = state;
511 
512 	spin_lock_bh(&conn->immed_queue_lock);
513 	list_add_tail(&qr->qr_list, &conn->immed_queue_list);
514 	atomic_inc(&cmd->immed_queue_count);
515 	atomic_set(&conn->check_immediate_queue, 1);
516 	spin_unlock_bh(&conn->immed_queue_lock);
517 
518 	wake_up(&conn->queues_wq);
519 }
520 
521 struct iscsi_queue_req *iscsit_get_cmd_from_immediate_queue(struct iscsi_conn *conn)
522 {
523 	struct iscsi_queue_req *qr;
524 
525 	spin_lock_bh(&conn->immed_queue_lock);
526 	if (list_empty(&conn->immed_queue_list)) {
527 		spin_unlock_bh(&conn->immed_queue_lock);
528 		return NULL;
529 	}
530 	qr = list_first_entry(&conn->immed_queue_list,
531 			      struct iscsi_queue_req, qr_list);
532 
533 	list_del(&qr->qr_list);
534 	if (qr->cmd)
535 		atomic_dec(&qr->cmd->immed_queue_count);
536 	spin_unlock_bh(&conn->immed_queue_lock);
537 
538 	return qr;
539 }
540 
541 static void iscsit_remove_cmd_from_immediate_queue(
542 	struct iscsi_cmd *cmd,
543 	struct iscsi_conn *conn)
544 {
545 	struct iscsi_queue_req *qr, *qr_tmp;
546 
547 	spin_lock_bh(&conn->immed_queue_lock);
548 	if (!atomic_read(&cmd->immed_queue_count)) {
549 		spin_unlock_bh(&conn->immed_queue_lock);
550 		return;
551 	}
552 
553 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
554 		if (qr->cmd != cmd)
555 			continue;
556 
557 		atomic_dec(&qr->cmd->immed_queue_count);
558 		list_del(&qr->qr_list);
559 		kmem_cache_free(lio_qr_cache, qr);
560 	}
561 	spin_unlock_bh(&conn->immed_queue_lock);
562 
563 	if (atomic_read(&cmd->immed_queue_count)) {
564 		pr_err("ITT: 0x%08x immed_queue_count: %d\n",
565 			cmd->init_task_tag,
566 			atomic_read(&cmd->immed_queue_count));
567 	}
568 }
569 
570 void iscsit_add_cmd_to_response_queue(
571 	struct iscsi_cmd *cmd,
572 	struct iscsi_conn *conn,
573 	u8 state)
574 {
575 	struct iscsi_queue_req *qr;
576 
577 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
578 	if (!qr) {
579 		pr_err("Unable to allocate memory for"
580 			" struct iscsi_queue_req\n");
581 		return;
582 	}
583 	INIT_LIST_HEAD(&qr->qr_list);
584 	qr->cmd = cmd;
585 	qr->state = state;
586 
587 	spin_lock_bh(&conn->response_queue_lock);
588 	list_add_tail(&qr->qr_list, &conn->response_queue_list);
589 	atomic_inc(&cmd->response_queue_count);
590 	spin_unlock_bh(&conn->response_queue_lock);
591 
592 	wake_up(&conn->queues_wq);
593 }
594 
595 struct iscsi_queue_req *iscsit_get_cmd_from_response_queue(struct iscsi_conn *conn)
596 {
597 	struct iscsi_queue_req *qr;
598 
599 	spin_lock_bh(&conn->response_queue_lock);
600 	if (list_empty(&conn->response_queue_list)) {
601 		spin_unlock_bh(&conn->response_queue_lock);
602 		return NULL;
603 	}
604 
605 	qr = list_first_entry(&conn->response_queue_list,
606 			      struct iscsi_queue_req, qr_list);
607 
608 	list_del(&qr->qr_list);
609 	if (qr->cmd)
610 		atomic_dec(&qr->cmd->response_queue_count);
611 	spin_unlock_bh(&conn->response_queue_lock);
612 
613 	return qr;
614 }
615 
616 static void iscsit_remove_cmd_from_response_queue(
617 	struct iscsi_cmd *cmd,
618 	struct iscsi_conn *conn)
619 {
620 	struct iscsi_queue_req *qr, *qr_tmp;
621 
622 	spin_lock_bh(&conn->response_queue_lock);
623 	if (!atomic_read(&cmd->response_queue_count)) {
624 		spin_unlock_bh(&conn->response_queue_lock);
625 		return;
626 	}
627 
628 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
629 				qr_list) {
630 		if (qr->cmd != cmd)
