xref: /linux/drivers/target/iscsi/iscsi_target_util.c (revision f2ee442115c9b6219083c019939a9cc0c9abb2f8)
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_transport.h>
26 #include <target/target_core_tmr.h>
27 #include <target/target_core_fabric_ops.h>
28 #include <target/target_core_configfs.h>
29 
30 #include "iscsi_target_core.h"
31 #include "iscsi_target_parameters.h"
32 #include "iscsi_target_seq_pdu_list.h"
33 #include "iscsi_target_datain_values.h"
34 #include "iscsi_target_erl0.h"
35 #include "iscsi_target_erl1.h"
36 #include "iscsi_target_erl2.h"
37 #include "iscsi_target_tpg.h"
38 #include "iscsi_target_tq.h"
39 #include "iscsi_target_util.h"
40 #include "iscsi_target.h"
41 
42 #define PRINT_BUFF(buff, len)					\
43 {								\
44 	int zzz;						\
45 								\
46 	pr_debug("%d:\n", __LINE__);				\
47 	for (zzz = 0; zzz < len; zzz++) {			\
48 		if (zzz % 16 == 0) {				\
49 			if (zzz)				\
50 				pr_debug("\n");			\
51 			pr_debug("%4i: ", zzz);			\
52 		}						\
53 		pr_debug("%02x ", (unsigned char) (buff)[zzz]);	\
54 	}							\
55 	if ((len + 1) % 16)					\
56 		pr_debug("\n");					\
57 }
58 
59 extern struct list_head g_tiqn_list;
60 extern spinlock_t tiqn_lock;
61 
62 /*
63  *	Called with cmd->r2t_lock held.
64  */
65 int iscsit_add_r2t_to_list(
66 	struct iscsi_cmd *cmd,
67 	u32 offset,
68 	u32 xfer_len,
69 	int recovery,
70 	u32 r2t_sn)
71 {
72 	struct iscsi_r2t *r2t;
73 
74 	r2t = kmem_cache_zalloc(lio_r2t_cache, GFP_ATOMIC);
75 	if (!r2t) {
76 		pr_err("Unable to allocate memory for struct iscsi_r2t.\n");
77 		return -1;
78 	}
79 	INIT_LIST_HEAD(&r2t->r2t_list);
80 
81 	r2t->recovery_r2t = recovery;
82 	r2t->r2t_sn = (!r2t_sn) ? cmd->r2t_sn++ : r2t_sn;
83 	r2t->offset = offset;
84 	r2t->xfer_len = xfer_len;
85 	list_add_tail(&r2t->r2t_list, &cmd->cmd_r2t_list);
86 	spin_unlock_bh(&cmd->r2t_lock);
87 
88 	iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, ISTATE_SEND_R2T);
89 
90 	spin_lock_bh(&cmd->r2t_lock);
91 	return 0;
92 }
93 
94 struct iscsi_r2t *iscsit_get_r2t_for_eos(
95 	struct iscsi_cmd *cmd,
96 	u32 offset,
97 	u32 length)
98 {
99 	struct iscsi_r2t *r2t;
100 
101 	spin_lock_bh(&cmd->r2t_lock);
102 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
103 		if ((r2t->offset <= offset) &&
104 		    (r2t->offset + r2t->xfer_len) >= (offset + length)) {
105 			spin_unlock_bh(&cmd->r2t_lock);
106 			return r2t;
107 		}
108 	}
109 	spin_unlock_bh(&cmd->r2t_lock);
110 
111 	pr_err("Unable to locate R2T for Offset: %u, Length:"
112 			" %u\n", offset, length);
113 	return NULL;
114 }
115 
116 struct iscsi_r2t *iscsit_get_r2t_from_list(struct iscsi_cmd *cmd)
117 {
118 	struct iscsi_r2t *r2t;
119 
120 	spin_lock_bh(&cmd->r2t_lock);
121 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
122 		if (!r2t->sent_r2t) {
123 			spin_unlock_bh(&cmd->r2t_lock);
124 			return r2t;
125 		}
126 	}
127 	spin_unlock_bh(&cmd->r2t_lock);
128 
129 	pr_err("Unable to locate next R2T to send for ITT:"
130 			" 0x%08x.\n", cmd->init_task_tag);
131 	return NULL;
132 }
133 
134 /*
135  *	Called with cmd->r2t_lock held.
136  */
137 void iscsit_free_r2t(struct iscsi_r2t *r2t, struct iscsi_cmd *cmd)
138 {
139 	list_del(&r2t->r2t_list);
140 	kmem_cache_free(lio_r2t_cache, r2t);
141 }
142 
143 void iscsit_free_r2ts_from_list(struct iscsi_cmd *cmd)
144 {
145 	struct iscsi_r2t *r2t, *r2t_tmp;
146 
147 	spin_lock_bh(&cmd->r2t_lock);
148 	list_for_each_entry_safe(r2t, r2t_tmp, &cmd->cmd_r2t_list, r2t_list)
149 		iscsit_free_r2t(r2t, cmd);
150 	spin_unlock_bh(&cmd->r2t_lock);
151 }
152 
153 /*
154  * May be called from software interrupt (timer) context for allocating
155  * iSCSI NopINs.
156  */
157 struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn *conn, gfp_t gfp_mask)
158 {
159 	struct iscsi_cmd *cmd;
160 
161 	cmd = kmem_cache_zalloc(lio_cmd_cache, gfp_mask);
162 	if (!cmd) {
163 		pr_err("Unable to allocate memory for struct iscsi_cmd.\n");
164 		return NULL;
165 	}
166 
167 	cmd->conn	= conn;
168 	INIT_LIST_HEAD(&cmd->i_list);
169 	INIT_LIST_HEAD(&cmd->datain_list);
170 	INIT_LIST_HEAD(&cmd->cmd_r2t_list);
171 	init_completion(&cmd->reject_comp);
172 	spin_lock_init(&cmd->datain_lock);
173 	spin_lock_init(&cmd->dataout_timeout_lock);
174 	spin_lock_init(&cmd->istate_lock);
175 	spin_lock_init(&cmd->error_lock);
176 	spin_lock_init(&cmd->r2t_lock);
177 
178 	return cmd;
179 }
180 
181 /*
182  * Called from iscsi_handle_scsi_cmd()
183  */
184 struct iscsi_cmd *iscsit_allocate_se_cmd(
185 	struct iscsi_conn *conn,
186 	u32 data_length,
187 	int data_direction,
188 	int iscsi_task_attr)
189 {
190 	struct iscsi_cmd *cmd;
191 	struct se_cmd *se_cmd;
192 	int sam_task_attr;
193 
194 	cmd = iscsit_allocate_cmd(conn, GFP_KERNEL);
195 	if (!cmd)
196 		return NULL;
197 
198 	cmd->data_direction = data_direction;
199 	cmd->data_length = data_length;
200 	/*
201 	 * Figure out the SAM Task Attribute for the incoming SCSI CDB
202 	 */
203 	if ((iscsi_task_attr == ISCSI_ATTR_UNTAGGED) ||
204 	    (iscsi_task_attr == ISCSI_ATTR_SIMPLE))
205 		sam_task_attr = MSG_SIMPLE_TAG;
206 	else if (iscsi_task_attr == ISCSI_ATTR_ORDERED)
207 		sam_task_attr = MSG_ORDERED_TAG;
208 	else if (iscsi_task_attr == ISCSI_ATTR_HEAD_OF_QUEUE)
209 		sam_task_attr = MSG_HEAD_TAG;
210 	else if (iscsi_task_attr == ISCSI_ATTR_ACA)
211 		sam_task_attr = MSG_ACA_TAG;
212 	else {
213 		pr_debug("Unknown iSCSI Task Attribute: 0x%02x, using"
214 			" MSG_SIMPLE_TAG\n", iscsi_task_attr);
215 		sam_task_attr = MSG_SIMPLE_TAG;
