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_list);
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 /*
180  * Called from iscsi_handle_scsi_cmd()
181  */
182 struct iscsi_cmd *iscsit_allocate_se_cmd(
183 	struct iscsi_conn *conn,
184 	u32 data_length,
185 	int data_direction,
186 	int iscsi_task_attr)
187 {
188 	struct iscsi_cmd *cmd;
189 	struct se_cmd *se_cmd;
190 	int sam_task_attr;
191 
192 	cmd = iscsit_allocate_cmd(conn, GFP_KERNEL);
193 	if (!cmd)
194 		return NULL;
195 
196 	cmd->data_direction = data_direction;
197 	cmd->data_length = data_length;
198 	/*
199 	 * Figure out the SAM Task Attribute for the incoming SCSI CDB
200 	 */
201 	if ((iscsi_task_attr == ISCSI_ATTR_UNTAGGED) ||
202 	    (iscsi_task_attr == ISCSI_ATTR_SIMPLE))
203 		sam_task_attr = MSG_SIMPLE_TAG;
204 	else if (iscsi_task_attr == ISCSI_ATTR_ORDERED)
205 		sam_task_attr = MSG_ORDERED_TAG;
206 	else if (iscsi_task_attr == ISCSI_ATTR_HEAD_OF_QUEUE)
207 		sam_task_attr = MSG_HEAD_TAG;
208 	else if (iscsi_task_attr == ISCSI_ATTR_ACA)
209 		sam_task_attr = MSG_ACA_TAG;
210 	else {
211 		pr_debug("Unknown iSCSI Task Attribute: 0x%02x, using"
212 			" MSG_SIMPLE_TAG\n", iscsi_task_attr);
213 		sam_task_attr = MSG_SIMPLE_TAG;
214 	}
215 
216 	se_cmd = &cmd->se_cmd;
217 	/*
218 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
219 	 */
220 	transport_init_se_cmd(se_cmd, &lio_target_fabric_configfs->tf_ops,
221 			conn->sess->se_sess, data_length, data_direction,
222 			sam_task_attr, &cmd->sense_buffer[0]);
223 	return cmd;
224 }
225 
226 struct iscsi_cmd *iscsit_allocate_se_cmd_for_tmr(
227 	struct iscsi_conn *conn,
228 	u8 function)
229 {
230 	struct iscsi_cmd *cmd;
231 	struct se_cmd *se_cmd;
232 	int rc;
233 	u8 tcm_function;
234 
235 	cmd = iscsit_allocate_cmd(conn, GFP_KERNEL);
236 	if (!cmd)
237 		return NULL;
238 
239 	cmd->data_direction = DMA_NONE;
240 
241 	cmd->tmr_req = kzalloc(sizeof(struct iscsi_tmr_req), GFP_KERNEL);
242 	if (!cmd->tmr_req) {
243 		pr_err("Unable to allocate memory for"
244 			" Task Management command!\n");
245 		goto out;
246 	}
247 	/*
248 	 * TASK_REASSIGN for ERL=2 / connection stays inside of
249 	 * LIO-Target $FABRIC_MOD
250 	 */
251 	if (function == ISCSI_TM_FUNC_TASK_REASSIGN)
252 		return cmd;
253 
254 	se_cmd = &cmd->se_cmd;
255 	/*
256 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
257 	 */
258 	transport_init_se_cmd(se_cmd, &lio_target_fabric_configfs->tf_ops,
259 				conn->sess->se_sess, 0, DMA_NONE,
260 				MSG_SIMPLE_TAG, &cmd->sense_buffer[0]);
261 
262 	switch (function) {
263 	case ISCSI_TM_FUNC_ABORT_TASK:
264 		tcm_function = TMR_ABORT_TASK;
265 		break;
266 	case ISCSI_TM_FUNC_ABORT_TASK_SET:
267 		tcm_function = TMR_ABORT_TASK_SET;
268 		break;
269 	case ISCSI_TM_FUNC_CLEAR_ACA:
270 		tcm_function = TMR_CLEAR_ACA;
271 		break;
272 	case ISCSI_TM_FUNC_CLEAR_TASK_SET:
273 		tcm_function = TMR_CLEAR_TASK_SET;
274 		break;
275 	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
276 		tcm_function = TMR_LUN_RESET;
277 		break;
278 	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
279 		tcm_function = TMR_TARGET_WARM_RESET;
280 		break;
281 	case ISCSI_TM_FUNC_TARGET_COLD_RESET:
282 		tcm_function = TMR_TARGET_COLD_RESET;
283 		break;
284 	default:
285 		pr_err("Unknown iSCSI TMR Function:"
286 			" 0x%02x\n", function);
287 		goto out;
288 	}
289 
290 	rc = core_tmr_alloc_req(se_cmd, cmd->tmr_req, tcm_function, GFP_KERNEL);
291 	if (rc < 0)
292 		goto out;
293 
294 	cmd->tmr_req->se_tmr_req = se_cmd->se_tmr_req;
295 
296 	return cmd;
297 out:
298 	iscsit_release_cmd(cmd);
299 	return NULL;
300 }
301 
302 int iscsit_decide_list_to_build(
303 	struct iscsi_cmd *cmd,
304 	u32 immediate_data_length)
305 {
306 	struct iscsi_build_list bl;
307 	struct iscsi_conn *conn = cmd->conn;
308 	struct iscsi_session *sess = conn->sess;
309 	struct iscsi_node_attrib *na;
310 
311 	if (sess->sess_ops->DataSequenceInOrder &&
312 	    sess->sess_ops->DataPDUInOrder)
313 		return 0;
314 
315 	if (cmd->data_direction == DMA_NONE)
316 		return 0;
317 
318 	na = iscsit_tpg_get_node_attrib(sess);
319 	memset(&bl, 0, sizeof(struct iscsi_build_list));
320 
321 	if (cmd->data_direction == DMA_FROM_DEVICE) {
322 		bl.data_direction = ISCSI_PDU_READ;
323 		bl.type = PDULIST_NORMAL;
324 		if (na->random_datain_pdu_offsets)
325 			bl.randomize |= RANDOM_DATAIN_PDU_OFFSETS;
326 		if (na->random_datain_seq_offsets)
327 			bl.randomize |= RANDOM_DATAIN_SEQ_OFFSETS;
328 	} else {
329 		bl.data_direction = ISCSI_PDU_WRITE;
330 		bl.immediate_data_length = immediate_data_length;
331 		if (na->random_r2t_offsets)
332 			bl.randomize |= RANDOM_R2T_OFFSETS;
333 
334 		if (!cmd->immediate_data && !cmd->unsolicited_data)
335 			bl.type = PDULIST_NORMAL;
336 		else if (cmd->immediate_data && !cmd->unsolicited_data)
337 			bl.type = PDULIST_IMMEDIATE;
338 		else if (!cmd->immediate_data && cmd->unsolicited_data)
339 			bl.type = PDULIST_UNSOLICITED;
340 		else if (cmd->immediate_data && cmd->unsolicited_data)
341 			bl.type = PDULIST_IMMEDIATE_AND_UNSOLICITED;
342 	}
343 
344 	return iscsit_do_build_list(cmd, &bl);
345 }
346 
347 struct iscsi_seq *iscsit_get_seq_holder_for_datain(
348 	struct iscsi_cmd *cmd,
349 	u32 seq_send_order)
350 {
351 	u32 i;
352 
353 	for (i = 0; i < cmd->seq_count; i++)
354 		if (cmd->seq_list[i].seq_send_order == seq_send_order)
355 			return &cmd->seq_list[i];
