1 /*******************************************************************************
2  * This file contains the iSCSI Target specific utility functions.
3  *
4  * (c) Copyright 2007-2013 Datera, Inc.
5  *
6  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  ******************************************************************************/
18 
19 #include <linux/list.h>
20 #include <linux/percpu_ida.h>
21 #include <scsi/scsi_tcq.h>
22 #include <scsi/iscsi_proto.h>
23 #include <target/target_core_base.h>
24 #include <target/target_core_fabric.h>
25 #include <target/target_core_configfs.h>
26 #include <target/iscsi/iscsi_transport.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, int state)
156 {
157 	struct iscsi_cmd *cmd;
158 	struct se_session *se_sess = conn->sess->se_sess;
159 	int size, tag;
160 
161 	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, state);
162 	if (tag < 0)
163 		return NULL;
164 
165 	size = sizeof(struct iscsi_cmd) + conn->conn_transport->priv_size;
166 	cmd = (struct iscsi_cmd *)(se_sess->sess_cmd_map + (tag * size));
167 	memset(cmd, 0, size);
168 
169 	cmd->se_cmd.map_tag = tag;
170 	cmd->conn = conn;
171 	INIT_LIST_HEAD(&cmd->i_conn_node);
172 	INIT_LIST_HEAD(&cmd->datain_list);
173 	INIT_LIST_HEAD(&cmd->cmd_r2t_list);
174 	spin_lock_init(&cmd->datain_lock);
175 	spin_lock_init(&cmd->dataout_timeout_lock);
176 	spin_lock_init(&cmd->istate_lock);
177 	spin_lock_init(&cmd->error_lock);
178 	spin_lock_init(&cmd->r2t_lock);
179 
180 	return cmd;
181 }
182 EXPORT_SYMBOL(iscsit_allocate_cmd);
183 
184 struct iscsi_seq *iscsit_get_seq_holder_for_datain(
185 	struct iscsi_cmd *cmd,
186 	u32 seq_send_order)
187 {
188 	u32 i;
189 
190 	for (i = 0; i < cmd->seq_count; i++)
191 		if (cmd->seq_list[i].seq_send_order == seq_send_order)
192 			return &cmd->seq_list[i];
193 
194 	return NULL;
195 }
196 
197 struct iscsi_seq *iscsit_get_seq_holder_for_r2t(struct iscsi_cmd *cmd)
198 {
199 	u32 i;
200 
201 	if (!cmd->seq_list) {
202 		pr_err("struct iscsi_cmd->seq_list is NULL!\n");
203 		return NULL;
204 	}
205 
206 	for (i = 0; i < cmd->seq_count; i++) {
207 		if (cmd->seq_list[i].type != SEQTYPE_NORMAL)
208 			continue;
209 		if (cmd->seq_list[i].seq_send_order == cmd->seq_send_order) {
210 			cmd->seq_send_order++;
211 			return &cmd->seq_list[i];
212 		}
213 	}
214 
215 	return NULL;
216 }
217 
218 struct iscsi_r2t *iscsit_get_holder_for_r2tsn(
219 	struct iscsi_cmd *cmd,
220 	u32 r2t_sn)
221 {
222 	struct iscsi_r2t *r2t;
223 
224 	spin_lock_bh(&cmd->r2t_lock);
225 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
226 		if (r2t->r2t_sn == r2t_sn) {
227 			spin_unlock_bh(&cmd->r2t_lock);
228 			return r2t;
229 		}
230 	}
231 	spin_unlock_bh(&cmd->r2t_lock);
232 
233 	return NULL;
234 }
235 
236 static inline int iscsit_check_received_cmdsn(struct iscsi_session *sess, u32 cmdsn)
237 {
238 	int ret;
239 
240 	/*
241 	 * This is the proper method of checking received CmdSN against
242 	 * ExpCmdSN and MaxCmdSN values, as well as accounting for out
243 	 * or order CmdSNs due to multiple connection sessions and/or
244 	 * CRC failures.
245 	 */
246 	if (iscsi_sna_gt(cmdsn, sess->max_cmd_sn)) {
247 		pr_err("Received CmdSN: 0x%08x is greater than"
248 		       " MaxCmdSN: 0x%08x, ignoring.\n", cmdsn,
249 		       sess->max_cmd_sn);
250 		ret = CMDSN_MAXCMDSN_OVERRUN;
251 
252 	} else if (cmdsn == sess->exp_cmd_sn) {
253 		sess->exp_cmd_sn++;
254 		pr_debug("Received CmdSN matches ExpCmdSN,"
255 		      " incremented ExpCmdSN to: 0x%08x\n",
256 		      sess->exp_cmd_sn);
257 		ret = CMDSN_NORMAL_OPERATION;
258 
259 	} else if (iscsi_sna_gt(cmdsn, sess->exp_cmd_sn)) {
260 		pr_debug("Received CmdSN: 0x%08x is greater"
261 		      " than ExpCmdSN: 0x%08x, not acknowledging.\n",
262 		      cmdsn, sess->exp_cmd_sn);
263 		ret = CMDSN_HIGHER_THAN_EXP;
264 
265 	} else {
266 		pr_err("Received CmdSN: 0x%08x is less than"
267 		       " ExpCmdSN: 0x%08x, ignoring.\n", cmdsn,
268 		       sess->exp_cmd_sn);
269 		ret = CMDSN_LOWER_THAN_EXP;
270 	}
271 
272 	return ret;
273 }
274 
275 /*
276  * Commands may be received out of order if MC/S is in use.
277  * Ensure they are executed in CmdSN order.
278  */
279 int iscsit_sequence_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
280 			unsigned char *buf, __be32 cmdsn)
281 {
282 	int ret, cmdsn_ret;
283 	bool reject = false;
284 	u8 reason = ISCSI_REASON_BOOKMARK_NO_RESOURCES;
285 
286 	mutex_lock(&conn->sess->cmdsn_mutex);
287 
288 	cmdsn_ret = iscsit_check_received_cmdsn(conn->sess, be32_to_cpu(cmdsn));
289 	switch (cmdsn_ret) {
290 	case CMDSN_NORMAL_OPERATION:
291 		ret = iscsit_execute_cmd(cmd, 0);
292 		if ((ret >= 0) && !list_empty(&conn->sess->sess_ooo_cmdsn_list))
293 			iscsit_execute_ooo_cmdsns(conn->sess);
294 		else if (ret < 0) {
295 			reject = true;
296 			ret = CMDSN_ERROR_CANNOT_RECOVER;
297 		}
298 		break;
299 	case CMDSN_HIGHER_THAN_EXP:
300 		ret = iscsit_handle_ooo_cmdsn(conn->sess, cmd, be32_to_cpu(cmdsn));
301 		if (ret < 0) {
302 			reject = true;
303 			ret = CMDSN_ERROR_CANNOT_RECOVER;
304 			break;
305 		}
306 		ret = CMDSN_HIGHER_THAN_EXP;
307 		break;
308 	case CMDSN_LOWER_THAN_EXP:
309 	case CMDSN_MAXCMDSN_OVERRUN:
310 	default:
311 		cmd->i_state = ISTATE_REMOVE;
312 		iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
313 		/*
314 		 * Existing callers for iscsit_sequence_cmd() will silently
315 		 * ignore commands with CMDSN_LOWER_THAN_EXP, so force this
316 		 * return for CMDSN_MAXCMDSN_OVERRUN as well..
