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/iscsi/iscsi_transport.h>
26 
27 #include <target/iscsi/iscsi_target_core.h>
28 #include "iscsi_target_parameters.h"
29 #include "iscsi_target_seq_pdu_list.h"
30 #include "iscsi_target_datain_values.h"
31 #include "iscsi_target_erl0.h"
32 #include "iscsi_target_erl1.h"
33 #include "iscsi_target_erl2.h"
34 #include "iscsi_target_tpg.h"
35 #include "iscsi_target_util.h"
36 #include "iscsi_target.h"
37 
38 #define PRINT_BUFF(buff, len)					\
39 {								\
40 	int zzz;						\
41 								\
42 	pr_debug("%d:\n", __LINE__);				\
43 	for (zzz = 0; zzz < len; zzz++) {			\
44 		if (zzz % 16 == 0) {				\
45 			if (zzz)				\
46 				pr_debug("\n");			\
47 			pr_debug("%4i: ", zzz);			\
48 		}						\
49 		pr_debug("%02x ", (unsigned char) (buff)[zzz]);	\
50 	}							\
51 	if ((len + 1) % 16)					\
52 		pr_debug("\n");					\
53 }
54 
55 extern struct list_head g_tiqn_list;
56 extern spinlock_t tiqn_lock;
57 
58 /*
59  *	Called with cmd->r2t_lock held.
60  */
61 int iscsit_add_r2t_to_list(
62 	struct iscsi_cmd *cmd,
63 	u32 offset,
64 	u32 xfer_len,
65 	int recovery,
66 	u32 r2t_sn)
67 {
68 	struct iscsi_r2t *r2t;
69 
70 	r2t = kmem_cache_zalloc(lio_r2t_cache, GFP_ATOMIC);
71 	if (!r2t) {
72 		pr_err("Unable to allocate memory for struct iscsi_r2t.\n");
73 		return -1;
74 	}
75 	INIT_LIST_HEAD(&r2t->r2t_list);
76 
77 	r2t->recovery_r2t = recovery;
78 	r2t->r2t_sn = (!r2t_sn) ? cmd->r2t_sn++ : r2t_sn;
79 	r2t->offset = offset;
80 	r2t->xfer_len = xfer_len;
81 	list_add_tail(&r2t->r2t_list, &cmd->cmd_r2t_list);
82 	spin_unlock_bh(&cmd->r2t_lock);
83 
84 	iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, ISTATE_SEND_R2T);
85 
86 	spin_lock_bh(&cmd->r2t_lock);
87 	return 0;
88 }
89 
90 struct iscsi_r2t *iscsit_get_r2t_for_eos(
91 	struct iscsi_cmd *cmd,
92 	u32 offset,
93 	u32 length)
94 {
95 	struct iscsi_r2t *r2t;
96 
97 	spin_lock_bh(&cmd->r2t_lock);
98 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
99 		if ((r2t->offset <= offset) &&
100 		    (r2t->offset + r2t->xfer_len) >= (offset + length)) {
101 			spin_unlock_bh(&cmd->r2t_lock);
102 			return r2t;
103 		}
104 	}
105 	spin_unlock_bh(&cmd->r2t_lock);
106 
107 	pr_err("Unable to locate R2T for Offset: %u, Length:"
108 			" %u\n", offset, length);
109 	return NULL;
110 }
111 
112 struct iscsi_r2t *iscsit_get_r2t_from_list(struct iscsi_cmd *cmd)
113 {
114 	struct iscsi_r2t *r2t;
115 
116 	spin_lock_bh(&cmd->r2t_lock);
117 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
118 		if (!r2t->sent_r2t) {
119 			spin_unlock_bh(&cmd->r2t_lock);
120 			return r2t;
121 		}
122 	}
123 	spin_unlock_bh(&cmd->r2t_lock);
124 
125 	pr_err("Unable to locate next R2T to send for ITT:"
126 			" 0x%08x.\n", cmd->init_task_tag);
127 	return NULL;
128 }
129 
130 /*
131  *	Called with cmd->r2t_lock held.
132  */
133 void iscsit_free_r2t(struct iscsi_r2t *r2t, struct iscsi_cmd *cmd)
134 {
135 	list_del(&r2t->r2t_list);
136 	kmem_cache_free(lio_r2t_cache, r2t);
137 }
138 
139 void iscsit_free_r2ts_from_list(struct iscsi_cmd *cmd)
140 {
141 	struct iscsi_r2t *r2t, *r2t_tmp;
142 
143 	spin_lock_bh(&cmd->r2t_lock);
144 	list_for_each_entry_safe(r2t, r2t_tmp, &cmd->cmd_r2t_list, r2t_list)
145 		iscsit_free_r2t(r2t, cmd);
146 	spin_unlock_bh(&cmd->r2t_lock);
147 }
148 
149 /*
150  * May be called from software interrupt (timer) context for allocating
151  * iSCSI NopINs.
152  */
153 struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn *conn, int state)
154 {
155 	struct iscsi_cmd *cmd;
156 	struct se_session *se_sess = conn->sess->se_sess;
157 	int size, tag;
158 
159 	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, state);
160 	if (tag < 0)
161 		return NULL;
162 
163 	size = sizeof(struct iscsi_cmd) + conn->conn_transport->priv_size;
164 	cmd = (struct iscsi_cmd *)(se_sess->sess_cmd_map + (tag * size));
165 	memset(cmd, 0, size);
166 
167 	cmd->se_cmd.map_tag = tag;
168 	cmd->conn = conn;
169 	INIT_LIST_HEAD(&cmd->i_conn_node);
170 	INIT_LIST_HEAD(&cmd->datain_list);
171 	INIT_LIST_HEAD(&cmd->cmd_r2t_list);
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 EXPORT_SYMBOL(iscsit_allocate_cmd);
181 
182 struct iscsi_seq *iscsit_get_seq_holder_for_datain(
183 	struct iscsi_cmd *cmd,
184 	u32 seq_send_order)
185 {
186 	u32 i;
187 
188 	for (i = 0; i < cmd->seq_count; i++)
189 		if (cmd->seq_list[i].seq_send_order == seq_send_order)
190 			return &cmd->seq_list[i];
191 
192 	return NULL;
193 }
194 
195 struct iscsi_seq *iscsit_get_seq_holder_for_r2t(struct iscsi_cmd *cmd)
196 {
197 	u32 i;
198 
199 	if (!cmd->seq_list) {
200 		pr_err("struct iscsi_cmd->seq_list is NULL!\n");
201 		return NULL;
202 	}
203 
204 	for (i = 0; i < cmd->seq_count; i++) {
205 		if (cmd->seq_list[i].type != SEQTYPE_NORMAL)
206 			continue;
207 		if (cmd->seq_list[i].seq_send_order == cmd->seq_send_order) {
208 			cmd->seq_send_order++;
209 			return &cmd->seq_list[i];
210 		}
211 	}
212 
213 	return NULL;
214 }
215 
216 struct iscsi_r2t *iscsit_get_holder_for_r2tsn(
217 	struct iscsi_cmd *cmd,
218 	u32 r2t_sn)
219 {
220 	struct iscsi_r2t *r2t;
221 
222 	spin_lock_bh(&cmd->r2t_lock);
223 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
224 		if (r2t->r2t_sn == r2t_sn) {
225 			spin_unlock_bh(&cmd->r2t_lock);
226 			return r2t;
227 		}
228 	}
229 	spin_unlock_bh(&cmd->r2t_lock);
230 
231 	return NULL;
232 }
233 
234 static inline int iscsit_check_received_cmdsn(struct iscsi_session *sess, u32 cmdsn)
235 {
236 	int ret;
237 
238 	/*
239 	 * This is the proper method of checking received CmdSN against
240 	 * ExpCmdSN and MaxCmdSN values, as well as accounting for out
241 	 * or order CmdSNs due to multiple connection sessions and/or
242 	 * CRC failures.