356 
357 	return NULL;
358 }
359 
360 struct iscsi_seq *iscsit_get_seq_holder_for_r2t(struct iscsi_cmd *cmd)
361 {
362 	u32 i;
363 
364 	if (!cmd->seq_list) {
365 		pr_err("struct iscsi_cmd->seq_list is NULL!\n");
366 		return NULL;
367 	}
368 
369 	for (i = 0; i < cmd->seq_count; i++) {
370 		if (cmd->seq_list[i].type != SEQTYPE_NORMAL)
371 			continue;
372 		if (cmd->seq_list[i].seq_send_order == cmd->seq_send_order) {
373 			cmd->seq_send_order++;
374 			return &cmd->seq_list[i];
375 		}
376 	}
377 
378 	return NULL;
379 }
380 
381 struct iscsi_r2t *iscsit_get_holder_for_r2tsn(
382 	struct iscsi_cmd *cmd,
383 	u32 r2t_sn)
384 {
385 	struct iscsi_r2t *r2t;
386 
387 	spin_lock_bh(&cmd->r2t_lock);
388 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
389 		if (r2t->r2t_sn == r2t_sn) {
390 			spin_unlock_bh(&cmd->r2t_lock);
391 			return r2t;
392 		}
393 	}
394 	spin_unlock_bh(&cmd->r2t_lock);
395 
396 	return NULL;
397 }
398 
399 static inline int iscsit_check_received_cmdsn(struct iscsi_session *sess, u32 cmdsn)
400 {
401 	int ret;
402 
403 	/*
404 	 * This is the proper method of checking received CmdSN against
405 	 * ExpCmdSN and MaxCmdSN values, as well as accounting for out
406 	 * or order CmdSNs due to multiple connection sessions and/or
407 	 * CRC failures.
408 	 */
409 	if (iscsi_sna_gt(cmdsn, sess->max_cmd_sn)) {
410 		pr_err("Received CmdSN: 0x%08x is greater than"
411 		       " MaxCmdSN: 0x%08x, protocol error.\n", cmdsn,
412 		       sess->max_cmd_sn);
413 		ret = CMDSN_ERROR_CANNOT_RECOVER;
414 
415 	} else if (cmdsn == sess->exp_cmd_sn) {
416 		sess->exp_cmd_sn++;
417 		pr_debug("Received CmdSN matches ExpCmdSN,"
418 		      " incremented ExpCmdSN to: 0x%08x\n",
419 		      sess->exp_cmd_sn);
420 		ret = CMDSN_NORMAL_OPERATION;
421 
422 	} else if (iscsi_sna_gt(cmdsn, sess->exp_cmd_sn)) {
423 		pr_debug("Received CmdSN: 0x%08x is greater"
424 		      " than ExpCmdSN: 0x%08x, not acknowledging.\n",
425 		      cmdsn, sess->exp_cmd_sn);
426 		ret = CMDSN_HIGHER_THAN_EXP;
427 
428 	} else {
429 		pr_err("Received CmdSN: 0x%08x is less than"
430 		       " ExpCmdSN: 0x%08x, ignoring.\n", cmdsn,
431 		       sess->exp_cmd_sn);
432 		ret = CMDSN_LOWER_THAN_EXP;
433 	}
434 
435 	return ret;
436 }
437 
438 /*
439  * Commands may be received out of order if MC/S is in use.
440  * Ensure they are executed in CmdSN order.
441  */
442 int iscsit_sequence_cmd(
443 	struct iscsi_conn *conn,
444 	struct iscsi_cmd *cmd,
445 	u32 cmdsn)
446 {
447 	int ret;
448 	int cmdsn_ret;
449 
450 	mutex_lock(&conn->sess->cmdsn_mutex);
451 
452 	cmdsn_ret = iscsit_check_received_cmdsn(conn->sess, cmdsn);
453 	switch (cmdsn_ret) {
454 	case CMDSN_NORMAL_OPERATION:
455 		ret = iscsit_execute_cmd(cmd, 0);
456 		if ((ret >= 0) && !list_empty(&conn->sess->sess_ooo_cmdsn_list))
457 			iscsit_execute_ooo_cmdsns(conn->sess);
458 		break;
459 	case CMDSN_HIGHER_THAN_EXP:
460 		ret = iscsit_handle_ooo_cmdsn(conn->sess, cmd, cmdsn);
461 		break;
462 	case CMDSN_LOWER_THAN_EXP:
463 		cmd->i_state = ISTATE_REMOVE;
464 		iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
465 		ret = cmdsn_ret;
466 		break;
467 	default:
468 		ret = cmdsn_ret;
469 		break;
470 	}
471 	mutex_unlock(&conn->sess->cmdsn_mutex);
472 
473 	return ret;
474 }
475 
476 int iscsit_check_unsolicited_dataout(struct iscsi_cmd *cmd, unsigned char *buf)
477 {
478 	struct iscsi_conn *conn = cmd->conn;
479 	struct se_cmd *se_cmd = &cmd->se_cmd;
480 	struct iscsi_data *hdr = (struct iscsi_data *) buf;
481 	u32 payload_length = ntoh24(hdr->dlength);
482 
483 	if (conn->sess->sess_ops->InitialR2T) {
484 		pr_err("Received unexpected unsolicited data"
485 			" while InitialR2T=Yes, protocol error.\n");
486 		transport_send_check_condition_and_sense(se_cmd,
487 				TCM_UNEXPECTED_UNSOLICITED_DATA, 0);
488 		return -1;
489 	}
490 
491 	if ((cmd->first_burst_len + payload_length) >
492 	     conn->sess->sess_ops->FirstBurstLength) {
493 		pr_err("Total %u bytes exceeds FirstBurstLength: %u"
494 			" for this Unsolicited DataOut Burst.\n",
495 			(cmd->first_burst_len + payload_length),
496 				conn->sess->sess_ops->FirstBurstLength);
497 		transport_send_check_condition_and_sense(se_cmd,
498 				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
499 		return -1;
500 	}
501 
502 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL))
503 		return 0;
504 
505 	if (((cmd->first_burst_len + payload_length) != cmd->data_length) &&
506 	    ((cmd->first_burst_len + payload_length) !=
507 	      conn->sess->sess_ops->FirstBurstLength)) {
508 		pr_err("Unsolicited non-immediate data received %u"
509 			" does not equal FirstBurstLength: %u, and does"
510 			" not equal ExpXferLen %u.\n",
511 			(cmd->first_burst_len + payload_length),
512 			conn->sess->sess_ops->FirstBurstLength, cmd->data_length);
513 		transport_send_check_condition_and_sense(se_cmd,
514 				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
515 		return -1;
516 	}
517 	return 0;
518 }
519 
520 struct iscsi_cmd *iscsit_find_cmd_from_itt(
521 	struct iscsi_conn *conn,
522 	u32 init_task_tag)
523 {
524 	struct iscsi_cmd *cmd;
525 
526 	spin_lock_bh(&conn->cmd_lock);
527 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_list) {
528 		if (cmd->init_task_tag == init_task_tag) {
529 			spin_unlock_bh(&conn->cmd_lock);
530 			return cmd;
531 		}
532 	}