317 		 */
318 		ret = CMDSN_LOWER_THAN_EXP;
319 		break;
320 	}
321 	mutex_unlock(&conn->sess->cmdsn_mutex);
322 
323 	if (reject)
324 		iscsit_reject_cmd(cmd, reason, buf);
325 
326 	return ret;
327 }
328 EXPORT_SYMBOL(iscsit_sequence_cmd);
329 
330 int iscsit_check_unsolicited_dataout(struct iscsi_cmd *cmd, unsigned char *buf)
331 {
332 	struct iscsi_conn *conn = cmd->conn;
333 	struct se_cmd *se_cmd = &cmd->se_cmd;
334 	struct iscsi_data *hdr = (struct iscsi_data *) buf;
335 	u32 payload_length = ntoh24(hdr->dlength);
336 
337 	if (conn->sess->sess_ops->InitialR2T) {
338 		pr_err("Received unexpected unsolicited data"
339 			" while InitialR2T=Yes, protocol error.\n");
340 		transport_send_check_condition_and_sense(se_cmd,
341 				TCM_UNEXPECTED_UNSOLICITED_DATA, 0);
342 		return -1;
343 	}
344 
345 	if ((cmd->first_burst_len + payload_length) >
346 	     conn->sess->sess_ops->FirstBurstLength) {
347 		pr_err("Total %u bytes exceeds FirstBurstLength: %u"
348 			" for this Unsolicited DataOut Burst.\n",
349 			(cmd->first_burst_len + payload_length),
350 				conn->sess->sess_ops->FirstBurstLength);
351 		transport_send_check_condition_and_sense(se_cmd,
352 				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
353 		return -1;
354 	}
355 
356 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL))
357 		return 0;
358 
359 	if (((cmd->first_burst_len + payload_length) != cmd->se_cmd.data_length) &&
360 	    ((cmd->first_burst_len + payload_length) !=
361 	      conn->sess->sess_ops->FirstBurstLength)) {
362 		pr_err("Unsolicited non-immediate data received %u"
363 			" does not equal FirstBurstLength: %u, and does"
364 			" not equal ExpXferLen %u.\n",
365 			(cmd->first_burst_len + payload_length),
366 			conn->sess->sess_ops->FirstBurstLength, cmd->se_cmd.data_length);
367 		transport_send_check_condition_and_sense(se_cmd,
368 				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
369 		return -1;
370 	}
371 	return 0;
372 }
373 
374 struct iscsi_cmd *iscsit_find_cmd_from_itt(
375 	struct iscsi_conn *conn,
376 	itt_t init_task_tag)
377 {
378 	struct iscsi_cmd *cmd;
379 
380 	spin_lock_bh(&conn->cmd_lock);
381 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
382 		if (cmd->init_task_tag == init_task_tag) {
383 			spin_unlock_bh(&conn->cmd_lock);
384 			return cmd;
385 		}
386 	}
387 	spin_unlock_bh(&conn->cmd_lock);
388 
389 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu",
390 			init_task_tag, conn->cid);
391 	return NULL;
392 }
393 
394 struct iscsi_cmd *iscsit_find_cmd_from_itt_or_dump(
395 	struct iscsi_conn *conn,
396 	itt_t init_task_tag,
397 	u32 length)
398 {
399 	struct iscsi_cmd *cmd;
400 
401 	spin_lock_bh(&conn->cmd_lock);
402 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
403 		if (cmd->init_task_tag == init_task_tag) {
404 			spin_unlock_bh(&conn->cmd_lock);
405 			return cmd;
406 		}
407 	}
408 	spin_unlock_bh(&conn->cmd_lock);
409 
410 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu,"
411 			" dumping payload\n", init_task_tag, conn->cid);
412 	if (length)
413 		iscsit_dump_data_payload(conn, length, 1);
414 
415 	return NULL;
416 }
417 
418 struct iscsi_cmd *iscsit_find_cmd_from_ttt(
419 	struct iscsi_conn *conn,
420 	u32 targ_xfer_tag)
421 {
422 	struct iscsi_cmd *cmd = NULL;
423 
424 	spin_lock_bh(&conn->cmd_lock);
425 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
426 		if (cmd->targ_xfer_tag == targ_xfer_tag) {
427 			spin_unlock_bh(&conn->cmd_lock);
428 			return cmd;
429 		}
430 	}
431 	spin_unlock_bh(&conn->cmd_lock);
432 
433 	pr_err("Unable to locate TTT: 0x%08x on CID: %hu\n",
434 			targ_xfer_tag, conn->cid);
435 	return NULL;
436 }
437 
438 int iscsit_find_cmd_for_recovery(
439 	struct iscsi_session *sess,
440 	struct iscsi_cmd **cmd_ptr,
441 	struct iscsi_conn_recovery **cr_ptr,
442 	itt_t init_task_tag)
443 {
444 	struct iscsi_cmd *cmd = NULL;
445 	struct iscsi_conn_recovery *cr;
446 	/*
447 	 * Scan through the inactive connection recovery list's command list.
448 	 * If init_task_tag matches the command is still alligent.
449 	 */
450 	spin_lock(&sess->cr_i_lock);
451 	list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
452 		spin_lock(&cr->conn_recovery_cmd_lock);
453 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
454 			if (cmd->init_task_tag == init_task_tag) {
455 				spin_unlock(&cr->conn_recovery_cmd_lock);
456 				spin_unlock(&sess->cr_i_lock);
457 
458 				*cr_ptr = cr;
459 				*cmd_ptr = cmd;
460 				return -2;
461 			}
462 		}
463 		spin_unlock(&cr->conn_recovery_cmd_lock);
464 	}
465 	spin_unlock(&sess->cr_i_lock);
466 	/*
467 	 * Scan through the active connection recovery list's command list.
468 	 * If init_task_tag matches the command is ready to be reassigned.