631 			continue;
632 
633 		atomic_dec(&qr->cmd->response_queue_count);
634 		list_del(&qr->qr_list);
635 		kmem_cache_free(lio_qr_cache, qr);
636 	}
637 	spin_unlock_bh(&conn->response_queue_lock);
638 
639 	if (atomic_read(&cmd->response_queue_count)) {
640 		pr_err("ITT: 0x%08x response_queue_count: %d\n",
641 			cmd->init_task_tag,
642 			atomic_read(&cmd->response_queue_count));
643 	}
644 }
645 
646 bool iscsit_conn_all_queues_empty(struct iscsi_conn *conn)
647 {
648 	bool empty;
649 
650 	spin_lock_bh(&conn->immed_queue_lock);
651 	empty = list_empty(&conn->immed_queue_list);
652 	spin_unlock_bh(&conn->immed_queue_lock);
653 
654 	if (!empty)
655 		return empty;
656 
657 	spin_lock_bh(&conn->response_queue_lock);
658 	empty = list_empty(&conn->response_queue_list);
659 	spin_unlock_bh(&conn->response_queue_lock);
660 
661 	return empty;
662 }
663 
664 void iscsit_free_queue_reqs_for_conn(struct iscsi_conn *conn)
665 {
666 	struct iscsi_queue_req *qr, *qr_tmp;
667 
668 	spin_lock_bh(&conn->immed_queue_lock);
669 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
670 		list_del(&qr->qr_list);
671 		if (qr->cmd)
672 			atomic_dec(&qr->cmd->immed_queue_count);
673 
674 		kmem_cache_free(lio_qr_cache, qr);
675 	}
676 	spin_unlock_bh(&conn->immed_queue_lock);
677 
678 	spin_lock_bh(&conn->response_queue_lock);
679 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
680 			qr_list) {
681 		list_del(&qr->qr_list);
682 		if (qr->cmd)
683 			atomic_dec(&qr->cmd->response_queue_count);
684 
685 		kmem_cache_free(lio_qr_cache, qr);
686 	}
687 	spin_unlock_bh(&conn->response_queue_lock);
688 }
689 
690 void iscsit_release_cmd(struct iscsi_cmd *cmd)
691 {
692 	kfree(cmd->buf_ptr);
693 	kfree(cmd->pdu_list);
694 	kfree(cmd->seq_list);
695 	kfree(cmd->tmr_req);
696 	kfree(cmd->iov_data);
697 	kfree(cmd->text_in_ptr);
698 
699 	kmem_cache_free(lio_cmd_cache, cmd);
700 }
701 
702 static void __iscsit_free_cmd(struct iscsi_cmd *cmd, bool scsi_cmd,
703 			      bool check_queues)
704 {
705 	struct iscsi_conn *conn = cmd->conn;
706 
707 	if (scsi_cmd) {
708 		if (cmd->data_direction == DMA_TO_DEVICE) {
709 			iscsit_stop_dataout_timer(cmd);
710 			iscsit_free_r2ts_from_list(cmd);
711 		}
712 		if (cmd->data_direction == DMA_FROM_DEVICE)
713 			iscsit_free_all_datain_reqs(cmd);
714 	}
715 
716 	if (conn && check_queues) {
717 		iscsit_remove_cmd_from_immediate_queue(cmd, conn);
718 		iscsit_remove_cmd_from_response_queue(cmd, conn);
719 	}
720 }
721 
722 void iscsit_free_cmd(struct iscsi_cmd *cmd, bool shutdown)
723 {
724 	struct se_cmd *se_cmd = NULL;
725 	int rc;
726 	/*
727 	 * Determine if a struct se_cmd is associated with
728 	 * this struct iscsi_cmd.
729 	 */
730 	switch (cmd->iscsi_opcode) {
731 	case ISCSI_OP_SCSI_CMD:
732 		se_cmd = &cmd->se_cmd;
733 		__iscsit_free_cmd(cmd, true, shutdown);
734 		/*
735 		 * Fallthrough
736 		 */
737 	case ISCSI_OP_SCSI_TMFUNC:
738 		rc = transport_generic_free_cmd(&cmd->se_cmd, 1);
739 		if (!rc && shutdown && se_cmd && se_cmd->se_sess) {
740 			__iscsit_free_cmd(cmd, true, shutdown);
741 			target_put_sess_cmd(se_cmd->se_sess, se_cmd);
742 		}
743 		break;
744 	case ISCSI_OP_REJECT:
745 		/*
746 		 * Handle special case for REJECT when iscsi_add_reject*() has
747 		 * overwritten the original iscsi_opcode assignment, and the
748 		 * associated cmd->se_cmd needs to be released.