243 	 */
244 	if (iscsi_sna_gt(cmdsn, sess->max_cmd_sn)) {
245 		pr_err("Received CmdSN: 0x%08x is greater than"
246 		       " MaxCmdSN: 0x%08x, ignoring.\n", cmdsn,
247 		       sess->max_cmd_sn);
248 		ret = CMDSN_MAXCMDSN_OVERRUN;
249 
250 	} else if (cmdsn == sess->exp_cmd_sn) {
251 		sess->exp_cmd_sn++;
252 		pr_debug("Received CmdSN matches ExpCmdSN,"
253 		      " incremented ExpCmdSN to: 0x%08x\n",
254 		      sess->exp_cmd_sn);
255 		ret = CMDSN_NORMAL_OPERATION;
256 
257 	} else if (iscsi_sna_gt(cmdsn, sess->exp_cmd_sn)) {
258 		pr_debug("Received CmdSN: 0x%08x is greater"
259 		      " than ExpCmdSN: 0x%08x, not acknowledging.\n",
260 		      cmdsn, sess->exp_cmd_sn);
261 		ret = CMDSN_HIGHER_THAN_EXP;
262 
263 	} else {
264 		pr_err("Received CmdSN: 0x%08x is less than"
265 		       " ExpCmdSN: 0x%08x, ignoring.\n", cmdsn,
266 		       sess->exp_cmd_sn);
267 		ret = CMDSN_LOWER_THAN_EXP;
268 	}
269 
270 	return ret;
271 }
272 
273 /*
274  * Commands may be received out of order if MC/S is in use.
275  * Ensure they are executed in CmdSN order.
276  */
277 int iscsit_sequence_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
278 			unsigned char *buf, __be32 cmdsn)
279 {
280 	int ret, cmdsn_ret;
281 	bool reject = false;
282 	u8 reason = ISCSI_REASON_BOOKMARK_NO_RESOURCES;
283 
284 	mutex_lock(&conn->sess->cmdsn_mutex);
285 
286 	cmdsn_ret = iscsit_check_received_cmdsn(conn->sess, be32_to_cpu(cmdsn));
287 	switch (cmdsn_ret) {
288 	case CMDSN_NORMAL_OPERATION:
289 		ret = iscsit_execute_cmd(cmd, 0);
290 		if ((ret >= 0) && !list_empty(&conn->sess->sess_ooo_cmdsn_list))
291 			iscsit_execute_ooo_cmdsns(conn->sess);
292 		else if (ret < 0) {
293 			reject = true;
294 			ret = CMDSN_ERROR_CANNOT_RECOVER;
295 		}
296 		break;
297 	case CMDSN_HIGHER_THAN_EXP:
298 		ret = iscsit_handle_ooo_cmdsn(conn->sess, cmd, be32_to_cpu(cmdsn));
299 		if (ret < 0) {
300 			reject = true;
301 			ret = CMDSN_ERROR_CANNOT_RECOVER;
302 			break;
303 		}
304 		ret = CMDSN_HIGHER_THAN_EXP;
305 		break;
306 	case CMDSN_LOWER_THAN_EXP:
307 	case CMDSN_MAXCMDSN_OVERRUN:
308 	default:
309 		cmd->i_state = ISTATE_REMOVE;
310 		iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
311 		/*
312 		 * Existing callers for iscsit_sequence_cmd() will silently
313 		 * ignore commands with CMDSN_LOWER_THAN_EXP, so force this
314 		 * return for CMDSN_MAXCMDSN_OVERRUN as well..