469 	 */
470 	spin_lock(&sess->cr_a_lock);
471 	list_for_each_entry(cr, &sess->cr_active_list, cr_list) {
472 		spin_lock(&cr->conn_recovery_cmd_lock);
473 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
474 			if (cmd->init_task_tag == init_task_tag) {
475 				spin_unlock(&cr->conn_recovery_cmd_lock);
476 				spin_unlock(&sess->cr_a_lock);
477 
478 				*cr_ptr = cr;
479 				*cmd_ptr = cmd;
480 				return 0;
481 			}
482 		}
483 		spin_unlock(&cr->conn_recovery_cmd_lock);
484 	}
485 	spin_unlock(&sess->cr_a_lock);
486 
487 	return -1;
488 }
489 
490 void iscsit_add_cmd_to_immediate_queue(
491 	struct iscsi_cmd *cmd,
492 	struct iscsi_conn *conn,
493 	u8 state)
494 {
495 	struct iscsi_queue_req *qr;
496 
497 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
498 	if (!qr) {
499 		pr_err("Unable to allocate memory for"
500 				" struct iscsi_queue_req\n");
501 		return;
502 	}
503 	INIT_LIST_HEAD(&qr->qr_list);
504 	qr->cmd = cmd;
505 	qr->state = state;
506 
507 	spin_lock_bh(&conn->immed_queue_lock);
508 	list_add_tail(&qr->qr_list, &conn->immed_queue_list);
509 	atomic_inc(&cmd->immed_queue_count);
510 	atomic_set(&conn->check_immediate_queue, 1);
511 	spin_unlock_bh(&conn->immed_queue_lock);
512 
513 	wake_up(&conn->queues_wq);
514 }
515 
516 struct iscsi_queue_req *iscsit_get_cmd_from_immediate_queue(struct iscsi_conn *conn)
517 {
518 	struct iscsi_queue_req *qr;
519 
520 	spin_lock_bh(&conn->immed_queue_lock);
521 	if (list_empty(&conn->immed_queue_list)) {
522 		spin_unlock_bh(&conn->immed_queue_lock);
523 		return NULL;
524 	}
525 	qr = list_first_entry(&conn->immed_queue_list,
526 			      struct iscsi_queue_req, qr_list);
527 
528 	list_del(&qr->qr_list);
529 	if (qr->cmd)
530 		atomic_dec(&qr->cmd->immed_queue_count);
531 	spin_unlock_bh(&conn->immed_queue_lock);
532 
533 	return qr;
534 }
535 
536 static void iscsit_remove_cmd_from_immediate_queue(
537 	struct iscsi_cmd *cmd,
538 	struct iscsi_conn *conn)
539 {
540 	struct iscsi_queue_req *qr, *qr_tmp;
541 
542 	spin_lock_bh(&conn->immed_queue_lock);
543 	if (!atomic_read(&cmd->immed_queue_count)) {
544 		spin_unlock_bh(&conn->immed_queue_lock);
545 		return;
546 	}
547 
548 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
549 		if (qr->cmd != cmd)
550 			continue;
551 
552 		atomic_dec(&qr->cmd->immed_queue_count);
553 		list_del(&qr->qr_list);
554 		kmem_cache_free(lio_qr_cache, qr);
555 	}
556 	spin_unlock_bh(&conn->immed_queue_lock);
557 
558 	if (atomic_read(&cmd->immed_queue_count)) {
559 		pr_err("ITT: 0x%08x immed_queue_count: %d\n",
560 			cmd->init_task_tag,
561 			atomic_read(&cmd->immed_queue_count));
562 	}
563 }
564 
565 void iscsit_add_cmd_to_response_queue(
566 	struct iscsi_cmd *cmd,
567 	struct iscsi_conn *conn,
568 	u8 state)
569 {
570 	struct iscsi_queue_req *qr;
571 
572 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
573 	if (!qr) {
574 		pr_err("Unable to allocate memory for"
575 			" struct iscsi_queue_req\n");
576 		return;
577 	}
578 	INIT_LIST_HEAD(&qr->qr_list);
579 	qr->cmd = cmd;
580 	qr->state = state;
581 
582 	spin_lock_bh(&conn->response_queue_lock);
583 	list_add_tail(&qr->qr_list, &conn->response_queue_list);
584 	atomic_inc(&cmd->response_queue_count);
585 	spin_unlock_bh(&conn->response_queue_lock);
586 
587 	wake_up(&conn->queues_wq);
588 }
589 
590 struct iscsi_queue_req *iscsit_get_cmd_from_response_queue(struct iscsi_conn *conn)
591 {
592 	struct iscsi_queue_req *qr;
593 
594 	spin_lock_bh(&conn->response_queue_lock);
595 	if (list_empty(&conn->response_queue_list)) {
596 		spin_unlock_bh(&conn->response_queue_lock);
597 		return NULL;
598 	}
599 
600 	qr = list_first_entry(&conn->response_queue_list,
601 			      struct iscsi_queue_req, qr_list);
602 
603 	list_del(&qr->qr_list);
604 	if (qr->cmd)
605 		atomic_dec(&qr->cmd->response_queue_count);
606 	spin_unlock_bh(&conn->response_queue_lock);
607 
608 	return qr;
609 }
610 
611 static void iscsit_remove_cmd_from_response_queue(
612 	struct iscsi_cmd *cmd,
613 	struct iscsi_conn *conn)
614 {
615 	struct iscsi_queue_req *qr, *qr_tmp;
616 
617 	spin_lock_bh(&conn->response_queue_lock);
618 	if (!atomic_read(&cmd->response_queue_count)) {
619 		spin_unlock_bh(&conn->response_queue_lock);
620 		return;
621 	}
622 
623 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
624 				qr_list) {
625 		if (qr->cmd != cmd)
626 			continue;
627 
628 		atomic_dec(&qr->cmd->response_queue_count);
629 		list_del(&qr->qr_list);
630 		kmem_cache_free(lio_qr_cache, qr);
631 	}
632 	spin_unlock_bh(&conn->response_queue_lock);
633 
634 	if (atomic_read(&cmd->response_queue_count)) {
635 		pr_err("ITT: 0x%08x response_queue_count: %d\n",
636 			cmd->init_task_tag,
637 			atomic_read(&cmd->response_queue_count));
638 	}
639 }
640 
641 bool iscsit_conn_all_queues_empty(struct iscsi_conn *conn)
642 {
643 	bool empty;
644 
645 	spin_lock_bh(&conn->immed_queue_lock);
646 	empty = list_empty(&conn->immed_queue_list);
647 	spin_unlock_bh(&conn->immed_queue_lock);
648 
649 	if (!empty)
650 		return empty;
651 
652 	spin_lock_bh(&conn->response_queue_lock);
