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 
28 #include "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_tq.h"
37 #include "iscsi_target_util.h"
38 #include "iscsi_target.h"
39 
40 #define PRINT_BUFF(buff, len)					\
41 {								\
42 	int zzz;						\
43 								\
44 	pr_debug("%d:\n", __LINE__);				\
45 	for (zzz = 0; zzz < len; zzz++) {			\
46 		if (zzz % 16 == 0) {				\
47 			if (zzz)				\
48 				pr_debug("\n");			\
49 			pr_debug("%4i: ", zzz);			\
50 		}						\
51 		pr_debug("%02x ", (unsigned char) (buff)[zzz]);	\
52 	}							\
53 	if ((len + 1) % 16)					\
54 		pr_debug("\n");					\
55 }
56 
57 extern struct list_head g_tiqn_list;
58 extern spinlock_t tiqn_lock;
59 
60 /*
61  *	Called with cmd->r2t_lock held.
62  */
63 int iscsit_add_r2t_to_list(
64 	struct iscsi_cmd *cmd,
65 	u32 offset,
66 	u32 xfer_len,
67 	int recovery,
68 	u32 r2t_sn)
69 {
70 	struct iscsi_r2t *r2t;
71 
72 	r2t = kmem_cache_zalloc(lio_r2t_cache, GFP_ATOMIC);
73 	if (!r2t) {
74 		pr_err("Unable to allocate memory for struct iscsi_r2t.\n");
75 		return -1;
76 	}
77 	INIT_LIST_HEAD(&r2t->r2t_list);
78 
79 	r2t->recovery_r2t = recovery;
80 	r2t->r2t_sn = (!r2t_sn) ? cmd->r2t_sn++ : r2t_sn;
81 	r2t->offset = offset;
82 	r2t->xfer_len = xfer_len;
83 	list_add_tail(&r2t->r2t_list, &cmd->cmd_r2t_list);
84 	spin_unlock_bh(&cmd->r2t_lock);
85 
86 	iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, ISTATE_SEND_R2T);
87 
88 	spin_lock_bh(&cmd->r2t_lock);
89 	return 0;
90 }
91 
92 struct iscsi_r2t *iscsit_get_r2t_for_eos(
93 	struct iscsi_cmd *cmd,
94 	u32 offset,
95 	u32 length)
96 {
97 	struct iscsi_r2t *r2t;
98 
99 	spin_lock_bh(&cmd->r2t_lock);
100 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
101 		if ((r2t->offset <= offset) &&
102 		    (r2t->offset + r2t->xfer_len) >= (offset + length)) {
103 			spin_unlock_bh(&cmd->r2t_lock);
104 			return r2t;
105 		}
106 	}
107 	spin_unlock_bh(&cmd->r2t_lock);
108 
109 	pr_err("Unable to locate R2T for Offset: %u, Length:"
110 			" %u\n", offset, length);
111 	return NULL;
112 }
113 
114 struct iscsi_r2t *iscsit_get_r2t_from_list(struct iscsi_cmd *cmd)
115 {
116 	struct iscsi_r2t *r2t;
117 
118 	spin_lock_bh(&cmd->r2t_lock);
119 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
120 		if (!r2t->sent_r2t) {
121 			spin_unlock_bh(&cmd->r2t_lock);
122 			return r2t;
123 		}
124 	}
125 	spin_unlock_bh(&cmd->r2t_lock);
126 
127 	pr_err("Unable to locate next R2T to send for ITT:"
128 			" 0x%08x.\n", cmd->init_task_tag);
129 	return NULL;
130 }
131 
132 /*
133  *	Called with cmd->r2t_lock held.
134  */
135 void iscsit_free_r2t(struct iscsi_r2t *r2t, struct iscsi_cmd *cmd)
136 {
137 	list_del(&r2t->r2t_list);
138 	kmem_cache_free(lio_r2t_cache, r2t);
139 }
140 
141 void iscsit_free_r2ts_from_list(struct iscsi_cmd *cmd)
142 {
143 	struct iscsi_r2t *r2t, *r2t_tmp;
144 
145 	spin_lock_bh(&cmd->r2t_lock);
146 	list_for_each_entry_safe(r2t, r2t_tmp, &cmd->cmd_r2t_list, r2t_list)
147 		iscsit_free_r2t(r2t, cmd);
148 	spin_unlock_bh(&cmd->r2t_lock);
149 }
150 
151 /*
152  * May be called from software interrupt (timer) context for allocating
153  * iSCSI NopINs.
154  */
155 struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn *conn, gfp_t gfp_mask)
156 {
157 	struct iscsi_cmd *cmd;
158 
159 	cmd = kmem_cache_zalloc(lio_cmd_cache, gfp_mask);
160 	if (!cmd) {
161 		pr_err("Unable to allocate memory for struct iscsi_cmd.\n");
162 		return NULL;
163 	}
164 
165 	cmd->conn	= conn;
166 	INIT_LIST_HEAD(&cmd->i_conn_node);
167 	INIT_LIST_HEAD(&cmd->datain_list);
168 	INIT_LIST_HEAD(&cmd->cmd_r2t_list);
169 	init_completion(&cmd->reject_comp);
170 	spin_lock_init(&cmd->datain_lock);
171 	spin_lock_init(&cmd->dataout_timeout_lock);
172 	spin_lock_init(&cmd->istate_lock);
173 	spin_lock_init(&cmd->error_lock);
174 	spin_lock_init(&cmd->r2t_lock);
175 
176 	return cmd;
177 }
178 
179 struct iscsi_seq *iscsit_get_seq_holder_for_datain(
180 	struct iscsi_cmd *cmd,
181 	u32 seq_send_order)
182 {
183 	u32 i;
184 
185 	for (i = 0; i < cmd->seq_count; i++)
186 		if (cmd->seq_list[i].seq_send_order == seq_send_order)
187 			return &cmd->seq_list[i];
188 
189 	return NULL;
190 }
191 
192 struct iscsi_seq *iscsit_get_seq_holder_for_r2t(struct iscsi_cmd *cmd)
193 {
194 	u32 i;
195 
196 	if (!cmd->seq_list) {
197 		pr_err("struct iscsi_cmd->seq_list is NULL!\n");
198 		return NULL;
199 	}
200 
201 	for (i = 0; i < cmd->seq_count; i++) {
202 		if (cmd->seq_list[i].type != SEQTYPE_NORMAL)
203 			continue;
204 		if (cmd->seq_list[i].seq_send_order == cmd->seq_send_order) {
205 			cmd->seq_send_order++;
206 			return &cmd->seq_list[i];
207 		}
208 	}
209 
210 	return NULL;
211 }
212 
213 struct iscsi_r2t *iscsit_get_holder_for_r2tsn(
214 	struct iscsi_cmd *cmd,
215 	u32 r2t_sn)
216 {
217 	struct iscsi_r2t *r2t;
218 
219 	spin_lock_bh(&cmd->r2t_lock);
220 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
221 		if (r2t->r2t_sn == r2t_sn) {
222 			spin_unlock_bh(&cmd->r2t_lock);
223 			return r2t;
224 		}
225 	}
226 	spin_unlock_bh(&cmd->r2t_lock);
227 
228 	return NULL;
229 }
230 
231 static inline int iscsit_check_received_cmdsn(struct iscsi_session *sess, u32 cmdsn)
232 {
233 	int ret;
234 
235 	/*
236 	 * This is the proper method of checking received CmdSN against
237 	 * ExpCmdSN and MaxCmdSN values, as well as accounting for out
238 	 * or order CmdSNs due to multiple connection sessions and/or
239 	 * CRC failures.