315 		 */
316 		ret = CMDSN_LOWER_THAN_EXP;
317 		break;
318 	}
319 	mutex_unlock(&conn->sess->cmdsn_mutex);
320 
321 	if (reject)
322 		iscsit_reject_cmd(cmd, reason, buf);
323 
324 	return ret;
325 }
326 EXPORT_SYMBOL(iscsit_sequence_cmd);
327 
328 int iscsit_check_unsolicited_dataout(struct iscsi_cmd *cmd, unsigned char *buf)
329 {
330 	struct iscsi_conn *conn = cmd->conn;
331 	struct se_cmd *se_cmd = &cmd->se_cmd;
332 	struct iscsi_data *hdr = (struct iscsi_data *) buf;
333 	u32 payload_length = ntoh24(hdr->dlength);
334 
335 	if (conn->sess->sess_ops->InitialR2T) {
336 		pr_err("Received unexpected unsolicited data"
337 			" while InitialR2T=Yes, protocol error.\n");
338 		transport_send_check_condition_and_sense(se_cmd,
339 				TCM_UNEXPECTED_UNSOLICITED_DATA, 0);
340 		return -1;
341 	}
342 
343 	if ((cmd->first_burst_len + payload_length) >
344 	     conn->sess->sess_ops->FirstBurstLength) {
345 		pr_err("Total %u bytes exceeds FirstBurstLength: %u"
346 			" for this Unsolicited DataOut Burst.\n",
347 			(cmd->first_burst_len + payload_length),
348 				conn->sess->sess_ops->FirstBurstLength);
349 		transport_send_check_condition_and_sense(se_cmd,
350 				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
351 		return -1;
352 	}
353 
354 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL))
355 		return 0;
356 
357 	if (((cmd->first_burst_len + payload_length) != cmd->se_cmd.data_length) &&
358 	    ((cmd->first_burst_len + payload_length) !=
359 	      conn->sess->sess_ops->FirstBurstLength)) {
360 		pr_err("Unsolicited non-immediate data received %u"
361 			" does not equal FirstBurstLength: %u, and does"
362 			" not equal ExpXferLen %u.\n",
363 			(cmd->first_burst_len + payload_length),
364 			conn->sess->sess_ops->FirstBurstLength, cmd->se_cmd.data_length);
365 		transport_send_check_condition_and_sense(se_cmd,
366 				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
367 		return -1;
368 	}
369 	return 0;
370 }
371 
372 struct iscsi_cmd *iscsit_find_cmd_from_itt(
373 	struct iscsi_conn *conn,
374 	itt_t init_task_tag)
375 {
376 	struct iscsi_cmd *cmd;
377 
378 	spin_lock_bh(&conn->cmd_lock);
379 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
380 		if (cmd->init_task_tag == init_task_tag) {
381 			spin_unlock_bh(&conn->cmd_lock);
382 			return cmd;
383 		}
384 	}
385 	spin_unlock_bh(&conn->cmd_lock);
386 
387 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu",
388 			init_task_tag, conn->cid);
389 	return NULL;
390 }
391 EXPORT_SYMBOL(iscsit_find_cmd_from_itt);
392 
393 struct iscsi_cmd *iscsit_find_cmd_from_itt_or_dump(
394 	struct iscsi_conn *conn,
395 	itt_t init_task_tag,
396 	u32 length)
397 {
398 	struct iscsi_cmd *cmd;
399 
400 	spin_lock_bh(&conn->cmd_lock);
401 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
402 		if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT)
403 			continue;
404 		if (cmd->init_task_tag == init_task_tag) {
405 			spin_unlock_bh(&conn->cmd_lock);
406 			return cmd;
407 		}
408 	}
409 	spin_unlock_bh(&conn->cmd_lock);
410 
411 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu,"
412 			" dumping payload\n", init_task_tag, conn->cid);
413 	if (length)
414 		iscsit_dump_data_payload(conn, length, 1);
415 
416 	return NULL;
417 }
418 
419 struct iscsi_cmd *iscsit_find_cmd_from_ttt(
420 	struct iscsi_conn *conn,
421 	u32 targ_xfer_tag)
422 {
423 	struct iscsi_cmd *cmd = NULL;
424 
425 	spin_lock_bh(&conn->cmd_lock);
426 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
427 		if (cmd->targ_xfer_tag == targ_xfer_tag) {
428 			spin_unlock_bh(&conn->cmd_lock);
429 			return cmd;
430 		}
431 	}
432 	spin_unlock_bh(&conn->cmd_lock);
433 
434 	pr_err("Unable to locate TTT: 0x%08x on CID: %hu\n",
435 			targ_xfer_tag, conn->cid);
436 	return NULL;
437 }
438 
439 int iscsit_find_cmd_for_recovery(
440 	struct iscsi_session *sess,
441 	struct iscsi_cmd **cmd_ptr,
442 	struct iscsi_conn_recovery **cr_ptr,
443 	itt_t init_task_tag)
444 {
445 	struct iscsi_cmd *cmd = NULL;
446 	struct iscsi_conn_recovery *cr;
447 	/*
448 	 * Scan through the inactive connection recovery list's command list.
449 	 * If init_task_tag matches the command is still alligent.
450 	 */
451 	spin_lock(&sess->cr_i_lock);
452 	list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
453 		spin_lock(&cr->conn_recovery_cmd_lock);
454 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
455 			if (cmd->init_task_tag == init_task_tag) {
456 				spin_unlock(&cr->conn_recovery_cmd_lock);
457 				spin_unlock(&sess->cr_i_lock);
458 
459 				*cr_ptr = cr;
460 				*cmd_ptr = cmd;
461 				return -2;
462 			}
463 		}
464 		spin_unlock(&cr->conn_recovery_cmd_lock);
465 	}
466 	spin_unlock(&sess->cr_i_lock);
467 	/*
468 	 * Scan through the active connection recovery list's command list.
469 	 * If init_task_tag matches the command is ready to be reassigned.
470 	 */
471 	spin_lock(&sess->cr_a_lock);
472 	list_for_each_entry(cr, &sess->cr_active_list, cr_list) {
473 		spin_lock(&cr->conn_recovery_cmd_lock);
474 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
475 			if (cmd->init_task_tag == init_task_tag) {
476 				spin_unlock(&cr->conn_recovery_cmd_lock);
477 				spin_unlock(&sess->cr_a_lock);
478 
479 				*cr_ptr = cr;
480 				*cmd_ptr = cmd;
481 				return 0;
482 			}
483 		}
484 		spin_unlock(&cr->conn_recovery_cmd_lock);
485 	}
486 	spin_unlock(&sess->cr_a_lock);
487 
488 	return -1;
489 }
490 
491 void iscsit_add_cmd_to_immediate_queue(
492 	struct iscsi_cmd *cmd,
493 	struct iscsi_conn *conn,
494 	u8 state)
495 {
496 	struct iscsi_queue_req *qr;
497 
498 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
499 	if (!qr) {
500 		pr_err("Unable to allocate memory for"
501 				" struct iscsi_queue_req\n");
502 		return;
503 	}
504 	INIT_LIST_HEAD(&qr->qr_list);
505 	qr->cmd = cmd;
506 	qr->state = state;
507 
508 	spin_lock_bh(&conn->immed_queue_lock);
509 	list_add_tail(&qr->qr_list, &conn->immed_queue_list);
510 	atomic_inc(&cmd->immed_queue_count);
511 	atomic_set(&conn->check_immediate_queue, 1);
512 	spin_unlock_bh(&conn->immed_queue_lock);
513 