653 	empty = list_empty(&conn->response_queue_list);
654 	spin_unlock_bh(&conn->response_queue_lock);
655 
656 	return empty;
657 }
658 
659 void iscsit_free_queue_reqs_for_conn(struct iscsi_conn *conn)
660 {
661 	struct iscsi_queue_req *qr, *qr_tmp;
662 
663 	spin_lock_bh(&conn->immed_queue_lock);
664 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
665 		list_del(&qr->qr_list);
666 		if (qr->cmd)
667 			atomic_dec(&qr->cmd->immed_queue_count);
668 
669 		kmem_cache_free(lio_qr_cache, qr);
670 	}
671 	spin_unlock_bh(&conn->immed_queue_lock);
672 
673 	spin_lock_bh(&conn->response_queue_lock);
674 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
675 			qr_list) {
676 		list_del(&qr->qr_list);
677 		if (qr->cmd)
678 			atomic_dec(&qr->cmd->response_queue_count);
679 
680 		kmem_cache_free(lio_qr_cache, qr);
681 	}
682 	spin_unlock_bh(&conn->response_queue_lock);
683 }
684 
685 void iscsit_release_cmd(struct iscsi_cmd *cmd)
686 {
687 	struct iscsi_session *sess;
688 	struct se_cmd *se_cmd = &cmd->se_cmd;
689 
690 	if (cmd->conn)
691 		sess = cmd->conn->sess;
692 	else
693 		sess = cmd->sess;
694 
695 	BUG_ON(!sess || !sess->se_sess);
696 
697 	kfree(cmd->buf_ptr);
698 	kfree(cmd->pdu_list);
699 	kfree(cmd->seq_list);
700 	kfree(cmd->tmr_req);
701 	kfree(cmd->iov_data);
702 	kfree(cmd->text_in_ptr);
703 
704 	percpu_ida_free(&sess->se_sess->sess_tag_pool, se_cmd->map_tag);
705 }
706 EXPORT_SYMBOL(iscsit_release_cmd);
707 
708 void __iscsit_free_cmd(struct iscsi_cmd *cmd, bool scsi_cmd,
709 		       bool check_queues)
710 {
711 	struct iscsi_conn *conn = cmd->conn;
712 
713 	if (scsi_cmd) {
714 		if (cmd->data_direction == DMA_TO_DEVICE) {
715 			iscsit_stop_dataout_timer(cmd);
716 			iscsit_free_r2ts_from_list(cmd);
717 		}
718 		if (cmd->data_direction == DMA_FROM_DEVICE)
719 			iscsit_free_all_datain_reqs(cmd);
720 	}
721 
722 	if (conn && check_queues) {
723 		iscsit_remove_cmd_from_immediate_queue(cmd, conn);
724 		iscsit_remove_cmd_from_response_queue(cmd, conn);
725 	}
726 }
727 
728 void iscsit_free_cmd(struct iscsi_cmd *cmd, bool shutdown)
729 {
730 	struct se_cmd *se_cmd = NULL;
731 	int rc;
732 	/*
733 	 * Determine if a struct se_cmd is associated with
734 	 * this struct iscsi_cmd.
735 	 */
736 	switch (cmd->iscsi_opcode) {
737 	case ISCSI_OP_SCSI_CMD:
738 		se_cmd = &cmd->se_cmd;
739 		__iscsit_free_cmd(cmd, true, shutdown);
740 		/*
741 		 * Fallthrough
742 		 */
743 	case ISCSI_OP_SCSI_TMFUNC:
744 		rc = transport_generic_free_cmd(&cmd->se_cmd, shutdown);
745 		if (!rc && shutdown && se_cmd && se_cmd->se_sess) {
746 			__iscsit_free_cmd(cmd, true, shutdown);
747 			target_put_sess_cmd(se_cmd->se_sess, se_cmd);
748 		}
749 		break;
750 	case ISCSI_OP_REJECT:
751 		/*
752 		 * Handle special case for REJECT when iscsi_add_reject*() has
753 		 * overwritten the original iscsi_opcode assignment, and the
754 		 * associated cmd->se_cmd needs to be released.
755 		 */
756 		if (cmd->se_cmd.se_tfo != NULL) {
757 			se_cmd = &cmd->se_cmd;
758 			__iscsit_free_cmd(cmd, true, shutdown);
759 
760 			rc = transport_generic_free_cmd(&cmd->se_cmd, shutdown);
761 			if (!rc && shutdown && se_cmd->se_sess) {
762 				__iscsit_free_cmd(cmd, true, shutdown);
763 				target_put_sess_cmd(se_cmd->se_sess, se_cmd);
764 			}
765 			break;
766 		}
767 		/* Fall-through */
768 	default:
769 		__iscsit_free_cmd(cmd, false, shutdown);
770 		iscsit_release_cmd(cmd);
771 		break;
772 	}
773 }
774 
775 int iscsit_check_session_usage_count(struct iscsi_session *sess)
776 {
777 	spin_lock_bh(&sess->session_usage_lock);
778 	if (sess->session_usage_count != 0) {
779 		sess->session_waiting_on_uc = 1;
780 		spin_unlock_bh(&sess->session_usage_lock);
781 		if (in_interrupt())
782 			return 2;
783 
784 		wait_for_completion(&sess->session_waiting_on_uc_comp);
785 		return 1;
786 	}
787 	spin_unlock_bh(&sess->session_usage_lock);
788 
789 	return 0;
790 }
791 
792 void iscsit_dec_session_usage_count(struct iscsi_session *sess)
793 {
794 	spin_lock_bh(&sess->session_usage_lock);
795 	sess->session_usage_count--;
796 
797 	if (!sess->session_usage_count && sess->session_waiting_on_uc)
798 		complete(&sess->session_waiting_on_uc_comp);
799 
800 	spin_unlock_bh(&sess->session_usage_lock);
801 }
802 
803 void iscsit_inc_session_usage_count(struct iscsi_session *sess)
804 {
805 	spin_lock_bh(&sess->session_usage_lock);
806 	sess->session_usage_count++;
807 	spin_unlock_bh(&sess->session_usage_lock);
808 }
809 
810 /*
811  *	Setup conn->if_marker and conn->of_marker values based upon
812  *	the initial marker-less interval. (see iSCSI v19 A.2)
813  */
814 int iscsit_set_sync_and_steering_values(struct iscsi_conn *conn)
815 {
816 	int login_ifmarker_count = 0, login_ofmarker_count = 0, next_marker = 0;
817 	/*
818 	 * IFMarkInt and OFMarkInt are negotiated as 32-bit words.
819 	 */
820 	u32 IFMarkInt = (conn->conn_ops->IFMarkInt * 4);
821 	u32 OFMarkInt = (conn->conn_ops->OFMarkInt * 4);
822 
823 	if (conn->conn_ops->OFMarker) {
824 		/*
825 		 * Account for the first Login Command received not
826 		 * via iscsi_recv_msg().