240 	 */
241 	if (iscsi_sna_gt(cmdsn, sess->max_cmd_sn)) {
242 		pr_err("Received CmdSN: 0x%08x is greater than"
243 		       " MaxCmdSN: 0x%08x, protocol error.\n", cmdsn,
244 		       sess->max_cmd_sn);
245 		ret = CMDSN_ERROR_CANNOT_RECOVER;
246 
247 	} else if (cmdsn == sess->exp_cmd_sn) {
248 		sess->exp_cmd_sn++;
249 		pr_debug("Received CmdSN matches ExpCmdSN,"
250 		      " incremented ExpCmdSN to: 0x%08x\n",
251 		      sess->exp_cmd_sn);
252 		ret = CMDSN_NORMAL_OPERATION;
253 
254 	} else if (iscsi_sna_gt(cmdsn, sess->exp_cmd_sn)) {
255 		pr_debug("Received CmdSN: 0x%08x is greater"
256 		      " than ExpCmdSN: 0x%08x, not acknowledging.\n",
257 		      cmdsn, sess->exp_cmd_sn);
258 		ret = CMDSN_HIGHER_THAN_EXP;
259 
260 	} else {
261 		pr_err("Received CmdSN: 0x%08x is less than"
262 		       " ExpCmdSN: 0x%08x, ignoring.\n", cmdsn,
263 		       sess->exp_cmd_sn);
264 		ret = CMDSN_LOWER_THAN_EXP;
265 	}
266 
267 	return ret;
268 }
269 
270 /*
271  * Commands may be received out of order if MC/S is in use.
272  * Ensure they are executed in CmdSN order.
273  */
274 int iscsit_sequence_cmd(
275 	struct iscsi_conn *conn,
276 	struct iscsi_cmd *cmd,
277 	__be32 cmdsn)
278 {
279 	int ret;
280 	int cmdsn_ret;
281 
282 	mutex_lock(&conn->sess->cmdsn_mutex);
283 
284 	cmdsn_ret = iscsit_check_received_cmdsn(conn->sess, be32_to_cpu(cmdsn));
285 	switch (cmdsn_ret) {
286 	case CMDSN_NORMAL_OPERATION:
287 		ret = iscsit_execute_cmd(cmd, 0);
288 		if ((ret >= 0) && !list_empty(&conn->sess->sess_ooo_cmdsn_list))
289 			iscsit_execute_ooo_cmdsns(conn->sess);
290 		break;
291 	case CMDSN_HIGHER_THAN_EXP:
292 		ret = iscsit_handle_ooo_cmdsn(conn->sess, cmd, be32_to_cpu(cmdsn));
293 		break;
294 	case CMDSN_LOWER_THAN_EXP:
295 		cmd->i_state = ISTATE_REMOVE;
296 		iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
297 		ret = cmdsn_ret;
298 		break;
299 	default:
300 		ret = cmdsn_ret;
301 		break;
302 	}
303 	mutex_unlock(&conn->sess->cmdsn_mutex);
304 
305 	return ret;
306 }
307 
308 int iscsit_check_unsolicited_dataout(struct iscsi_cmd *cmd, unsigned char *buf)
309 {
310 	struct iscsi_conn *conn = cmd->conn;
311 	struct se_cmd *se_cmd = &cmd->se_cmd;
312 	struct iscsi_data *hdr = (struct iscsi_data *) buf;
313 	u32 payload_length = ntoh24(hdr->dlength);
314 
315 	if (conn->sess->sess_ops->InitialR2T) {
316 		pr_err("Received unexpected unsolicited data"
317 			" while InitialR2T=Yes, protocol error.\n");
318 		transport_send_check_condition_and_sense(se_cmd,
319 				TCM_UNEXPECTED_UNSOLICITED_DATA, 0);
320 		return -1;
321 	}
322 
323 	if ((cmd->first_burst_len + payload_length) >
324 	     conn->sess->sess_ops->FirstBurstLength) {
325 		pr_err("Total %u bytes exceeds FirstBurstLength: %u"
326 			" for this Unsolicited DataOut Burst.\n",
327 			(cmd->first_burst_len + payload_length),
328 				conn->sess->sess_ops->FirstBurstLength);
329 		transport_send_check_condition_and_sense(se_cmd,
330 				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
331 		return -1;
332 	}
333 
334 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL))
335 		return 0;
336 
337 	if (((cmd->first_burst_len + payload_length) != cmd->se_cmd.data_length) &&
338 	    ((cmd->first_burst_len + payload_length) !=
339 	      conn->sess->sess_ops->FirstBurstLength)) {
340 		pr_err("Unsolicited non-immediate data received %u"
341 			" does not equal FirstBurstLength: %u, and does"
342 			" not equal ExpXferLen %u.\n",
343 			(cmd->first_burst_len + payload_length),
344 			conn->sess->sess_ops->FirstBurstLength, cmd->se_cmd.data_length);
345 		transport_send_check_condition_and_sense(se_cmd,
346 				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
347 		return -1;
348 	}
349 	return 0;
350 }
351 
352 struct iscsi_cmd *iscsit_find_cmd_from_itt(
353 	struct iscsi_conn *conn,
354 	itt_t init_task_tag)
355 {
356 	struct iscsi_cmd *cmd;
357 
358 	spin_lock_bh(&conn->cmd_lock);
359 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
360 		if (cmd->init_task_tag == init_task_tag) {
361 			spin_unlock_bh(&conn->cmd_lock);
362 			return cmd;
363 		}
364 	}
365 	spin_unlock_bh(&conn->cmd_lock);
366 
367 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu",
368 			init_task_tag, conn->cid);
369 	return NULL;
370 }
371 
372 struct iscsi_cmd *iscsit_find_cmd_from_itt_or_dump(
373 	struct iscsi_conn *conn,
374 	itt_t init_task_tag,
375 	u32 length)
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 			" dumping payload\n", init_task_tag, conn->cid);
390 	if (length)
391 		iscsit_dump_data_payload(conn, length, 1);
392 
393 	return NULL;
394 }
395 
396 struct iscsi_cmd *iscsit_find_cmd_from_ttt(
397 	struct iscsi_conn *conn,
398 	u32 targ_xfer_tag)
399 {
400 	struct iscsi_cmd *cmd = NULL;
401 
402 	spin_lock_bh(&conn->cmd_lock);
403 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
404 		if (cmd->targ_xfer_tag == targ_xfer_tag) {
405 			spin_unlock_bh(&conn->cmd_lock);
406 			return cmd;
407 		}
408 	}
409 	spin_unlock_bh(&conn->cmd_lock);
410 
411 	pr_err("Unable to locate TTT: 0x%08x on CID: %hu\n",
412 			targ_xfer_tag, conn->cid);
413 	return NULL;
414 }
415 
416 int iscsit_find_cmd_for_recovery(
417 	struct iscsi_session *sess,
418 	struct iscsi_cmd **cmd_ptr,
419 	struct iscsi_conn_recovery **cr_ptr,
420 	itt_t init_task_tag)
421 {
422 	struct iscsi_cmd *cmd = NULL;
423 	struct iscsi_conn_recovery *cr;
424 	/*
425 	 * Scan through the inactive connection recovery list's command list.