216 	}
217 
218 	se_cmd = &cmd->se_cmd;
219 	/*
220 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
221 	 */
222 	transport_init_se_cmd(se_cmd, &lio_target_fabric_configfs->tf_ops,
223 			conn->sess->se_sess, data_length, data_direction,
224 			sam_task_attr, &cmd->sense_buffer[0]);
225 	return cmd;
226 }
227 
228 struct iscsi_cmd *iscsit_allocate_se_cmd_for_tmr(
229 	struct iscsi_conn *conn,
230 	u8 function)
231 {
232 	struct iscsi_cmd *cmd;
233 	struct se_cmd *se_cmd;
234 	u8 tcm_function;
235 
236 	cmd = iscsit_allocate_cmd(conn, GFP_KERNEL);
237 	if (!cmd)
238 		return NULL;
239 
240 	cmd->data_direction = DMA_NONE;
241 
242 	cmd->tmr_req = kzalloc(sizeof(struct iscsi_tmr_req), GFP_KERNEL);
243 	if (!cmd->tmr_req) {
244 		pr_err("Unable to allocate memory for"
245 			" Task Management command!\n");
246 		goto out;
247 	}
248 	/*
249 	 * TASK_REASSIGN for ERL=2 / connection stays inside of
250 	 * LIO-Target $FABRIC_MOD
251 	 */
252 	if (function == ISCSI_TM_FUNC_TASK_REASSIGN)
253 		return cmd;
254 
255 	se_cmd = &cmd->se_cmd;
256 	/*
257 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
258 	 */
259 	transport_init_se_cmd(se_cmd, &lio_target_fabric_configfs->tf_ops,
260 				conn->sess->se_sess, 0, DMA_NONE,
261 				MSG_SIMPLE_TAG, &cmd->sense_buffer[0]);
262 
263 	switch (function) {
264 	case ISCSI_TM_FUNC_ABORT_TASK:
265 		tcm_function = TMR_ABORT_TASK;
266 		break;
267 	case ISCSI_TM_FUNC_ABORT_TASK_SET:
268 		tcm_function = TMR_ABORT_TASK_SET;
269 		break;
270 	case ISCSI_TM_FUNC_CLEAR_ACA:
271 		tcm_function = TMR_CLEAR_ACA;
272 		break;
273 	case ISCSI_TM_FUNC_CLEAR_TASK_SET:
274 		tcm_function = TMR_CLEAR_TASK_SET;
275 		break;
276 	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
277 		tcm_function = TMR_LUN_RESET;
278 		break;
279 	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
280 		tcm_function = TMR_TARGET_WARM_RESET;
281 		break;
282 	case ISCSI_TM_FUNC_TARGET_COLD_RESET:
283 		tcm_function = TMR_TARGET_COLD_RESET;
284 		break;
285 	default:
286 		pr_err("Unknown iSCSI TMR Function:"
287 			" 0x%02x\n", function);
288 		goto out;
289 	}
290 
291 	se_cmd->se_tmr_req = core_tmr_alloc_req(se_cmd,
292 				(void *)cmd->tmr_req, tcm_function,
293 				GFP_KERNEL);
294 	if (!se_cmd->se_tmr_req)
295 		goto out;
296 
297 	cmd->tmr_req->se_tmr_req = se_cmd->se_tmr_req;
298 
299 	return cmd;
300 out:
301 	iscsit_release_cmd(cmd);
302 	return NULL;
303 }
304 
305 int iscsit_decide_list_to_build(
306 	struct iscsi_cmd *cmd,
307 	u32 immediate_data_length)
308 {
309 	struct iscsi_build_list bl;
310 	struct iscsi_conn *conn = cmd->conn;
311 	struct iscsi_session *sess = conn->sess;
312 	struct iscsi_node_attrib *na;
313 
314 	if (sess->sess_ops->DataSequenceInOrder &&
315 	    sess->sess_ops->DataPDUInOrder)
316 		return 0;
317 
318 	if (cmd->data_direction == DMA_NONE)
319 		return 0;
320 
321 	na = iscsit_tpg_get_node_attrib(sess);
322 	memset(&bl, 0, sizeof(struct iscsi_build_list));
323 
324 	if (cmd->data_direction == DMA_FROM_DEVICE) {
325 		bl.data_direction = ISCSI_PDU_READ;
326 		bl.type = PDULIST_NORMAL;
327 		if (na->random_datain_pdu_offsets)
328 			bl.randomize |= RANDOM_DATAIN_PDU_OFFSETS;
329 		if (na->random_datain_seq_offsets)
330 			bl.randomize |= RANDOM_DATAIN_SEQ_OFFSETS;
331 	} else {
332 		bl.data_direction = ISCSI_PDU_WRITE;
333 		bl.immediate_data_length = immediate_data_length;
334 		if (na->random_r2t_offsets)
335 			bl.randomize |= RANDOM_R2T_OFFSETS;
336 
337 		if (!cmd->immediate_data && !cmd->unsolicited_data)
338 			bl.type = PDULIST_NORMAL;
339 		else if (cmd->immediate_data && !cmd->unsolicited_data)
340 			bl.type = PDULIST_IMMEDIATE;
341 		else if (!cmd->immediate_data && cmd->unsolicited_data)
342 			bl.type = PDULIST_UNSOLICITED;
343 		else if (cmd->immediate_data && cmd->unsolicited_data)
344 			bl.type = PDULIST_IMMEDIATE_AND_UNSOLICITED;
345 	}
346 
347 	return iscsit_do_build_list(cmd, &bl);
348 }
349 
350 struct iscsi_seq *iscsit_get_seq_holder_for_datain(
351 	struct iscsi_cmd *cmd,
352 	u32 seq_send_order)
353 {
354 	u32 i;
355 
356 	for (i = 0; i < cmd->seq_count; i++)
357 		if (cmd->seq_list[i].seq_send_order == seq_send_order)
358 			return &cmd->seq_list[i];
359 
360 	return NULL;
361 }
362 
363 struct iscsi_seq *iscsit_get_seq_holder_for_r2t(struct iscsi_cmd *cmd)
364 {
365 	u32 i;
366 
367 	if (!cmd->seq_list) {
368 		pr_err("struct iscsi_cmd->seq_list is NULL!\n");
369 		return NULL;
370 	}
371 
372 	for (i = 0; i < cmd->seq_count; i++) {
373 		if (cmd->seq_list[i].type != SEQTYPE_NORMAL)
374 			continue;
375 		if (cmd->seq_list[i].seq_send_order == cmd->seq_send_order) {
376 			cmd->seq_send_order++;
377 			return &cmd->seq_list[i];
378 		}
379 	}
380 
381 	return NULL;
382 }
383 
384 struct iscsi_r2t *iscsit_get_holder_for_r2tsn(
385 	struct iscsi_cmd *cmd,
386 	u32 r2t_sn)
387 {
388 	struct iscsi_r2t *r2t;
389 
390 	spin_lock_bh(&cmd->r2t_lock);
391 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
392 		if (r2t->r2t_sn == r2t_sn) {
393 			spin_unlock_bh(&cmd->r2t_lock);
394 			return r2t;
395 		}
396 	}
397 	spin_unlock_bh(&cmd->r2t_lock);
398 
399 	return NULL;
400 }
401 
402 static inline int iscsit_check_received_cmdsn(struct iscsi_session *sess, u32 cmdsn)
403 {
404 	int ret;
405 
406 	/*
407 	 * This is the proper method of checking received CmdSN against
408 	 * ExpCmdSN and MaxCmdSN values, as well as accounting for out
409 	 * or order CmdSNs due to multiple connection sessions and/or
410 	 * CRC failures.