533 	spin_unlock_bh(&conn->cmd_lock);
534 
535 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu",
536 			init_task_tag, conn->cid);
537 	return NULL;
538 }
539 
540 struct iscsi_cmd *iscsit_find_cmd_from_itt_or_dump(
541 	struct iscsi_conn *conn,
542 	u32 init_task_tag,
543 	u32 length)
544 {
545 	struct iscsi_cmd *cmd;
546 
547 	spin_lock_bh(&conn->cmd_lock);
548 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_list) {
549 		if (cmd->init_task_tag == init_task_tag) {
550 			spin_unlock_bh(&conn->cmd_lock);
551 			return cmd;
552 		}
553 	}
554 	spin_unlock_bh(&conn->cmd_lock);
555 
556 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu,"
557 			" dumping payload\n", init_task_tag, conn->cid);
558 	if (length)
559 		iscsit_dump_data_payload(conn, length, 1);
560 
561 	return NULL;
562 }
563 
564 struct iscsi_cmd *iscsit_find_cmd_from_ttt(
565 	struct iscsi_conn *conn,
566 	u32 targ_xfer_tag)
567 {
568 	struct iscsi_cmd *cmd = NULL;
569 
570 	spin_lock_bh(&conn->cmd_lock);
571 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_list) {
572 		if (cmd->targ_xfer_tag == targ_xfer_tag) {
573 			spin_unlock_bh(&conn->cmd_lock);
574 			return cmd;
575 		}
576 	}
577 	spin_unlock_bh(&conn->cmd_lock);
578 
579 	pr_err("Unable to locate TTT: 0x%08x on CID: %hu\n",
580 			targ_xfer_tag, conn->cid);
581 	return NULL;
582 }
583 
584 int iscsit_find_cmd_for_recovery(
585 	struct iscsi_session *sess,
586 	struct iscsi_cmd **cmd_ptr,
587 	struct iscsi_conn_recovery **cr_ptr,
588 	u32 init_task_tag)
589 {
590 	struct iscsi_cmd *cmd = NULL;
591 	struct iscsi_conn_recovery *cr;
592 	/*
593 	 * Scan through the inactive connection recovery list's command list.
594 	 * If init_task_tag matches the command is still alligent.
595 	 */
596 	spin_lock(&sess->cr_i_lock);
597 	list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
598 		spin_lock(&cr->conn_recovery_cmd_lock);
599 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_list) {
600 			if (cmd->init_task_tag == init_task_tag) {
601 				spin_unlock(&cr->conn_recovery_cmd_lock);
602 				spin_unlock(&sess->cr_i_lock);
603 
604 				*cr_ptr = cr;
605 				*cmd_ptr = cmd;
606 				return -2;
607 			}
608 		}
609 		spin_unlock(&cr->conn_recovery_cmd_lock);
610 	}
611 	spin_unlock(&sess->cr_i_lock);
612 	/*
613 	 * Scan through the active connection recovery list's command list.
614 	 * If init_task_tag matches the command is ready to be reassigned.
615 	 */
616 	spin_lock(&sess->cr_a_lock);
617 	list_for_each_entry(cr, &sess->cr_active_list, cr_list) {
618 		spin_lock(&cr->conn_recovery_cmd_lock);
619 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_list) {
620 			if (cmd->init_task_tag == init_task_tag) {
621 				spin_unlock(&cr->conn_recovery_cmd_lock);
622 				spin_unlock(&sess->cr_a_lock);
623 
624 				*cr_ptr = cr;
625 				*cmd_ptr = cmd;
626 				return 0;
627 			}
628 		}
629 		spin_unlock(&cr->conn_recovery_cmd_lock);
630 	}
631 	spin_unlock(&sess->cr_a_lock);
632 
633 	return -1;
634 }
635 
636 void iscsit_add_cmd_to_immediate_queue(
637 	struct iscsi_cmd *cmd,
638 	struct iscsi_conn *conn,
639 	u8 state)
640 {
641 	struct iscsi_queue_req *qr;
642 
643 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
644 	if (!qr) {
645 		pr_err("Unable to allocate memory for"
646 				" struct iscsi_queue_req\n");
647 		return;
648 	}
649 	INIT_LIST_HEAD(&qr->qr_list);
650 	qr->cmd = cmd;
651 	qr->state = state;
652 
653 	spin_lock_bh(&conn->immed_queue_lock);
654 	list_add_tail(&qr->qr_list, &conn->immed_queue_list);
655 	atomic_inc(&cmd->immed_queue_count);
656 	atomic_set(&conn->check_immediate_queue, 1);
657 	spin_unlock_bh(&conn->immed_queue_lock);
658 
659 	wake_up_process(conn->thread_set->tx_thread);
660 }
661 
662 struct iscsi_queue_req *iscsit_get_cmd_from_immediate_queue(struct iscsi_conn *conn)
663 {
664 	struct iscsi_queue_req *qr;
665 
666 	spin_lock_bh(&conn->immed_queue_lock);
667 	if (list_empty(&conn->immed_queue_list)) {
668 		spin_unlock_bh(&conn->immed_queue_lock);
669 		return NULL;
670 	}
671 	list_for_each_entry(qr, &conn->immed_queue_list, qr_list)
672 		break;
673 
674 	list_del(&qr->qr_list);
675 	if (qr->cmd)
676 		atomic_dec(&qr->cmd->immed_queue_count);
677 	spin_unlock_bh(&conn->immed_queue_lock);
678 
679 	return qr;
680 }
681 
682 static void iscsit_remove_cmd_from_immediate_queue(
683 	struct iscsi_cmd *cmd,
684 	struct iscsi_conn *conn)
685 {
686 	struct iscsi_queue_req *qr, *qr_tmp;
687 
688 	spin_lock_bh(&conn->immed_queue_lock);
689 	if (!atomic_read(&cmd->immed_queue_count)) {
690 		spin_unlock_bh(&conn->immed_queue_lock);
691 		return;
692 	}
693 
694 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
695 		if (qr->cmd != cmd)
696 			continue;
697 
698 		atomic_dec(&qr->cmd->immed_queue_count);
699 		list_del(&qr->qr_list);
700 		kmem_cache_free(lio_qr_cache, qr);
701 	}
702 	spin_unlock_bh(&conn->immed_queue_lock);
703 
704 	if (atomic_read(&cmd->immed_queue_count)) {
705 		pr_err("ITT: 0x%08x immed_queue_count: %d\n",
706 			cmd->init_task_tag,
707 			atomic_read(&cmd->immed_queue_count));
708 	}
709 }
710 
711 void iscsit_add_cmd_to_response_queue(
712 	struct iscsi_cmd *cmd,
713 	struct iscsi_conn *conn,
714 	u8 state)
715 {
716 	struct iscsi_queue_req *qr;
717 
718 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
719 	if (!qr) {
720 		pr_err("Unable to allocate memory for"
721 			" struct iscsi_queue_req\n");