426 	 * If init_task_tag matches the command is still alligent.
427 	 */
428 	spin_lock(&sess->cr_i_lock);
429 	list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
430 		spin_lock(&cr->conn_recovery_cmd_lock);
431 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
432 			if (cmd->init_task_tag == init_task_tag) {
433 				spin_unlock(&cr->conn_recovery_cmd_lock);
434 				spin_unlock(&sess->cr_i_lock);
435 
436 				*cr_ptr = cr;
437 				*cmd_ptr = cmd;
438 				return -2;
439 			}
440 		}
441 		spin_unlock(&cr->conn_recovery_cmd_lock);
442 	}
443 	spin_unlock(&sess->cr_i_lock);
444 	/*
445 	 * Scan through the active connection recovery list's command list.
446 	 * If init_task_tag matches the command is ready to be reassigned.
447 	 */
448 	spin_lock(&sess->cr_a_lock);
449 	list_for_each_entry(cr, &sess->cr_active_list, cr_list) {
450 		spin_lock(&cr->conn_recovery_cmd_lock);
451 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
452 			if (cmd->init_task_tag == init_task_tag) {
453 				spin_unlock(&cr->conn_recovery_cmd_lock);
454 				spin_unlock(&sess->cr_a_lock);
455 
456 				*cr_ptr = cr;
457 				*cmd_ptr = cmd;
458 				return 0;
459 			}
460 		}
461 		spin_unlock(&cr->conn_recovery_cmd_lock);
462 	}
463 	spin_unlock(&sess->cr_a_lock);
464 
465 	return -1;
466 }
467 
468 void iscsit_add_cmd_to_immediate_queue(
469 	struct iscsi_cmd *cmd,
470 	struct iscsi_conn *conn,
471 	u8 state)
472 {
473 	struct iscsi_queue_req *qr;
474 
475 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
476 	if (!qr) {
477 		pr_err("Unable to allocate memory for"
478 				" struct iscsi_queue_req\n");
479 		return;
480 	}
481 	INIT_LIST_HEAD(&qr->qr_list);
482 	qr->cmd = cmd;
483 	qr->state = state;
484 
485 	spin_lock_bh(&conn->immed_queue_lock);
486 	list_add_tail(&qr->qr_list, &conn->immed_queue_list);
487 	atomic_inc(&cmd->immed_queue_count);
488 	atomic_set(&conn->check_immediate_queue, 1);
489 	spin_unlock_bh(&conn->immed_queue_lock);
490 
491 	wake_up(&conn->queues_wq);
492 }
493 
494 struct iscsi_queue_req *iscsit_get_cmd_from_immediate_queue(struct iscsi_conn *conn)
495 {
496 	struct iscsi_queue_req *qr;
497 
498 	spin_lock_bh(&conn->immed_queue_lock);
499 	if (list_empty(&conn->immed_queue_list)) {
500 		spin_unlock_bh(&conn->immed_queue_lock);
501 		return NULL;
502 	}
503 	list_for_each_entry(qr, &conn->immed_queue_list, qr_list)
504 		break;
505 
506 	list_del(&qr->qr_list);
507 	if (qr->cmd)
508 		atomic_dec(&qr->cmd->immed_queue_count);
509 	spin_unlock_bh(&conn->immed_queue_lock);
510 
511 	return qr;
512 }
513 
514 static void iscsit_remove_cmd_from_immediate_queue(
515 	struct iscsi_cmd *cmd,
516 	struct iscsi_conn *conn)
517 {
518 	struct iscsi_queue_req *qr, *qr_tmp;
519 
520 	spin_lock_bh(&conn->immed_queue_lock);
521 	if (!atomic_read(&cmd->immed_queue_count)) {
522 		spin_unlock_bh(&conn->immed_queue_lock);
523 		return;
524 	}
525 
526 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
527 		if (qr->cmd != cmd)
528 			continue;
529 
530 		atomic_dec(&qr->cmd->immed_queue_count);
531 		list_del(&qr->qr_list);
532 		kmem_cache_free(lio_qr_cache, qr);
533 	}
534 	spin_unlock_bh(&conn->immed_queue_lock);
535 
536 	if (atomic_read(&cmd->immed_queue_count)) {
537 		pr_err("ITT: 0x%08x immed_queue_count: %d\n",
538 			cmd->init_task_tag,
539 			atomic_read(&cmd->immed_queue_count));
540 	}
541 }
542 
543 void iscsit_add_cmd_to_response_queue(
544 	struct iscsi_cmd *cmd,
545 	struct iscsi_conn *conn,
546 	u8 state)
547 {
548 	struct iscsi_queue_req *qr;
549 
550 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
551 	if (!qr) {
552 		pr_err("Unable to allocate memory for"
553 			" struct iscsi_queue_req\n");
554 		return;
555 	}
556 	INIT_LIST_HEAD(&qr->qr_list);
557 	qr->cmd = cmd;
558 	qr->state = state;
559 
560 	spin_lock_bh(&conn->response_queue_lock);
561 	list_add_tail(&qr->qr_list, &conn->response_queue_list);
562 	atomic_inc(&cmd->response_queue_count);
563 	spin_unlock_bh(&conn->response_queue_lock);
564 
565 	wake_up(&conn->queues_wq);
566 }
567 
568 struct iscsi_queue_req *iscsit_get_cmd_from_response_queue(struct iscsi_conn *conn)
569 {
570 	struct iscsi_queue_req *qr;
571 
572 	spin_lock_bh(&conn->response_queue_lock);
573 	if (list_empty(&conn->response_queue_list)) {
574 		spin_unlock_bh(&conn->response_queue_lock);
575 		return NULL;
576 	}
577 
578 	list_for_each_entry(qr, &conn->response_queue_list, qr_list)
579 		break;
580 
581 	list_del(&qr->qr_list);
582 	if (qr->cmd)
583 		atomic_dec(&qr->cmd->response_queue_count);
584 	spin_unlock_bh(&conn->response_queue_lock);
585 
586 	return qr;
587 }
588 
589 static void iscsit_remove_cmd_from_response_queue(
590 	struct iscsi_cmd *cmd,
591 	struct iscsi_conn *conn)
592 {
593 	struct iscsi_queue_req *qr, *qr_tmp;
594 
595 	spin_lock_bh(&conn->response_queue_lock);