411 	 */
412 	if (iscsi_sna_gt(cmdsn, sess->max_cmd_sn)) {
413 		pr_err("Received CmdSN: 0x%08x is greater than"
414 		       " MaxCmdSN: 0x%08x, protocol error.\n", cmdsn,
415 		       sess->max_cmd_sn);
416 		ret = CMDSN_ERROR_CANNOT_RECOVER;
417 
418 	} else if (cmdsn == sess->exp_cmd_sn) {
419 		sess->exp_cmd_sn++;
420 		pr_debug("Received CmdSN matches ExpCmdSN,"
421 		      " incremented ExpCmdSN to: 0x%08x\n",
422 		      sess->exp_cmd_sn);
423 		ret = CMDSN_NORMAL_OPERATION;
424 
425 	} else if (iscsi_sna_gt(cmdsn, sess->exp_cmd_sn)) {
426 		pr_debug("Received CmdSN: 0x%08x is greater"
427 		      " than ExpCmdSN: 0x%08x, not acknowledging.\n",
428 		      cmdsn, sess->exp_cmd_sn);
429 		ret = CMDSN_HIGHER_THAN_EXP;
430 
431 	} else {
432 		pr_err("Received CmdSN: 0x%08x is less than"
433 		       " ExpCmdSN: 0x%08x, ignoring.\n", cmdsn,
434 		       sess->exp_cmd_sn);
435 		ret = CMDSN_LOWER_THAN_EXP;
436 	}
437 
438 	return ret;
439 }
440 
441 /*
442  * Commands may be received out of order if MC/S is in use.
443  * Ensure they are executed in CmdSN order.
444  */
445 int iscsit_sequence_cmd(
446 	struct iscsi_conn *conn,
447 	struct iscsi_cmd *cmd,
448 	u32 cmdsn)
449 {
450 	int ret;
451 	int cmdsn_ret;
452 
453 	mutex_lock(&conn->sess->cmdsn_mutex);
454 
455 	cmdsn_ret = iscsit_check_received_cmdsn(conn->sess, cmdsn);
456 	switch (cmdsn_ret) {
457 	case CMDSN_NORMAL_OPERATION:
458 		ret = iscsit_execute_cmd(cmd, 0);
459 		if ((ret >= 0) && !list_empty(&conn->sess->sess_ooo_cmdsn_list))
460 			iscsit_execute_ooo_cmdsns(conn->sess);
461 		break;
462 	case CMDSN_HIGHER_THAN_EXP:
463 		ret = iscsit_handle_ooo_cmdsn(conn->sess, cmd, cmdsn);
464 		break;
465 	case CMDSN_LOWER_THAN_EXP:
466 		cmd->i_state = ISTATE_REMOVE;
467 		iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
468 		ret = cmdsn_ret;
469 		break;
470 	default:
471 		ret = cmdsn_ret;
472 		break;
473 	}
474 	mutex_unlock(&conn->sess->cmdsn_mutex);
475 
476 	return ret;
477 }
478 
479 int iscsit_check_unsolicited_dataout(struct iscsi_cmd *cmd, unsigned char *buf)
480 {
481 	struct iscsi_conn *conn = cmd->conn;
482 	struct se_cmd *se_cmd = &cmd->se_cmd;
483 	struct iscsi_data *hdr = (struct iscsi_data *) buf;
484 	u32 payload_length = ntoh24(hdr->dlength);
485 
486 	if (conn->sess->sess_ops->InitialR2T) {
487 		pr_err("Received unexpected unsolicited data"
488 			" while InitialR2T=Yes, protocol error.\n");
489 		transport_send_check_condition_and_sense(se_cmd,
490 				TCM_UNEXPECTED_UNSOLICITED_DATA, 0);
491 		return -1;
492 	}
493 
494 	if ((cmd->first_burst_len + payload_length) >
495 	     conn->sess->sess_ops->FirstBurstLength) {
496 		pr_err("Total %u bytes exceeds FirstBurstLength: %u"
497 			" for this Unsolicited DataOut Burst.\n",
498 			(cmd->first_burst_len + payload_length),
499 				conn->sess->sess_ops->FirstBurstLength);
500 		transport_send_check_condition_and_sense(se_cmd,
501 				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
502 		return -1;
503 	}
504 
505 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL))
506 		return 0;
507 
508 	if (((cmd->first_burst_len + payload_length) != cmd->data_length) &&
509 	    ((cmd->first_burst_len + payload_length) !=
510 	      conn->sess->sess_ops->FirstBurstLength)) {
511 		pr_err("Unsolicited non-immediate data received %u"
512 			" does not equal FirstBurstLength: %u, and does"
513 			" not equal ExpXferLen %u.\n",
514 			(cmd->first_burst_len + payload_length),
515 			conn->sess->sess_ops->FirstBurstLength, cmd->data_length);
516 		transport_send_check_condition_and_sense(se_cmd,
517 				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
518 		return -1;
519 	}
520 	return 0;
521 }
522 
523 struct iscsi_cmd *iscsit_find_cmd_from_itt(
524 	struct iscsi_conn *conn,
525 	u32 init_task_tag)
526 {
527 	struct iscsi_cmd *cmd;
528 
529 	spin_lock_bh(&conn->cmd_lock);
530 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_list) {
531 		if (cmd->init_task_tag == init_task_tag) {
532 			spin_unlock_bh(&conn->cmd_lock);
533 			return cmd;
534 		}
535 	}
536 	spin_unlock_bh(&conn->cmd_lock);
537 
538 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu",
539 			init_task_tag, conn->cid);
540 	return NULL;
541 }
542 
543 struct iscsi_cmd *iscsit_find_cmd_from_itt_or_dump(
544 	struct iscsi_conn *conn,
545 	u32 init_task_tag,
546 	u32 length)
547 {
548 	struct iscsi_cmd *cmd;
549 
550 	spin_lock_bh(&conn->cmd_lock);
551 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_list) {
552 		if (cmd->init_task_tag == init_task_tag) {
553 			spin_unlock_bh(&conn->cmd_lock);
554 			return cmd;
555 		}
556 	}
557 	spin_unlock_bh(&conn->cmd_lock);
558 
559 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu,"
560 			" dumping payload\n", init_task_tag, conn->cid);
561 	if (length)
562 		iscsit_dump_data_payload(conn, length, 1);
563 
564 	return NULL;
565 }
566 
567 struct iscsi_cmd *iscsit_find_cmd_from_ttt(
568 	struct iscsi_conn *conn,
569 	u32 targ_xfer_tag)
570 {
571 	struct iscsi_cmd *cmd = NULL;
572 
573 	spin_lock_bh(&conn->cmd_lock);
574 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_list) {
575 		if (cmd->targ_xfer_tag == targ_xfer_tag) {
576 			spin_unlock_bh(&conn->cmd_lock);
577 			return cmd;
578 		}
579 	}
580 	spin_unlock_bh(&conn->cmd_lock);
581 
582 	pr_err("Unable to locate TTT: 0x%08x on CID: %hu\n",
583 			targ_xfer_tag, conn->cid);
584 	return NULL;
585 }
586 
587 int iscsit_find_cmd_for_recovery(
588 	struct iscsi_session *sess,
589 	struct iscsi_cmd **cmd_ptr,
590 	struct iscsi_conn_recovery **cr_ptr,
591 	u32 init_task_tag)
592 {
593 	struct iscsi_cmd *cmd = NULL;
594 	struct iscsi_conn_recovery *cr;
595 	/*
596 	 * Scan through the inactive connection recovery list's command list.
597 	 * If init_task_tag matches the command is still alligent.
598 	 */
599 	spin_lock(&sess->cr_i_lock);
600 	list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
601 		spin_lock(&cr->conn_recovery_cmd_lock);
602 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_list) {
603 			if (cmd->init_task_tag == init_task_tag) {
604 				spin_unlock(&cr->conn_recovery_cmd_lock);
605 				spin_unlock(&sess->cr_i_lock);
606 
607 				*cr_ptr = cr;
608 				*cmd_ptr = cmd;
609 				return -2;
610 			}
611 		}
612 		spin_unlock(&cr->conn_recovery_cmd_lock);
613 	}
614 	spin_unlock(&sess->cr_i_lock);
615 	/*
616 	 * Scan through the active connection recovery list's command list.