722 		return;
723 	}
724 	INIT_LIST_HEAD(&qr->qr_list);
725 	qr->cmd = cmd;
726 	qr->state = state;
727 
728 	spin_lock_bh(&conn->response_queue_lock);
729 	list_add_tail(&qr->qr_list, &conn->response_queue_list);
730 	atomic_inc(&cmd->response_queue_count);
731 	spin_unlock_bh(&conn->response_queue_lock);
732 
733 	wake_up_process(conn->thread_set->tx_thread);
734 }
735 
736 struct iscsi_queue_req *iscsit_get_cmd_from_response_queue(struct iscsi_conn *conn)
737 {
738 	struct iscsi_queue_req *qr;
739 
740 	spin_lock_bh(&conn->response_queue_lock);
741 	if (list_empty(&conn->response_queue_list)) {
742 		spin_unlock_bh(&conn->response_queue_lock);
743 		return NULL;
744 	}
745 
746 	list_for_each_entry(qr, &conn->response_queue_list, qr_list)
747 		break;
748 
749 	list_del(&qr->qr_list);
750 	if (qr->cmd)
751 		atomic_dec(&qr->cmd->response_queue_count);
752 	spin_unlock_bh(&conn->response_queue_lock);
753 
754 	return qr;
755 }
756 
757 static void iscsit_remove_cmd_from_response_queue(
758 	struct iscsi_cmd *cmd,
759 	struct iscsi_conn *conn)
760 {
761 	struct iscsi_queue_req *qr, *qr_tmp;
762 
763 	spin_lock_bh(&conn->response_queue_lock);
764 	if (!atomic_read(&cmd->response_queue_count)) {
765 		spin_unlock_bh(&conn->response_queue_lock);
766 		return;
767 	}
768 
769 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
770 				qr_list) {
771 		if (qr->cmd != cmd)
772 			continue;
773 
774 		atomic_dec(&qr->cmd->response_queue_count);
775 		list_del(&qr->qr_list);
776 		kmem_cache_free(lio_qr_cache, qr);
777 	}
778 	spin_unlock_bh(&conn->response_queue_lock);
779 
780 	if (atomic_read(&cmd->response_queue_count)) {
781 		pr_err("ITT: 0x%08x response_queue_count: %d\n",
782 			cmd->init_task_tag,
783 			atomic_read(&cmd->response_queue_count));
784 	}
785 }
786 
787 void iscsit_free_queue_reqs_for_conn(struct iscsi_conn *conn)
788 {
789 	struct iscsi_queue_req *qr, *qr_tmp;
790 
791 	spin_lock_bh(&conn->immed_queue_lock);
792 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
793 		list_del(&qr->qr_list);
794 		if (qr->cmd)
795 			atomic_dec(&qr->cmd->immed_queue_count);
796 
797 		kmem_cache_free(lio_qr_cache, qr);
798 	}
799 	spin_unlock_bh(&conn->immed_queue_lock);
800 
801 	spin_lock_bh(&conn->response_queue_lock);
802 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
803 			qr_list) {
804 		list_del(&qr->qr_list);
805 		if (qr->cmd)
806 			atomic_dec(&qr->cmd->response_queue_count);
807 
808 		kmem_cache_free(lio_qr_cache, qr);
809 	}
810 	spin_unlock_bh(&conn->response_queue_lock);
811 }
812 
813 void iscsit_release_cmd(struct iscsi_cmd *cmd)
814 {
815 	struct iscsi_conn *conn = cmd->conn;
816 	int i;
817 
818 	iscsit_free_r2ts_from_list(cmd);
819 	iscsit_free_all_datain_reqs(cmd);
820 
821 	kfree(cmd->buf_ptr);
822 	kfree(cmd->pdu_list);
823 	kfree(cmd->seq_list);
824 	kfree(cmd->tmr_req);
825 	kfree(cmd->iov_data);
826 
827 	for (i = 0; i < cmd->t_mem_sg_nents; i++)
828 		__free_page(sg_page(&cmd->t_mem_sg[i]));
829 
830 	kfree(cmd->t_mem_sg);
831 
832 	if (conn) {
833 		iscsit_remove_cmd_from_immediate_queue(cmd, conn);
834 		iscsit_remove_cmd_from_response_queue(cmd, conn);
835 	}
836 
837 	kmem_cache_free(lio_cmd_cache, cmd);
838 }
839 
840 void iscsit_free_cmd(struct iscsi_cmd *cmd)
841 {
842 	/*
843 	 * Determine if a struct se_cmd is assoicated with
844 	 * this struct iscsi_cmd.
845 	 */
846 	switch (cmd->iscsi_opcode) {
847 	case ISCSI_OP_SCSI_CMD:
848 	case ISCSI_OP_SCSI_TMFUNC:
849 		transport_generic_free_cmd(&cmd->se_cmd, 1);
850 		break;
851 	case ISCSI_OP_REJECT:
852 		/*
853 		 * Handle special case for REJECT when iscsi_add_reject*() has
854 		 * overwritten the original iscsi_opcode assignment, and the
855 		 * associated cmd->se_cmd needs to be released.
856 		 */
857 		if (cmd->se_cmd.se_tfo != NULL) {
858 			transport_generic_free_cmd(&cmd->se_cmd, 1);
859 			break;
860 		}
861 		/* Fall-through */
862 	default:
863 		iscsit_release_cmd(cmd);
864 		break;
865 	}
866 }
867 
868 int iscsit_check_session_usage_count(struct iscsi_session *sess)
869 {
870 	spin_lock_bh(&sess->session_usage_lock);
871 	if (sess->session_usage_count != 0) {
872 		sess->session_waiting_on_uc = 1;
873 		spin_unlock_bh(&sess->session_usage_lock);
874 		if (in_interrupt())
875 			return 2;
876 
877 		wait_for_completion(&sess->session_waiting_on_uc_comp);
878 		return 1;
879 	}
880 	spin_unlock_bh(&sess->session_usage_lock);
881 
882 	return 0;
883 }
884 
885 void iscsit_dec_session_usage_count(struct iscsi_session *sess)
886 {
887 	spin_lock_bh(&sess->session_usage_lock);
888 	sess->session_usage_count--;
889 
890 	if (!sess->session_usage_count && sess->session_waiting_on_uc)
891 		complete(&sess->session_waiting_on_uc_comp);
892 
893 	spin_unlock_bh(&sess->session_usage_lock);
894 }
895 
896 void iscsit_inc_session_usage_count(struct iscsi_session *sess)
897 {
898 	spin_lock_bh(&sess->session_usage_lock);
899 	sess->session_usage_count++;
900 	spin_unlock_bh(&sess->session_usage_lock);
901 }
902 
903 /*
904  *	Setup conn->if_marker and conn->of_marker values based upon
905  *	the initial marker-less interval. (see iSCSI v19 A.2)
906  */
907 int iscsit_set_sync_and_steering_values(struct iscsi_conn *conn)
908 {
909 	int login_ifmarker_count = 0, login_ofmarker_count = 0, next_marker = 0;
910 	/*
911 	 * IFMarkInt and OFMarkInt are negotiated as 32-bit words.