514 	wake_up(&conn->queues_wq);
515 }
516 
517 struct iscsi_queue_req *iscsit_get_cmd_from_immediate_queue(struct iscsi_conn *conn)
518 {
519 	struct iscsi_queue_req *qr;
520 
521 	spin_lock_bh(&conn->immed_queue_lock);
522 	if (list_empty(&conn->immed_queue_list)) {
523 		spin_unlock_bh(&conn->immed_queue_lock);
524 		return NULL;
525 	}
526 	qr = list_first_entry(&conn->immed_queue_list,
527 			      struct iscsi_queue_req, qr_list);
528 
529 	list_del(&qr->qr_list);
530 	if (qr->cmd)
531 		atomic_dec(&qr->cmd->immed_queue_count);
532 	spin_unlock_bh(&conn->immed_queue_lock);
533 
534 	return qr;
535 }
536 
537 static void iscsit_remove_cmd_from_immediate_queue(
538 	struct iscsi_cmd *cmd,
539 	struct iscsi_conn *conn)
540 {
541 	struct iscsi_queue_req *qr, *qr_tmp;
542 
543 	spin_lock_bh(&conn->immed_queue_lock);
544 	if (!atomic_read(&cmd->immed_queue_count)) {
545 		spin_unlock_bh(&conn->immed_queue_lock);
546 		return;
547 	}
548 
549 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
550 		if (qr->cmd != cmd)
551 			continue;
552 
553 		atomic_dec(&qr->cmd->immed_queue_count);
554 		list_del(&qr->qr_list);
555 		kmem_cache_free(lio_qr_cache, qr);
556 	}
557 	spin_unlock_bh(&conn->immed_queue_lock);
558 
559 	if (atomic_read(&cmd->immed_queue_count)) {
560 		pr_err("ITT: 0x%08x immed_queue_count: %d\n",
561 			cmd->init_task_tag,
562 			atomic_read(&cmd->immed_queue_count));
563 	}
564 }
565 
566 void iscsit_add_cmd_to_response_queue(
567 	struct iscsi_cmd *cmd,
568 	struct iscsi_conn *conn,
569 	u8 state)
570 {
571 	struct iscsi_queue_req *qr;
572 
573 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
574 	if (!qr) {
575 		pr_err("Unable to allocate memory for"
576 			" struct iscsi_queue_req\n");
577 		return;
578 	}
579 	INIT_LIST_HEAD(&qr->qr_list);
580 	qr->cmd = cmd;
581 	qr->state = state;
582 
583 	spin_lock_bh(&conn->response_queue_lock);
584 	list_add_tail(&qr->qr_list, &conn->response_queue_list);
585 	atomic_inc(&cmd->response_queue_count);
586 	spin_unlock_bh(&conn->response_queue_lock);
587 
588 	wake_up(&conn->queues_wq);
589 }
590 
591 struct iscsi_queue_req *iscsit_get_cmd_from_response_queue(struct iscsi_conn *conn)
592 {
593 	struct iscsi_queue_req *qr;
594 
595 	spin_lock_bh(&conn->response_queue_lock);
596 	if (list_empty(&conn->response_queue_list)) {
597 		spin_unlock_bh(&conn->response_queue_lock);
598 		return NULL;
599 	}
600 
601 	qr = list_first_entry(&conn->response_queue_list,
602 			      struct iscsi_queue_req, qr_list);
603 
604 	list_del(&qr->qr_list);
605 	if (qr->cmd)
606 		atomic_dec(&qr->cmd->response_queue_count);
607 	spin_unlock_bh(&conn->response_queue_lock);
608 
609 	return qr;
610 }
611 
612 static void iscsit_remove_cmd_from_response_queue(
613 	struct iscsi_cmd *cmd,
614 	struct iscsi_conn *conn)
615 {
616 	struct iscsi_queue_req *qr, *qr_tmp;
617 
618 	spin_lock_bh(&conn->response_queue_lock);
619 	if (!atomic_read(&cmd->response_queue_count)) {
620 		spin_unlock_bh(&conn->response_queue_lock);
621 		return;
622 	}
623 
624 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
625 				qr_list) {
626 		if (qr->cmd != cmd)
627 			continue;
628 
629 		atomic_dec(&qr->cmd->response_queue_count);
630 		list_del(&qr->qr_list);
631 		kmem_cache_free(lio_qr_cache, qr);
632 	}
633 	spin_unlock_bh(&conn->response_queue_lock);
634 
635 	if (atomic_read(&cmd->response_queue_count)) {
636 		pr_err("ITT: 0x%08x response_queue_count: %d\n",
637 			cmd->init_task_tag,
638 			atomic_read(&cmd->response_queue_count));
639 	}
640 }
641 
642 bool iscsit_conn_all_queues_empty(struct iscsi_conn *conn)
643 {
644 	bool empty;
645 
646 	spin_lock_bh(&conn->immed_queue_lock);
647 	empty = list_empty(&conn->immed_queue_list);
648 	spin_unlock_bh(&conn->immed_queue_lock);
649 
650 	if (!empty)
651 		return empty;
652 
653 	spin_lock_bh(&conn->response_queue_lock);
654 	empty = list_empty(&conn->response_queue_list);
655 	spin_unlock_bh(&conn->response_queue_lock);
656 
657 	return empty;
658 }
659 
660 void iscsit_free_queue_reqs_for_conn(struct iscsi_conn *conn)
661 {
662 	struct iscsi_queue_req *qr, *qr_tmp;
663 
664 	spin_lock_bh(&conn->immed_queue_lock);
665 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
666 		list_del(&qr->qr_list);
667 		if (qr->cmd)
668 			atomic_dec(&qr->cmd->immed_queue_count);
669 
670 		kmem_cache_free(lio_qr_cache, qr);
671 	}
672 	spin_unlock_bh(&conn->immed_queue_lock);
673 
674 	spin_lock_bh(&conn->response_queue_lock);
675 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
676 			qr_list) {
677 		list_del(&qr->qr_list);
678 		if (qr->cmd)
679 			atomic_dec(&qr->cmd->response_queue_count);
680 
681 		kmem_cache_free(lio_qr_cache, qr);
682 	}
683 	spin_unlock_bh(&conn->response_queue_lock);
684 }
685 
686 void iscsit_release_cmd(struct iscsi_cmd *cmd)
687 {
688 	struct iscsi_session *sess;
689 	struct se_cmd *se_cmd = &cmd->se_cmd;
690 
691 	if (cmd->conn)
692 		sess = cmd->conn->sess;
693 	else
694 		sess = cmd->sess;
695 
696 	BUG_ON(!sess || !sess->se_sess);
697 
698 	kfree(cmd->buf_ptr);
699 	kfree(cmd->pdu_list);
700 	kfree(cmd->seq_list);
701 	kfree(cmd->tmr_req);
702 	kfree(cmd->iov_data);
703 	kfree(cmd->text_in_ptr);
704 
705 	percpu_ida_free(&sess->se_sess->sess_tag_pool, se_cmd->map_tag);
706 }
707 EXPORT_SYMBOL(iscsit_release_cmd);
708 
709 void __iscsit_free_cmd(struct iscsi_cmd *cmd, bool scsi_cmd,
710 		       bool check_queues)
711 {
712 	struct iscsi_conn *conn = cmd->conn;
713 
714 	if (scsi_cmd) {
715 		if (cmd->data_direction == DMA_TO_DEVICE) {
716 			iscsit_stop_dataout_timer(cmd);
717 			iscsit_free_r2ts_from_list(cmd);
718 		}
719 		if (cmd->data_direction == DMA_FROM_DEVICE)
720 			iscsit_free_all_datain_reqs(cmd);
721 	}
722 
723 	if (conn && check_queues) {
724 		iscsit_remove_cmd_from_immediate_queue(cmd, conn);
725 		iscsit_remove_cmd_from_response_queue(cmd, conn);
726 	}
727 }
728 
729 void iscsit_free_cmd(struct iscsi_cmd *cmd, bool shutdown)
730 {
731 	struct se_cmd *se_cmd = NULL;
732 	int rc;
733 	/*
734 	 * Determine if a struct se_cmd is associated with
735 	 * this struct iscsi_cmd.
