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 	init_completion(&cmd->reject_comp);
182 	spin_lock_init(&cmd->datain_lock);
183 	spin_lock_init(&cmd->dataout_timeout_lock);
184 	spin_lock_init(&cmd->istate_lock);
185 	spin_lock_init(&cmd->error_lock);
186 	spin_lock_init(&cmd->r2t_lock);
187 
188 	return cmd;
189 }
190 EXPORT_SYMBOL(iscsit_allocate_cmd);
191 
192 struct iscsi_seq *iscsit_get_seq_holder_for_datain(
193 	struct iscsi_cmd *cmd,
194 	u32 seq_send_order)
195 {
196 	u32 i;
197 
198 	for (i = 0; i < cmd->seq_count; i++)
199 		if (cmd->seq_list[i].seq_send_order == seq_send_order)
200 			return &cmd->seq_list[i];
201 
202 	return NULL;
203 }
204 
205 struct iscsi_seq *iscsit_get_seq_holder_for_r2t(struct iscsi_cmd *cmd)
206 {
207 	u32 i;
208 
209 	if (!cmd->seq_list) {
210 		pr_err("struct iscsi_cmd->seq_list is NULL!\n");
211 		return NULL;
212 	}
213 
214 	for (i = 0; i < cmd->seq_count; i++) {
215 		if (cmd->seq_list[i].type != SEQTYPE_NORMAL)
216 			continue;
217 		if (cmd->seq_list[i].seq_send_order == cmd->seq_send_order) {
218 			cmd->seq_send_order++;
219 			return &cmd->seq_list[i];
220 		}
221 	}
222 
223 	return NULL;
224 }
225 
226 struct iscsi_r2t *iscsit_get_holder_for_r2tsn(
227 	struct iscsi_cmd *cmd,
228 	u32 r2t_sn)
229 {
230 	struct iscsi_r2t *r2t;
231 
232 	spin_lock_bh(&cmd->r2t_lock);
233 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
234 		if (r2t->r2t_sn == r2t_sn) {
235 			spin_unlock_bh(&cmd->r2t_lock);
236 			return r2t;
237 		}
238 	}
239 	spin_unlock_bh(&cmd->r2t_lock);
240 
241 	return NULL;
242 }
243 
244 static inline int iscsit_check_received_cmdsn(struct iscsi_session *sess, u32 cmdsn)
245 {
246 	int ret;
247 
248 	/*
249 	 * This is the proper method of checking received CmdSN against
250 	 * ExpCmdSN and MaxCmdSN values, as well as accounting for out
251 	 * or order CmdSNs due to multiple connection sessions and/or
252 	 * CRC failures.
253 	 */
254 	if (iscsi_sna_gt(cmdsn, sess->max_cmd_sn)) {
255 		pr_err("Received CmdSN: 0x%08x is greater than"
256 		       " MaxCmdSN: 0x%08x, protocol error.\n", cmdsn,
257 		       sess->max_cmd_sn);
258 		ret = CMDSN_ERROR_CANNOT_RECOVER;
259 
260 	} else if (cmdsn == sess->exp_cmd_sn) {
261 		sess->exp_cmd_sn++;
262 		pr_debug("Received CmdSN matches ExpCmdSN,"
263 		      " incremented ExpCmdSN to: 0x%08x\n",
264 		      sess->exp_cmd_sn);
265 		ret = CMDSN_NORMAL_OPERATION;
266 
267 	} else if (iscsi_sna_gt(cmdsn, sess->exp_cmd_sn)) {
268 		pr_debug("Received CmdSN: 0x%08x is greater"
269 		      " than ExpCmdSN: 0x%08x, not acknowledging.\n",
270 		      cmdsn, sess->exp_cmd_sn);
271 		ret = CMDSN_HIGHER_THAN_EXP;
272 
273 	} else {
274 		pr_err("Received CmdSN: 0x%08x is less than"
275 		       " ExpCmdSN: 0x%08x, ignoring.\n", cmdsn,
276 		       sess->exp_cmd_sn);
277 		ret = CMDSN_LOWER_THAN_EXP;
278 	}
279 
280 	return ret;
281 }
282 
283 /*
284  * Commands may be received out of order if MC/S is in use.
285  * Ensure they are executed in CmdSN order.
286  */
287 int iscsit_sequence_cmd(
288 	struct iscsi_conn *conn,
289 	struct iscsi_cmd *cmd,
290 	__be32 cmdsn)
291 {
292 	int ret;
293 	int cmdsn_ret;
294 
295 	mutex_lock(&conn->sess->cmdsn_mutex);
296 
297 	cmdsn_ret = iscsit_check_received_cmdsn(conn->sess, be32_to_cpu(cmdsn));
298 	switch (cmdsn_ret) {
299 	case CMDSN_NORMAL_OPERATION:
300 		ret = iscsit_execute_cmd(cmd, 0);
301 		if ((ret >= 0) && !list_empty(&conn->sess->sess_ooo_cmdsn_list))
302 			iscsit_execute_ooo_cmdsns(conn->sess);
303 		break;
304 	case CMDSN_HIGHER_THAN_EXP:
305 		ret = iscsit_handle_ooo_cmdsn(conn->sess, cmd, be32_to_cpu(cmdsn));
306 		break;
307 	case CMDSN_LOWER_THAN_EXP:
308 		cmd->i_state = ISTATE_REMOVE;
309 		iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
310 		ret = cmdsn_ret;
311 		break;
312 	default:
313 		ret = cmdsn_ret;
314 		break;
315 	}
316 	mutex_unlock(&conn->sess->cmdsn_mutex);
317 
318 	return ret;
319 }
320 EXPORT_SYMBOL(iscsit_sequence_cmd);
321 
322 int iscsit_check_unsolicited_dataout(struct iscsi_cmd *cmd, unsigned char *buf)
323 {
324 	struct iscsi_conn *conn = cmd->conn;
325 	struct se_cmd *se_cmd = &cmd->se_cmd;
326 	struct iscsi_data *hdr = (struct iscsi_data *) buf;
327 	u32 payload_length = ntoh24(hdr->dlength);