827 		 */
828 		conn->of_marker += ISCSI_HDR_LEN;
829 		if (conn->of_marker <= OFMarkInt) {
830 			conn->of_marker = (OFMarkInt - conn->of_marker);
831 		} else {
832 			login_ofmarker_count = (conn->of_marker / OFMarkInt);
833 			next_marker = (OFMarkInt * (login_ofmarker_count + 1)) +
834 					(login_ofmarker_count * MARKER_SIZE);
835 			conn->of_marker = (next_marker - conn->of_marker);
836 		}
837 		conn->of_marker_offset = 0;
838 		pr_debug("Setting OFMarker value to %u based on Initial"
839 			" Markerless Interval.\n", conn->of_marker);
840 	}
841 
842 	if (conn->conn_ops->IFMarker) {
843 		if (conn->if_marker <= IFMarkInt) {
844 			conn->if_marker = (IFMarkInt - conn->if_marker);
845 		} else {
846 			login_ifmarker_count = (conn->if_marker / IFMarkInt);
847 			next_marker = (IFMarkInt * (login_ifmarker_count + 1)) +
848 					(login_ifmarker_count * MARKER_SIZE);
849 			conn->if_marker = (next_marker - conn->if_marker);
850 		}
851 		pr_debug("Setting IFMarker value to %u based on Initial"
852 			" Markerless Interval.\n", conn->if_marker);
853 	}
854 
855 	return 0;
856 }
857 
858 struct iscsi_conn *iscsit_get_conn_from_cid(struct iscsi_session *sess, u16 cid)
859 {
860 	struct iscsi_conn *conn;
861 
862 	spin_lock_bh(&sess->conn_lock);
863 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
864 		if ((conn->cid == cid) &&
865 		    (conn->conn_state == TARG_CONN_STATE_LOGGED_IN)) {
866 			iscsit_inc_conn_usage_count(conn);
867 			spin_unlock_bh(&sess->conn_lock);
868 			return conn;
869 		}
870 	}
871 	spin_unlock_bh(&sess->conn_lock);
872 
873 	return NULL;
874 }
875 
876 struct iscsi_conn *iscsit_get_conn_from_cid_rcfr(struct iscsi_session *sess, u16 cid)
877 {
878 	struct iscsi_conn *conn;
879 
880 	spin_lock_bh(&sess->conn_lock);
881 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
882 		if (conn->cid == cid) {
883 			iscsit_inc_conn_usage_count(conn);
884 			spin_lock(&conn->state_lock);
885 			atomic_set(&conn->connection_wait_rcfr, 1);
886 			spin_unlock(&conn->state_lock);
887 			spin_unlock_bh(&sess->conn_lock);
888 			return conn;
889 		}
890 	}
891 	spin_unlock_bh(&sess->conn_lock);
892 
893 	return NULL;
894 }
895 
896 void iscsit_check_conn_usage_count(struct iscsi_conn *conn)
897 {
898 	spin_lock_bh(&conn->conn_usage_lock);
899 	if (conn->conn_usage_count != 0) {
900 		conn->conn_waiting_on_uc = 1;
901 		spin_unlock_bh(&conn->conn_usage_lock);
902 
903 		wait_for_completion(&conn->conn_waiting_on_uc_comp);
904 		return;
905 	}
906 	spin_unlock_bh(&conn->conn_usage_lock);
907 }
908 
909 void iscsit_dec_conn_usage_count(struct iscsi_conn *conn)
910 {
911 	spin_lock_bh(&conn->conn_usage_lock);
912 	conn->conn_usage_count--;
913 
914 	if (!conn->conn_usage_count && conn->conn_waiting_on_uc)
915 		complete(&conn->conn_waiting_on_uc_comp);
916 
917 	spin_unlock_bh(&conn->conn_usage_lock);
918 }
919 
920 void iscsit_inc_conn_usage_count(struct iscsi_conn *conn)
921 {
922 	spin_lock_bh(&conn->conn_usage_lock);
923 	conn->conn_usage_count++;
924 	spin_unlock_bh(&conn->conn_usage_lock);
925 }
926 
927 static int iscsit_add_nopin(struct iscsi_conn *conn, int want_response)
928 {
929 	u8 state;
930 	struct iscsi_cmd *cmd;
931 
932 	cmd = iscsit_allocate_cmd(conn, TASK_RUNNING);
933 	if (!cmd)
934 		return -1;
935 
936 	cmd->iscsi_opcode = ISCSI_OP_NOOP_IN;
937 	state = (want_response) ? ISTATE_SEND_NOPIN_WANT_RESPONSE :
938 				ISTATE_SEND_NOPIN_NO_RESPONSE;
939 	cmd->init_task_tag = RESERVED_ITT;
940 	spin_lock_bh(&conn->sess->ttt_lock);
941 	cmd->targ_xfer_tag = (want_response) ? conn->sess->targ_xfer_tag++ :
942 			0xFFFFFFFF;
943 	if (want_response && (cmd->targ_xfer_tag == 0xFFFFFFFF))
944 		cmd->targ_xfer_tag = conn->sess->targ_xfer_tag++;
945 	spin_unlock_bh(&conn->sess->ttt_lock);
946 
947 	spin_lock_bh(&conn->cmd_lock);
948 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
949 	spin_unlock_bh(&conn->cmd_lock);
950 
951 	if (want_response)
952 		iscsit_start_nopin_response_timer(conn);
953 	iscsit_add_cmd_to_immediate_queue(cmd, conn, state);
954 
955 	return 0;
956 }
957 
958 static void iscsit_handle_nopin_response_timeout(unsigned long data)
959 {
960 	struct iscsi_conn *conn = (struct iscsi_conn *) data;
961 
962 	iscsit_inc_conn_usage_count(conn);
963 
964 	spin_lock_bh(&conn->nopin_timer_lock);
965 	if (conn->nopin_response_timer_flags & ISCSI_TF_STOP) {
966 		spin_unlock_bh(&conn->nopin_timer_lock);
967 		iscsit_dec_conn_usage_count(conn);
968 		return;
969 	}
970 
971 	pr_debug("Did not receive response to NOPIN on CID: %hu on"
972 		" SID: %u, failing connection.\n", conn->cid,
973 			conn->sess->sid);
974 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
975 	spin_unlock_bh(&conn->nopin_timer_lock);
976 
977 	{
978 	struct iscsi_portal_group *tpg = conn->sess->tpg;
979 	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
980 
981 	if (tiqn) {
982 		spin_lock_bh(&tiqn->sess_err_stats.lock);
983 		strcpy(tiqn->sess_err_stats.last_sess_fail_rem_name,
984 				conn->sess->sess_ops->InitiatorName);
985 		tiqn->sess_err_stats.last_sess_failure_type =
986 				ISCSI_SESS_ERR_CXN_TIMEOUT;
987 		tiqn->sess_err_stats.cxn_timeout_errors++;
988 		atomic_long_inc(&conn->sess->conn_timeout_errors);
989 		spin_unlock_bh(&tiqn->sess_err_stats.lock);
990 	}
991 	}
992 
993 	iscsit_cause_connection_reinstatement(conn, 0);
994 	iscsit_dec_conn_usage_count(conn);
995 }
996 
997 void iscsit_mod_nopin_response_timer(struct iscsi_conn *conn)
998 {
999 	struct iscsi_session *sess = conn->sess;
1000 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1001 
1002 	spin_lock_bh(&conn->nopin_timer_lock);
1003 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
1004 		spin_unlock_bh(&conn->nopin_timer_lock);
1005 		return;
1006 	}
1007 
1008 	mod_timer(&conn->nopin_response_timer,
1009 		(get_jiffies_64() + na->nopin_response_timeout * HZ));
1010 	spin_unlock_bh(&conn->nopin_timer_lock);
1011 }
1012 
1013 /*
1014  *	Called with conn->nopin_timer_lock held.