736 	 */
737 	switch (cmd->iscsi_opcode) {
738 	case ISCSI_OP_SCSI_CMD:
739 		se_cmd = &cmd->se_cmd;
740 		__iscsit_free_cmd(cmd, true, shutdown);
741 		/*
742 		 * Fallthrough
743 		 */
744 	case ISCSI_OP_SCSI_TMFUNC:
745 		rc = transport_generic_free_cmd(&cmd->se_cmd, shutdown);
746 		if (!rc && shutdown && se_cmd && se_cmd->se_sess) {
747 			__iscsit_free_cmd(cmd, true, shutdown);
748 			target_put_sess_cmd(se_cmd);
749 		}
750 		break;
751 	case ISCSI_OP_REJECT:
752 		/*
753 		 * Handle special case for REJECT when iscsi_add_reject*() has
754 		 * overwritten the original iscsi_opcode assignment, and the
755 		 * associated cmd->se_cmd needs to be released.
756 		 */
757 		if (cmd->se_cmd.se_tfo != NULL) {
758 			se_cmd = &cmd->se_cmd;
759 			__iscsit_free_cmd(cmd, true, shutdown);
760 
761 			rc = transport_generic_free_cmd(&cmd->se_cmd, shutdown);
762 			if (!rc && shutdown && se_cmd->se_sess) {
763 				__iscsit_free_cmd(cmd, true, shutdown);
764 				target_put_sess_cmd(se_cmd);
765 			}
766 			break;
767 		}
768 		/* Fall-through */
769 	default:
770 		__iscsit_free_cmd(cmd, false, shutdown);
771 		iscsit_release_cmd(cmd);
772 		break;
773 	}
774 }
775 
776 int iscsit_check_session_usage_count(struct iscsi_session *sess)
777 {
778 	spin_lock_bh(&sess->session_usage_lock);
779 	if (sess->session_usage_count != 0) {
780 		sess->session_waiting_on_uc = 1;
781 		spin_unlock_bh(&sess->session_usage_lock);
782 		if (in_interrupt())
783 			return 2;
784 
785 		wait_for_completion(&sess->session_waiting_on_uc_comp);
786 		return 1;
787 	}
788 	spin_unlock_bh(&sess->session_usage_lock);
789 
790 	return 0;
791 }
792 
793 void iscsit_dec_session_usage_count(struct iscsi_session *sess)
794 {
795 	spin_lock_bh(&sess->session_usage_lock);
796 	sess->session_usage_count--;
797 
798 	if (!sess->session_usage_count && sess->session_waiting_on_uc)
799 		complete(&sess->session_waiting_on_uc_comp);
800 
801 	spin_unlock_bh(&sess->session_usage_lock);
802 }
803 
804 void iscsit_inc_session_usage_count(struct iscsi_session *sess)
805 {
806 	spin_lock_bh(&sess->session_usage_lock);
807 	sess->session_usage_count++;
808 	spin_unlock_bh(&sess->session_usage_lock);
809 }
810 
811 struct iscsi_conn *iscsit_get_conn_from_cid(struct iscsi_session *sess, u16 cid)
812 {
813 	struct iscsi_conn *conn;
814 
815 	spin_lock_bh(&sess->conn_lock);
816 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
817 		if ((conn->cid == cid) &&
818 		    (conn->conn_state == TARG_CONN_STATE_LOGGED_IN)) {
819 			iscsit_inc_conn_usage_count(conn);
820 			spin_unlock_bh(&sess->conn_lock);
821 			return conn;
822 		}
823 	}
824 	spin_unlock_bh(&sess->conn_lock);
825 
826 	return NULL;
827 }
828 
829 struct iscsi_conn *iscsit_get_conn_from_cid_rcfr(struct iscsi_session *sess, u16 cid)
830 {
831 	struct iscsi_conn *conn;
832 
833 	spin_lock_bh(&sess->conn_lock);
834 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
835 		if (conn->cid == cid) {
836 			iscsit_inc_conn_usage_count(conn);
837 			spin_lock(&conn->state_lock);
838 			atomic_set(&conn->connection_wait_rcfr, 1);
839 			spin_unlock(&conn->state_lock);
840 			spin_unlock_bh(&sess->conn_lock);
841 			return conn;
842 		}
843 	}
844 	spin_unlock_bh(&sess->conn_lock);
845 
846 	return NULL;
847 }
848 
849 void iscsit_check_conn_usage_count(struct iscsi_conn *conn)
850 {
851 	spin_lock_bh(&conn->conn_usage_lock);
852 	if (conn->conn_usage_count != 0) {
853 		conn->conn_waiting_on_uc = 1;
854 		spin_unlock_bh(&conn->conn_usage_lock);
855 
856 		wait_for_completion(&conn->conn_waiting_on_uc_comp);
857 		return;
858 	}
859 	spin_unlock_bh(&conn->conn_usage_lock);
860 }
861 
862 void iscsit_dec_conn_usage_count(struct iscsi_conn *conn)
863 {
864 	spin_lock_bh(&conn->conn_usage_lock);
865 	conn->conn_usage_count--;
866 
867 	if (!conn->conn_usage_count && conn->conn_waiting_on_uc)
868 		complete(&conn->conn_waiting_on_uc_comp);
869 
870 	spin_unlock_bh(&conn->conn_usage_lock);
871 }
872 
873 void iscsit_inc_conn_usage_count(struct iscsi_conn *conn)
874 {
875 	spin_lock_bh(&conn->conn_usage_lock);
876 	conn->conn_usage_count++;
877 	spin_unlock_bh(&conn->conn_usage_lock);
878 }
879 
880 static int iscsit_add_nopin(struct iscsi_conn *conn, int want_response)
881 {
882 	u8 state;
883 	struct iscsi_cmd *cmd;
884 
885 	cmd = iscsit_allocate_cmd(conn, TASK_RUNNING);
886 	if (!cmd)
887 		return -1;
888 
889 	cmd->iscsi_opcode = ISCSI_OP_NOOP_IN;
890 	state = (want_response) ? ISTATE_SEND_NOPIN_WANT_RESPONSE :
891 				ISTATE_SEND_NOPIN_NO_RESPONSE;
892 	cmd->init_task_tag = RESERVED_ITT;
893 	cmd->targ_xfer_tag = (want_response) ?