617 	 * If init_task_tag matches the command is ready to be reassigned.
618 	 */
619 	spin_lock(&sess->cr_a_lock);
620 	list_for_each_entry(cr, &sess->cr_active_list, cr_list) {
621 		spin_lock(&cr->conn_recovery_cmd_lock);
622 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_list) {
623 			if (cmd->init_task_tag == init_task_tag) {
624 				spin_unlock(&cr->conn_recovery_cmd_lock);
625 				spin_unlock(&sess->cr_a_lock);
626 
627 				*cr_ptr = cr;
628 				*cmd_ptr = cmd;
629 				return 0;
630 			}
631 		}
632 		spin_unlock(&cr->conn_recovery_cmd_lock);
633 	}
634 	spin_unlock(&sess->cr_a_lock);
635 
636 	return -1;
637 }
638 
639 void iscsit_add_cmd_to_immediate_queue(
640 	struct iscsi_cmd *cmd,
641 	struct iscsi_conn *conn,
642 	u8 state)
643 {
644 	struct iscsi_queue_req *qr;
645 
646 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
647 	if (!qr) {
648 		pr_err("Unable to allocate memory for"
649 				" struct iscsi_queue_req\n");
650 		return;
651 	}
652 	INIT_LIST_HEAD(&qr->qr_list);
653 	qr->cmd = cmd;
654 	qr->state = state;
655 
656 	spin_lock_bh(&conn->immed_queue_lock);
657 	list_add_tail(&qr->qr_list, &conn->immed_queue_list);
658 	atomic_inc(&cmd->immed_queue_count);
659 	atomic_set(&conn->check_immediate_queue, 1);
660 	spin_unlock_bh(&conn->immed_queue_lock);
661 
662 	wake_up_process(conn->thread_set->tx_thread);
663 }
664 
665 struct iscsi_queue_req *iscsit_get_cmd_from_immediate_queue(struct iscsi_conn *conn)
666 {
667 	struct iscsi_queue_req *qr;
668 
669 	spin_lock_bh(&conn->immed_queue_lock);
670 	if (list_empty(&conn->immed_queue_list)) {
671 		spin_unlock_bh(&conn->immed_queue_lock);
672 		return NULL;
673 	}
674 	list_for_each_entry(qr, &conn->immed_queue_list, qr_list)
675 		break;
676 
677 	list_del(&qr->qr_list);
678 	if (qr->cmd)
679 		atomic_dec(&qr->cmd->immed_queue_count);
680 	spin_unlock_bh(&conn->immed_queue_lock);
681 
682 	return qr;
683 }
684 
685 static void iscsit_remove_cmd_from_immediate_queue(
686 	struct iscsi_cmd *cmd,
687 	struct iscsi_conn *conn)
688 {
689 	struct iscsi_queue_req *qr, *qr_tmp;
690 
691 	spin_lock_bh(&conn->immed_queue_lock);
692 	if (!atomic_read(&cmd->immed_queue_count)) {
693 		spin_unlock_bh(&conn->immed_queue_lock);
694 		return;
695 	}
696 
697 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
698 		if (qr->cmd != cmd)
699 			continue;
700 
701 		atomic_dec(&qr->cmd->immed_queue_count);
702 		list_del(&qr->qr_list);
703 		kmem_cache_free(lio_qr_cache, qr);
704 	}
705 	spin_unlock_bh(&conn->immed_queue_lock);
706 
707 	if (atomic_read(&cmd->immed_queue_count)) {
708 		pr_err("ITT: 0x%08x immed_queue_count: %d\n",
709 			cmd->init_task_tag,
710 			atomic_read(&cmd->immed_queue_count));
711 	}
712 }
713 
714 void iscsit_add_cmd_to_response_queue(
715 	struct iscsi_cmd *cmd,
716 	struct iscsi_conn *conn,
717 	u8 state)
718 {
719 	struct iscsi_queue_req *qr;
720 
721 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
722 	if (!qr) {
723 		pr_err("Unable to allocate memory for"
724 			" struct iscsi_queue_req\n");
725 		return;
726 	}
727 	INIT_LIST_HEAD(&qr->qr_list);
728 	qr->cmd = cmd;
729 	qr->state = state;
730 
731 	spin_lock_bh(&conn->response_queue_lock);
732 	list_add_tail(&qr->qr_list, &conn->response_queue_list);
733 	atomic_inc(&cmd->response_queue_count);
734 	spin_unlock_bh(&conn->response_queue_lock);
735 
736 	wake_up_process(conn->thread_set->tx_thread);
737 }
738 
739 struct iscsi_queue_req *iscsit_get_cmd_from_response_queue(struct iscsi_conn *conn)
740 {
741 	struct iscsi_queue_req *qr;
742 
743 	spin_lock_bh(&conn->response_queue_lock);
744 	if (list_empty(&conn->response_queue_list)) {
745 		spin_unlock_bh(&conn->response_queue_lock);
746 		return NULL;
747 	}
748 
749 	list_for_each_entry(qr, &conn->response_queue_list, qr_list)
750 		break;
751 
752 	list_del(&qr->qr_list);
753 	if (qr->cmd)
754 		atomic_dec(&qr->cmd->response_queue_count);
755 	spin_unlock_bh(&conn->response_queue_lock);
756 
757 	return qr;
758 }
759 
760 static void iscsit_remove_cmd_from_response_queue(
761 	struct iscsi_cmd *cmd,
762 	struct iscsi_conn *conn)
763 {
764 	struct iscsi_queue_req *qr, *qr_tmp;
765 
766 	spin_lock_bh(&conn->response_queue_lock);
767 	if (!atomic_read(&cmd->response_queue_count)) {
768 		spin_unlock_bh(&conn->response_queue_lock);
769 		return;
770 	}
771 
772 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
773 				qr_list) {
774 		if (qr->cmd != cmd)
775 			continue;
776 
777 		atomic_dec(&qr->cmd->response_queue_count);
778 		list_del(&qr->qr_list);
779 		kmem_cache_free(lio_qr_cache, qr);
780 	}
781 	spin_unlock_bh(&conn->response_queue_lock);
782 
783 	if (atomic_read(&cmd->response_queue_count)) {
784 		pr_err("ITT: 0x%08x response_queue_count: %d\n",
785 			cmd->init_task_tag,
786 			atomic_read(&cmd->response_queue_count));
787 	}
788 }
789 
790 void iscsit_free_queue_reqs_for_conn(struct iscsi_conn *conn)
791 {
792 	struct iscsi_queue_req *qr, *qr_tmp;
793 
794 	spin_lock_bh(&conn->immed_queue_lock);
795 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
796 		list_del(&qr->qr_list);
797 		if (qr->cmd)
798 			atomic_dec(&qr->cmd->immed_queue_count);
799 
800 		kmem_cache_free(lio_qr_cache, qr);
801 	}
802 	spin_unlock_bh(&conn->immed_queue_lock);
803 
804 	spin_lock_bh(&conn->response_queue_lock);
805 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
806 			qr_list) {
807 		list_del(&qr->qr_list);
808 		if (qr->cmd)
809 			atomic_dec(&qr->cmd->response_queue_count);
810 
811 		kmem_cache_free(lio_qr_cache, qr);
812 	}
813 	spin_unlock_bh(&conn->response_queue_lock);
814 }
815 
816 void iscsit_release_cmd(struct iscsi_cmd *cmd)
817 {
818 	struct iscsi_conn *conn = cmd->conn;
819 	int i;
820 
821 	iscsit_free_r2ts_from_list(cmd);
822 	iscsit_free_all_datain_reqs(cmd);
823 
824 	kfree(cmd->buf_ptr);
825 	kfree(cmd->pdu_list);
826 	kfree(cmd->seq_list);
827 	kfree(cmd->tmr_req);
828 	kfree(cmd->iov_data);
829 
830 	for (i = 0; i < cmd->t_mem_sg_nents; i++)
831 		__free_page(sg_page(&cmd->t_mem_sg[i]));
832 
833 	kfree(cmd->t_mem_sg);
834 
835 	if (conn) {
836 		iscsit_remove_cmd_from_immediate_queue(cmd, conn);
837 		iscsit_remove_cmd_from_response_queue(cmd, conn);
838 	}
839 
840 	kmem_cache_free(lio_cmd_cache, cmd);
841 }
842 
843 void iscsit_free_cmd(struct iscsi_cmd *cmd)
844 {
845 	/*
846 	 * Determine if a struct se_cmd is assoicated with
847 	 * this struct iscsi_cmd.