596 	if (!atomic_read(&cmd->response_queue_count)) {
597 		spin_unlock_bh(&conn->response_queue_lock);
598 		return;
599 	}
600 
601 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
602 				qr_list) {
603 		if (qr->cmd != cmd)
604 			continue;
605 
606 		atomic_dec(&qr->cmd->response_queue_count);
607 		list_del(&qr->qr_list);
608 		kmem_cache_free(lio_qr_cache, qr);
609 	}
610 	spin_unlock_bh(&conn->response_queue_lock);
611 
612 	if (atomic_read(&cmd->response_queue_count)) {
613 		pr_err("ITT: 0x%08x response_queue_count: %d\n",
614 			cmd->init_task_tag,
615 			atomic_read(&cmd->response_queue_count));
616 	}
617 }
618 
619 bool iscsit_conn_all_queues_empty(struct iscsi_conn *conn)
620 {
621 	bool empty;
622 
623 	spin_lock_bh(&conn->immed_queue_lock);
624 	empty = list_empty(&conn->immed_queue_list);
625 	spin_unlock_bh(&conn->immed_queue_lock);
626 
627 	if (!empty)
628 		return empty;
629 
630 	spin_lock_bh(&conn->response_queue_lock);
631 	empty = list_empty(&conn->response_queue_list);
632 	spin_unlock_bh(&conn->response_queue_lock);
633 
634 	return empty;
635 }
636 
637 void iscsit_free_queue_reqs_for_conn(struct iscsi_conn *conn)
638 {
639 	struct iscsi_queue_req *qr, *qr_tmp;
640 
641 	spin_lock_bh(&conn->immed_queue_lock);
642 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
643 		list_del(&qr->qr_list);
644 		if (qr->cmd)
645 			atomic_dec(&qr->cmd->immed_queue_count);
646 
647 		kmem_cache_free(lio_qr_cache, qr);
648 	}
649 	spin_unlock_bh(&conn->immed_queue_lock);
650 
651 	spin_lock_bh(&conn->response_queue_lock);
652 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
653 			qr_list) {
654 		list_del(&qr->qr_list);
655 		if (qr->cmd)
656 			atomic_dec(&qr->cmd->response_queue_count);
657 
658 		kmem_cache_free(lio_qr_cache, qr);
659 	}
660 	spin_unlock_bh(&conn->response_queue_lock);
661 }
662 
663 void iscsit_release_cmd(struct iscsi_cmd *cmd)
664 {
665 	struct iscsi_conn *conn = cmd->conn;
666 
667 	iscsit_free_r2ts_from_list(cmd);
668 	iscsit_free_all_datain_reqs(cmd);
669 
670 	kfree(cmd->buf_ptr);
671 	kfree(cmd->pdu_list);
672 	kfree(cmd->seq_list);
673 	kfree(cmd->tmr_req);
674 	kfree(cmd->iov_data);
675 
676 	if (conn) {
677 		iscsit_remove_cmd_from_immediate_queue(cmd, conn);
678 		iscsit_remove_cmd_from_response_queue(cmd, conn);
679 	}
680 
681 	kmem_cache_free(lio_cmd_cache, cmd);
682 }
683 
684 void iscsit_free_cmd(struct iscsi_cmd *cmd)
685 {
686 	/*
687 	 * Determine if a struct se_cmd is assoicated with
688 	 * this struct iscsi_cmd.
689 	 */
690 	switch (cmd->iscsi_opcode) {
691 	case ISCSI_OP_SCSI_CMD:
692 	case ISCSI_OP_SCSI_TMFUNC:
693 		transport_generic_free_cmd(&cmd->se_cmd, 1);
694 		break;
695 	case ISCSI_OP_REJECT:
696 		/*
697 		 * Handle special case for REJECT when iscsi_add_reject*() has
698 		 * overwritten the original iscsi_opcode assignment, and the
699 		 * associated cmd->se_cmd needs to be released.
700 		 */
701 		if (cmd->se_cmd.se_tfo != NULL) {
702 			transport_generic_free_cmd(&cmd->se_cmd, 1);
703 			break;
704 		}
705 		/* Fall-through */
706 	default:
707 		iscsit_release_cmd(cmd);
708 		break;
709 	}
710 }
711 
712 int iscsit_check_session_usage_count(struct iscsi_session *sess)
713 {
714 	spin_lock_bh(&sess->session_usage_lock);
715 	if (sess->session_usage_count != 0) {
716 		sess->session_waiting_on_uc = 1;
717 		spin_unlock_bh(&sess->session_usage_lock);
718 		if (in_interrupt())
719 			return 2;
720 
721 		wait_for_completion(&sess->session_waiting_on_uc_comp);
722 		return 1;
723 	}
724 	spin_unlock_bh(&sess->session_usage_lock);
725 
726 	return 0;
727 }
728 
729 void iscsit_dec_session_usage_count(struct iscsi_session *sess)
730 {
731 	spin_lock_bh(&sess->session_usage_lock);
732 	sess->session_usage_count--;
733 
734 	if (!sess->session_usage_count && sess->session_waiting_on_uc)
735 		complete(&sess->session_waiting_on_uc_comp);
736 
737 	spin_unlock_bh(&sess->session_usage_lock);
738 }
739 
740 void iscsit_inc_session_usage_count(struct iscsi_session *sess)
741 {
742 	spin_lock_bh(&sess->session_usage_lock);
743 	sess->session_usage_count++;
744 	spin_unlock_bh(&sess->session_usage_lock);
745 }
746 
747 /*
748  *	Setup conn->if_marker and conn->of_marker values based upon
749  *	the initial marker-less interval. (see iSCSI v19 A.2)
750  */
751 int iscsit_set_sync_and_steering_values(struct iscsi_conn *conn)
752 {
753 	int login_ifmarker_count = 0, login_ofmarker_count = 0, next_marker = 0;
754 	/*
755 	 * IFMarkInt and OFMarkInt are negotiated as 32-bit words.
756 	 */
757 	u32 IFMarkInt = (conn->conn_ops->IFMarkInt * 4);
758 	u32 OFMarkInt = (conn->conn_ops->OFMarkInt * 4);
759 
760 	if (conn->conn_ops->OFMarker) {
761 		/*
762 		 * Account for the first Login Command received not
763 		 * via iscsi_recv_msg().