749 		 */
750 		if (cmd->se_cmd.se_tfo != NULL) {
751 			se_cmd = &cmd->se_cmd;
752 			__iscsit_free_cmd(cmd, true, shutdown);
753 
754 			rc = transport_generic_free_cmd(&cmd->se_cmd, 1);
755 			if (!rc && shutdown && se_cmd->se_sess) {
756 				__iscsit_free_cmd(cmd, true, shutdown);
757 				target_put_sess_cmd(se_cmd->se_sess, se_cmd);
758 			}
759 			break;
760 		}
761 		/* Fall-through */
762 	default:
763 		__iscsit_free_cmd(cmd, false, shutdown);
764 		cmd->release_cmd(cmd);
765 		break;
766 	}
767 }
768 
769 int iscsit_check_session_usage_count(struct iscsi_session *sess)
770 {
771 	spin_lock_bh(&sess->session_usage_lock);
772 	if (sess->session_usage_count != 0) {
773 		sess->session_waiting_on_uc = 1;
774 		spin_unlock_bh(&sess->session_usage_lock);
775 		if (in_interrupt())
776 			return 2;
777 
778 		wait_for_completion(&sess->session_waiting_on_uc_comp);
779 		return 1;
780 	}
781 	spin_unlock_bh(&sess->session_usage_lock);
782 
783 	return 0;
784 }
785 
786 void iscsit_dec_session_usage_count(struct iscsi_session *sess)
787 {
788 	spin_lock_bh(&sess->session_usage_lock);
789 	sess->session_usage_count--;
790 
791 	if (!sess->session_usage_count && sess->session_waiting_on_uc)
792 		complete(&sess->session_waiting_on_uc_comp);
793 
794 	spin_unlock_bh(&sess->session_usage_lock);
795 }
796 
797 void iscsit_inc_session_usage_count(struct iscsi_session *sess)
798 {
799 	spin_lock_bh(&sess->session_usage_lock);
800 	sess->session_usage_count++;
801 	spin_unlock_bh(&sess->session_usage_lock);
802 }
803 
804 /*
805  *	Setup conn->if_marker and conn->of_marker values based upon
806  *	the initial marker-less interval. (see iSCSI v19 A.2)
807  */
808 int iscsit_set_sync_and_steering_values(struct iscsi_conn *conn)
809 {
810 	int login_ifmarker_count = 0, login_ofmarker_count = 0, next_marker = 0;
811 	/*
812 	 * IFMarkInt and OFMarkInt are negotiated as 32-bit words.
813 	 */
814 	u32 IFMarkInt = (conn->conn_ops->IFMarkInt * 4);
815 	u32 OFMarkInt = (conn->conn_ops->OFMarkInt * 4);
816 
817 	if (conn->conn_ops->OFMarker) {
818 		/*
819 		 * Account for the first Login Command received not
820 		 * via iscsi_recv_msg().
821 		 */
822 		conn->of_marker += ISCSI_HDR_LEN;
823 		if (conn->of_marker <= OFMarkInt) {
824 			conn->of_marker = (OFMarkInt - conn->of_marker);
825 		} else {
826 			login_ofmarker_count = (conn->of_marker / OFMarkInt);
827 			next_marker = (OFMarkInt * (login_ofmarker_count + 1)) +
828 					(login_ofmarker_count * MARKER_SIZE);
829 			conn->of_marker = (next_marker - conn->of_marker);
830 		}
831 		conn->of_marker_offset = 0;
832 		pr_debug("Setting OFMarker value to %u based on Initial"
833 			" Markerless Interval.\n", conn->of_marker);
834 	}
835 
836 	if (conn->conn_ops->IFMarker) {
837 		if (conn->if_marker <= IFMarkInt) {
838 			conn->if_marker = (IFMarkInt - conn->if_marker);
839 		} else {
840 			login_ifmarker_count = (conn->if_marker / IFMarkInt);
841 			next_marker = (IFMarkInt * (login_ifmarker_count + 1)) +
842 					(login_ifmarker_count * MARKER_SIZE);
843 			conn->if_marker = (next_marker - conn->if_marker);
844 		}
845 		pr_debug("Setting IFMarker value to %u based on Initial"
846 			" Markerless Interval.\n", conn->if_marker);
847 	}
848 
849 	return 0;
850 }
851 
852 struct iscsi_conn *iscsit_get_conn_from_cid(struct iscsi_session *sess, u16 cid)
853 {
854 	struct iscsi_conn *conn;
855 
856 	spin_lock_bh(&sess->conn_lock);
857 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
858 		if ((conn->cid == cid) &&
859 		    (conn->conn_state == TARG_CONN_STATE_LOGGED_IN)) {
860 			iscsit_inc_conn_usage_count(conn);
861 			spin_unlock_bh(&sess->conn_lock);
862 			return conn;
863 		}
864 	}
865 	spin_unlock_bh(&sess->conn_lock);
866 
867 	return NULL;
868 }
869 
870 struct iscsi_conn *iscsit_get_conn_from_cid_rcfr(struct iscsi_session *sess, u16 cid)
871 {
872 	struct iscsi_conn *conn;
873 
874 	spin_lock_bh(&sess->conn_lock);
875 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
876 		if (conn->cid == cid) {
877 			iscsit_inc_conn_usage_count(conn);