328 
329 	if (conn->sess->sess_ops->InitialR2T) {
330 		pr_err("Received unexpected unsolicited data"
331 			" while InitialR2T=Yes, protocol error.\n");
332 		transport_send_check_condition_and_sense(se_cmd,
333 				TCM_UNEXPECTED_UNSOLICITED_DATA, 0);
334 		return -1;
335 	}
336 
337 	if ((cmd->first_burst_len + payload_length) >
338 	     conn->sess->sess_ops->FirstBurstLength) {
339 		pr_err("Total %u bytes exceeds FirstBurstLength: %u"
340 			" for this Unsolicited DataOut Burst.\n",
341 			(cmd->first_burst_len + payload_length),
342 				conn->sess->sess_ops->FirstBurstLength);
343 		transport_send_check_condition_and_sense(se_cmd,
344 				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
345 		return -1;
346 	}
347 
348 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL))
349 		return 0;
350 
351 	if (((cmd->first_burst_len + payload_length) != cmd->se_cmd.data_length) &&
352 	    ((cmd->first_burst_len + payload_length) !=
353 	      conn->sess->sess_ops->FirstBurstLength)) {
354 		pr_err("Unsolicited non-immediate data received %u"
355 			" does not equal FirstBurstLength: %u, and does"
356 			" not equal ExpXferLen %u.\n",
357 			(cmd->first_burst_len + payload_length),
358 			conn->sess->sess_ops->FirstBurstLength, cmd->se_cmd.data_length);
359 		transport_send_check_condition_and_sense(se_cmd,
360 				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
361 		return -1;
362 	}
363 	return 0;
364 }
365 
366 struct iscsi_cmd *iscsit_find_cmd_from_itt(
367 	struct iscsi_conn *conn,
368 	itt_t init_task_tag)
369 {
370 	struct iscsi_cmd *cmd;
371 
372 	spin_lock_bh(&conn->cmd_lock);
373 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
374 		if (cmd->init_task_tag == init_task_tag) {
375 			spin_unlock_bh(&conn->cmd_lock);
376 			return cmd;
377 		}
378 	}
379 	spin_unlock_bh(&conn->cmd_lock);
380 
381 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu",
382 			init_task_tag, conn->cid);
383 	return NULL;
384 }
385 
386 struct iscsi_cmd *iscsit_find_cmd_from_itt_or_dump(
387 	struct iscsi_conn *conn,
388 	itt_t init_task_tag,
389 	u32 length)
390 {
391 	struct iscsi_cmd *cmd;
392 
393 	spin_lock_bh(&conn->cmd_lock);
394 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
395 		if (cmd->init_task_tag == init_task_tag) {
396 			spin_unlock_bh(&conn->cmd_lock);
397 			return cmd;
398 		}
399 	}
400 	spin_unlock_bh(&conn->cmd_lock);
401 
402 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu,"
403 			" dumping payload\n", init_task_tag, conn->cid);
404 	if (length)
405 		iscsit_dump_data_payload(conn, length, 1);
406 
407 	return NULL;
408 }
409 
410 struct iscsi_cmd *iscsit_find_cmd_from_ttt(
411 	struct iscsi_conn *conn,
412 	u32 targ_xfer_tag)
413 {
414 	struct iscsi_cmd *cmd = NULL;
415 
416 	spin_lock_bh(&conn->cmd_lock);
417 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
418 		if (cmd->targ_xfer_tag == targ_xfer_tag) {
419 			spin_unlock_bh(&conn->cmd_lock);
420 			return cmd;
421 		}
422 	}
423 	spin_unlock_bh(&conn->cmd_lock);
424 
425 	pr_err("Unable to locate TTT: 0x%08x on CID: %hu\n",
426 			targ_xfer_tag, conn->cid);
427 	return NULL;
428 }
429 
430 int iscsit_find_cmd_for_recovery(
431 	struct iscsi_session *sess,
432 	struct iscsi_cmd **cmd_ptr,
433 	struct iscsi_conn_recovery **cr_ptr,
434 	itt_t init_task_tag)
435 {
436 	struct iscsi_cmd *cmd = NULL;
437 	struct iscsi_conn_recovery *cr;
438 	/*
439 	 * Scan through the inactive connection recovery list's command list.
440 	 * If init_task_tag matches the command is still alligent.
441 	 */
442 	spin_lock(&sess->cr_i_lock);
443 	list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
444 		spin_lock(&cr->conn_recovery_cmd_lock);
445 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
446 			if (cmd->init_task_tag == init_task_tag) {
447 				spin_unlock(&cr->conn_recovery_cmd_lock);
448 				spin_unlock(&sess->cr_i_lock);
449 
450 				*cr_ptr = cr;
451 				*cmd_ptr = cmd;
452 				return -2;
453 			}
454 		}
455 		spin_unlock(&cr->conn_recovery_cmd_lock);
456 	}
457 	spin_unlock(&sess->cr_i_lock);
458 	/*
459 	 * Scan through the active connection recovery list's command list.
460 	 * If init_task_tag matches the command is ready to be reassigned.