848 	 */
849 	switch (cmd->iscsi_opcode) {
850 	case ISCSI_OP_SCSI_CMD:
851 	case ISCSI_OP_SCSI_TMFUNC:
852 		transport_generic_free_cmd(&cmd->se_cmd, 1);
853 		break;
854 	default:
855 		iscsit_release_cmd(cmd);
856 		break;
857 	}
858 }
859 
860 int iscsit_check_session_usage_count(struct iscsi_session *sess)
861 {
862 	spin_lock_bh(&sess->session_usage_lock);
863 	if (sess->session_usage_count != 0) {
864 		sess->session_waiting_on_uc = 1;
865 		spin_unlock_bh(&sess->session_usage_lock);
866 		if (in_interrupt())
867 			return 2;
868 
869 		wait_for_completion(&sess->session_waiting_on_uc_comp);
870 		return 1;
871 	}
872 	spin_unlock_bh(&sess->session_usage_lock);
873 
874 	return 0;
875 }
876 
877 void iscsit_dec_session_usage_count(struct iscsi_session *sess)
878 {
879 	spin_lock_bh(&sess->session_usage_lock);
880 	sess->session_usage_count--;
881 
882 	if (!sess->session_usage_count && sess->session_waiting_on_uc)
883 		complete(&sess->session_waiting_on_uc_comp);
884 
885 	spin_unlock_bh(&sess->session_usage_lock);
886 }
887 
888 void iscsit_inc_session_usage_count(struct iscsi_session *sess)
889 {
890 	spin_lock_bh(&sess->session_usage_lock);
891 	sess->session_usage_count++;
892 	spin_unlock_bh(&sess->session_usage_lock);
893 }
894 
895 /*
896  *	Setup conn->if_marker and conn->of_marker values based upon
897  *	the initial marker-less interval. (see iSCSI v19 A.2)
898  */
899 int iscsit_set_sync_and_steering_values(struct iscsi_conn *conn)
900 {
901 	int login_ifmarker_count = 0, login_ofmarker_count = 0, next_marker = 0;
902 	/*
903 	 * IFMarkInt and OFMarkInt are negotiated as 32-bit words.
904 	 */
905 	u32 IFMarkInt = (conn->conn_ops->IFMarkInt * 4);
906 	u32 OFMarkInt = (conn->conn_ops->OFMarkInt * 4);
907 
908 	if (conn->conn_ops->OFMarker) {
909 		/*
910 		 * Account for the first Login Command received not
911 		 * via iscsi_recv_msg().
912 		 */
913 		conn->of_marker += ISCSI_HDR_LEN;
914 		if (conn->of_marker <= OFMarkInt) {
915 			conn->of_marker = (OFMarkInt - conn->of_marker);
916 		} else {
917 			login_ofmarker_count = (conn->of_marker / OFMarkInt);
918 			next_marker = (OFMarkInt * (login_ofmarker_count + 1)) +
919 					(login_ofmarker_count * MARKER_SIZE);
920 			conn->of_marker = (next_marker - conn->of_marker);
921 		}
922 		conn->of_marker_offset = 0;
923 		pr_debug("Setting OFMarker value to %u based on Initial"
924 			" Markerless Interval.\n", conn->of_marker);
925 	}
926 
927 	if (conn->conn_ops->IFMarker) {
928 		if (conn->if_marker <= IFMarkInt) {
929 			conn->if_marker = (IFMarkInt - conn->if_marker);
930 		} else {
931 			login_ifmarker_count = (conn->if_marker / IFMarkInt);
932 			next_marker = (IFMarkInt * (login_ifmarker_count + 1)) +
933 					(login_ifmarker_count * MARKER_SIZE);
934 			conn->if_marker = (next_marker - conn->if_marker);
935 		}
936 		pr_debug("Setting IFMarker value to %u based on Initial"
937 			" Markerless Interval.\n", conn->if_marker);
938 	}
939 
940 	return 0;
941 }
942 
943 struct iscsi_conn *iscsit_get_conn_from_cid(struct iscsi_session *sess, u16 cid)
944 {
945 	struct iscsi_conn *conn;
946 
947 	spin_lock_bh(&sess->conn_lock);
948 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
949 		if ((conn->cid == cid) &&
950 		    (conn->conn_state == TARG_CONN_STATE_LOGGED_IN)) {
951 			iscsit_inc_conn_usage_count(conn);
952 			spin_unlock_bh(&sess->conn_lock);
953 			return conn;
954 		}
955 	}
956 	spin_unlock_bh(&sess->conn_lock);
957 
958 	return NULL;
959 }
960 
961 struct iscsi_conn *iscsit_get_conn_from_cid_rcfr(struct iscsi_session *sess, u16 cid)
962 {
963 	struct iscsi_conn *conn;
964 
965 	spin_lock_bh(&sess->conn_lock);
966 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
967 		if (conn->cid == cid) {
968 			iscsit_inc_conn_usage_count(conn);
969 			spin_lock(&conn->state_lock);
970 			atomic_set(&conn->connection_wait_rcfr, 1);
971 			spin_unlock(&conn->state_lock);
972 			spin_unlock_bh(&sess->conn_lock);
973 			return conn;
974 		}
975 	}
976 	spin_unlock_bh(&sess->conn_lock);
977 
978 	return NULL;
979 }
980 
981 void iscsit_check_conn_usage_count(struct iscsi_conn *conn)
982 {
983 	spin_lock_bh(&conn->conn_usage_lock);
984 	if (conn->conn_usage_count != 0) {
985 		conn->conn_waiting_on_uc = 1;
986 		spin_unlock_bh(&conn->conn_usage_lock);
987 
988 		wait_for_completion(&conn->conn_waiting_on_uc_comp);
989 		return;
990 	}
991 	spin_unlock_bh(&conn->conn_usage_lock);
992 }
993 
994 void iscsit_dec_conn_usage_count(struct iscsi_conn *conn)
995 {
996 	spin_lock_bh(&conn->conn_usage_lock);
997 	conn->conn_usage_count--;
998 
999 	if (!conn->conn_usage_count && conn->conn_waiting_on_uc)
1000 		complete(&conn->conn_waiting_on_uc_comp);
1001 
1002 	spin_unlock_bh(&conn->conn_usage_lock);
1003 }
1004 
1005 void iscsit_inc_conn_usage_count(struct iscsi_conn *conn)
1006 {
1007 	spin_lock_bh(&conn->conn_usage_lock);
1008 	conn->conn_usage_count++;
1009 	spin_unlock_bh(&conn->conn_usage_lock);
1010 }
1011 
1012 static int iscsit_add_nopin(struct iscsi_conn *conn, int want_response)
1013 {
1014 	u8 state;
1015 	struct iscsi_cmd *cmd;
1016 
1017 	cmd = iscsit_allocate_cmd(conn, GFP_ATOMIC);
1018 	if (!cmd)
1019 		return -1;
1020 
1021 	cmd->iscsi_opcode = ISCSI_OP_NOOP_IN;
1022 	state = (want_response) ? ISTATE_SEND_NOPIN_WANT_RESPONSE :
1023 				ISTATE_SEND_NOPIN_NO_RESPONSE;
1024 	cmd->init_task_tag = 0xFFFFFFFF;
1025 	spin_lock_bh(&conn->sess->ttt_lock);
1026 	cmd->targ_xfer_tag = (want_response) ? conn->sess->targ_xfer_tag++ :
1027 			0xFFFFFFFF;
1028 	if (want_response && (cmd->targ_xfer_tag == 0xFFFFFFFF))
1029 		cmd->targ_xfer_tag = conn->sess->targ_xfer_tag++;