878 			spin_lock(&conn->state_lock);
879 			atomic_set(&conn->connection_wait_rcfr, 1);
880 			spin_unlock(&conn->state_lock);
881 			spin_unlock_bh(&sess->conn_lock);
882 			return conn;
883 		}
884 	}
885 	spin_unlock_bh(&sess->conn_lock);
886 
887 	return NULL;
888 }
889 
890 void iscsit_check_conn_usage_count(struct iscsi_conn *conn)
891 {
892 	spin_lock_bh(&conn->conn_usage_lock);
893 	if (conn->conn_usage_count != 0) {
894 		conn->conn_waiting_on_uc = 1;
895 		spin_unlock_bh(&conn->conn_usage_lock);
896 
897 		wait_for_completion(&conn->conn_waiting_on_uc_comp);
898 		return;
899 	}
900 	spin_unlock_bh(&conn->conn_usage_lock);
901 }
902 
903 void iscsit_dec_conn_usage_count(struct iscsi_conn *conn)
904 {
905 	spin_lock_bh(&conn->conn_usage_lock);
906 	conn->conn_usage_count--;
907 
908 	if (!conn->conn_usage_count && conn->conn_waiting_on_uc)
909 		complete(&conn->conn_waiting_on_uc_comp);
910 
911 	spin_unlock_bh(&conn->conn_usage_lock);
912 }
913 
914 void iscsit_inc_conn_usage_count(struct iscsi_conn *conn)
915 {
916 	spin_lock_bh(&conn->conn_usage_lock);
917 	conn->conn_usage_count++;
918 	spin_unlock_bh(&conn->conn_usage_lock);
919 }
920 
921 static int iscsit_add_nopin(struct iscsi_conn *conn, int want_response)
922 {
923 	u8 state;
924 	struct iscsi_cmd *cmd;
925 
926 	cmd = iscsit_allocate_cmd(conn, GFP_ATOMIC);
927 	if (!cmd)
928 		return -1;
929 
930 	cmd->iscsi_opcode = ISCSI_OP_NOOP_IN;
931 	state = (want_response) ? ISTATE_SEND_NOPIN_WANT_RESPONSE :
932 				ISTATE_SEND_NOPIN_NO_RESPONSE;
933 	cmd->init_task_tag = RESERVED_ITT;
934 	spin_lock_bh(&conn->sess->ttt_lock);
935 	cmd->targ_xfer_tag = (want_response) ? conn->sess->targ_xfer_tag++ :
936 			0xFFFFFFFF;
937 	if (want_response && (cmd->targ_xfer_tag == 0xFFFFFFFF))
938 		cmd->targ_xfer_tag = conn->sess->targ_xfer_tag++;
939 	spin_unlock_bh(&conn->sess->ttt_lock);
940 
941 	spin_lock_bh(&conn->cmd_lock);
942 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
943 	spin_unlock_bh(&conn->cmd_lock);
944 
945 	if (want_response)
946 		iscsit_start_nopin_response_timer(conn);
947 	iscsit_add_cmd_to_immediate_queue(cmd, conn, state);
948 
949 	return 0;
950 }
951 
952 static void iscsit_handle_nopin_response_timeout(unsigned long data)
953 {
954 	struct iscsi_conn *conn = (struct iscsi_conn *) data;
955 
956 	iscsit_inc_conn_usage_count(conn);
957 
958 	spin_lock_bh(&conn->nopin_timer_lock);
959 	if (conn->nopin_response_timer_flags & ISCSI_TF_STOP) {
960 		spin_unlock_bh(&conn->nopin_timer_lock);
961 		iscsit_dec_conn_usage_count(conn);
962 		return;
963 	}
964 
965 	pr_debug("Did not receive response to NOPIN on CID: %hu on"
966 		" SID: %u, failing connection.\n", conn->cid,
967 			conn->sess->sid);
968 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
969 	spin_unlock_bh(&conn->nopin_timer_lock);
970 
971 	{
972 	struct iscsi_portal_group *tpg = conn->sess->tpg;
973 	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
974 
975 	if (tiqn) {
976 		spin_lock_bh(&tiqn->sess_err_stats.lock);
977 		strcpy(tiqn->sess_err_stats.last_sess_fail_rem_name,
978 				conn->sess->sess_ops->InitiatorName);
979 		tiqn->sess_err_stats.last_sess_failure_type =
980 				ISCSI_SESS_ERR_CXN_TIMEOUT;
981 		tiqn->sess_err_stats.cxn_timeout_errors++;
982 		conn->sess->conn_timeout_errors++;
983 		spin_unlock_bh(&tiqn->sess_err_stats.lock);
984 	}
985 	}
986 
987 	iscsit_cause_connection_reinstatement(conn, 0);
988 	iscsit_dec_conn_usage_count(conn);
989 }
990 
991 void iscsit_mod_nopin_response_timer(struct iscsi_conn *conn)
992 {
993 	struct iscsi_session *sess = conn->sess;
994 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
995 
996 	spin_lock_bh(&conn->nopin_timer_lock);
997 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
998 		spin_unlock_bh(&conn->nopin_timer_lock);
999 		return;
1000 	}
1001 
1002 	mod_timer(&conn->nopin_response_timer,
1003 		(get_jiffies_64() + na->nopin_response_timeout * HZ));
1004 	spin_unlock_bh(&conn->nopin_timer_lock);
1005 }
1006 
1007 /*
1008  *	Called with conn->nopin_timer_lock held.