461 	 */
462 	spin_lock(&sess->cr_a_lock);
463 	list_for_each_entry(cr, &sess->cr_active_list, cr_list) {
464 		spin_lock(&cr->conn_recovery_cmd_lock);
465 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
466 			if (cmd->init_task_tag == init_task_tag) {
467 				spin_unlock(&cr->conn_recovery_cmd_lock);
468 				spin_unlock(&sess->cr_a_lock);
469 
470 				*cr_ptr = cr;
471 				*cmd_ptr = cmd;
472 				return 0;
473 			}
474 		}
475 		spin_unlock(&cr->conn_recovery_cmd_lock);
476 	}
477 	spin_unlock(&sess->cr_a_lock);
478 
479 	return -1;
480 }
481 
482 void iscsit_add_cmd_to_immediate_queue(
483 	struct iscsi_cmd *cmd,
484 	struct iscsi_conn *conn,
485 	u8 state)
486 {
487 	struct iscsi_queue_req *qr;
488 
489 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
490 	if (!qr) {
491 		pr_err("Unable to allocate memory for"
492 				" struct iscsi_queue_req\n");
493 		return;
494 	}
495 	INIT_LIST_HEAD(&qr->qr_list);
496 	qr->cmd = cmd;
497 	qr->state = state;
498 
499 	spin_lock_bh(&conn->immed_queue_lock);
500 	list_add_tail(&qr->qr_list, &conn->immed_queue_list);
501 	atomic_inc(&cmd->immed_queue_count);
502 	atomic_set(&conn->check_immediate_queue, 1);
503 	spin_unlock_bh(&conn->immed_queue_lock);
504 
505 	wake_up(&conn->queues_wq);
506 }
507 
508 struct iscsi_queue_req *iscsit_get_cmd_from_immediate_queue(struct iscsi_conn *conn)
509 {
510 	struct iscsi_queue_req *qr;
511 
512 	spin_lock_bh(&conn->immed_queue_lock);
513 	if (list_empty(&conn->immed_queue_list)) {
514 		spin_unlock_bh(&conn->immed_queue_lock);
515 		return NULL;
516 	}
517 	qr = list_first_entry(&conn->immed_queue_list,
518 			      struct iscsi_queue_req, qr_list);
519 
520 	list_del(&qr->qr_list);
521 	if (qr->cmd)
522 		atomic_dec(&qr->cmd->immed_queue_count);
523 	spin_unlock_bh(&conn->immed_queue_lock);
524 
525 	return qr;
526 }
527 
528 static void iscsit_remove_cmd_from_immediate_queue(
529 	struct iscsi_cmd *cmd,
530 	struct iscsi_conn *conn)
531 {
532 	struct iscsi_queue_req *qr, *qr_tmp;
533 
534 	spin_lock_bh(&conn->immed_queue_lock);
535 	if (!atomic_read(&cmd->immed_queue_count)) {
536 		spin_unlock_bh(&conn->immed_queue_lock);
537 		return;
538 	}
539 
540 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
541 		if (qr->cmd != cmd)
542 			continue;
543 
544 		atomic_dec(&qr->cmd->immed_queue_count);
545 		list_del(&qr->qr_list);
546 		kmem_cache_free(lio_qr_cache, qr);
547 	}
548 	spin_unlock_bh(&conn->immed_queue_lock);
549 
550 	if (atomic_read(&cmd->immed_queue_count)) {
551 		pr_err("ITT: 0x%08x immed_queue_count: %d\n",
552 			cmd->init_task_tag,
553 			atomic_read(&cmd->immed_queue_count));
554 	}
555 }
556 
557 void iscsit_add_cmd_to_response_queue(
558 	struct iscsi_cmd *cmd,
559 	struct iscsi_conn *conn,
560 	u8 state)
561 {
562 	struct iscsi_queue_req *qr;
563 
564 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
565 	if (!qr) {
566 		pr_err("Unable to allocate memory for"
567 			" struct iscsi_queue_req\n");
568 		return;
569 	}
570 	INIT_LIST_HEAD(&qr->qr_list);
571 	qr->cmd = cmd;
572 	qr->state = state;
573 
574 	spin_lock_bh(&conn->response_queue_lock);
575 	list_add_tail(&qr->qr_list, &conn->response_queue_list);
576 	atomic_inc(&cmd->response_queue_count);
577 	spin_unlock_bh(&conn->response_queue_lock);
578 
579 	wake_up(&conn->queues_wq);
580 }
581 
582 struct iscsi_queue_req *iscsit_get_cmd_from_response_queue(struct iscsi_conn *conn)
583 {
584 	struct iscsi_queue_req *qr;
585 
586 	spin_lock_bh(&conn->response_queue_lock);
587 	if (list_empty(&conn->response_queue_list)) {
588 		spin_unlock_bh(&conn->response_queue_lock);
589 		return NULL;
590 	}
591 
592 	qr = list_first_entry(&conn->response_queue_list,
593 			      struct iscsi_queue_req, qr_list);
594 
595 	list_del(&qr->qr_list);
596 	if (qr->cmd)
597 		atomic_dec(&qr->cmd->response_queue_count);
598 	spin_unlock_bh(&conn->response_queue_lock);
599 
600 	return qr;
601 }
602 
603 static void iscsit_remove_cmd_from_response_queue(
604 	struct iscsi_cmd *cmd,
605 	struct iscsi_conn *conn)
606 {
607 	struct iscsi_queue_req *qr, *qr_tmp;
608 
609 	spin_lock_bh(&conn->response_queue_lock);
610 	if (!atomic_read(&cmd->response_queue_count)) {
611 		spin_unlock_bh(&conn->response_queue_lock);
612 		return;
613 	}
614 
615 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
616 				qr_list) {
617 		if (qr->cmd != cmd)
618 			continue;
619 
620 		atomic_dec(&qr->cmd->response_queue_count);
621 		list_del(&qr->qr_list);
622 		kmem_cache_free(lio_qr_cache, qr);
623 	}
624 	spin_unlock_bh(&conn->response_queue_lock);
625 
626 	if (atomic_read(&cmd->response_queue_count)) {
627 		pr_err("ITT: 0x%08x response_queue_count: %d\n",
628 			cmd->init_task_tag,
629 			atomic_read(&cmd->response_queue_count));
630 	}
631 }
632 
633 bool iscsit_conn_all_queues_empty(struct iscsi_conn *conn)
634 {
635 	bool empty;
636 
637 	spin_lock_bh(&conn->immed_queue_lock);
638 	empty = list_empty(&conn->immed_queue_list);
639 	spin_unlock_bh(&conn->immed_queue_lock);
640 
641 	if (!empty)
642 		return empty;
643 
644 	spin_lock_bh(&conn->response_queue_lock);
645 	empty = list_empty(&conn->response_queue_list);
646 	spin_unlock_bh(&conn->response_queue_lock);
647 
648 	return empty;
649 }
650 
651 void iscsit_free_queue_reqs_for_conn(struct iscsi_conn *conn)
652 {
653 	struct iscsi_queue_req *qr, *qr_tmp;
654 
655 	spin_lock_bh(&conn->immed_queue_lock);
656 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
657 		list_del(&qr->qr_list);
658 		if (qr->cmd)
659 			atomic_dec(&qr->cmd->immed_queue_count);
660 
661 		kmem_cache_free(lio_qr_cache, qr);
662 	}
663 	spin_unlock_bh(&conn->immed_queue_lock);
664 
665 	spin_lock_bh(&conn->response_queue_lock);
666 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
667 			qr_list) {
668 		list_del(&qr->qr_list);
669 		if (qr->cmd)
670 			atomic_dec(&qr->cmd->response_queue_count);
671 
672 		kmem_cache_free(lio_qr_cache, qr);
673 	}
674 	spin_unlock_bh(&conn->response_queue_lock);
675 }
676 
677 void iscsit_release_cmd(struct iscsi_cmd *cmd)
678 {
679 	kfree(cmd->buf_ptr);
680 	kfree(cmd->pdu_list);
681 	kfree(cmd->seq_list);
682 	kfree(cmd->tmr_req);
683 	kfree(cmd->iov_data);
684 
685 	kmem_cache_free(lio_cmd_cache, cmd);
686 }
687 
688 static void __iscsit_free_cmd(struct iscsi_cmd *cmd, bool scsi_cmd,
689 			      bool check_queues)
690 {
691 	struct iscsi_conn *conn = cmd->conn;
692 
693 	if (scsi_cmd) {
694 		if (cmd->data_direction == DMA_TO_DEVICE) {
695 			iscsit_stop_dataout_timer(cmd);
696 			iscsit_free_r2ts_from_list(cmd);
697 		}
698 		if (cmd->data_direction == DMA_FROM_DEVICE)
699 			iscsit_free_all_datain_reqs(cmd);
700 	}
701 
702 	if (conn && check_queues) {
703 		iscsit_remove_cmd_from_immediate_queue(cmd, conn);
704 		iscsit_remove_cmd_from_response_queue(cmd, conn);
705 	}
706 }
707 
708 void iscsit_free_cmd(struct iscsi_cmd *cmd, bool shutdown)
709 {
710 	struct se_cmd *se_cmd = NULL;
711 	int rc;
712 	/*
713 	 * Determine if a struct se_cmd is associated with
714 	 * this struct iscsi_cmd.