1030 	spin_unlock_bh(&conn->sess->ttt_lock);
1031 
1032 	spin_lock_bh(&conn->cmd_lock);
1033 	list_add_tail(&cmd->i_list, &conn->conn_cmd_list);
1034 	spin_unlock_bh(&conn->cmd_lock);
1035 
1036 	if (want_response)
1037 		iscsit_start_nopin_response_timer(conn);
1038 	iscsit_add_cmd_to_immediate_queue(cmd, conn, state);
1039 
1040 	return 0;
1041 }
1042 
1043 static void iscsit_handle_nopin_response_timeout(unsigned long data)
1044 {
1045 	struct iscsi_conn *conn = (struct iscsi_conn *) data;
1046 
1047 	iscsit_inc_conn_usage_count(conn);
1048 
1049 	spin_lock_bh(&conn->nopin_timer_lock);
1050 	if (conn->nopin_response_timer_flags & ISCSI_TF_STOP) {
1051 		spin_unlock_bh(&conn->nopin_timer_lock);
1052 		iscsit_dec_conn_usage_count(conn);
1053 		return;
1054 	}
1055 
1056 	pr_debug("Did not receive response to NOPIN on CID: %hu on"
1057 		" SID: %u, failing connection.\n", conn->cid,
1058 			conn->sess->sid);
1059 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
1060 	spin_unlock_bh(&conn->nopin_timer_lock);
1061 
1062 	{
1063 	struct iscsi_portal_group *tpg = conn->sess->tpg;
1064 	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
1065 
1066 	if (tiqn) {
1067 		spin_lock_bh(&tiqn->sess_err_stats.lock);
1068 		strcpy(tiqn->sess_err_stats.last_sess_fail_rem_name,
1069 				(void *)conn->sess->sess_ops->InitiatorName);
1070 		tiqn->sess_err_stats.last_sess_failure_type =
1071 				ISCSI_SESS_ERR_CXN_TIMEOUT;
1072 		tiqn->sess_err_stats.cxn_timeout_errors++;
1073 		conn->sess->conn_timeout_errors++;
1074 		spin_unlock_bh(&tiqn->sess_err_stats.lock);
1075 	}
1076 	}
1077 
1078 	iscsit_cause_connection_reinstatement(conn, 0);
1079 	iscsit_dec_conn_usage_count(conn);
1080 }
1081 
1082 void iscsit_mod_nopin_response_timer(struct iscsi_conn *conn)
1083 {
1084 	struct iscsi_session *sess = conn->sess;
1085 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1086 
1087 	spin_lock_bh(&conn->nopin_timer_lock);
1088 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
1089 		spin_unlock_bh(&conn->nopin_timer_lock);
1090 		return;
1091 	}
1092 
1093 	mod_timer(&conn->nopin_response_timer,
1094 		(get_jiffies_64() + na->nopin_response_timeout * HZ));
1095 	spin_unlock_bh(&conn->nopin_timer_lock);
1096 }
1097 
1098 /*
1099  *	Called with conn->nopin_timer_lock held.
1100  */
1101 void iscsit_start_nopin_response_timer(struct iscsi_conn *conn)
1102 {
1103 	struct iscsi_session *sess = conn->sess;
1104 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1105 
1106 	spin_lock_bh(&conn->nopin_timer_lock);
1107 	if (conn->nopin_response_timer_flags & ISCSI_TF_RUNNING) {
1108 		spin_unlock_bh(&conn->nopin_timer_lock);
1109 		return;
1110 	}
1111 
1112 	init_timer(&conn->nopin_response_timer);
1113 	conn->nopin_response_timer.expires =
1114 		(get_jiffies_64() + na->nopin_response_timeout * HZ);
1115 	conn->nopin_response_timer.data = (unsigned long)conn;
1116 	conn->nopin_response_timer.function = iscsit_handle_nopin_response_timeout;
1117 	conn->nopin_response_timer_flags &= ~ISCSI_TF_STOP;
1118 	conn->nopin_response_timer_flags |= ISCSI_TF_RUNNING;
1119 	add_timer(&conn->nopin_response_timer);
1120 
1121 	pr_debug("Started NOPIN Response Timer on CID: %d to %u"
1122 		" seconds\n", conn->cid, na->nopin_response_timeout);
1123 	spin_unlock_bh(&conn->nopin_timer_lock);
1124 }
1125 
1126 void iscsit_stop_nopin_response_timer(struct iscsi_conn *conn)
1127 {
1128 	spin_lock_bh(&conn->nopin_timer_lock);
1129 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
1130 		spin_unlock_bh(&conn->nopin_timer_lock);
1131 		return;
1132 	}
1133 	conn->nopin_response_timer_flags |= ISCSI_TF_STOP;
1134 	spin_unlock_bh(&conn->nopin_timer_lock);
1135 
1136 	del_timer_sync(&conn->nopin_response_timer);
1137 
1138 	spin_lock_bh(&conn->nopin_timer_lock);
1139 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
1140 	spin_unlock_bh(&conn->nopin_timer_lock);
1141 }
1142 
1143 static void iscsit_handle_nopin_timeout(unsigned long data)
1144 {
1145 	struct iscsi_conn *conn = (struct iscsi_conn *) data;
1146 
1147 	iscsit_inc_conn_usage_count(conn);
1148 
1149 	spin_lock_bh(&conn->nopin_timer_lock);
1150 	if (conn->nopin_timer_flags & ISCSI_TF_STOP) {
1151 		spin_unlock_bh(&conn->nopin_timer_lock);
1152 		iscsit_dec_conn_usage_count(conn);
1153 		return;
1154 	}
1155 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1156 	spin_unlock_bh(&conn->nopin_timer_lock);
1157 
1158 	iscsit_add_nopin(conn, 1);
1159 	iscsit_dec_conn_usage_count(conn);
1160 }
1161 
1162 /*
1163  * Called with conn->nopin_timer_lock held.
1164  */
1165 void __iscsit_start_nopin_timer(struct iscsi_conn *conn)
1166 {
1167 	struct iscsi_session *sess = conn->sess;
1168 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1169 	/*
1170 	* NOPIN timeout is disabled.
1171 	 */
1172 	if (!na->nopin_timeout)
1173 		return;
1174 
1175 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING)
1176 		return;
1177 
1178 	init_timer(&conn->nopin_timer);
1179 	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1180 	conn->nopin_timer.data = (unsigned long)conn;
1181 	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1182 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1183 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1184 	add_timer(&conn->nopin_timer);
1185 
1186 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1187 		" interval\n", conn->cid, na->nopin_timeout);
1188 }
1189 
1190 void iscsit_start_nopin_timer(struct iscsi_conn *conn)
1191 {
1192 	struct iscsi_session *sess = conn->sess;
1193 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1194 	/*
1195 	 * NOPIN timeout is disabled..