894 			     session_get_next_ttt(conn->sess) : 0xFFFFFFFF;
895 	spin_lock_bh(&conn->cmd_lock);
896 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
897 	spin_unlock_bh(&conn->cmd_lock);
898 
899 	if (want_response)
900 		iscsit_start_nopin_response_timer(conn);
901 	iscsit_add_cmd_to_immediate_queue(cmd, conn, state);
902 
903 	return 0;
904 }
905 
906 static void iscsit_handle_nopin_response_timeout(unsigned long data)
907 {
908 	struct iscsi_conn *conn = (struct iscsi_conn *) data;
909 
910 	iscsit_inc_conn_usage_count(conn);
911 
912 	spin_lock_bh(&conn->nopin_timer_lock);
913 	if (conn->nopin_response_timer_flags & ISCSI_TF_STOP) {
914 		spin_unlock_bh(&conn->nopin_timer_lock);
915 		iscsit_dec_conn_usage_count(conn);
916 		return;
917 	}
918 
919 	pr_debug("Did not receive response to NOPIN on CID: %hu on"
920 		" SID: %u, failing connection.\n", conn->cid,
921 			conn->sess->sid);
922 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
923 	spin_unlock_bh(&conn->nopin_timer_lock);
924 
925 	{
926 	struct iscsi_portal_group *tpg = conn->sess->tpg;
927 	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
928 
929 	if (tiqn) {
930 		spin_lock_bh(&tiqn->sess_err_stats.lock);
931 		strcpy(tiqn->sess_err_stats.last_sess_fail_rem_name,
932 				conn->sess->sess_ops->InitiatorName);
933 		tiqn->sess_err_stats.last_sess_failure_type =
934 				ISCSI_SESS_ERR_CXN_TIMEOUT;
935 		tiqn->sess_err_stats.cxn_timeout_errors++;
936 		atomic_long_inc(&conn->sess->conn_timeout_errors);
937 		spin_unlock_bh(&tiqn->sess_err_stats.lock);
938 	}
939 	}
940 
941 	iscsit_cause_connection_reinstatement(conn, 0);
942 	iscsit_dec_conn_usage_count(conn);
943 }
944 
945 void iscsit_mod_nopin_response_timer(struct iscsi_conn *conn)
946 {
947 	struct iscsi_session *sess = conn->sess;
948 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
949 
950 	spin_lock_bh(&conn->nopin_timer_lock);
951 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
952 		spin_unlock_bh(&conn->nopin_timer_lock);
953 		return;
954 	}
955 
956 	mod_timer(&conn->nopin_response_timer,
957 		(get_jiffies_64() + na->nopin_response_timeout * HZ));
958 	spin_unlock_bh(&conn->nopin_timer_lock);
959 }
960 
961 /*
962  *	Called with conn->nopin_timer_lock held.
963  */
964 void iscsit_start_nopin_response_timer(struct iscsi_conn *conn)
965 {
966 	struct iscsi_session *sess = conn->sess;
967 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
968 
969 	spin_lock_bh(&conn->nopin_timer_lock);
970 	if (conn->nopin_response_timer_flags & ISCSI_TF_RUNNING) {
971 		spin_unlock_bh(&conn->nopin_timer_lock);
972 		return;
973 	}
974 
975 	init_timer(&conn->nopin_response_timer);
976 	conn->nopin_response_timer.expires =
977 		(get_jiffies_64() + na->nopin_response_timeout * HZ);
978 	conn->nopin_response_timer.data = (unsigned long)conn;
979 	conn->nopin_response_timer.function = iscsit_handle_nopin_response_timeout;
980 	conn->nopin_response_timer_flags &= ~ISCSI_TF_STOP;
981 	conn->nopin_response_timer_flags |= ISCSI_TF_RUNNING;
982 	add_timer(&conn->nopin_response_timer);
983 
984 	pr_debug("Started NOPIN Response Timer on CID: %d to %u"
985 		" seconds\n", conn->cid, na->nopin_response_timeout);
986 	spin_unlock_bh(&conn->nopin_timer_lock);
987 }
988 
989 void iscsit_stop_nopin_response_timer(struct iscsi_conn *conn)
990 {
991 	spin_lock_bh(&conn->nopin_timer_lock);
992 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
993 		spin_unlock_bh(&conn->nopin_timer_lock);
994 		return;
995 	}
996 	conn->nopin_response_timer_flags |= ISCSI_TF_STOP;
997 	spin_unlock_bh(&conn->nopin_timer_lock);
998 
999 	del_timer_sync(&conn->nopin_response_timer);
1000 
1001 	spin_lock_bh(&conn->nopin_timer_lock);
1002 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
1003 	spin_unlock_bh(&conn->nopin_timer_lock);
1004 }
1005 
1006 static void iscsit_handle_nopin_timeout(unsigned long data)
1007 {
1008 	struct iscsi_conn *conn = (struct iscsi_conn *) data;
1009 
1010 	iscsit_inc_conn_usage_count(conn);
1011 
1012 	spin_lock_bh(&conn->nopin_timer_lock);
1013 	if (conn->nopin_timer_flags & ISCSI_TF_STOP) {
1014 		spin_unlock_bh(&conn->nopin_timer_lock);
1015 		iscsit_dec_conn_usage_count(conn);
1016 		return;
1017 	}
1018 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1019 	spin_unlock_bh(&conn->nopin_timer_lock);
1020 
1021 	iscsit_add_nopin(conn, 1);
1022 	iscsit_dec_conn_usage_count(conn);
1023 }
1024 
1025 /*
1026  * Called with conn->nopin_timer_lock held.