715 	 */
716 	switch (cmd->iscsi_opcode) {
717 	case ISCSI_OP_SCSI_CMD:
718 		se_cmd = &cmd->se_cmd;
719 		__iscsit_free_cmd(cmd, true, shutdown);
720 		/*
721 		 * Fallthrough
722 		 */
723 	case ISCSI_OP_SCSI_TMFUNC:
724 		rc = transport_generic_free_cmd(&cmd->se_cmd, 1);
725 		if (!rc && shutdown && se_cmd && se_cmd->se_sess) {
726 			__iscsit_free_cmd(cmd, true, shutdown);
727 			target_put_sess_cmd(se_cmd->se_sess, se_cmd);
728 		}
729 		break;
730 	case ISCSI_OP_REJECT:
731 		/*
732 		 * Handle special case for REJECT when iscsi_add_reject*() has
733 		 * overwritten the original iscsi_opcode assignment, and the
734 		 * associated cmd->se_cmd needs to be released.
735 		 */
736 		if (cmd->se_cmd.se_tfo != NULL) {
737 			se_cmd = &cmd->se_cmd;
738 			__iscsit_free_cmd(cmd, true, shutdown);
739 
740 			rc = transport_generic_free_cmd(&cmd->se_cmd, 1);
741 			if (!rc && shutdown && se_cmd->se_sess) {
742 				__iscsit_free_cmd(cmd, true, shutdown);
743 				target_put_sess_cmd(se_cmd->se_sess, se_cmd);
744 			}
745 			break;
746 		}
747 		/* Fall-through */
748 	default:
749 		__iscsit_free_cmd(cmd, false, shutdown);
750 		cmd->release_cmd(cmd);
751 		break;
752 	}
753 }
754 
755 int iscsit_check_session_usage_count(struct iscsi_session *sess)
756 {
757 	spin_lock_bh(&sess->session_usage_lock);
758 	if (sess->session_usage_count != 0) {
759 		sess->session_waiting_on_uc = 1;
760 		spin_unlock_bh(&sess->session_usage_lock);
761 		if (in_interrupt())
762 			return 2;
763 
764 		wait_for_completion(&sess->session_waiting_on_uc_comp);
765 		return 1;
766 	}
767 	spin_unlock_bh(&sess->session_usage_lock);
768 
769 	return 0;
770 }
771 
772 void iscsit_dec_session_usage_count(struct iscsi_session *sess)
773 {
774 	spin_lock_bh(&sess->session_usage_lock);
775 	sess->session_usage_count--;
776 
777 	if (!sess->session_usage_count && sess->session_waiting_on_uc)
778 		complete(&sess->session_waiting_on_uc_comp);
779 
780 	spin_unlock_bh(&sess->session_usage_lock);
781 }
782 
783 void iscsit_inc_session_usage_count(struct iscsi_session *sess)
784 {
785 	spin_lock_bh(&sess->session_usage_lock);
786 	sess->session_usage_count++;
787 	spin_unlock_bh(&sess->session_usage_lock);
788 }
789 
790 /*
791  *	Setup conn->if_marker and conn->of_marker values based upon
792  *	the initial marker-less interval. (see iSCSI v19 A.2)
793  */
794 int iscsit_set_sync_and_steering_values(struct iscsi_conn *conn)
795 {
796 	int login_ifmarker_count = 0, login_ofmarker_count = 0, next_marker = 0;
797 	/*
798 	 * IFMarkInt and OFMarkInt are negotiated as 32-bit words.
799 	 */
800 	u32 IFMarkInt = (conn->conn_ops->IFMarkInt * 4);
801 	u32 OFMarkInt = (conn->conn_ops->OFMarkInt * 4);
802 
803 	if (conn->conn_ops->OFMarker) {
804 		/*
805 		 * Account for the first Login Command received not
806 		 * via iscsi_recv_msg().