1009  */
1010 void iscsit_start_nopin_response_timer(struct iscsi_conn *conn)
1011 {
1012 	struct iscsi_session *sess = conn->sess;
1013 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1014 
1015 	spin_lock_bh(&conn->nopin_timer_lock);
1016 	if (conn->nopin_response_timer_flags & ISCSI_TF_RUNNING) {
1017 		spin_unlock_bh(&conn->nopin_timer_lock);
1018 		return;
1019 	}
1020 
1021 	init_timer(&conn->nopin_response_timer);
1022 	conn->nopin_response_timer.expires =
1023 		(get_jiffies_64() + na->nopin_response_timeout * HZ);
1024 	conn->nopin_response_timer.data = (unsigned long)conn;
1025 	conn->nopin_response_timer.function = iscsit_handle_nopin_response_timeout;
1026 	conn->nopin_response_timer_flags &= ~ISCSI_TF_STOP;
1027 	conn->nopin_response_timer_flags |= ISCSI_TF_RUNNING;
1028 	add_timer(&conn->nopin_response_timer);
1029 
1030 	pr_debug("Started NOPIN Response Timer on CID: %d to %u"
1031 		" seconds\n", conn->cid, na->nopin_response_timeout);
1032 	spin_unlock_bh(&conn->nopin_timer_lock);
1033 }
1034 
1035 void iscsit_stop_nopin_response_timer(struct iscsi_conn *conn)
1036 {
1037 	spin_lock_bh(&conn->nopin_timer_lock);
1038 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
1039 		spin_unlock_bh(&conn->nopin_timer_lock);
1040 		return;
1041 	}
1042 	conn->nopin_response_timer_flags |= ISCSI_TF_STOP;
1043 	spin_unlock_bh(&conn->nopin_timer_lock);
1044 
1045 	del_timer_sync(&conn->nopin_response_timer);
1046 
1047 	spin_lock_bh(&conn->nopin_timer_lock);
1048 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
1049 	spin_unlock_bh(&conn->nopin_timer_lock);
1050 }
1051 
1052 static void iscsit_handle_nopin_timeout(unsigned long data)
1053 {
1054 	struct iscsi_conn *conn = (struct iscsi_conn *) data;
1055 
1056 	iscsit_inc_conn_usage_count(conn);
1057 
1058 	spin_lock_bh(&conn->nopin_timer_lock);
1059 	if (conn->nopin_timer_flags & ISCSI_TF_STOP) {
1060 		spin_unlock_bh(&conn->nopin_timer_lock);
1061 		iscsit_dec_conn_usage_count(conn);
1062 		return;
1063 	}
1064 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1065 	spin_unlock_bh(&conn->nopin_timer_lock);
1066 
1067 	iscsit_add_nopin(conn, 1);
1068 	iscsit_dec_conn_usage_count(conn);
1069 }
1070 
1071 /*
1072  * Called with conn->nopin_timer_lock held.
1073  */
1074 void __iscsit_start_nopin_timer(struct iscsi_conn *conn)
1075 {
1076 	struct iscsi_session *sess = conn->sess;
1077 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1078 	/*
1079 	* NOPIN timeout is disabled.
1080 	 */
1081 	if (!na->nopin_timeout)
1082 		return;
1083 
1084 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING)
1085 		return;
1086 
1087 	init_timer(&conn->nopin_timer);
1088 	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1089 	conn->nopin_timer.data = (unsigned long)conn;
1090 	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1091 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1092 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1093 	add_timer(&conn->nopin_timer);
1094 
1095 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1096 		" interval\n", conn->cid, na->nopin_timeout);
1097 }
1098 
1099 void iscsit_start_nopin_timer(struct iscsi_conn *conn)
1100 {
1101 	struct iscsi_session *sess = conn->sess;
1102 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1103 	/*
1104 	 * NOPIN timeout is disabled..