1015  */
1016 void iscsit_start_nopin_response_timer(struct iscsi_conn *conn)
1017 {
1018 	struct iscsi_session *sess = conn->sess;
1019 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1020 
1021 	spin_lock_bh(&conn->nopin_timer_lock);
1022 	if (conn->nopin_response_timer_flags & ISCSI_TF_RUNNING) {
1023 		spin_unlock_bh(&conn->nopin_timer_lock);
1024 		return;
1025 	}
1026 
1027 	init_timer(&conn->nopin_response_timer);
1028 	conn->nopin_response_timer.expires =
1029 		(get_jiffies_64() + na->nopin_response_timeout * HZ);
1030 	conn->nopin_response_timer.data = (unsigned long)conn;
1031 	conn->nopin_response_timer.function = iscsit_handle_nopin_response_timeout;
1032 	conn->nopin_response_timer_flags &= ~ISCSI_TF_STOP;
1033 	conn->nopin_response_timer_flags |= ISCSI_TF_RUNNING;
1034 	add_timer(&conn->nopin_response_timer);
1035 
1036 	pr_debug("Started NOPIN Response Timer on CID: %d to %u"
1037 		" seconds\n", conn->cid, na->nopin_response_timeout);
1038 	spin_unlock_bh(&conn->nopin_timer_lock);
1039 }
1040 
1041 void iscsit_stop_nopin_response_timer(struct iscsi_conn *conn)
1042 {
1043 	spin_lock_bh(&conn->nopin_timer_lock);
1044 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
1045 		spin_unlock_bh(&conn->nopin_timer_lock);
1046 		return;
1047 	}
1048 	conn->nopin_response_timer_flags |= ISCSI_TF_STOP;
1049 	spin_unlock_bh(&conn->nopin_timer_lock);
1050 
1051 	del_timer_sync(&conn->nopin_response_timer);
1052 
1053 	spin_lock_bh(&conn->nopin_timer_lock);
1054 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
1055 	spin_unlock_bh(&conn->nopin_timer_lock);
1056 }
1057 
1058 static void iscsit_handle_nopin_timeout(unsigned long data)
1059 {
1060 	struct iscsi_conn *conn = (struct iscsi_conn *) data;
1061 
1062 	iscsit_inc_conn_usage_count(conn);
1063 
1064 	spin_lock_bh(&conn->nopin_timer_lock);
1065 	if (conn->nopin_timer_flags & ISCSI_TF_STOP) {
1066 		spin_unlock_bh(&conn->nopin_timer_lock);
1067 		iscsit_dec_conn_usage_count(conn);
1068 		return;
1069 	}
1070 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1071 	spin_unlock_bh(&conn->nopin_timer_lock);
1072 
1073 	iscsit_add_nopin(conn, 1);
1074 	iscsit_dec_conn_usage_count(conn);
1075 }
1076 
1077 /*
1078  * Called with conn->nopin_timer_lock held.
1079  */
1080 void __iscsit_start_nopin_timer(struct iscsi_conn *conn)
1081 {
1082 	struct iscsi_session *sess = conn->sess;
1083 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1084 	/*
1085 	* NOPIN timeout is disabled.
1086 	 */
1087 	if (!na->nopin_timeout)
1088 		return;
1089 
1090 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING)
1091 		return;
1092 
1093 	init_timer(&conn->nopin_timer);
1094 	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1095 	conn->nopin_timer.data = (unsigned long)conn;
1096 	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1097 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1098 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1099 	add_timer(&conn->nopin_timer);
1100 
1101 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1102 		" interval\n", conn->cid, na->nopin_timeout);
1103 }
1104 
1105 void iscsit_start_nopin_timer(struct iscsi_conn *conn)
1106 {
1107 	struct iscsi_session *sess = conn->sess;
1108 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1109 	/*
1110 	 * NOPIN timeout is disabled..
1111 	 */
1112 	if (!na->nopin_timeout)
1113 		return;
1114 
1115 	spin_lock_bh(&conn->nopin_timer_lock);
1116 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING) {
1117 		spin_unlock_bh(&conn->nopin_timer_lock);
1118 		return;
1119 	}
1120 
1121 	init_timer(&conn->nopin_timer);
1122 	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1123 	conn->nopin_timer.data = (unsigned long)conn;
1124 	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1125 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1126 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1127 	add_timer(&conn->nopin_timer);
1128 
1129 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1130 			" interval\n", conn->cid, na->nopin_timeout);
1131 	spin_unlock_bh(&conn->nopin_timer_lock);
1132 }
1133 
1134 void iscsit_stop_nopin_timer(struct iscsi_conn *conn)
1135 {
1136 	spin_lock_bh(&conn->nopin_timer_lock);
1137 	if (!(conn->nopin_timer_flags & ISCSI_TF_RUNNING)) {
1138 		spin_unlock_bh(&conn->nopin_timer_lock);
1139 		return;
1140 	}
1141 	conn->nopin_timer_flags |= ISCSI_TF_STOP;
1142 	spin_unlock_bh(&conn->nopin_timer_lock);
1143 
1144 	del_timer_sync(&conn->nopin_timer);
1145 
1146 	spin_lock_bh(&conn->nopin_timer_lock);
1147 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1148 	spin_unlock_bh(&conn->nopin_timer_lock);
1149 }
1150 
1151 int iscsit_send_tx_data(
1152 	struct iscsi_cmd *cmd,
1153 	struct iscsi_conn *conn,
1154 	int use_misc)
1155 {
1156 	int tx_sent, tx_size;
1157 	u32 iov_count;
1158 	struct kvec *iov;
1159 
1160 send_data:
1161 	tx_size = cmd->tx_size;
1162 
1163 	if (!use_misc) {