912 	 */
913 	u32 IFMarkInt = (conn->conn_ops->IFMarkInt * 4);
914 	u32 OFMarkInt = (conn->conn_ops->OFMarkInt * 4);
915 
916 	if (conn->conn_ops->OFMarker) {
917 		/*
918 		 * Account for the first Login Command received not
919 		 * via iscsi_recv_msg().
920 		 */
921 		conn->of_marker += ISCSI_HDR_LEN;
922 		if (conn->of_marker <= OFMarkInt) {
923 			conn->of_marker = (OFMarkInt - conn->of_marker);
924 		} else {
925 			login_ofmarker_count = (conn->of_marker / OFMarkInt);
926 			next_marker = (OFMarkInt * (login_ofmarker_count + 1)) +
927 					(login_ofmarker_count * MARKER_SIZE);
928 			conn->of_marker = (next_marker - conn->of_marker);
929 		}
930 		conn->of_marker_offset = 0;
931 		pr_debug("Setting OFMarker value to %u based on Initial"
932 			" Markerless Interval.\n", conn->of_marker);
933 	}
934 
935 	if (conn->conn_ops->IFMarker) {
936 		if (conn->if_marker <= IFMarkInt) {
937 			conn->if_marker = (IFMarkInt - conn->if_marker);
938 		} else {
939 			login_ifmarker_count = (conn->if_marker / IFMarkInt);
940 			next_marker = (IFMarkInt * (login_ifmarker_count + 1)) +
941 					(login_ifmarker_count * MARKER_SIZE);
942 			conn->if_marker = (next_marker - conn->if_marker);
943 		}
944 		pr_debug("Setting IFMarker value to %u based on Initial"
945 			" Markerless Interval.\n", conn->if_marker);
946 	}
947 
948 	return 0;
949 }
950 
951 struct iscsi_conn *iscsit_get_conn_from_cid(struct iscsi_session *sess, u16 cid)
952 {
953 	struct iscsi_conn *conn;
954 
955 	spin_lock_bh(&sess->conn_lock);
956 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
957 		if ((conn->cid == cid) &&
958 		    (conn->conn_state == TARG_CONN_STATE_LOGGED_IN)) {
959 			iscsit_inc_conn_usage_count(conn);
960 			spin_unlock_bh(&sess->conn_lock);
961 			return conn;
962 		}
963 	}
964 	spin_unlock_bh(&sess->conn_lock);
965 
966 	return NULL;
967 }
968 
969 struct iscsi_conn *iscsit_get_conn_from_cid_rcfr(struct iscsi_session *sess, u16 cid)
970 {
971 	struct iscsi_conn *conn;
972 
973 	spin_lock_bh(&sess->conn_lock);
974 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
975 		if (conn->cid == cid) {
976 			iscsit_inc_conn_usage_count(conn);
977 			spin_lock(&conn->state_lock);
978 			atomic_set(&conn->connection_wait_rcfr, 1);
979 			spin_unlock(&conn->state_lock);
980 			spin_unlock_bh(&sess->conn_lock);
981 			return conn;
982 		}
983 	}
984 	spin_unlock_bh(&sess->conn_lock);
985 
986 	return NULL;
987 }
988 
989 void iscsit_check_conn_usage_count(struct iscsi_conn *conn)
990 {
991 	spin_lock_bh(&conn->conn_usage_lock);
992 	if (conn->conn_usage_count != 0) {
993 		conn->conn_waiting_on_uc = 1;
994 		spin_unlock_bh(&conn->conn_usage_lock);
995 
996 		wait_for_completion(&conn->conn_waiting_on_uc_comp);
997 		return;
998 	}
999 	spin_unlock_bh(&conn->conn_usage_lock);
1000 }
1001 
1002 void iscsit_dec_conn_usage_count(struct iscsi_conn *conn)
1003 {
1004 	spin_lock_bh(&conn->conn_usage_lock);
1005 	conn->conn_usage_count--;
1006 
1007 	if (!conn->conn_usage_count && conn->conn_waiting_on_uc)
1008 		complete(&conn->conn_waiting_on_uc_comp);
1009 
1010 	spin_unlock_bh(&conn->conn_usage_lock);
1011 }
1012 
1013 void iscsit_inc_conn_usage_count(struct iscsi_conn *conn)
1014 {
1015 	spin_lock_bh(&conn->conn_usage_lock);
1016 	conn->conn_usage_count++;
1017 	spin_unlock_bh(&conn->conn_usage_lock);
1018 }
1019 
1020 static int iscsit_add_nopin(struct iscsi_conn *conn, int want_response)
1021 {
1022 	u8 state;
1023 	struct iscsi_cmd *cmd;
1024 
1025 	cmd = iscsit_allocate_cmd(conn, GFP_ATOMIC);
1026 	if (!cmd)
1027 		return -1;
1028 
1029 	cmd->iscsi_opcode = ISCSI_OP_NOOP_IN;
1030 	state = (want_response) ? ISTATE_SEND_NOPIN_WANT_RESPONSE :
1031 				ISTATE_SEND_NOPIN_NO_RESPONSE;
1032 	cmd->init_task_tag = 0xFFFFFFFF;
1033 	spin_lock_bh(&conn->sess->ttt_lock);
1034 	cmd->targ_xfer_tag = (want_response) ? conn->sess->targ_xfer_tag++ :
1035 			0xFFFFFFFF;
1036 	if (want_response && (cmd->targ_xfer_tag == 0xFFFFFFFF))
1037 		cmd->targ_xfer_tag = conn->sess->targ_xfer_tag++;
1038 	spin_unlock_bh(&conn->sess->ttt_lock);
1039 
1040 	spin_lock_bh(&conn->cmd_lock);
1041 	list_add_tail(&cmd->i_list, &conn->conn_cmd_list);
1042 	spin_unlock_bh(&conn->cmd_lock);
1043 
1044 	if (want_response)
1045 		iscsit_start_nopin_response_timer(conn);
1046 	iscsit_add_cmd_to_immediate_queue(cmd, conn, state);
1047 
1048 	return 0;
1049 }
1050 
1051 static void iscsit_handle_nopin_response_timeout(unsigned long data)
1052 {
1053 	struct iscsi_conn *conn = (struct iscsi_conn *) data;
1054 
1055 	iscsit_inc_conn_usage_count(conn);
1056 
1057 	spin_lock_bh(&conn->nopin_timer_lock);
1058 	if (conn->nopin_response_timer_flags & ISCSI_TF_STOP) {
1059 		spin_unlock_bh(&conn->nopin_timer_lock);
1060 		iscsit_dec_conn_usage_count(conn);
1061 		return;
1062 	}
1063 
1064 	pr_debug("Did not receive response to NOPIN on CID: %hu on"
1065 		" SID: %u, failing connection.\n", conn->cid,
1066 			conn->sess->sid);
1067 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
1068 	spin_unlock_bh(&conn->nopin_timer_lock);
1069 
1070 	{
1071 	struct iscsi_portal_group *tpg = conn->sess->tpg;
1072 	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
1073 
1074 	if (tiqn) {
1075 		spin_lock_bh(&tiqn->sess_err_stats.lock);
1076 		strcpy(tiqn->sess_err_stats.last_sess_fail_rem_name,
1077 				conn->sess->sess_ops->InitiatorName);
1078 		tiqn->sess_err_stats.last_sess_failure_type =
1079 				ISCSI_SESS_ERR_CXN_TIMEOUT;
1080 		tiqn->sess_err_stats.cxn_timeout_errors++;
1081 		conn->sess->conn_timeout_errors++;
1082 		spin_unlock_bh(&tiqn->sess_err_stats.lock);
1083 	}
1084 	}
1085 
1086 	iscsit_cause_connection_reinstatement(conn, 0);
1087 	iscsit_dec_conn_usage_count(conn);
1088 }
1089 
1090 void iscsit_mod_nopin_response_timer(struct iscsi_conn *conn)
1091 {
1092 	struct iscsi_session *sess = conn->sess;
1093 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1094 
1095 	spin_lock_bh(&conn->nopin_timer_lock);
1096 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
1097 		spin_unlock_bh(&conn->nopin_timer_lock);
1098 		return;
1099 	}
1100 
1101 	mod_timer(&conn->nopin_response_timer,
1102 		(get_jiffies_64() + na->nopin_response_timeout * HZ));
1103 	spin_unlock_bh(&conn->nopin_timer_lock);
1104 }
1105 
1106 /*
1107  *	Called with conn->nopin_timer_lock held.