764 		 */
765 		conn->of_marker += ISCSI_HDR_LEN;
766 		if (conn->of_marker <= OFMarkInt) {
767 			conn->of_marker = (OFMarkInt - conn->of_marker);
768 		} else {
769 			login_ofmarker_count = (conn->of_marker / OFMarkInt);
770 			next_marker = (OFMarkInt * (login_ofmarker_count + 1)) +
771 					(login_ofmarker_count * MARKER_SIZE);
772 			conn->of_marker = (next_marker - conn->of_marker);
773 		}
774 		conn->of_marker_offset = 0;
775 		pr_debug("Setting OFMarker value to %u based on Initial"
776 			" Markerless Interval.\n", conn->of_marker);
777 	}
778 
779 	if (conn->conn_ops->IFMarker) {
780 		if (conn->if_marker <= IFMarkInt) {
781 			conn->if_marker = (IFMarkInt - conn->if_marker);
782 		} else {
783 			login_ifmarker_count = (conn->if_marker / IFMarkInt);
784 			next_marker = (IFMarkInt * (login_ifmarker_count + 1)) +
785 					(login_ifmarker_count * MARKER_SIZE);
786 			conn->if_marker = (next_marker - conn->if_marker);
787 		}
788 		pr_debug("Setting IFMarker value to %u based on Initial"
789 			" Markerless Interval.\n", conn->if_marker);
790 	}
791 
792 	return 0;
793 }
794 
795 struct iscsi_conn *iscsit_get_conn_from_cid(struct iscsi_session *sess, u16 cid)
796 {
797 	struct iscsi_conn *conn;
798 
799 	spin_lock_bh(&sess->conn_lock);
800 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
801 		if ((conn->cid == cid) &&
802 		    (conn->conn_state == TARG_CONN_STATE_LOGGED_IN)) {
803 			iscsit_inc_conn_usage_count(conn);
804 			spin_unlock_bh(&sess->conn_lock);
805 			return conn;
806 		}
807 	}
808 	spin_unlock_bh(&sess->conn_lock);
809 
810 	return NULL;
811 }
812 
813 struct iscsi_conn *iscsit_get_conn_from_cid_rcfr(struct iscsi_session *sess, u16 cid)
814 {
815 	struct iscsi_conn *conn;
816 
817 	spin_lock_bh(&sess->conn_lock);
818 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
819 		if (conn->cid == cid) {
820 			iscsit_inc_conn_usage_count(conn);
821 			spin_lock(&conn->state_lock);
822 			atomic_set(&conn->connection_wait_rcfr, 1);
823 			spin_unlock(&conn->state_lock);
824 			spin_unlock_bh(&sess->conn_lock);
825 			return conn;
826 		}
827 	}
828 	spin_unlock_bh(&sess->conn_lock);
829 
830 	return NULL;
831 }
832 
833 void iscsit_check_conn_usage_count(struct iscsi_conn *conn)
834 {
835 	spin_lock_bh(&conn->conn_usage_lock);
836 	if (conn->conn_usage_count != 0) {
837 		conn->conn_waiting_on_uc = 1;
838 		spin_unlock_bh(&conn->conn_usage_lock);
839 
840 		wait_for_completion(&conn->conn_waiting_on_uc_comp);
841 		return;
842 	}
843 	spin_unlock_bh(&conn->conn_usage_lock);
844 }
845 
846 void iscsit_dec_conn_usage_count(struct iscsi_conn *conn)
847 {
848 	spin_lock_bh(&conn->conn_usage_lock);
849 	conn->conn_usage_count--;
850 
851 	if (!conn->conn_usage_count && conn->conn_waiting_on_uc)
852 		complete(&conn->conn_waiting_on_uc_comp);
853 
854 	spin_unlock_bh(&conn->conn_usage_lock);
855 }
856 
857 void iscsit_inc_conn_usage_count(struct iscsi_conn *conn)
858 {
859 	spin_lock_bh(&conn->conn_usage_lock);
860 	conn->conn_usage_count++;
861 	spin_unlock_bh(&conn->conn_usage_lock);
862 }
863 
864 static int iscsit_add_nopin(struct iscsi_conn *conn, int want_response)
865 {
866 	u8 state;
867 	struct iscsi_cmd *cmd;
868 
869 	cmd = iscsit_allocate_cmd(conn, GFP_ATOMIC);
870 	if (!cmd)
871 		return -1;
872 
873 	cmd->iscsi_opcode = ISCSI_OP_NOOP_IN;
874 	state = (want_response) ? ISTATE_SEND_NOPIN_WANT_RESPONSE :
875 				ISTATE_SEND_NOPIN_NO_RESPONSE;
876 	cmd->init_task_tag = RESERVED_ITT;
877 	spin_lock_bh(&conn->sess->ttt_lock);
878 	cmd->targ_xfer_tag = (want_response) ? conn->sess->targ_xfer_tag++ :
879 			0xFFFFFFFF;
880 	if (want_response && (cmd->targ_xfer_tag == 0xFFFFFFFF))
881 		cmd->targ_xfer_tag = conn->sess->targ_xfer_tag++;
882 	spin_unlock_bh(&conn->sess->ttt_lock);
883 
884 	spin_lock_bh(&conn->cmd_lock);
885 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
886 	spin_unlock_bh(&conn->cmd_lock);
887 
888 	if (want_response)
889 		iscsit_start_nopin_response_timer(conn);
890 	iscsit_add_cmd_to_immediate_queue(cmd, conn, state);
891 
892 	return 0;
893 }
894 
895 static void iscsit_handle_nopin_response_timeout(unsigned long data)
896 {
897 	struct iscsi_conn *conn = (struct iscsi_conn *) data;
898 
899 	iscsit_inc_conn_usage_count(conn);
900 
901 	spin_lock_bh(&conn->nopin_timer_lock);
902 	if (conn->nopin_response_timer_flags & ISCSI_TF_STOP) {
903 		spin_unlock_bh(&conn->nopin_timer_lock);
904 		iscsit_dec_conn_usage_count(conn);
905 		return;
906 	}
907 
908 	pr_debug("Did not receive response to NOPIN on CID: %hu on"
909 		" SID: %u, failing connection.\n", conn->cid,
910 			conn->sess->sid);
911 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
912 	spin_unlock_bh(&conn->nopin_timer_lock);
913 
914 	{
915 	struct iscsi_portal_group *tpg = conn->sess->tpg;
916 	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
917 
918 	if (tiqn) {
919 		spin_lock_bh(&tiqn->sess_err_stats.lock);
920 		strcpy(tiqn->sess_err_stats.last_sess_fail_rem_name,
921 				conn->sess->sess_ops->InitiatorName);
922 		tiqn->sess_err_stats.last_sess_failure_type =
923 				ISCSI_SESS_ERR_CXN_TIMEOUT;
924 		tiqn->sess_err_stats.cxn_timeout_errors++;
925 		conn->sess->conn_timeout_errors++;
926 		spin_unlock_bh(&tiqn->sess_err_stats.lock);
927 	}
928 	}
929 
930 	iscsit_cause_connection_reinstatement(conn, 0);
931 	iscsit_dec_conn_usage_count(conn);
932 }
933 
934 void iscsit_mod_nopin_response_timer(struct iscsi_conn *conn)
935 {
936 	struct iscsi_session *sess = conn->sess;
937 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
938 
939 	spin_lock_bh(&conn->nopin_timer_lock);
940 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
941 		spin_unlock_bh(&conn->nopin_timer_lock);
942 		return;
943 	}
944 
945 	mod_timer(&conn->nopin_response_timer,
946 		(get_jiffies_64() + na->nopin_response_timeout * HZ));
947 	spin_unlock_bh(&conn->nopin_timer_lock);
948 }
949 
950 /*
951  *	Called with conn->nopin_timer_lock held.