807 		 */
808 		conn->of_marker += ISCSI_HDR_LEN;
809 		if (conn->of_marker <= OFMarkInt) {
810 			conn->of_marker = (OFMarkInt - conn->of_marker);
811 		} else {
812 			login_ofmarker_count = (conn->of_marker / OFMarkInt);
813 			next_marker = (OFMarkInt * (login_ofmarker_count + 1)) +
814 					(login_ofmarker_count * MARKER_SIZE);
815 			conn->of_marker = (next_marker - conn->of_marker);
816 		}
817 		conn->of_marker_offset = 0;
818 		pr_debug("Setting OFMarker value to %u based on Initial"
819 			" Markerless Interval.\n", conn->of_marker);
820 	}
821 
822 	if (conn->conn_ops->IFMarker) {
823 		if (conn->if_marker <= IFMarkInt) {
824 			conn->if_marker = (IFMarkInt - conn->if_marker);
825 		} else {
826 			login_ifmarker_count = (conn->if_marker / IFMarkInt);
827 			next_marker = (IFMarkInt * (login_ifmarker_count + 1)) +
828 					(login_ifmarker_count * MARKER_SIZE);
829 			conn->if_marker = (next_marker - conn->if_marker);
830 		}
831 		pr_debug("Setting IFMarker value to %u based on Initial"
832 			" Markerless Interval.\n", conn->if_marker);
833 	}
834 
835 	return 0;
836 }
837 
838 struct iscsi_conn *iscsit_get_conn_from_cid(struct iscsi_session *sess, u16 cid)
839 {
840 	struct iscsi_conn *conn;
841 
842 	spin_lock_bh(&sess->conn_lock);
843 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
844 		if ((conn->cid == cid) &&
845 		    (conn->conn_state == TARG_CONN_STATE_LOGGED_IN)) {
846 			iscsit_inc_conn_usage_count(conn);
847 			spin_unlock_bh(&sess->conn_lock);
848 			return conn;
849 		}
850 	}
851 	spin_unlock_bh(&sess->conn_lock);
852 
853 	return NULL;
854 }
855 
856 struct iscsi_conn *iscsit_get_conn_from_cid_rcfr(struct iscsi_session *sess, u16 cid)
857 {
858 	struct iscsi_conn *conn;
859 
860 	spin_lock_bh(&sess->conn_lock);
861 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
862 		if (conn->cid == cid) {
863 			iscsit_inc_conn_usage_count(conn);
864 			spin_lock(&conn->state_lock);
865 			atomic_set(&conn->connection_wait_rcfr, 1);
866 			spin_unlock(&conn->state_lock);
867 			spin_unlock_bh(&sess->conn_lock);
868 			return conn;
869 		}
870 	}
871 	spin_unlock_bh(&sess->conn_lock);
872 
873 	return NULL;
874 }
875 
876 void iscsit_check_conn_usage_count(struct iscsi_conn *conn)
877 {
878 	spin_lock_bh(&conn->conn_usage_lock);
879 	if (conn->conn_usage_count != 0) {
880 		conn->conn_waiting_on_uc = 1;
881 		spin_unlock_bh(&conn->conn_usage_lock);
882 
883 		wait_for_completion(&conn->conn_waiting_on_uc_comp);
884 		return;
885 	}
886 	spin_unlock_bh(&conn->conn_usage_lock);
887 }
888 
889 void iscsit_dec_conn_usage_count(struct iscsi_conn *conn)
890 {
891 	spin_lock_bh(&conn->conn_usage_lock);
892 	conn->conn_usage_count--;
893 
894 	if (!conn->conn_usage_count && conn->conn_waiting_on_uc)
895 		complete(&conn->conn_waiting_on_uc_comp);
896 
897 	spin_unlock_bh(&conn->conn_usage_lock);
898 }
899 
900 void iscsit_inc_conn_usage_count(struct iscsi_conn *conn)
901 {
902 	spin_lock_bh(&conn->conn_usage_lock);
903 	conn->conn_usage_count++;
904 	spin_unlock_bh(&conn->conn_usage_lock);
905 }
906 
907 static int iscsit_add_nopin(struct iscsi_conn *conn, int want_response)
908 {
909 	u8 state;
910 	struct iscsi_cmd *cmd;
911 
912 	cmd = iscsit_allocate_cmd(conn, GFP_ATOMIC);
913 	if (!cmd)
914 		return -1;
915 
916 	cmd->iscsi_opcode = ISCSI_OP_NOOP_IN;
917 	state = (want_response) ? ISTATE_SEND_NOPIN_WANT_RESPONSE :
918 				ISTATE_SEND_NOPIN_NO_RESPONSE;
919 	cmd->init_task_tag = RESERVED_ITT;
920 	spin_lock_bh(&conn->sess->ttt_lock);
921 	cmd->targ_xfer_tag = (want_response) ? conn->sess->targ_xfer_tag++ :
922 			0xFFFFFFFF;
923 	if (want_response && (cmd->targ_xfer_tag == 0xFFFFFFFF))
924 		cmd->targ_xfer_tag = conn->sess->targ_xfer_tag++;
925 	spin_unlock_bh(&conn->sess->ttt_lock);
926 
927 	spin_lock_bh(&conn->cmd_lock);
928 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
929 	spin_unlock_bh(&conn->cmd_lock);
930 
931 	if (want_response)
932 		iscsit_start_nopin_response_timer(conn);
933 	iscsit_add_cmd_to_immediate_queue(cmd, conn, state);
934 
935 	return 0;
936 }
937 
938 static void iscsit_handle_nopin_response_timeout(unsigned long data)
939 {
940 	struct iscsi_conn *conn = (struct iscsi_conn *) data;
941 
942 	iscsit_inc_conn_usage_count(conn);
943 
944 	spin_lock_bh(&conn->nopin_timer_lock);
945 	if (conn->nopin_response_timer_flags & ISCSI_TF_STOP) {
946 		spin_unlock_bh(&conn->nopin_timer_lock);
947 		iscsit_dec_conn_usage_count(conn);
948 		return;
949 	}
950 
951 	pr_debug("Did not receive response to NOPIN on CID: %hu on"
952 		" SID: %u, failing connection.\n", conn->cid,
953 			conn->sess->sid);
954 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
955 	spin_unlock_bh(&conn->nopin_timer_lock);
956 
957 	{
958 	struct iscsi_portal_group *tpg = conn->sess->tpg;
959 	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
960 
961 	if (tiqn) {
962 		spin_lock_bh(&tiqn->sess_err_stats.lock);
963 		strcpy(tiqn->sess_err_stats.last_sess_fail_rem_name,
964 				conn->sess->sess_ops->InitiatorName);
965 		tiqn->sess_err_stats.last_sess_failure_type =
966 				ISCSI_SESS_ERR_CXN_TIMEOUT;
967 		tiqn->sess_err_stats.cxn_timeout_errors++;
968 		conn->sess->conn_timeout_errors++;
969 		spin_unlock_bh(&tiqn->sess_err_stats.lock);
970 	}
971 	}
972 
973 	iscsit_cause_connection_reinstatement(conn, 0);
974 	iscsit_dec_conn_usage_count(conn);
975 }
976 
977 void iscsit_mod_nopin_response_timer(struct iscsi_conn *conn)
978 {
979 	struct iscsi_session *sess = conn->sess;
980 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
981 
982 	spin_lock_bh(&conn->nopin_timer_lock);
983 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
984 		spin_unlock_bh(&conn->nopin_timer_lock);
985 		return;
986 	}
987 
988 	mod_timer(&conn->nopin_response_timer,
989 		(get_jiffies_64() + na->nopin_response_timeout * HZ));
990 	spin_unlock_bh(&conn->nopin_timer_lock);
991 }
992 
993 /*
994  *	Called with conn->nopin_timer_lock held.