1108  */
1109 void iscsit_start_nopin_response_timer(struct iscsi_conn *conn)
1110 {
1111 	struct iscsi_session *sess = conn->sess;
1112 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1113 
1114 	spin_lock_bh(&conn->nopin_timer_lock);
1115 	if (conn->nopin_response_timer_flags & ISCSI_TF_RUNNING) {
1116 		spin_unlock_bh(&conn->nopin_timer_lock);
1117 		return;
1118 	}
1119 
1120 	init_timer(&conn->nopin_response_timer);
1121 	conn->nopin_response_timer.expires =
1122 		(get_jiffies_64() + na->nopin_response_timeout * HZ);
1123 	conn->nopin_response_timer.data = (unsigned long)conn;
1124 	conn->nopin_response_timer.function = iscsit_handle_nopin_response_timeout;
1125 	conn->nopin_response_timer_flags &= ~ISCSI_TF_STOP;
1126 	conn->nopin_response_timer_flags |= ISCSI_TF_RUNNING;
1127 	add_timer(&conn->nopin_response_timer);
1128 
1129 	pr_debug("Started NOPIN Response Timer on CID: %d to %u"
1130 		" seconds\n", conn->cid, na->nopin_response_timeout);
1131 	spin_unlock_bh(&conn->nopin_timer_lock);
1132 }
1133 
1134 void iscsit_stop_nopin_response_timer(struct iscsi_conn *conn)
1135 {
1136 	spin_lock_bh(&conn->nopin_timer_lock);
1137 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
1138 		spin_unlock_bh(&conn->nopin_timer_lock);
1139 		return;
1140 	}
1141 	conn->nopin_response_timer_flags |= ISCSI_TF_STOP;
1142 	spin_unlock_bh(&conn->nopin_timer_lock);
1143 
1144 	del_timer_sync(&conn->nopin_response_timer);
1145 
1146 	spin_lock_bh(&conn->nopin_timer_lock);
1147 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
1148 	spin_unlock_bh(&conn->nopin_timer_lock);
1149 }
1150 
1151 static void iscsit_handle_nopin_timeout(unsigned long data)
1152 {
1153 	struct iscsi_conn *conn = (struct iscsi_conn *) data;
1154 
1155 	iscsit_inc_conn_usage_count(conn);
1156 
1157 	spin_lock_bh(&conn->nopin_timer_lock);
1158 	if (conn->nopin_timer_flags & ISCSI_TF_STOP) {
1159 		spin_unlock_bh(&conn->nopin_timer_lock);
1160 		iscsit_dec_conn_usage_count(conn);
1161 		return;
1162 	}
1163 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1164 	spin_unlock_bh(&conn->nopin_timer_lock);
1165 
1166 	iscsit_add_nopin(conn, 1);
1167 	iscsit_dec_conn_usage_count(conn);
1168 }
1169 
1170 /*
1171  * Called with conn->nopin_timer_lock held.
1172  */
1173 void __iscsit_start_nopin_timer(struct iscsi_conn *conn)
1174 {
1175 	struct iscsi_session *sess = conn->sess;
1176 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1177 	/*
1178 	* NOPIN timeout is disabled.
1179 	 */
1180 	if (!na->nopin_timeout)
1181 		return;
1182 
1183 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING)
1184 		return;
1185 
1186 	init_timer(&conn->nopin_timer);
1187 	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1188 	conn->nopin_timer.data = (unsigned long)conn;
1189 	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1190 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1191 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1192 	add_timer(&conn->nopin_timer);
1193 
1194 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1195 		" interval\n", conn->cid, na->nopin_timeout);
1196 }
1197 
1198 void iscsit_start_nopin_timer(struct iscsi_conn *conn)
1199 {
1200 	struct iscsi_session *sess = conn->sess;
1201 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1202 	/*
1203 	 * NOPIN timeout is disabled..