952  */
953 void iscsit_start_nopin_response_timer(struct iscsi_conn *conn)
954 {
955 	struct iscsi_session *sess = conn->sess;
956 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
957 
958 	spin_lock_bh(&conn->nopin_timer_lock);
959 	if (conn->nopin_response_timer_flags & ISCSI_TF_RUNNING) {
960 		spin_unlock_bh(&conn->nopin_timer_lock);
961 		return;
962 	}
963 
964 	init_timer(&conn->nopin_response_timer);
965 	conn->nopin_response_timer.expires =
966 		(get_jiffies_64() + na->nopin_response_timeout * HZ);
967 	conn->nopin_response_timer.data = (unsigned long)conn;
968 	conn->nopin_response_timer.function = iscsit_handle_nopin_response_timeout;
969 	conn->nopin_response_timer_flags &= ~ISCSI_TF_STOP;
970 	conn->nopin_response_timer_flags |= ISCSI_TF_RUNNING;
971 	add_timer(&conn->nopin_response_timer);
972 
973 	pr_debug("Started NOPIN Response Timer on CID: %d to %u"
974 		" seconds\n", conn->cid, na->nopin_response_timeout);
975 	spin_unlock_bh(&conn->nopin_timer_lock);
976 }
977 
978 void iscsit_stop_nopin_response_timer(struct iscsi_conn *conn)
979 {
980 	spin_lock_bh(&conn->nopin_timer_lock);
981 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
982 		spin_unlock_bh(&conn->nopin_timer_lock);
983 		return;
984 	}
985 	conn->nopin_response_timer_flags |= ISCSI_TF_STOP;
986 	spin_unlock_bh(&conn->nopin_timer_lock);
987 
988 	del_timer_sync(&conn->nopin_response_timer);
989 
990 	spin_lock_bh(&conn->nopin_timer_lock);
991 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
992 	spin_unlock_bh(&conn->nopin_timer_lock);
993 }
994 
995 static void iscsit_handle_nopin_timeout(unsigned long data)
996 {
997 	struct iscsi_conn *conn = (struct iscsi_conn *) data;
998 
999 	iscsit_inc_conn_usage_count(conn);
1000 
1001 	spin_lock_bh(&conn->nopin_timer_lock);
1002 	if (conn->nopin_timer_flags & ISCSI_TF_STOP) {
1003 		spin_unlock_bh(&conn->nopin_timer_lock);
1004 		iscsit_dec_conn_usage_count(conn);
1005 		return;
1006 	}
1007 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1008 	spin_unlock_bh(&conn->nopin_timer_lock);
1009 
1010 	iscsit_add_nopin(conn, 1);
1011 	iscsit_dec_conn_usage_count(conn);
1012 }
1013 
1014 /*
1015  * Called with conn->nopin_timer_lock held.
1016  */
1017 void __iscsit_start_nopin_timer(struct iscsi_conn *conn)
1018 {
1019 	struct iscsi_session *sess = conn->sess;
1020 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1021 	/*
1022 	* NOPIN timeout is disabled.
1023 	 */
1024 	if (!na->nopin_timeout)
1025 		return;
1026 
1027 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING)
1028 		return;
1029 
1030 	init_timer(&conn->nopin_timer);
1031 	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1032 	conn->nopin_timer.data = (unsigned long)conn;
1033 	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1034 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1035 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1036 	add_timer(&conn->nopin_timer);
1037 
1038 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1039 		" interval\n", conn->cid, na->nopin_timeout);
1040 }
1041 
1042 void iscsit_start_nopin_timer(struct iscsi_conn *conn)
1043 {
1044 	struct iscsi_session *sess = conn->sess;
1045 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1046 	/*
1047 	 * NOPIN timeout is disabled..
1048 	 */
1049 	if (!na->nopin_timeout)
1050 		return;
1051 
1052 	spin_lock_bh(&conn->nopin_timer_lock);
1053 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING) {
1054 		spin_unlock_bh(&conn->nopin_timer_lock);
1055 		return;
1056 	}
1057 
1058 	init_timer(&conn->nopin_timer);
1059 	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1060 	conn->nopin_timer.data = (unsigned long)conn;
1061 	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1062 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1063 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1064 	add_timer(&conn->nopin_timer);
1065 
1066 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1067 			" interval\n", conn->cid, na->nopin_timeout);
1068 	spin_unlock_bh(&conn->nopin_timer_lock);
1069 }
1070 
1071 void iscsit_stop_nopin_timer(struct iscsi_conn *conn)
1072 {
1073 	spin_lock_bh(&conn->nopin_timer_lock);
1074 	if (!(conn->nopin_timer_flags & ISCSI_TF_RUNNING)) {
1075 		spin_unlock_bh(&conn->nopin_timer_lock);
1076 		return;
1077 	}
1078 	conn->nopin_timer_flags |= ISCSI_TF_STOP;
1079 	spin_unlock_bh(&conn->nopin_timer_lock);
1080 
1081 	del_timer_sync(&conn->nopin_timer);
1082 
1083 	spin_lock_bh(&conn->nopin_timer_lock);
1084 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1085 	spin_unlock_bh(&conn->nopin_timer_lock);
1086 }
1087 
1088 int iscsit_send_tx_data(
1089 	struct iscsi_cmd *cmd,
1090 	struct iscsi_conn *conn,
1091 	int use_misc)
1092 {
1093 	int tx_sent, tx_size;
1094 	u32 iov_count;
1095 	struct kvec *iov;
1096 
1097 send_data:
1098 	tx_size = cmd->tx_size;
1099 
1100 	if (!use_misc) {
1101 		iov = &cmd->iov_data[0];
1102 		iov_count = cmd->iov_data_count;
1103 	} else {
1104 		iov = &cmd->iov_misc[0];