995  */
996 void iscsit_start_nopin_response_timer(struct iscsi_conn *conn)
997 {
998 	struct iscsi_session *sess = conn->sess;
999 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1000 
1001 	spin_lock_bh(&conn->nopin_timer_lock);
1002 	if (conn->nopin_response_timer_flags & ISCSI_TF_RUNNING) {
1003 		spin_unlock_bh(&conn->nopin_timer_lock);
1004 		return;
1005 	}
1006 
1007 	init_timer(&conn->nopin_response_timer);
1008 	conn->nopin_response_timer.expires =
1009 		(get_jiffies_64() + na->nopin_response_timeout * HZ);
1010 	conn->nopin_response_timer.data = (unsigned long)conn;
1011 	conn->nopin_response_timer.function = iscsit_handle_nopin_response_timeout;
1012 	conn->nopin_response_timer_flags &= ~ISCSI_TF_STOP;
1013 	conn->nopin_response_timer_flags |= ISCSI_TF_RUNNING;
1014 	add_timer(&conn->nopin_response_timer);
1015 
1016 	pr_debug("Started NOPIN Response Timer on CID: %d to %u"
1017 		" seconds\n", conn->cid, na->nopin_response_timeout);
1018 	spin_unlock_bh(&conn->nopin_timer_lock);
1019 }
1020 
1021 void iscsit_stop_nopin_response_timer(struct iscsi_conn *conn)
1022 {
1023 	spin_lock_bh(&conn->nopin_timer_lock);
1024 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
1025 		spin_unlock_bh(&conn->nopin_timer_lock);
1026 		return;
1027 	}
1028 	conn->nopin_response_timer_flags |= ISCSI_TF_STOP;
1029 	spin_unlock_bh(&conn->nopin_timer_lock);
1030 
1031 	del_timer_sync(&conn->nopin_response_timer);
1032 
1033 	spin_lock_bh(&conn->nopin_timer_lock);
1034 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
1035 	spin_unlock_bh(&conn->nopin_timer_lock);
1036 }
1037 
1038 static void iscsit_handle_nopin_timeout(unsigned long data)
1039 {
1040 	struct iscsi_conn *conn = (struct iscsi_conn *) data;
1041 
1042 	iscsit_inc_conn_usage_count(conn);
1043 
1044 	spin_lock_bh(&conn->nopin_timer_lock);
1045 	if (conn->nopin_timer_flags & ISCSI_TF_STOP) {
1046 		spin_unlock_bh(&conn->nopin_timer_lock);
1047 		iscsit_dec_conn_usage_count(conn);
1048 		return;
1049 	}
1050 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1051 	spin_unlock_bh(&conn->nopin_timer_lock);
1052 
1053 	iscsit_add_nopin(conn, 1);
1054 	iscsit_dec_conn_usage_count(conn);
1055 }
1056 
1057 /*
1058  * Called with conn->nopin_timer_lock held.
1059  */
1060 void __iscsit_start_nopin_timer(struct iscsi_conn *conn)
1061 {
1062 	struct iscsi_session *sess = conn->sess;
1063 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1064 	/*
1065 	* NOPIN timeout is disabled.
1066 	 */
1067 	if (!na->nopin_timeout)
1068 		return;
1069 
1070 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING)
1071 		return;
1072 
1073 	init_timer(&conn->nopin_timer);
1074 	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1075 	conn->nopin_timer.data = (unsigned long)conn;
1076 	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1077 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1078 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1079 	add_timer(&conn->nopin_timer);
1080 
1081 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1082 		" interval\n", conn->cid, na->nopin_timeout);
1083 }
1084 
1085 void iscsit_start_nopin_timer(struct iscsi_conn *conn)
1086 {
1087 	struct iscsi_session *sess = conn->sess;
1088 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1089 	/*
1090 	 * NOPIN timeout is disabled..
1091 	 */
1092 	if (!na->nopin_timeout)
1093 		return;
1094 
1095 	spin_lock_bh(&conn->nopin_timer_lock);
1096 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING) {
1097 		spin_unlock_bh(&conn->nopin_timer_lock);
1098 		return;
1099 	}
1100 
1101 	init_timer(&conn->nopin_timer);
1102 	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1103 	conn->nopin_timer.data = (unsigned long)conn;
1104 	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1105 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1106 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1107 	add_timer(&conn->nopin_timer);
1108 
1109 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1110 			" interval\n", conn->cid, na->nopin_timeout);
1111 	spin_unlock_bh(&conn->nopin_timer_lock);
1112 }
1113 
1114 void iscsit_stop_nopin_timer(struct iscsi_conn *conn)
1115 {
1116 	spin_lock_bh(&conn->nopin_timer_lock);
1117 	if (!(conn->nopin_timer_flags & ISCSI_TF_RUNNING)) {
1118 		spin_unlock_bh(&conn->nopin_timer_lock);
1119 		return;
1120 	}
1121 	conn->nopin_timer_flags |= ISCSI_TF_STOP;
1122 	spin_unlock_bh(&conn->nopin_timer_lock);
1123 
1124 	del_timer_sync(&conn->nopin_timer);
1125 
1126 	spin_lock_bh(&conn->nopin_timer_lock);
1127 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1128 	spin_unlock_bh(&conn->nopin_timer_lock);
1129 }
1130 
1131 int iscsit_send_tx_data(
1132 	struct iscsi_cmd *cmd,
1133 	struct iscsi_conn *conn,
1134 	int use_misc)
1135 {
1136 	int tx_sent, tx_size;
1137 	u32 iov_count;
1138 	struct kvec *iov;
1139 
1140 send_data:
1141 	tx_size = cmd->tx_size;
1142 
1143 	if (!use_misc) {