1027  */
1028 void __iscsit_start_nopin_timer(struct iscsi_conn *conn)
1029 {
1030 	struct iscsi_session *sess = conn->sess;
1031 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1032 	/*
1033 	* NOPIN timeout is disabled.
1034 	 */
1035 	if (!na->nopin_timeout)
1036 		return;
1037 
1038 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING)
1039 		return;
1040 
1041 	init_timer(&conn->nopin_timer);
1042 	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1043 	conn->nopin_timer.data = (unsigned long)conn;
1044 	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1045 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1046 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1047 	add_timer(&conn->nopin_timer);
1048 
1049 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1050 		" interval\n", conn->cid, na->nopin_timeout);
1051 }
1052 
1053 void iscsit_start_nopin_timer(struct iscsi_conn *conn)
1054 {
1055 	struct iscsi_session *sess = conn->sess;
1056 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1057 	/*
1058 	 * NOPIN timeout is disabled..
1059 	 */
1060 	if (!na->nopin_timeout)
1061 		return;
1062 
1063 	spin_lock_bh(&conn->nopin_timer_lock);
1064 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING) {
1065 		spin_unlock_bh(&conn->nopin_timer_lock);
1066 		return;
1067 	}
1068 
1069 	init_timer(&conn->nopin_timer);
1070 	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1071 	conn->nopin_timer.data = (unsigned long)conn;
1072 	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1073 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1074 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1075 	add_timer(&conn->nopin_timer);
1076 
1077 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1078 			" interval\n", conn->cid, na->nopin_timeout);
1079 	spin_unlock_bh(&conn->nopin_timer_lock);
1080 }
1081 
1082 void iscsit_stop_nopin_timer(struct iscsi_conn *conn)
1083 {
1084 	spin_lock_bh(&conn->nopin_timer_lock);
1085 	if (!(conn->nopin_timer_flags & ISCSI_TF_RUNNING)) {
1086 		spin_unlock_bh(&conn->nopin_timer_lock);
1087 		return;
1088 	}
1089 	conn->nopin_timer_flags |= ISCSI_TF_STOP;
1090 	spin_unlock_bh(&conn->nopin_timer_lock);
1091 
1092 	del_timer_sync(&conn->nopin_timer);
1093 
1094 	spin_lock_bh(&conn->nopin_timer_lock);
1095 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1096 	spin_unlock_bh(&conn->nopin_timer_lock);
1097 }
1098 
1099 int iscsit_send_tx_data(
1100 	struct iscsi_cmd *cmd,
1101 	struct iscsi_conn *conn,
1102 	int use_misc)
1103 {
1104 	int tx_sent, tx_size;
1105 	u32 iov_count;
1106 	struct kvec *iov;
1107 
1108 send_data:
1109 	tx_size = cmd->tx_size;
1110 
1111 	if (!use_misc) {
1112 		iov = &cmd->iov_data[0];
1113 		iov_count = cmd->iov_data_count;
1114 	} else {
1115 		iov = &cmd->iov_misc[0];
1116 		iov_count = cmd->iov_misc_count;
1117 	}
1118 
1119 	tx_sent = tx_data(conn, &iov[0], iov_count, tx_size);
1120 	if (tx_size != tx_sent) {
1121 		if (tx_sent == -EAGAIN) {
1122 			pr_err("tx_data() returned -EAGAIN\n");
1123 			goto send_data;
1124 		} else
1125 			return -1;
1126 	}
1127 	cmd->tx_size = 0;
1128 
1129 	return 0;
1130 }
1131 
1132 int iscsit_fe_sendpage_sg(
1133 	struct iscsi_cmd *cmd,
1134 	struct iscsi_conn *conn)
1135 {
1136 	struct scatterlist *sg = cmd->first_data_sg;
1137 	struct kvec iov;
1138 	u32 tx_hdr_size, data_len;
1139 	u32 offset = cmd->first_data_sg_off;
1140 	int tx_sent, iov_off;
1141 
1142 send_hdr:
1143 	tx_hdr_size = ISCSI_HDR_LEN;
1144 	if (conn->conn_ops->HeaderDigest)
1145 		tx_hdr_size += ISCSI_CRC_LEN;
1146 
1147 	iov.iov_base = cmd->pdu;
1148 	iov.iov_len = tx_hdr_size;
1149 
1150 	tx_sent = tx_data(conn, &iov, 1, tx_hdr_size);
1151 	if (tx_hdr_size != tx_sent) {
1152 		if (tx_sent == -EAGAIN) {
1153 			pr_err("tx_data() returned -EAGAIN\n");
1154 			goto send_hdr;
1155 		}
1156 		return -1;
1157 	}
1158 
1159 	data_len = cmd->tx_size - tx_hdr_size - cmd->padding;
1160 	/*
1161 	 * Set iov_off used by padding and data digest tx_data() calls below
1162 	 * in order to determine proper offset into cmd->iov_data[]
1163 	 */
1164 	if (conn->conn_ops->DataDigest) {
1165 		data_len -= ISCSI_CRC_LEN;
1166 		if (cmd->padding)
1167 			iov_off = (cmd->iov_data_count - 2);
1168 		else
1169 			iov_off = (cmd->iov_data_count - 1);
1170 	} else {
1171 		iov_off = (cmd->iov_data_count - 1);
1172 	}
1173 	/*
1174 	 * Perform sendpage() for each page in the scatterlist
1175 	 */
1176 	while (data_len) {
1177 		u32 space = (sg->length - offset);
1178 		u32 sub_len = min_t(u32, data_len, space);
1179 send_pg:
1180 		tx_sent = conn->sock->ops->sendpage(conn->sock,
1181 					sg_page(sg), sg->offset + offset, sub_len, 0);
1182 		if (tx_sent != sub_len) {
1183 			if (tx_sent == -EAGAIN) {
1184 				pr_err("tcp_sendpage() returned"
1185 						" -EAGAIN\n");
1186 				goto send_pg;
1187 			}
1188 
1189 			pr_err("tcp_sendpage() failure: %d\n",
1190 					tx_sent);
1191 			return -1;
1192 		}
1193 
1194 		data_len -= sub_len;
1195 		offset = 0;
1196 		sg = sg_next(sg);
1197 	}
1198 
1199 send_padding:
1200 	if (cmd->padding) {
1201 		struct kvec *iov_p = &cmd->iov_data[iov_off++];
1202 
1203 		tx_sent = tx_data(conn, iov_p, 1, cmd->padding);
1204 		if (cmd->padding != tx_sent) {
1205 			if (tx_sent == -EAGAIN) {
1206 				pr_err("tx_data() returned -EAGAIN\n");
1207 				goto send_padding;
1208 			}
1209 			return -1;
1210 		}
1211 	}
1212 
1213 send_datacrc:
1214 	if (conn->conn_ops->DataDigest) {
1215 		struct kvec *iov_d = &cmd->iov_data[iov_off];
1216 
1217 		tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN);
1218 		if (ISCSI_CRC_LEN != tx_sent) {
1219 			if (tx_sent == -EAGAIN) {
1220 				pr_err("tx_data() returned -EAGAIN\n");
1221 				goto send_datacrc;
1222 			}
1223 			return -1;
1224 		}
1225 	}
1226 
1227 	return 0;
1228 }
1229 
1230 /*
1231  *      This function is used for mainly sending a ISCSI_TARG_LOGIN_RSP PDU
1232  *      back to the Initiator when an expection condition occurs with the
1233  *      errors set in status_class and status_detail.