1105 		iov_count = cmd->iov_misc_count;
1106 	}
1107 
1108 	tx_sent = tx_data(conn, &iov[0], iov_count, tx_size);
1109 	if (tx_size != tx_sent) {
1110 		if (tx_sent == -EAGAIN) {
1111 			pr_err("tx_data() returned -EAGAIN\n");
1112 			goto send_data;
1113 		} else
1114 			return -1;
1115 	}
1116 	cmd->tx_size = 0;
1117 
1118 	return 0;
1119 }
1120 
1121 int iscsit_fe_sendpage_sg(
1122 	struct iscsi_cmd *cmd,
1123 	struct iscsi_conn *conn)
1124 {
1125 	struct scatterlist *sg = cmd->first_data_sg;
1126 	struct kvec iov;
1127 	u32 tx_hdr_size, data_len;
1128 	u32 offset = cmd->first_data_sg_off;
1129 	int tx_sent, iov_off;
1130 
1131 send_hdr:
1132 	tx_hdr_size = ISCSI_HDR_LEN;
1133 	if (conn->conn_ops->HeaderDigest)
1134 		tx_hdr_size += ISCSI_CRC_LEN;
1135 
1136 	iov.iov_base = cmd->pdu;
1137 	iov.iov_len = tx_hdr_size;
1138 
1139 	tx_sent = tx_data(conn, &iov, 1, tx_hdr_size);
1140 	if (tx_hdr_size != tx_sent) {
1141 		if (tx_sent == -EAGAIN) {
1142 			pr_err("tx_data() returned -EAGAIN\n");
1143 			goto send_hdr;
1144 		}
1145 		return -1;
1146 	}
1147 
1148 	data_len = cmd->tx_size - tx_hdr_size - cmd->padding;
1149 	/*
1150 	 * Set iov_off used by padding and data digest tx_data() calls below
1151 	 * in order to determine proper offset into cmd->iov_data[]
1152 	 */
1153 	if (conn->conn_ops->DataDigest) {
1154 		data_len -= ISCSI_CRC_LEN;
1155 		if (cmd->padding)
1156 			iov_off = (cmd->iov_data_count - 2);
1157 		else
1158 			iov_off = (cmd->iov_data_count - 1);
1159 	} else {
1160 		iov_off = (cmd->iov_data_count - 1);
1161 	}
1162 	/*
1163 	 * Perform sendpage() for each page in the scatterlist
1164 	 */
1165 	while (data_len) {
1166 		u32 space = (sg->length - offset);
1167 		u32 sub_len = min_t(u32, data_len, space);
1168 send_pg:
1169 		tx_sent = conn->sock->ops->sendpage(conn->sock,
1170 					sg_page(sg), sg->offset + offset, sub_len, 0);
1171 		if (tx_sent != sub_len) {
1172 			if (tx_sent == -EAGAIN) {
1173 				pr_err("tcp_sendpage() returned"
1174 						" -EAGAIN\n");
1175 				goto send_pg;
1176 			}
1177 
1178 			pr_err("tcp_sendpage() failure: %d\n",
1179 					tx_sent);
1180 			return -1;
1181 		}
1182 
1183 		data_len -= sub_len;
1184 		offset = 0;
1185 		sg = sg_next(sg);
1186 	}
1187 
1188 send_padding:
1189 	if (cmd->padding) {
1190 		struct kvec *iov_p = &cmd->iov_data[iov_off++];
1191 
1192 		tx_sent = tx_data(conn, iov_p, 1, cmd->padding);
1193 		if (cmd->padding != tx_sent) {
1194 			if (tx_sent == -EAGAIN) {
1195 				pr_err("tx_data() returned -EAGAIN\n");
1196 				goto send_padding;
1197 			}
1198 			return -1;
1199 		}
1200 	}
1201 
1202 send_datacrc:
1203 	if (conn->conn_ops->DataDigest) {
1204 		struct kvec *iov_d = &cmd->iov_data[iov_off];
1205 
1206 		tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN);
1207 		if (ISCSI_CRC_LEN != tx_sent) {
1208 			if (tx_sent == -EAGAIN) {
1209 				pr_err("tx_data() returned -EAGAIN\n");
1210 				goto send_datacrc;
1211 			}
1212 			return -1;
1213 		}
1214 	}
1215 
1216 	return 0;
1217 }
1218 
1219 /*
1220  *      This function is used for mainly sending a ISCSI_TARG_LOGIN_RSP PDU
1221  *      back to the Initiator when an expection condition occurs with the
1222  *      errors set in status_class and status_detail.
1223  *
1224  *      Parameters:     iSCSI Connection, Status Class, Status Detail.
1225  *      Returns:        0 on success, -1 on error.
1226  */
1227 int iscsit_tx_login_rsp(struct iscsi_conn *conn, u8 status_class, u8 status_detail)
1228 {
1229 	u8 iscsi_hdr[ISCSI_HDR_LEN];
1230 	int err;
1231 	struct kvec iov;
1232 	struct iscsi_login_rsp *hdr;
1233 
1234 	iscsit_collect_login_stats(conn, status_class, status_detail);
1235 
1236 	memset(&iov, 0, sizeof(struct kvec));
1237 	memset(&iscsi_hdr, 0x0, ISCSI_HDR_LEN);
1238 
1239 	hdr	= (struct iscsi_login_rsp *)&iscsi_hdr;
1240 	hdr->opcode		= ISCSI_OP_LOGIN_RSP;
1241 	hdr->status_class	= status_class;
1242 	hdr->status_detail	= status_detail;
1243 	hdr->itt		= conn->login_itt;
1244 
1245 	iov.iov_base		= &iscsi_hdr;
1246 	iov.iov_len		= ISCSI_HDR_LEN;
1247 
1248 	PRINT_BUFF(iscsi_hdr, ISCSI_HDR_LEN);
1249 
1250 	err = tx_data(conn, &iov, 1, ISCSI_HDR_LEN);
1251 	if (err != ISCSI_HDR_LEN) {
1252 		pr_err("tx_data returned less than expected\n");
1253 		return -1;
1254 	}
1255 
1256 	return 0;
1257 }
1258 
1259 void iscsit_print_session_params(struct iscsi_session *sess)
1260 {
1261 	struct iscsi_conn *conn;
1262 
1263 	pr_debug("-----------------------------[Session Params for"
1264 		" SID: %u]-----------------------------\n", sess->sid);
1265 	spin_lock_bh(&sess->conn_lock);
1266 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
1267 		iscsi_dump_conn_ops(conn->conn_ops);
1268 	spin_unlock_bh(&sess->conn_lock);
1269 
1270 	iscsi_dump_sess_ops(sess->sess_ops);
1271 }
1272 
1273 static int iscsit_do_rx_data(
1274 	struct iscsi_conn *conn,
1275 	struct iscsi_data_count *count)
1276 {
1277 	int data = count->data_length, rx_loop = 0, total_rx = 0, iov_len;
1278 	struct kvec *iov_p;
1279 	struct msghdr msg;
1280 