1204 	 */
1205 	if (!na->nopin_timeout)
1206 		return;
1207 
1208 	spin_lock_bh(&conn->nopin_timer_lock);
1209 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING) {
1210 		spin_unlock_bh(&conn->nopin_timer_lock);
1211 		return;
1212 	}
1213 
1214 	init_timer(&conn->nopin_timer);
1215 	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1216 	conn->nopin_timer.data = (unsigned long)conn;
1217 	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1218 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1219 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1220 	add_timer(&conn->nopin_timer);
1221 
1222 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1223 			" interval\n", conn->cid, na->nopin_timeout);
1224 	spin_unlock_bh(&conn->nopin_timer_lock);
1225 }
1226 
1227 void iscsit_stop_nopin_timer(struct iscsi_conn *conn)
1228 {
1229 	spin_lock_bh(&conn->nopin_timer_lock);
1230 	if (!(conn->nopin_timer_flags & ISCSI_TF_RUNNING)) {
1231 		spin_unlock_bh(&conn->nopin_timer_lock);
1232 		return;
1233 	}
1234 	conn->nopin_timer_flags |= ISCSI_TF_STOP;
1235 	spin_unlock_bh(&conn->nopin_timer_lock);
1236 
1237 	del_timer_sync(&conn->nopin_timer);
1238 
1239 	spin_lock_bh(&conn->nopin_timer_lock);
1240 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1241 	spin_unlock_bh(&conn->nopin_timer_lock);
1242 }
1243 
1244 int iscsit_send_tx_data(
1245 	struct iscsi_cmd *cmd,
1246 	struct iscsi_conn *conn,
1247 	int use_misc)
1248 {
1249 	int tx_sent, tx_size;
1250 	u32 iov_count;
1251 	struct kvec *iov;
1252 
1253 send_data:
1254 	tx_size = cmd->tx_size;
1255 
1256 	if (!use_misc) {
1257 		iov = &cmd->iov_data[0];
1258 		iov_count = cmd->iov_data_count;
1259 	} else {
1260 		iov = &cmd->iov_misc[0];
1261 		iov_count = cmd->iov_misc_count;
1262 	}
1263 
1264 	tx_sent = tx_data(conn, &iov[0], iov_count, tx_size);
1265 	if (tx_size != tx_sent) {
1266 		if (tx_sent == -EAGAIN) {
1267 			pr_err("tx_data() returned -EAGAIN\n");
1268 			goto send_data;
1269 		} else
1270 			return -1;
1271 	}
1272 	cmd->tx_size = 0;
1273 
1274 	return 0;
1275 }
1276 
1277 int iscsit_fe_sendpage_sg(
1278 	struct iscsi_cmd *cmd,
1279 	struct iscsi_conn *conn)
1280 {
1281 	struct scatterlist *sg = cmd->first_data_sg;
1282 	struct kvec iov;
1283 	u32 tx_hdr_size, data_len;
1284 	u32 offset = cmd->first_data_sg_off;
1285 	int tx_sent, iov_off;
1286 
1287 send_hdr:
1288 	tx_hdr_size = ISCSI_HDR_LEN;
1289 	if (conn->conn_ops->HeaderDigest)
1290 		tx_hdr_size += ISCSI_CRC_LEN;
1291 
1292 	iov.iov_base = cmd->pdu;
1293 	iov.iov_len = tx_hdr_size;
1294 
1295 	tx_sent = tx_data(conn, &iov, 1, tx_hdr_size);
1296 	if (tx_hdr_size != tx_sent) {
1297 		if (tx_sent == -EAGAIN) {
1298 			pr_err("tx_data() returned -EAGAIN\n");
1299 			goto send_hdr;
1300 		}
1301 		return -1;
1302 	}
1303 
1304 	data_len = cmd->tx_size - tx_hdr_size - cmd->padding;
1305 	/*
1306 	 * Set iov_off used by padding and data digest tx_data() calls below
1307 	 * in order to determine proper offset into cmd->iov_data[]
1308 	 */
1309 	if (conn->conn_ops->DataDigest) {
1310 		data_len -= ISCSI_CRC_LEN;
1311 		if (cmd->padding)
1312 			iov_off = (cmd->iov_data_count - 2);
1313 		else
1314 			iov_off = (cmd->iov_data_count - 1);
1315 	} else {
1316 		iov_off = (cmd->iov_data_count - 1);
1317 	}
1318 	/*
1319 	 * Perform sendpage() for each page in the scatterlist
1320 	 */
1321 	while (data_len) {
1322 		u32 space = (sg->length - offset);
1323 		u32 sub_len = min_t(u32, data_len, space);
1324 send_pg:
1325 		tx_sent = conn->sock->ops->sendpage(conn->sock,
1326 					sg_page(sg), sg->offset + offset, sub_len, 0);
1327 		if (tx_sent != sub_len) {
1328 			if (tx_sent == -EAGAIN) {
1329 				pr_err("tcp_sendpage() returned"
1330 						" -EAGAIN\n");
1331 				goto send_pg;
1332 			}
1333 
1334 			pr_err("tcp_sendpage() failure: %d\n",
1335 					tx_sent);
1336 			return -1;
1337 		}
1338 
1339 		data_len -= sub_len;
1340 		offset = 0;
1341 		sg = sg_next(sg);
1342 	}
1343 
1344 send_padding:
1345 	if (cmd->padding) {
1346 		struct kvec *iov_p = &cmd->iov_data[iov_off++];
1347 
1348 		tx_sent = tx_data(conn, iov_p, 1, cmd->padding);
1349 		if (cmd->padding != tx_sent) {
1350 			if (tx_sent == -EAGAIN) {
1351 				pr_err("tx_data() returned -EAGAIN\n");
1352 				goto send_padding;
1353 			}
1354 			return -1;
1355 		}
1356 	}
1357 
1358 send_datacrc:
1359 	if (conn->conn_ops->DataDigest) {
1360 		struct kvec *iov_d = &cmd->iov_data[iov_off];
1361 
1362 		tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN);
1363 		if (ISCSI_CRC_LEN != tx_sent) {
1364 			if (tx_sent == -EAGAIN) {
1365 				pr_err("tx_data() returned -EAGAIN\n");
1366 				goto send_datacrc;
1367 			}
1368 			return -1;
1369 		}
1370 	}
1371 
1372 	return 0;
1373 }
1374 
1375 /*
1376  *      This function is used for mainly sending a ISCSI_TARG_LOGIN_RSP PDU
1377  *      back to the Initiator when an expection condition occurs with the
1378  *      errors set in status_class and status_detail.
1379  *
1380  *      Parameters:     iSCSI Connection, Status Class, Status Detail.
1381  *      Returns:        0 on success, -1 on error.
1382  */
1383 int iscsit_tx_login_rsp(struct iscsi_conn *conn, u8 status_class, u8 status_detail)
1384 {
1385 	u8 iscsi_hdr[ISCSI_HDR_LEN];
1386 	int err;
1387 	struct kvec iov;
1388 	struct iscsi_login_rsp *hdr;
1389 
1390 	iscsit_collect_login_stats(conn, status_class, status_detail);
1391 
1392 	memset(&iov, 0, sizeof(struct kvec));
1393 	memset(&iscsi_hdr, 0x0, ISCSI_HDR_LEN);
1394 
1395 	hdr	= (struct iscsi_login_rsp *)&iscsi_hdr;
1396 	hdr->opcode		= ISCSI_OP_LOGIN_RSP;
1397 	hdr->status_class	= status_class;
1398 	hdr->status_detail	= status_detail;
1399 	hdr->itt		= cpu_to_be32(conn->login_itt);
1400 
1401 	iov.iov_base		= &iscsi_hdr;
1402 	iov.iov_len		= ISCSI_HDR_LEN;
1403 
1404 	PRINT_BUFF(iscsi_hdr, ISCSI_HDR_LEN);
1405 
1406 	err = tx_data(conn, &iov, 1, ISCSI_HDR_LEN);