1105 	 */
1106 	if (!na->nopin_timeout)
1107 		return;
1108 
1109 	spin_lock_bh(&conn->nopin_timer_lock);
1110 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING) {
1111 		spin_unlock_bh(&conn->nopin_timer_lock);
1112 		return;
1113 	}
1114 
1115 	init_timer(&conn->nopin_timer);
1116 	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1117 	conn->nopin_timer.data = (unsigned long)conn;
1118 	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1119 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1120 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1121 	add_timer(&conn->nopin_timer);
1122 
1123 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1124 			" interval\n", conn->cid, na->nopin_timeout);
1125 	spin_unlock_bh(&conn->nopin_timer_lock);
1126 }
1127 
1128 void iscsit_stop_nopin_timer(struct iscsi_conn *conn)
1129 {
1130 	spin_lock_bh(&conn->nopin_timer_lock);
1131 	if (!(conn->nopin_timer_flags & ISCSI_TF_RUNNING)) {
1132 		spin_unlock_bh(&conn->nopin_timer_lock);
1133 		return;
1134 	}
1135 	conn->nopin_timer_flags |= ISCSI_TF_STOP;
1136 	spin_unlock_bh(&conn->nopin_timer_lock);
1137 
1138 	del_timer_sync(&conn->nopin_timer);
1139 
1140 	spin_lock_bh(&conn->nopin_timer_lock);
1141 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1142 	spin_unlock_bh(&conn->nopin_timer_lock);
1143 }
1144 
1145 int iscsit_send_tx_data(
1146 	struct iscsi_cmd *cmd,
1147 	struct iscsi_conn *conn,
1148 	int use_misc)
1149 {
1150 	int tx_sent, tx_size;
1151 	u32 iov_count;
1152 	struct kvec *iov;
1153 
1154 send_data:
1155 	tx_size = cmd->tx_size;
1156 
1157 	if (!use_misc) {
1158 		iov = &cmd->iov_data[0];
1159 		iov_count = cmd->iov_data_count;
1160 	} else {
1161 		iov = &cmd->iov_misc[0];
1162 		iov_count = cmd->iov_misc_count;
1163 	}
1164 
1165 	tx_sent = tx_data(conn, &iov[0], iov_count, tx_size);
1166 	if (tx_size != tx_sent) {
1167 		if (tx_sent == -EAGAIN) {
1168 			pr_err("tx_data() returned -EAGAIN\n");
1169 			goto send_data;
1170 		} else
1171 			return -1;
1172 	}
1173 	cmd->tx_size = 0;
1174 
1175 	return 0;
1176 }
1177 
1178 int iscsit_fe_sendpage_sg(
1179 	struct iscsi_cmd *cmd,
1180 	struct iscsi_conn *conn)
1181 {
1182 	struct scatterlist *sg = cmd->first_data_sg;
1183 	struct kvec iov;
1184 	u32 tx_hdr_size, data_len;
1185 	u32 offset = cmd->first_data_sg_off;
1186 	int tx_sent, iov_off;
1187 
1188 send_hdr:
1189 	tx_hdr_size = ISCSI_HDR_LEN;
1190 	if (conn->conn_ops->HeaderDigest)
1191 		tx_hdr_size += ISCSI_CRC_LEN;
1192 
1193 	iov.iov_base = cmd->pdu;
1194 	iov.iov_len = tx_hdr_size;
1195 
1196 	tx_sent = tx_data(conn, &iov, 1, tx_hdr_size);
1197 	if (tx_hdr_size != tx_sent) {
1198 		if (tx_sent == -EAGAIN) {
1199 			pr_err("tx_data() returned -EAGAIN\n");
1200 			goto send_hdr;
1201 		}
1202 		return -1;
1203 	}
1204 
1205 	data_len = cmd->tx_size - tx_hdr_size - cmd->padding;
1206 	/*
1207 	 * Set iov_off used by padding and data digest tx_data() calls below
1208 	 * in order to determine proper offset into cmd->iov_data[]
1209 	 */
1210 	if (conn->conn_ops->DataDigest) {
1211 		data_len -= ISCSI_CRC_LEN;
1212 		if (cmd->padding)
1213 			iov_off = (cmd->iov_data_count - 2);
1214 		else
1215 			iov_off = (cmd->iov_data_count - 1);
1216 	} else {
1217 		iov_off = (cmd->iov_data_count - 1);
1218 	}
1219 	/*
1220 	 * Perform sendpage() for each page in the scatterlist
1221 	 */
1222 	while (data_len) {
1223 		u32 space = (sg->length - offset);
1224 		u32 sub_len = min_t(u32, data_len, space);
1225 send_pg:
1226 		tx_sent = conn->sock->ops->sendpage(conn->sock,
1227 					sg_page(sg), sg->offset + offset, sub_len, 0);
1228 		if (tx_sent != sub_len) {