1144 		iov = &cmd->iov_data[0];
1145 		iov_count = cmd->iov_data_count;
1146 	} else {
1147 		iov = &cmd->iov_misc[0];
1148 		iov_count = cmd->iov_misc_count;
1149 	}
1150 
1151 	tx_sent = tx_data(conn, &iov[0], iov_count, tx_size);
1152 	if (tx_size != tx_sent) {
1153 		if (tx_sent == -EAGAIN) {
1154 			pr_err("tx_data() returned -EAGAIN\n");
1155 			goto send_data;
1156 		} else
1157 			return -1;
1158 	}
1159 	cmd->tx_size = 0;
1160 
1161 	return 0;
1162 }
1163 
1164 int iscsit_fe_sendpage_sg(
1165 	struct iscsi_cmd *cmd,
1166 	struct iscsi_conn *conn)
1167 {
1168 	struct scatterlist *sg = cmd->first_data_sg;
1169 	struct kvec iov;
1170 	u32 tx_hdr_size, data_len;
1171 	u32 offset = cmd->first_data_sg_off;
1172 	int tx_sent, iov_off;
1173 
1174 send_hdr:
1175 	tx_hdr_size = ISCSI_HDR_LEN;
1176 	if (conn->conn_ops->HeaderDigest)
1177 		tx_hdr_size += ISCSI_CRC_LEN;
1178 
1179 	iov.iov_base = cmd->pdu;
1180 	iov.iov_len = tx_hdr_size;
1181 
1182 	tx_sent = tx_data(conn, &iov, 1, tx_hdr_size);
1183 	if (tx_hdr_size != tx_sent) {
1184 		if (tx_sent == -EAGAIN) {
1185 			pr_err("tx_data() returned -EAGAIN\n");
1186 			goto send_hdr;
1187 		}
1188 		return -1;
1189 	}
1190 
1191 	data_len = cmd->tx_size - tx_hdr_size - cmd->padding;
1192 	/*
1193 	 * Set iov_off used by padding and data digest tx_data() calls below
1194 	 * in order to determine proper offset into cmd->iov_data[]
1195 	 */
1196 	if (conn->conn_ops->DataDigest) {
1197 		data_len -= ISCSI_CRC_LEN;
1198 		if (cmd->padding)
1199 			iov_off = (cmd->iov_data_count - 2);
1200 		else
1201 			iov_off = (cmd->iov_data_count - 1);
1202 	} else {
1203 		iov_off = (cmd->iov_data_count - 1);
1204 	}
1205 	/*
1206 	 * Perform sendpage() for each page in the scatterlist
1207 	 */
1208 	while (data_len) {
1209 		u32 space = (sg->length - offset);
1210 		u32 sub_len = min_t(u32, data_len, space);
1211 send_pg:
1212 		tx_sent = conn->sock->ops->sendpage(conn->sock,
1213 					sg_page(sg), sg->offset + offset, sub_len, 0);
1214 		if (tx_sent != sub_len) {
1215 			if (tx_sent == -EAGAIN) {
1216 				pr_err("tcp_sendpage() returned"
1217 						" -EAGAIN\n");
1218 				goto send_pg;
1219 			}
1220 
1221 			pr_err("tcp_sendpage() failure: %d\n",
1222 					tx_sent);
1223 			return -1;
1224 		}
1225 
1226 		data_len -= sub_len;
1227 		offset = 0;
1228 		sg = sg_next(sg);
1229 	}
1230 
1231 send_padding:
1232 	if (cmd->padding) {
1233 		struct kvec *iov_p = &cmd->iov_data[iov_off++];
1234 
1235 		tx_sent = tx_data(conn, iov_p, 1, cmd->padding);
1236 		if (cmd->padding != tx_sent) {
1237 			if (tx_sent == -EAGAIN) {
1238 				pr_err("tx_data() returned -EAGAIN\n");
1239 				goto send_padding;
1240 			}
1241 			return -1;
1242 		}
1243 	}
1244 
1245 send_datacrc:
1246 	if (conn->conn_ops->DataDigest) {
1247 		struct kvec *iov_d = &cmd->iov_data[iov_off];
1248 
1249 		tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN);
1250 		if (ISCSI_CRC_LEN != tx_sent) {
1251 			if (tx_sent == -EAGAIN) {
1252 				pr_err("tx_data() returned -EAGAIN\n");
1253 				goto send_datacrc;
1254 			}
1255 			return -1;
1256 		}
1257 	}
1258 
1259 	return 0;
1260 }
1261 
1262 /*
1263  *      This function is used for mainly sending a ISCSI_TARG_LOGIN_RSP PDU
1264  *      back to the Initiator when an expection condition occurs with the
1265  *      errors set in status_class and status_detail.
1266  *
1267  *      Parameters:     iSCSI Connection, Status Class, Status Detail.
1268  *      Returns:        0 on success, -1 on error.
1269  */
1270 int iscsit_tx_login_rsp(struct iscsi_conn *conn, u8 status_class, u8 status_detail)
1271 {
1272 	struct iscsi_login_rsp *hdr;
1273 	struct iscsi_login *login = conn->conn_login;
1274 
1275 	login->login_failed = 1;
1276 	iscsit_collect_login_stats(conn, status_class, status_detail);
1277 
1278 	hdr	= (struct iscsi_login_rsp *)&login->rsp[0];
1279 	hdr->opcode		= ISCSI_OP_LOGIN_RSP;
1280 	hdr->status_class	= status_class;
1281 	hdr->status_detail	= status_detail;
1282 	hdr->itt		= conn->login_itt;
1283 
1284 	return conn->conn_transport->iscsit_put_login_tx(conn, login, 0);
1285 }
1286 
1287 void iscsit_print_session_params(struct iscsi_session *sess)
1288 {
1289 	struct iscsi_conn *conn;
1290 
1291 	pr_debug("-----------------------------[Session Params for"
1292 		" SID: %u]-----------------------------\n", sess->sid);
1293 	spin_lock_bh(&sess->conn_lock);
1294 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
1295 		iscsi_dump_conn_ops(conn->conn_ops);
1296 	spin_unlock_bh(&sess->conn_lock);
1297 
1298 	iscsi_dump_sess_ops(sess->sess_ops);
1299 }
1300 
1301 static int iscsit_do_rx_data(
1302 	struct iscsi_conn *conn,
1303 	struct iscsi_data_count *count)
1304 {
1305 	int data = count->data_length, rx_loop = 0, total_rx = 0, iov_len;
1306 	struct kvec *iov_p;
1307 	struct msghdr msg;
1308 
1309 	if (!conn || !conn->sock || !conn->conn_ops)
1310 		return -1;
1311 
1312 	memset(&msg, 0, sizeof(struct msghdr));