1196 	 */
1197 	if (!na->nopin_timeout)
1198 		return;
1199 
1200 	spin_lock_bh(&conn->nopin_timer_lock);
1201 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING) {
1202 		spin_unlock_bh(&conn->nopin_timer_lock);
1203 		return;
1204 	}
1205 
1206 	init_timer(&conn->nopin_timer);
1207 	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1208 	conn->nopin_timer.data = (unsigned long)conn;
1209 	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1210 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1211 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1212 	add_timer(&conn->nopin_timer);
1213 
1214 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1215 			" interval\n", conn->cid, na->nopin_timeout);
1216 	spin_unlock_bh(&conn->nopin_timer_lock);
1217 }
1218 
1219 void iscsit_stop_nopin_timer(struct iscsi_conn *conn)
1220 {
1221 	spin_lock_bh(&conn->nopin_timer_lock);
1222 	if (!(conn->nopin_timer_flags & ISCSI_TF_RUNNING)) {
1223 		spin_unlock_bh(&conn->nopin_timer_lock);
1224 		return;
1225 	}
1226 	conn->nopin_timer_flags |= ISCSI_TF_STOP;
1227 	spin_unlock_bh(&conn->nopin_timer_lock);
1228 
1229 	del_timer_sync(&conn->nopin_timer);
1230 
1231 	spin_lock_bh(&conn->nopin_timer_lock);
1232 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1233 	spin_unlock_bh(&conn->nopin_timer_lock);
1234 }
1235 
1236 int iscsit_send_tx_data(
1237 	struct iscsi_cmd *cmd,
1238 	struct iscsi_conn *conn,
1239 	int use_misc)
1240 {
1241 	int tx_sent, tx_size;
1242 	u32 iov_count;
1243 	struct kvec *iov;
1244 
1245 send_data:
1246 	tx_size = cmd->tx_size;
1247 
1248 	if (!use_misc) {
1249 		iov = &cmd->iov_data[0];
1250 		iov_count = cmd->iov_data_count;
1251 	} else {
1252 		iov = &cmd->iov_misc[0];
1253 		iov_count = cmd->iov_misc_count;
1254 	}
1255 
1256 	tx_sent = tx_data(conn, &iov[0], iov_count, tx_size);
1257 	if (tx_size != tx_sent) {
1258 		if (tx_sent == -EAGAIN) {
1259 			pr_err("tx_data() returned -EAGAIN\n");
1260 			goto send_data;
1261 		} else
1262 			return -1;
1263 	}
1264 	cmd->tx_size = 0;
1265 
1266 	return 0;
1267 }
1268 
1269 int iscsit_fe_sendpage_sg(
1270 	struct iscsi_cmd *cmd,
1271 	struct iscsi_conn *conn)
1272 {
1273 	struct scatterlist *sg = cmd->first_data_sg;
1274 	struct kvec iov;
1275 	u32 tx_hdr_size, data_len;
1276 	u32 offset = cmd->first_data_sg_off;
1277 	int tx_sent, iov_off;
1278 
1279 send_hdr:
1280 	tx_hdr_size = ISCSI_HDR_LEN;
1281 	if (conn->conn_ops->HeaderDigest)
1282 		tx_hdr_size += ISCSI_CRC_LEN;
1283 
1284 	iov.iov_base = cmd->pdu;
1285 	iov.iov_len = tx_hdr_size;
1286 
1287 	tx_sent = tx_data(conn, &iov, 1, tx_hdr_size);
1288 	if (tx_hdr_size != tx_sent) {
1289 		if (tx_sent == -EAGAIN) {
1290 			pr_err("tx_data() returned -EAGAIN\n");
1291 			goto send_hdr;
1292 		}
1293 		return -1;
1294 	}
1295 
1296 	data_len = cmd->tx_size - tx_hdr_size - cmd->padding;
1297 	/*
1298 	 * Set iov_off used by padding and data digest tx_data() calls below
1299 	 * in order to determine proper offset into cmd->iov_data[]
1300 	 */
1301 	if (conn->conn_ops->DataDigest) {
1302 		data_len -= ISCSI_CRC_LEN;
1303 		if (cmd->padding)
1304 			iov_off = (cmd->iov_data_count - 2);
1305 		else
1306 			iov_off = (cmd->iov_data_count - 1);
1307 	} else {
1308 		iov_off = (cmd->iov_data_count - 1);
1309 	}
1310 	/*
1311 	 * Perform sendpage() for each page in the scatterlist
1312 	 */
1313 	while (data_len) {
1314 		u32 space = (sg->length - offset);
1315 		u32 sub_len = min_t(u32, data_len, space);
1316 send_pg:
1317 		tx_sent = conn->sock->ops->sendpage(conn->sock,
1318 					sg_page(sg), sg->offset + offset, sub_len, 0);
1319 		if (tx_sent != sub_len) {
1320 			if (tx_sent == -EAGAIN) {
1321 				pr_err("tcp_sendpage() returned"
1322 						" -EAGAIN\n");
1323 				goto send_pg;
1324 			}
1325 
1326 			pr_err("tcp_sendpage() failure: %d\n",
1327 					tx_sent);
1328 			return -1;
1329 		}
1330 
1331 		data_len -= sub_len;
1332 		offset = 0;
1333 		sg = sg_next(sg);
1334 	}
1335 
1336 send_padding:
1337 	if (cmd->padding) {
1338 		struct kvec *iov_p = &cmd->iov_data[iov_off++];
1339 
1340 		tx_sent = tx_data(conn, iov_p, 1, cmd->padding);
1341 		if (cmd->padding != tx_sent) {
1342 			if (tx_sent == -EAGAIN) {
1343 				pr_err("tx_data() returned -EAGAIN\n");
1344 				goto send_padding;
1345 			}
1346 			return -1;
1347 		}
1348 	}
1349 
1350 send_datacrc:
1351 	if (conn->conn_ops->DataDigest) {
1352 		struct kvec *iov_d = &cmd->iov_data[iov_off];
1353 
1354 		tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN);
1355 		if (ISCSI_CRC_LEN != tx_sent) {
1356 			if (tx_sent == -EAGAIN) {
1357 				pr_err("tx_data() returned -EAGAIN\n");
1358 				goto send_datacrc;
1359 			}
1360 			return -1;
1361 		}
1362 	}
1363 
1364 	return 0;
1365 }
1366 
1367 /*
1368  *      This function is used for mainly sending a ISCSI_TARG_LOGIN_RSP PDU
1369  *      back to the Initiator when an expection condition occurs with the
1370  *      errors set in status_class and status_detail.
1371  *
1372  *      Parameters:     iSCSI Connection, Status Class, Status Detail.
1373  *      Returns:        0 on success, -1 on error.