1229 			if (tx_sent == -EAGAIN) {
1230 				pr_err("tcp_sendpage() returned"
1231 						" -EAGAIN\n");
1232 				goto send_pg;
1233 			}
1234 
1235 			pr_err("tcp_sendpage() failure: %d\n",
1236 					tx_sent);
1237 			return -1;
1238 		}
1239 
1240 		data_len -= sub_len;
1241 		offset = 0;
1242 		sg = sg_next(sg);
1243 	}
1244 
1245 send_padding:
1246 	if (cmd->padding) {
1247 		struct kvec *iov_p = &cmd->iov_data[iov_off++];
1248 
1249 		tx_sent = tx_data(conn, iov_p, 1, cmd->padding);
1250 		if (cmd->padding != tx_sent) {
1251 			if (tx_sent == -EAGAIN) {
1252 				pr_err("tx_data() returned -EAGAIN\n");
1253 				goto send_padding;
1254 			}
1255 			return -1;
1256 		}
1257 	}
1258 
1259 send_datacrc:
1260 	if (conn->conn_ops->DataDigest) {
1261 		struct kvec *iov_d = &cmd->iov_data[iov_off];
1262 
1263 		tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN);
1264 		if (ISCSI_CRC_LEN != tx_sent) {
1265 			if (tx_sent == -EAGAIN) {
1266 				pr_err("tx_data() returned -EAGAIN\n");
1267 				goto send_datacrc;
1268 			}
1269 			return -1;
1270 		}
1271 	}
1272 
1273 	return 0;
1274 }
1275 
1276 /*
1277  *      This function is used for mainly sending a ISCSI_TARG_LOGIN_RSP PDU
1278  *      back to the Initiator when an expection condition occurs with the
1279  *      errors set in status_class and status_detail.
1280  *
1281  *      Parameters:     iSCSI Connection, Status Class, Status Detail.
1282  *      Returns:        0 on success, -1 on error.
1283  */
1284 int iscsit_tx_login_rsp(struct iscsi_conn *conn, u8 status_class, u8 status_detail)
1285 {
1286 	struct iscsi_login_rsp *hdr;
1287 	struct iscsi_login *login = conn->conn_login;
1288 
1289 	login->login_failed = 1;
1290 	iscsit_collect_login_stats(conn, status_class, status_detail);
1291 
1292 	hdr	= (struct iscsi_login_rsp *)&login->rsp[0];
1293 	hdr->opcode		= ISCSI_OP_LOGIN_RSP;
1294 	hdr->status_class	= status_class;
1295 	hdr->status_detail	= status_detail;
1296 	hdr->itt		= conn->login_itt;
1297 
1298 	return conn->conn_transport->iscsit_put_login_tx(conn, login, 0);
1299 }
1300 
1301 void iscsit_print_session_params(struct iscsi_session *sess)
1302 {
1303 	struct iscsi_conn *conn;
1304 
1305 	pr_debug("-----------------------------[Session Params for"
1306 		" SID: %u]-----------------------------\n", sess->sid);
1307 	spin_lock_bh(&sess->conn_lock);
1308 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
1309 		iscsi_dump_conn_ops(conn->conn_ops);
1310 	spin_unlock_bh(&sess->conn_lock);
1311 
1312 	iscsi_dump_sess_ops(sess->sess_ops);
1313 }
1314 
1315 static int iscsit_do_rx_data(
1316 	struct iscsi_conn *conn,
1317 	struct iscsi_data_count *count)
1318 {
1319 	int data = count->data_length, rx_loop = 0, total_rx = 0, iov_len;
1320 	struct kvec *iov_p;
1321 	struct msghdr msg;
1322 
1323 	if (!conn || !conn->sock || !conn->conn_ops)
1324 		return -1;
1325 
1326 	memset(&msg, 0, sizeof(struct msghdr));
1327 
1328 	iov_p = count->iov;
1329 	iov_len	= count->iov_count;
1330 
1331 	while (total_rx < data) {
1332 		rx_loop = kernel_recvmsg(conn->sock, &msg, iov_p, iov_len,
1333 					(data - total_rx), MSG_WAITALL);
1334 		if (rx_loop <= 0) {
1335 			pr_debug("rx_loop: %d total_rx: %d\n",
1336 				rx_loop, total_rx);
1337 			return rx_loop;
1338 		}
1339 		total_rx += rx_loop;
1340 		pr_debug("rx_loop: %d, total_rx: %d, data: %d\n",
1341 				rx_loop, total_rx, data);
1342 	}
1343 
1344 	return total_rx;
1345 }
1346 
1347 static int iscsit_do_tx_data(
1348 	struct iscsi_conn *conn,
1349 	struct iscsi_data_count *count)
1350 {
1351 	int data = count->data_length, total_tx = 0, tx_loop = 0, iov_len;
1352 	struct kvec *iov_p;