1281 	if (!conn || !conn->sock || !conn->conn_ops)
1282 		return -1;
1283 
1284 	memset(&msg, 0, sizeof(struct msghdr));
1285 
1286 	iov_p = count->iov;
1287 	iov_len	= count->iov_count;
1288 
1289 	while (total_rx < data) {
1290 		rx_loop = kernel_recvmsg(conn->sock, &msg, iov_p, iov_len,
1291 					(data - total_rx), MSG_WAITALL);
1292 		if (rx_loop <= 0) {
1293 			pr_debug("rx_loop: %d total_rx: %d\n",
1294 				rx_loop, total_rx);
1295 			return rx_loop;
1296 		}
1297 		total_rx += rx_loop;
1298 		pr_debug("rx_loop: %d, total_rx: %d, data: %d\n",
1299 				rx_loop, total_rx, data);
1300 	}
1301 
1302 	return total_rx;
1303 }
1304 
1305 static int iscsit_do_tx_data(
1306 	struct iscsi_conn *conn,
1307 	struct iscsi_data_count *count)
1308 {
1309 	int data = count->data_length, total_tx = 0, tx_loop = 0, iov_len;
1310 	struct kvec *iov_p;
1311 	struct msghdr msg;
1312 
1313 	if (!conn || !conn->sock || !conn->conn_ops)
1314 		return -1;
1315 
1316 	if (data <= 0) {
1317 		pr_err("Data length is: %d\n", data);
1318 		return -1;
1319 	}
1320 
1321 	memset(&msg, 0, sizeof(struct msghdr));
1322 
1323 	iov_p = count->iov;
1324 	iov_len = count->iov_count;
1325 
1326 	while (total_tx < data) {
1327 		tx_loop = kernel_sendmsg(conn->sock, &msg, iov_p, iov_len,
1328 					(data - total_tx));
1329 		if (tx_loop <= 0) {
1330 			pr_debug("tx_loop: %d total_tx %d\n",
1331 				tx_loop, total_tx);
1332 			return tx_loop;
1333 		}
1334 		total_tx += tx_loop;
1335 		pr_debug("tx_loop: %d, total_tx: %d, data: %d\n",
1336 					tx_loop, total_tx, data);
1337 	}
1338 
1339 	return total_tx;
1340 }
1341 
1342 int rx_data(
1343 	struct iscsi_conn *conn,
1344 	struct kvec *iov,
1345 	int iov_count,
1346 	int data)
1347 {
1348 	struct iscsi_data_count c;
1349 
1350 	if (!conn || !conn->sock || !conn->conn_ops)
1351 		return -1;
1352 
1353 	memset(&c, 0, sizeof(struct iscsi_data_count));
1354 	c.iov = iov;
1355 	c.iov_count = iov_count;
1356 	c.data_length = data;
1357 	c.type = ISCSI_RX_DATA;
1358 
1359 	return iscsit_do_rx_data(conn, &c);
1360 }
1361 
1362 int tx_data(
1363 	struct iscsi_conn *conn,
1364 	struct kvec *iov,
1365 	int iov_count,
1366 	int data)
1367 {
1368 	struct iscsi_data_count c;
1369 
1370 	if (!conn || !conn->sock || !conn->conn_ops)
1371 		return -1;
1372 
1373 	memset(&c, 0, sizeof(struct iscsi_data_count));
1374 	c.iov = iov;
1375 	c.iov_count = iov_count;
1376 	c.data_length = data;
1377 	c.type = ISCSI_TX_DATA;
1378 
1379 	return iscsit_do_tx_data(conn, &c);
1380 }
1381 
1382 void iscsit_collect_login_stats(
1383 	struct iscsi_conn *conn,
1384 	u8 status_class,
1385 	u8 status_detail)
1386 {
1387 	struct iscsi_param *intrname = NULL;
1388 	struct iscsi_tiqn *tiqn;
1389 	struct iscsi_login_stats *ls;
1390 
1391 	tiqn = iscsit_snmp_get_tiqn(conn);
1392 	if (!tiqn)
1393 		return;
1394 
1395 	ls = &tiqn->login_stats;
1396 
1397 	spin_lock(&ls->lock);
1398 	if (!strcmp(conn->login_ip, ls->last_intr_fail_ip_addr) &&
1399 	    ((get_jiffies_64() - ls->last_fail_time) < 10)) {
1400 		/* We already have the failure info for this login */
1401 		spin_unlock(&ls->lock);
1402 		return;
1403 	}
1404 
1405 	if (status_class == ISCSI_STATUS_CLS_SUCCESS)
1406 		ls->accepts++;
1407 	else if (status_class == ISCSI_STATUS_CLS_REDIRECT) {
1408 		ls->redirects++;
1409 		ls->last_fail_type = ISCSI_LOGIN_FAIL_REDIRECT;
1410 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1411 		 (status_detail == ISCSI_LOGIN_STATUS_AUTH_FAILED)) {
1412 		ls->authenticate_fails++;
1413 		ls->last_fail_type =  ISCSI_LOGIN_FAIL_AUTHENTICATE;
1414 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1415 		 (status_detail == ISCSI_LOGIN_STATUS_TGT_FORBIDDEN)) {
1416 		ls->authorize_fails++;
1417 		ls->last_fail_type = ISCSI_LOGIN_FAIL_AUTHORIZE;
1418 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR) &&
1419 		 (status_detail == ISCSI_LOGIN_STATUS_INIT_ERR)) {
1420 		ls->negotiate_fails++;
1421 		ls->last_fail_type = ISCSI_LOGIN_FAIL_NEGOTIATE;
1422 	} else {
1423 		ls->other_fails++;
1424 		ls->last_fail_type = ISCSI_LOGIN_FAIL_OTHER;
1425 	}
1426 
1427 	/* Save initiator name, ip address and time, if it is a failed login */
1428 	if (status_class != ISCSI_STATUS_CLS_SUCCESS) {
1429 		if (conn->param_list)
1430 			intrname = iscsi_find_param_from_key(INITIATORNAME,
1431 							     conn->param_list);
1432 		strcpy(ls->last_intr_fail_name,
1433 		       (intrname ? intrname->value : "Unknown"));
1434 
1435 		ls->last_intr_fail_ip_family = conn->sock->sk->sk_family;
1436 		snprintf(ls->last_intr_fail_ip_addr, IPV6_ADDRESS_SPACE,
1437 				"%s", conn->login_ip);
1438 		ls->last_fail_time = get_jiffies_64();
1439 	}
1440 
1441 	spin_unlock(&ls->lock);
1442 }
1443 
1444 struct iscsi_tiqn *iscsit_snmp_get_tiqn(struct iscsi_conn *conn)
1445 {
1446 	struct iscsi_portal_group *tpg;
1447 
1448 	if (!conn || !conn->sess)
1449 		return NULL;
1450 
1451 	tpg = conn->sess->tpg;
1452 	if (!tpg)
1453 		return NULL;
1454 
1455 	if (!tpg->tpg_tiqn)
1456 		return NULL;
1457 
1458 	return tpg->tpg_tiqn;
1459 }
1460