1313 
1314 	iov_p = count->iov;
1315 	iov_len	= count->iov_count;
1316 
1317 	while (total_rx < data) {
1318 		rx_loop = kernel_recvmsg(conn->sock, &msg, iov_p, iov_len,
1319 					(data - total_rx), MSG_WAITALL);
1320 		if (rx_loop <= 0) {
1321 			pr_debug("rx_loop: %d total_rx: %d\n",
1322 				rx_loop, total_rx);
1323 			return rx_loop;
1324 		}
1325 		total_rx += rx_loop;
1326 		pr_debug("rx_loop: %d, total_rx: %d, data: %d\n",
1327 				rx_loop, total_rx, data);
1328 	}
1329 
1330 	return total_rx;
1331 }
1332 
1333 static int iscsit_do_tx_data(
1334 	struct iscsi_conn *conn,
1335 	struct iscsi_data_count *count)
1336 {
1337 	int data = count->data_length, total_tx = 0, tx_loop = 0, iov_len;
1338 	struct kvec *iov_p;
1339 	struct msghdr msg;
1340 
1341 	if (!conn || !conn->sock || !conn->conn_ops)
1342 		return -1;
1343 
1344 	if (data <= 0) {
1345 		pr_err("Data length is: %d\n", data);
1346 		return -1;
1347 	}
1348 
1349 	memset(&msg, 0, sizeof(struct msghdr));
1350 
1351 	iov_p = count->iov;
1352 	iov_len = count->iov_count;
1353 
1354 	while (total_tx < data) {
1355 		tx_loop = kernel_sendmsg(conn->sock, &msg, iov_p, iov_len,
1356 					(data - total_tx));
1357 		if (tx_loop <= 0) {
1358 			pr_debug("tx_loop: %d total_tx %d\n",
1359 				tx_loop, total_tx);
1360 			return tx_loop;
1361 		}
1362 		total_tx += tx_loop;
1363 		pr_debug("tx_loop: %d, total_tx: %d, data: %d\n",
1364 					tx_loop, total_tx, data);
1365 	}
1366 
1367 	return total_tx;
1368 }
1369 
1370 int rx_data(
1371 	struct iscsi_conn *conn,
1372 	struct kvec *iov,
1373 	int iov_count,
1374 	int data)
1375 {
1376 	struct iscsi_data_count c;
1377 
1378 	if (!conn || !conn->sock || !conn->conn_ops)
1379 		return -1;
1380 
1381 	memset(&c, 0, sizeof(struct iscsi_data_count));
1382 	c.iov = iov;
1383 	c.iov_count = iov_count;
1384 	c.data_length = data;
1385 	c.type = ISCSI_RX_DATA;
1386 
1387 	return iscsit_do_rx_data(conn, &c);
1388 }
1389 
1390 int tx_data(
1391 	struct iscsi_conn *conn,
1392 	struct kvec *iov,
1393 	int iov_count,
1394 	int data)
1395 {
1396 	struct iscsi_data_count c;
1397 
1398 	if (!conn || !conn->sock || !conn->conn_ops)
1399 		return -1;
1400 
1401 	memset(&c, 0, sizeof(struct iscsi_data_count));
1402 	c.iov = iov;
1403 	c.iov_count = iov_count;
1404 	c.data_length = data;
1405 	c.type = ISCSI_TX_DATA;
1406 
1407 	return iscsit_do_tx_data(conn, &c);
1408 }
1409 
1410 void iscsit_collect_login_stats(
1411 	struct iscsi_conn *conn,
1412 	u8 status_class,
1413 	u8 status_detail)
1414 {
1415 	struct iscsi_param *intrname = NULL;
1416 	struct iscsi_tiqn *tiqn;
1417 	struct iscsi_login_stats *ls;
1418 
1419 	tiqn = iscsit_snmp_get_tiqn(conn);
1420 	if (!tiqn)
1421 		return;
1422 
1423 	ls = &tiqn->login_stats;
1424 
1425 	spin_lock(&ls->lock);
1426 	if (!strcmp(conn->login_ip, ls->last_intr_fail_ip_addr) &&
1427 	    ((get_jiffies_64() - ls->last_fail_time) < 10)) {
1428 		/* We already have the failure info for this login */
1429 		spin_unlock(&ls->lock);
1430 		return;
1431 	}
1432 
1433 	if (status_class == ISCSI_STATUS_CLS_SUCCESS)
1434 		ls->accepts++;
1435 	else if (status_class == ISCSI_STATUS_CLS_REDIRECT) {
1436 		ls->redirects++;
1437 		ls->last_fail_type = ISCSI_LOGIN_FAIL_REDIRECT;
1438 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1439 		 (status_detail == ISCSI_LOGIN_STATUS_AUTH_FAILED)) {
1440 		ls->authenticate_fails++;
1441 		ls->last_fail_type =  ISCSI_LOGIN_FAIL_AUTHENTICATE;
1442 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1443 		 (status_detail == ISCSI_LOGIN_STATUS_TGT_FORBIDDEN)) {
1444 		ls->authorize_fails++;
1445 		ls->last_fail_type = ISCSI_LOGIN_FAIL_AUTHORIZE;
1446 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR) &&
1447 		 (status_detail == ISCSI_LOGIN_STATUS_INIT_ERR)) {
1448 		ls->negotiate_fails++;
1449 		ls->last_fail_type = ISCSI_LOGIN_FAIL_NEGOTIATE;
1450 	} else {
1451 		ls->other_fails++;
1452 		ls->last_fail_type = ISCSI_LOGIN_FAIL_OTHER;
1453 	}
1454 
1455 	/* Save initiator name, ip address and time, if it is a failed login */
1456 	if (status_class != ISCSI_STATUS_CLS_SUCCESS) {
1457 		if (conn->param_list)
1458 			intrname = iscsi_find_param_from_key(INITIATORNAME,
1459 							     conn->param_list);
1460 		strcpy(ls->last_intr_fail_name,
1461 		       (intrname ? intrname->value : "Unknown"));
1462 
1463 		ls->last_intr_fail_ip_family = conn->login_family;
1464 
1465 		snprintf(ls->last_intr_fail_ip_addr, IPV6_ADDRESS_SPACE,
1466 				"%s", conn->login_ip);
1467 		ls->last_fail_time = get_jiffies_64();
1468 	}
1469 
1470 	spin_unlock(&ls->lock);
1471 }
1472 
1473 struct iscsi_tiqn *iscsit_snmp_get_tiqn(struct iscsi_conn *conn)
1474 {
1475 	struct iscsi_portal_group *tpg;
1476 
1477 	if (!conn || !conn->sess)
1478 		return NULL;
1479 
1480 	tpg = conn->sess->tpg;
1481 	if (!tpg)
1482 		return NULL;
1483 
1484 	if (!tpg->tpg_tiqn)
1485 		return NULL;
1486 
1487 	return tpg->tpg_tiqn;
1488 }
1489