1353 	struct msghdr msg;
1354 
1355 	if (!conn || !conn->sock || !conn->conn_ops)
1356 		return -1;
1357 
1358 	if (data <= 0) {
1359 		pr_err("Data length is: %d\n", data);
1360 		return -1;
1361 	}
1362 
1363 	memset(&msg, 0, sizeof(struct msghdr));
1364 
1365 	iov_p = count->iov;
1366 	iov_len = count->iov_count;
1367 
1368 	while (total_tx < data) {
1369 		tx_loop = kernel_sendmsg(conn->sock, &msg, iov_p, iov_len,
1370 					(data - total_tx));
1371 		if (tx_loop <= 0) {
1372 			pr_debug("tx_loop: %d total_tx %d\n",
1373 				tx_loop, total_tx);
1374 			return tx_loop;
1375 		}
1376 		total_tx += tx_loop;
1377 		pr_debug("tx_loop: %d, total_tx: %d, data: %d\n",
1378 					tx_loop, total_tx, data);
1379 	}
1380 
1381 	return total_tx;
1382 }
1383 
1384 int rx_data(
1385 	struct iscsi_conn *conn,
1386 	struct kvec *iov,
1387 	int iov_count,
1388 	int data)
1389 {
1390 	struct iscsi_data_count c;
1391 
1392 	if (!conn || !conn->sock || !conn->conn_ops)
1393 		return -1;
1394 
1395 	memset(&c, 0, sizeof(struct iscsi_data_count));
1396 	c.iov = iov;
1397 	c.iov_count = iov_count;
1398 	c.data_length = data;
1399 	c.type = ISCSI_RX_DATA;
1400 
1401 	return iscsit_do_rx_data(conn, &c);
1402 }
1403 
1404 int tx_data(
1405 	struct iscsi_conn *conn,
1406 	struct kvec *iov,
1407 	int iov_count,
1408 	int data)
1409 {
1410 	struct iscsi_data_count c;
1411 
1412 	if (!conn || !conn->sock || !conn->conn_ops)
1413 		return -1;
1414 
1415 	memset(&c, 0, sizeof(struct iscsi_data_count));
1416 	c.iov = iov;
1417 	c.iov_count = iov_count;
1418 	c.data_length = data;
1419 	c.type = ISCSI_TX_DATA;
1420 
1421 	return iscsit_do_tx_data(conn, &c);
1422 }
1423 
1424 void iscsit_collect_login_stats(
1425 	struct iscsi_conn *conn,
1426 	u8 status_class,
1427 	u8 status_detail)
1428 {
1429 	struct iscsi_param *intrname = NULL;
1430 	struct iscsi_tiqn *tiqn;
1431 	struct iscsi_login_stats *ls;
1432 
1433 	tiqn = iscsit_snmp_get_tiqn(conn);
1434 	if (!tiqn)
1435 		return;
1436 
1437 	ls = &tiqn->login_stats;
1438 
1439 	spin_lock(&ls->lock);
1440 	if (!strcmp(conn->login_ip, ls->last_intr_fail_ip_addr) &&
1441 	    ((get_jiffies_64() - ls->last_fail_time) < 10)) {
1442 		/* We already have the failure info for this login */
1443 		spin_unlock(&ls->lock);
1444 		return;
1445 	}
1446 
1447 	if (status_class == ISCSI_STATUS_CLS_SUCCESS)
1448 		ls->accepts++;
1449 	else if (status_class == ISCSI_STATUS_CLS_REDIRECT) {
1450 		ls->redirects++;
1451 		ls->last_fail_type = ISCSI_LOGIN_FAIL_REDIRECT;
1452 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1453 		 (status_detail == ISCSI_LOGIN_STATUS_AUTH_FAILED)) {
1454 		ls->authenticate_fails++;
1455 		ls->last_fail_type =  ISCSI_LOGIN_FAIL_AUTHENTICATE;
1456 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1457 		 (status_detail == ISCSI_LOGIN_STATUS_TGT_FORBIDDEN)) {
1458 		ls->authorize_fails++;
1459 		ls->last_fail_type = ISCSI_LOGIN_FAIL_AUTHORIZE;
1460 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR) &&
1461 		 (status_detail == ISCSI_LOGIN_STATUS_INIT_ERR)) {
1462 		ls->negotiate_fails++;
1463 		ls->last_fail_type = ISCSI_LOGIN_FAIL_NEGOTIATE;
1464 	} else {
1465 		ls->other_fails++;
1466 		ls->last_fail_type = ISCSI_LOGIN_FAIL_OTHER;
1467 	}
1468 
1469 	/* Save initiator name, ip address and time, if it is a failed login */
1470 	if (status_class != ISCSI_STATUS_CLS_SUCCESS) {
1471 		if (conn->param_list)
1472 			intrname = iscsi_find_param_from_key(INITIATORNAME,
1473 							     conn->param_list);
1474 		strcpy(ls->last_intr_fail_name,
1475 		       (intrname ? intrname->value : "Unknown"));
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