1164 		iov = &cmd->iov_data[0];
1165 		iov_count = cmd->iov_data_count;
1166 	} else {
1167 		iov = &cmd->iov_misc[0];
1168 		iov_count = cmd->iov_misc_count;
1169 	}
1170 
1171 	tx_sent = tx_data(conn, &iov[0], iov_count, tx_size);
1172 	if (tx_size != tx_sent) {
1173 		if (tx_sent == -EAGAIN) {
1174 			pr_err("tx_data() returned -EAGAIN\n");
1175 			goto send_data;
1176 		} else
1177 			return -1;
1178 	}
1179 	cmd->tx_size = 0;
1180 
1181 	return 0;
1182 }
1183 
1184 int iscsit_fe_sendpage_sg(
1185 	struct iscsi_cmd *cmd,
1186 	struct iscsi_conn *conn)
1187 {
1188 	struct scatterlist *sg = cmd->first_data_sg;
1189 	struct kvec iov;
1190 	u32 tx_hdr_size, data_len;
1191 	u32 offset = cmd->first_data_sg_off;
1192 	int tx_sent, iov_off;
1193 
1194 send_hdr:
1195 	tx_hdr_size = ISCSI_HDR_LEN;
1196 	if (conn->conn_ops->HeaderDigest)
1197 		tx_hdr_size += ISCSI_CRC_LEN;
1198 
1199 	iov.iov_base = cmd->pdu;
1200 	iov.iov_len = tx_hdr_size;
1201 
1202 	tx_sent = tx_data(conn, &iov, 1, tx_hdr_size);
1203 	if (tx_hdr_size != tx_sent) {
1204 		if (tx_sent == -EAGAIN) {
1205 			pr_err("tx_data() returned -EAGAIN\n");
1206 			goto send_hdr;
1207 		}
1208 		return -1;
1209 	}
1210 
1211 	data_len = cmd->tx_size - tx_hdr_size - cmd->padding;
1212 	/*
1213 	 * Set iov_off used by padding and data digest tx_data() calls below
1214 	 * in order to determine proper offset into cmd->iov_data[]
1215 	 */
1216 	if (conn->conn_ops->DataDigest) {
1217 		data_len -= ISCSI_CRC_LEN;
1218 		if (cmd->padding)
1219 			iov_off = (cmd->iov_data_count - 2);
1220 		else
1221 			iov_off = (cmd->iov_data_count - 1);
1222 	} else {
1223 		iov_off = (cmd->iov_data_count - 1);
1224 	}
1225 	/*
1226 	 * Perform sendpage() for each page in the scatterlist
1227 	 */
1228 	while (data_len) {
1229 		u32 space = (sg->length - offset);
1230 		u32 sub_len = min_t(u32, data_len, space);
1231 send_pg:
1232 		tx_sent = conn->sock->ops->sendpage(conn->sock,
1233 					sg_page(sg), sg->offset + offset, sub_len, 0);
1234 		if (tx_sent != sub_len) {
1235 			if (tx_sent == -EAGAIN) {
1236 				pr_err("tcp_sendpage() returned"
1237 						" -EAGAIN\n");
1238 				goto send_pg;
1239 			}
1240 
1241 			pr_err("tcp_sendpage() failure: %d\n",
1242 					tx_sent);
1243 			return -1;
1244 		}
1245 
1246 		data_len -= sub_len;
1247 		offset = 0;
1248 		sg = sg_next(sg);
1249 	}
1250 
1251 send_padding:
1252 	if (cmd->padding) {
1253 		struct kvec *iov_p = &cmd->iov_data[iov_off++];
1254 
1255 		tx_sent = tx_data(conn, iov_p, 1, cmd->padding);
1256 		if (cmd->padding != tx_sent) {
1257 			if (tx_sent == -EAGAIN) {
1258 				pr_err("tx_data() returned -EAGAIN\n");
1259 				goto send_padding;
1260 			}
1261 			return -1;
1262 		}
1263 	}
1264 
1265 send_datacrc:
1266 	if (conn->conn_ops->DataDigest) {
1267 		struct kvec *iov_d = &cmd->iov_data[iov_off];
1268 
1269 		tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN);
1270 		if (ISCSI_CRC_LEN != tx_sent) {
1271 			if (tx_sent == -EAGAIN) {
1272 				pr_err("tx_data() returned -EAGAIN\n");
1273 				goto send_datacrc;
1274 			}
1275 			return -1;
1276 		}
1277 	}
1278 
1279 	return 0;
1280 }
1281 
1282 /*
1283  *      This function is used for mainly sending a ISCSI_TARG_LOGIN_RSP PDU
1284  *      back to the Initiator when an expection condition occurs with the
1285  *      errors set in status_class and status_detail.
1286  *
1287  *      Parameters:     iSCSI Connection, Status Class, Status Detail.
1288  *      Returns:        0 on success, -1 on error.
1289  */
1290 int iscsit_tx_login_rsp(struct iscsi_conn *conn, u8 status_class, u8 status_detail)
1291 {
1292 	struct iscsi_login_rsp *hdr;
1293 	struct iscsi_login *login = conn->conn_login;
1294 
1295 	login->login_failed = 1;
1296 	iscsit_collect_login_stats(conn, status_class, status_detail);
1297 
1298 	memset(&login->rsp[0], 0, ISCSI_HDR_LEN);
1299 
1300 	hdr	= (struct iscsi_login_rsp *)&login->rsp[0];
1301 	hdr->opcode		= ISCSI_OP_LOGIN_RSP;
1302 	hdr->status_class	= status_class;
1303 	hdr->status_detail	= status_detail;
1304 	hdr->itt		= conn->login_itt;
1305 
1306 	return conn->conn_transport->iscsit_put_login_tx(conn, login, 0);
1307 }
1308 
1309 void iscsit_print_session_params(struct iscsi_session *sess)
1310 {
1311 	struct iscsi_conn *conn;
1312 
1313 	pr_debug("-----------------------------[Session Params for"
1314 		" SID: %u]-----------------------------\n", sess->sid);
1315 	spin_lock_bh(&sess->conn_lock);
1316 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
1317 		iscsi_dump_conn_ops(conn->conn_ops);
1318 	spin_unlock_bh(&sess->conn_lock);
1319 
1320 	iscsi_dump_sess_ops(sess->sess_ops);
1321 }
1322 
1323 static int iscsit_do_rx_data(
1324 	struct iscsi_conn *conn,
1325 	struct iscsi_data_count *count)
1326 {
1327 	int data = count->data_length, rx_loop = 0, total_rx = 0, iov_len;
1328 	struct kvec *iov_p;
1329 	struct msghdr msg;
1330 
1331 	if (!conn || !conn->sock || !conn->conn_ops)
1332 		return -1;
1333 