1407 	if (err != ISCSI_HDR_LEN) {
1408 		pr_err("tx_data returned less than expected\n");
1409 		return -1;
1410 	}
1411 
1412 	return 0;
1413 }
1414 
1415 void iscsit_print_session_params(struct iscsi_session *sess)
1416 {
1417 	struct iscsi_conn *conn;
1418 
1419 	pr_debug("-----------------------------[Session Params for"
1420 		" SID: %u]-----------------------------\n", sess->sid);
1421 	spin_lock_bh(&sess->conn_lock);
1422 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
1423 		iscsi_dump_conn_ops(conn->conn_ops);
1424 	spin_unlock_bh(&sess->conn_lock);
1425 
1426 	iscsi_dump_sess_ops(sess->sess_ops);
1427 }
1428 
1429 static int iscsit_do_rx_data(
1430 	struct iscsi_conn *conn,
1431 	struct iscsi_data_count *count)
1432 {
1433 	int data = count->data_length, rx_loop = 0, total_rx = 0, iov_len;
1434 	struct kvec *iov_p;
1435 	struct msghdr msg;
1436 
1437 	if (!conn || !conn->sock || !conn->conn_ops)
1438 		return -1;
1439 
1440 	memset(&msg, 0, sizeof(struct msghdr));
1441 
1442 	iov_p = count->iov;
1443 	iov_len	= count->iov_count;
1444 
1445 	while (total_rx < data) {
1446 		rx_loop = kernel_recvmsg(conn->sock, &msg, iov_p, iov_len,
1447 					(data - total_rx), MSG_WAITALL);
1448 		if (rx_loop <= 0) {
1449 			pr_debug("rx_loop: %d total_rx: %d\n",
1450 				rx_loop, total_rx);
1451 			return rx_loop;
1452 		}
1453 		total_rx += rx_loop;
1454 		pr_debug("rx_loop: %d, total_rx: %d, data: %d\n",
1455 				rx_loop, total_rx, data);
1456 	}
1457 
1458 	return total_rx;
1459 }
1460 
1461 static int iscsit_do_tx_data(
1462 	struct iscsi_conn *conn,
1463 	struct iscsi_data_count *count)
1464 {
1465 	int data = count->data_length, total_tx = 0, tx_loop = 0, iov_len;
1466 	struct kvec *iov_p;
1467 	struct msghdr msg;
1468 
1469 	if (!conn || !conn->sock || !conn->conn_ops)
1470 		return -1;
1471 
1472 	if (data <= 0) {
1473 		pr_err("Data length is: %d\n", data);
1474 		return -1;
1475 	}
1476 
1477 	memset(&msg, 0, sizeof(struct msghdr));
1478 
1479 	iov_p = count->iov;
1480 	iov_len = count->iov_count;
1481 
1482 	while (total_tx < data) {
1483 		tx_loop = kernel_sendmsg(conn->sock, &msg, iov_p, iov_len,
1484 					(data - total_tx));
1485 		if (tx_loop <= 0) {
1486 			pr_debug("tx_loop: %d total_tx %d\n",
1487 				tx_loop, total_tx);
1488 			return tx_loop;
1489 		}
1490 		total_tx += tx_loop;
1491 		pr_debug("tx_loop: %d, total_tx: %d, data: %d\n",
1492 					tx_loop, total_tx, data);
1493 	}
1494 
1495 	return total_tx;
1496 }
1497 
1498 int rx_data(
1499 	struct iscsi_conn *conn,
1500 	struct kvec *iov,
1501 	int iov_count,
1502 	int data)
1503 {
1504 	struct iscsi_data_count c;
1505 
1506 	if (!conn || !conn->sock || !conn->conn_ops)
1507 		return -1;
1508 
1509 	memset(&c, 0, sizeof(struct iscsi_data_count));
1510 	c.iov = iov;
1511 	c.iov_count = iov_count;
1512 	c.data_length = data;
1513 	c.type = ISCSI_RX_DATA;
1514 
1515 	return iscsit_do_rx_data(conn, &c);
1516 }
1517 
1518 int tx_data(
1519 	struct iscsi_conn *conn,
1520 	struct kvec *iov,
1521 	int iov_count,
1522 	int data)
1523 {
1524 	struct iscsi_data_count c;
1525 
1526 	if (!conn || !conn->sock || !conn->conn_ops)
1527 		return -1;
1528 
1529 	memset(&c, 0, sizeof(struct iscsi_data_count));
1530 	c.iov = iov;
1531 	c.iov_count = iov_count;
1532 	c.data_length = data;
1533 	c.type = ISCSI_TX_DATA;
1534 
1535 	return iscsit_do_tx_data(conn, &c);
1536 }
1537 
1538 void iscsit_collect_login_stats(
1539 	struct iscsi_conn *conn,
1540 	u8 status_class,
1541 	u8 status_detail)
1542 {
1543 	struct iscsi_param *intrname = NULL;
1544 	struct iscsi_tiqn *tiqn;
1545 	struct iscsi_login_stats *ls;
1546 
1547 	tiqn = iscsit_snmp_get_tiqn(conn);
1548 	if (!tiqn)
1549 		return;
1550 
1551 	ls = &tiqn->login_stats;
1552 
1553 	spin_lock(&ls->lock);
1554 	if (!strcmp(conn->login_ip, ls->last_intr_fail_ip_addr) &&
1555 	    ((get_jiffies_64() - ls->last_fail_time) < 10)) {
1556 		/* We already have the failure info for this login */
1557 		spin_unlock(&ls->lock);
1558 		return;
1559 	}
1560 
1561 	if (status_class == ISCSI_STATUS_CLS_SUCCESS)
1562 		ls->accepts++;
1563 	else if (status_class == ISCSI_STATUS_CLS_REDIRECT) {
1564 		ls->redirects++;
1565 		ls->last_fail_type = ISCSI_LOGIN_FAIL_REDIRECT;
1566 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1567 		 (status_detail == ISCSI_LOGIN_STATUS_AUTH_FAILED)) {
1568 		ls->authenticate_fails++;
1569 		ls->last_fail_type =  ISCSI_LOGIN_FAIL_AUTHENTICATE;
1570 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1571 		 (status_detail == ISCSI_LOGIN_STATUS_TGT_FORBIDDEN)) {
1572 		ls->authorize_fails++;
1573 		ls->last_fail_type = ISCSI_LOGIN_FAIL_AUTHORIZE;
1574 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR) &&
1575 		 (status_detail == ISCSI_LOGIN_STATUS_INIT_ERR)) {
1576 		ls->negotiate_fails++;
1577 		ls->last_fail_type = ISCSI_LOGIN_FAIL_NEGOTIATE;
1578 	} else {
1579 		ls->other_fails++;
1580 		ls->last_fail_type = ISCSI_LOGIN_FAIL_OTHER;
1581 	}
1582 
1583 	/* Save initiator name, ip address and time, if it is a failed login */
1584 	if (status_class != ISCSI_STATUS_CLS_SUCCESS) {
1585 		if (conn->param_list)
1586 			intrname = iscsi_find_param_from_key(INITIATORNAME,
1587 							     conn->param_list);
1588 		strcpy(ls->last_intr_fail_name,
1589 		       (intrname ? intrname->value : "Unknown"));
1590 
1591 		ls->last_intr_fail_ip_family = conn->sock->sk->sk_family;
1592 		snprintf(ls->last_intr_fail_ip_addr, IPV6_ADDRESS_SPACE,
1593 				"%s", conn->login_ip);
1594 		ls->last_fail_time = get_jiffies_64();
1595 	}
1596 
1597 	spin_unlock(&ls->lock);
1598 }
1599 
1600 struct iscsi_tiqn *iscsit_snmp_get_tiqn(struct iscsi_conn *conn)
1601 {
1602 	struct iscsi_portal_group *tpg;
1603 
1604 	if (!conn || !conn->sess)
1605 		return NULL;
1606 
1607 	tpg = conn->sess->tpg;
1608 	if (!tpg)
1609 		return NULL;
1610 
1611 	if (!tpg->tpg_tiqn)
1612 		return NULL;
1613 
1614 	return tpg->tpg_tiqn;
1615 }
1616