1374  */
1375 int iscsit_tx_login_rsp(struct iscsi_conn *conn, u8 status_class, u8 status_detail)
1376 {
1377 	u8 iscsi_hdr[ISCSI_HDR_LEN];
1378 	int err;
1379 	struct kvec iov;
1380 	struct iscsi_login_rsp *hdr;
1381 
1382 	iscsit_collect_login_stats(conn, status_class, status_detail);
1383 
1384 	memset(&iov, 0, sizeof(struct kvec));
1385 	memset(&iscsi_hdr, 0x0, ISCSI_HDR_LEN);
1386 
1387 	hdr	= (struct iscsi_login_rsp *)&iscsi_hdr;
1388 	hdr->opcode		= ISCSI_OP_LOGIN_RSP;
1389 	hdr->status_class	= status_class;
1390 	hdr->status_detail	= status_detail;
1391 	hdr->itt		= cpu_to_be32(conn->login_itt);
1392 
1393 	iov.iov_base		= &iscsi_hdr;
1394 	iov.iov_len		= ISCSI_HDR_LEN;
1395 
1396 	PRINT_BUFF(iscsi_hdr, ISCSI_HDR_LEN);
1397 
1398 	err = tx_data(conn, &iov, 1, ISCSI_HDR_LEN);
1399 	if (err != ISCSI_HDR_LEN) {
1400 		pr_err("tx_data returned less than expected\n");
1401 		return -1;
1402 	}
1403 
1404 	return 0;
1405 }
1406 
1407 void iscsit_print_session_params(struct iscsi_session *sess)
1408 {
1409 	struct iscsi_conn *conn;
1410 
1411 	pr_debug("-----------------------------[Session Params for"
1412 		" SID: %u]-----------------------------\n", sess->sid);
1413 	spin_lock_bh(&sess->conn_lock);
1414 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
1415 		iscsi_dump_conn_ops(conn->conn_ops);
1416 	spin_unlock_bh(&sess->conn_lock);
1417 
1418 	iscsi_dump_sess_ops(sess->sess_ops);
1419 }
1420 
1421 static int iscsit_do_rx_data(
1422 	struct iscsi_conn *conn,
1423 	struct iscsi_data_count *count)
1424 {
1425 	int data = count->data_length, rx_loop = 0, total_rx = 0, iov_len;
1426 	struct kvec *iov_p;
1427 	struct msghdr msg;
1428 
1429 	if (!conn || !conn->sock || !conn->conn_ops)
1430 		return -1;
1431 
1432 	memset(&msg, 0, sizeof(struct msghdr));
1433 
1434 	iov_p = count->iov;
1435 	iov_len	= count->iov_count;
1436 
1437 	while (total_rx < data) {
1438 		rx_loop = kernel_recvmsg(conn->sock, &msg, iov_p, iov_len,
1439 					(data - total_rx), MSG_WAITALL);
1440 		if (rx_loop <= 0) {
1441 			pr_debug("rx_loop: %d total_rx: %d\n",
1442 				rx_loop, total_rx);
1443 			return rx_loop;
1444 		}
1445 		total_rx += rx_loop;
1446 		pr_debug("rx_loop: %d, total_rx: %d, data: %d\n",
1447 				rx_loop, total_rx, data);
1448 	}
1449 
1450 	return total_rx;
1451 }
1452 
1453 static int iscsit_do_tx_data(
1454 	struct iscsi_conn *conn,
1455 	struct iscsi_data_count *count)
1456 {
1457 	int data = count->data_length, total_tx = 0, tx_loop = 0, iov_len;
1458 	struct kvec *iov_p;
1459 	struct msghdr msg;
1460 
1461 	if (!conn || !conn->sock || !conn->conn_ops)
1462 		return -1;
1463 
1464 	if (data <= 0) {
1465 		pr_err("Data length is: %d\n", data);
1466 		return -1;
1467 	}
1468 
1469 	memset(&msg, 0, sizeof(struct msghdr));
1470 
1471 	iov_p = count->iov;
1472 	iov_len = count->iov_count;
1473 
1474 	while (total_tx < data) {
1475 		tx_loop = kernel_sendmsg(conn->sock, &msg, iov_p, iov_len,
1476 					(data - total_tx));
1477 		if (tx_loop <= 0) {
1478 			pr_debug("tx_loop: %d total_tx %d\n",
1479 				tx_loop, total_tx);
1480 			return tx_loop;
1481 		}
1482 		total_tx += tx_loop;
1483 		pr_debug("tx_loop: %d, total_tx: %d, data: %d\n",
1484 					tx_loop, total_tx, data);
1485 	}
1486 
1487 	return total_tx;
1488 }
1489 
1490 int rx_data(
1491 	struct iscsi_conn *conn,
1492 	struct kvec *iov,
1493 	int iov_count,
1494 	int data)
1495 {
1496 	struct iscsi_data_count c;
1497 
1498 	if (!conn || !conn->sock || !conn->conn_ops)
1499 		return -1;
1500 
1501 	memset(&c, 0, sizeof(struct iscsi_data_count));
1502 	c.iov = iov;
1503 	c.iov_count = iov_count;
1504 	c.data_length = data;
1505 	c.type = ISCSI_RX_DATA;
1506 
1507 	return iscsit_do_rx_data(conn, &c);
1508 }
1509 
1510 int tx_data(
1511 	struct iscsi_conn *conn,
1512 	struct kvec *iov,
1513 	int iov_count,
1514 	int data)
1515 {
1516 	struct iscsi_data_count c;
1517 
1518 	if (!conn || !conn->sock || !conn->conn_ops)
1519 		return -1;
1520 
1521 	memset(&c, 0, sizeof(struct iscsi_data_count));
1522 	c.iov = iov;
1523 	c.iov_count = iov_count;
1524 	c.data_length = data;
1525 	c.type = ISCSI_TX_DATA;
1526 
1527 	return iscsit_do_tx_data(conn, &c);
1528 }
1529 
1530 void iscsit_collect_login_stats(
1531 	struct iscsi_conn *conn,
1532 	u8 status_class,
1533 	u8 status_detail)
1534 {
1535 	struct iscsi_param *intrname = NULL;
1536 	struct iscsi_tiqn *tiqn;
1537 	struct iscsi_login_stats *ls;
1538 
1539 	tiqn = iscsit_snmp_get_tiqn(conn);
1540 	if (!tiqn)
1541 		return;
1542 
1543 	ls = &tiqn->login_stats;
1544 
1545 	spin_lock(&ls->lock);
1546 	if (!strcmp(conn->login_ip, ls->last_intr_fail_ip_addr) &&
1547 	    ((get_jiffies_64() - ls->last_fail_time) < 10)) {
1548 		/* We already have the failure info for this login */
1549 		spin_unlock(&ls->lock);
1550 		return;
1551 	}
1552 
1553 	if (status_class == ISCSI_STATUS_CLS_SUCCESS)
1554 		ls->accepts++;
1555 	else if (status_class == ISCSI_STATUS_CLS_REDIRECT) {
1556 		ls->redirects++;
1557 		ls->last_fail_type = ISCSI_LOGIN_FAIL_REDIRECT;
1558 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1559 		 (status_detail == ISCSI_LOGIN_STATUS_AUTH_FAILED)) {
1560 		ls->authenticate_fails++;
1561 		ls->last_fail_type =  ISCSI_LOGIN_FAIL_AUTHENTICATE;
1562 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1563 		 (status_detail == ISCSI_LOGIN_STATUS_TGT_FORBIDDEN)) {
1564 		ls->authorize_fails++;
1565 		ls->last_fail_type = ISCSI_LOGIN_FAIL_AUTHORIZE;
1566 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR) &&
1567 		 (status_detail == ISCSI_LOGIN_STATUS_INIT_ERR)) {
1568 		ls->negotiate_fails++;
1569 		ls->last_fail_type = ISCSI_LOGIN_FAIL_NEGOTIATE;
1570 	} else {
1571 		ls->other_fails++;
1572 		ls->last_fail_type = ISCSI_LOGIN_FAIL_OTHER;
1573 	}
1574 
1575 	/* Save initiator name, ip address and time, if it is a failed login */
1576 	if (status_class != ISCSI_STATUS_CLS_SUCCESS) {
1577 		if (conn->param_list)
1578 			intrname = iscsi_find_param_from_key(INITIATORNAME,
1579 							     conn->param_list);
1580 		strcpy(ls->last_intr_fail_name,
1581 		       (intrname ? intrname->value : "Unknown"));
1582 
1583 		ls->last_intr_fail_ip_family = conn->sock->sk->sk_family;
1584 		snprintf(ls->last_intr_fail_ip_addr, IPV6_ADDRESS_SPACE,
1585 				"%s", conn->login_ip);
1586 		ls->last_fail_time = get_jiffies_64();
1587 	}
1588 
1589 	spin_unlock(&ls->lock);
1590 }
1591 
1592 struct iscsi_tiqn *iscsit_snmp_get_tiqn(struct iscsi_conn *conn)
1593 {
1594 	struct iscsi_portal_group *tpg;
1595 
1596 	if (!conn || !conn->sess)
1597 		return NULL;
1598 
1599 	tpg = conn->sess->tpg;
1600 	if (!tpg)
1601 		return NULL;
1602 
1603 	if (!tpg->tpg_tiqn)
1604 		return NULL;
1605 
1606 	return tpg->tpg_tiqn;
1607 }
1608