1334 	memset(&msg, 0, sizeof(struct msghdr));
1335 
1336 	iov_p = count->iov;
1337 	iov_len	= count->iov_count;
1338 
1339 	while (total_rx < data) {
1340 		rx_loop = kernel_recvmsg(conn->sock, &msg, iov_p, iov_len,
1341 					(data - total_rx), MSG_WAITALL);
1342 		if (rx_loop <= 0) {
1343 			pr_debug("rx_loop: %d total_rx: %d\n",
1344 				rx_loop, total_rx);
1345 			return rx_loop;
1346 		}
1347 		total_rx += rx_loop;
1348 		pr_debug("rx_loop: %d, total_rx: %d, data: %d\n",
1349 				rx_loop, total_rx, data);
1350 	}
1351 
1352 	return total_rx;
1353 }
1354 
1355 static int iscsit_do_tx_data(
1356 	struct iscsi_conn *conn,
1357 	struct iscsi_data_count *count)
1358 {
1359 	int data = count->data_length, total_tx = 0, tx_loop = 0, iov_len;
1360 	struct kvec *iov_p;
1361 	struct msghdr msg;
1362 
1363 	if (!conn || !conn->sock || !conn->conn_ops)
1364 		return -1;
1365 
1366 	if (data <= 0) {
1367 		pr_err("Data length is: %d\n", data);
1368 		return -1;
1369 	}
1370 
1371 	memset(&msg, 0, sizeof(struct msghdr));
1372 
1373 	iov_p = count->iov;
1374 	iov_len = count->iov_count;
1375 
1376 	while (total_tx < data) {
1377 		tx_loop = kernel_sendmsg(conn->sock, &msg, iov_p, iov_len,
1378 					(data - total_tx));
1379 		if (tx_loop <= 0) {
1380 			pr_debug("tx_loop: %d total_tx %d\n",
1381 				tx_loop, total_tx);
1382 			return tx_loop;
1383 		}
1384 		total_tx += tx_loop;
1385 		pr_debug("tx_loop: %d, total_tx: %d, data: %d\n",
1386 					tx_loop, total_tx, data);
1387 	}
1388 
1389 	return total_tx;
1390 }
1391 
1392 int rx_data(
1393 	struct iscsi_conn *conn,
1394 	struct kvec *iov,
1395 	int iov_count,
1396 	int data)
1397 {
1398 	struct iscsi_data_count c;
1399 
1400 	if (!conn || !conn->sock || !conn->conn_ops)
1401 		return -1;
1402 
1403 	memset(&c, 0, sizeof(struct iscsi_data_count));
1404 	c.iov = iov;
1405 	c.iov_count = iov_count;
1406 	c.data_length = data;
1407 	c.type = ISCSI_RX_DATA;
1408 
1409 	return iscsit_do_rx_data(conn, &c);
1410 }
1411 
1412 int tx_data(
1413 	struct iscsi_conn *conn,
1414 	struct kvec *iov,
1415 	int iov_count,
1416 	int data)
1417 {
1418 	struct iscsi_data_count c;
1419 
1420 	if (!conn || !conn->sock || !conn->conn_ops)
1421 		return -1;
1422 
1423 	memset(&c, 0, sizeof(struct iscsi_data_count));
1424 	c.iov = iov;
1425 	c.iov_count = iov_count;
1426 	c.data_length = data;
1427 	c.type = ISCSI_TX_DATA;
1428 
1429 	return iscsit_do_tx_data(conn, &c);
1430 }
1431 
1432 void iscsit_collect_login_stats(
1433 	struct iscsi_conn *conn,
1434 	u8 status_class,
1435 	u8 status_detail)
1436 {
1437 	struct iscsi_param *intrname = NULL;
1438 	struct iscsi_tiqn *tiqn;
1439 	struct iscsi_login_stats *ls;
1440 
1441 	tiqn = iscsit_snmp_get_tiqn(conn);
1442 	if (!tiqn)
1443 		return;
1444 
1445 	ls = &tiqn->login_stats;
1446 
1447 	spin_lock(&ls->lock);
1448 	if (!strcmp(conn->login_ip, ls->last_intr_fail_ip_addr) &&
1449 	    ((get_jiffies_64() - ls->last_fail_time) < 10)) {
1450 		/* We already have the failure info for this login */
1451 		spin_unlock(&ls->lock);
1452 		return;
1453 	}
1454 
1455 	if (status_class == ISCSI_STATUS_CLS_SUCCESS)
1456 		ls->accepts++;
1457 	else if (status_class == ISCSI_STATUS_CLS_REDIRECT) {
1458 		ls->redirects++;
1459 		ls->last_fail_type = ISCSI_LOGIN_FAIL_REDIRECT;
1460 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1461 		 (status_detail == ISCSI_LOGIN_STATUS_AUTH_FAILED)) {
1462 		ls->authenticate_fails++;
1463 		ls->last_fail_type =  ISCSI_LOGIN_FAIL_AUTHENTICATE;
1464 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1465 		 (status_detail == ISCSI_LOGIN_STATUS_TGT_FORBIDDEN)) {
1466 		ls->authorize_fails++;
1467 		ls->last_fail_type = ISCSI_LOGIN_FAIL_AUTHORIZE;
1468 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR) &&
1469 		 (status_detail == ISCSI_LOGIN_STATUS_INIT_ERR)) {
1470 		ls->negotiate_fails++;
1471 		ls->last_fail_type = ISCSI_LOGIN_FAIL_NEGOTIATE;
1472 	} else {
1473 		ls->other_fails++;
1474 		ls->last_fail_type = ISCSI_LOGIN_FAIL_OTHER;
1475 	}
1476 
1477 	/* Save initiator name, ip address and time, if it is a failed login */
1478 	if (status_class != ISCSI_STATUS_CLS_SUCCESS) {
1479 		if (conn->param_list)
1480 			intrname = iscsi_find_param_from_key(INITIATORNAME,
1481 							     conn->param_list);
1482 		strcpy(ls->last_intr_fail_name,
1483 		       (intrname ? intrname->value : "Unknown"));
1484 
1485 		ls->last_intr_fail_ip_family = conn->login_family;
1486 
1487 		snprintf(ls->last_intr_fail_ip_addr, IPV6_ADDRESS_SPACE,
1488 				"%s", conn->login_ip);
1489 		ls->last_fail_time = get_jiffies_64();
1490 	}
1491 
1492 	spin_unlock(&ls->lock);
1493 }
1494 
1495 struct iscsi_tiqn *iscsit_snmp_get_tiqn(struct iscsi_conn *conn)
1496 {
1497 	struct iscsi_portal_group *tpg;
1498 
1499 	if (!conn || !conn->sess)
1500 		return NULL;
1501 
1502 	tpg = conn->sess->tpg;
1503 	if (!tpg)
1504 		return NULL;
1505 
1506 	if (!tpg->tpg_tiqn)
1507 		return NULL;
1508 
1509 	return tpg->tpg_tiqn;
1510 }
1511