1234  *
1235  *      Parameters:     iSCSI Connection, Status Class, Status Detail.
1236  *      Returns:        0 on success, -1 on error.
1237  */
1238 int iscsit_tx_login_rsp(struct iscsi_conn *conn, u8 status_class, u8 status_detail)
1239 {
1240 	struct iscsi_login_rsp *hdr;
1241 	struct iscsi_login *login = conn->conn_login;
1242 
1243 	login->login_failed = 1;
1244 	iscsit_collect_login_stats(conn, status_class, status_detail);
1245 
1246 	memset(&login->rsp[0], 0, ISCSI_HDR_LEN);
1247 
1248 	hdr	= (struct iscsi_login_rsp *)&login->rsp[0];
1249 	hdr->opcode		= ISCSI_OP_LOGIN_RSP;
1250 	hdr->status_class	= status_class;
1251 	hdr->status_detail	= status_detail;
1252 	hdr->itt		= conn->login_itt;
1253 
1254 	return conn->conn_transport->iscsit_put_login_tx(conn, login, 0);
1255 }
1256 
1257 void iscsit_print_session_params(struct iscsi_session *sess)
1258 {
1259 	struct iscsi_conn *conn;
1260 
1261 	pr_debug("-----------------------------[Session Params for"
1262 		" SID: %u]-----------------------------\n", sess->sid);
1263 	spin_lock_bh(&sess->conn_lock);
1264 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
1265 		iscsi_dump_conn_ops(conn->conn_ops);
1266 	spin_unlock_bh(&sess->conn_lock);
1267 
1268 	iscsi_dump_sess_ops(sess->sess_ops);
1269 }
1270 
1271 static int iscsit_do_rx_data(
1272 	struct iscsi_conn *conn,
1273 	struct iscsi_data_count *count)
1274 {
1275 	int data = count->data_length, rx_loop = 0, total_rx = 0;
1276 	struct msghdr msg;
1277 
1278 	if (!conn || !conn->sock || !conn->conn_ops)
1279 		return -1;
1280 
1281 	memset(&msg, 0, sizeof(struct msghdr));
1282 	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC,
1283 		      count->iov, count->iov_count, data);
1284 
1285 	while (total_rx < data) {
1286 		rx_loop = sock_recvmsg(conn->sock, &msg,
1287 				      (data - total_rx), MSG_WAITALL);
1288 		if (rx_loop <= 0) {
1289 			pr_debug("rx_loop: %d total_rx: %d\n",
1290 				rx_loop, total_rx);
1291 			return rx_loop;
1292 		}
1293 		total_rx += rx_loop;
1294 		pr_debug("rx_loop: %d, total_rx: %d, data: %d\n",
1295 				rx_loop, total_rx, data);
1296 	}
1297 
1298 	return total_rx;
1299 }
1300 
1301 static int iscsit_do_tx_data(
1302 	struct iscsi_conn *conn,
1303 	struct iscsi_data_count *count)
1304 {
1305 	int ret, iov_len;
1306 	struct kvec *iov_p;
1307 	struct msghdr msg;
1308 
1309 	if (!conn || !conn->sock || !conn->conn_ops)
1310 		return -1;
1311 
1312 	if (count->data_length <= 0) {
1313 		pr_err("Data length is: %d\n", count->data_length);
1314 		return -1;
1315 	}
1316 
1317 	memset(&msg, 0, sizeof(struct msghdr));
1318 
1319 	iov_p = count->iov;
1320 	iov_len = count->iov_count;
1321 
1322 	ret = kernel_sendmsg(conn->sock, &msg, iov_p, iov_len,
1323 			     count->data_length);
1324 	if (ret != count->data_length) {
1325 		pr_err("Unexpected ret: %d send data %d\n",
1326 		       ret, count->data_length);
1327 		return -EPIPE;
1328 	}
1329 	pr_debug("ret: %d, sent data: %d\n", ret, count->data_length);
1330 
1331 	return ret;
1332 }
1333 
1334 int rx_data(
1335 	struct iscsi_conn *conn,
1336 	struct kvec *iov,
1337 	int iov_count,
1338 	int data)
1339 {
1340 	struct iscsi_data_count c;
1341 
1342 	if (!conn || !conn->sock || !conn->conn_ops)
1343 		return -1;
1344 
1345 	memset(&c, 0, sizeof(struct iscsi_data_count));
1346 	c.iov = iov;
1347 	c.iov_count = iov_count;
1348 	c.data_length = data;
1349 	c.type = ISCSI_RX_DATA;
1350 
1351 	return iscsit_do_rx_data(conn, &c);
1352 }
1353 
1354 int tx_data(
1355 	struct iscsi_conn *conn,
1356 	struct kvec *iov,
1357 	int iov_count,
1358 	int data)
1359 {
1360 	struct iscsi_data_count c;
1361 
1362 	if (!conn || !conn->sock || !conn->conn_ops)
1363 		return -1;
1364 
1365 	memset(&c, 0, sizeof(struct iscsi_data_count));
1366 	c.iov = iov;
1367 	c.iov_count = iov_count;
1368 	c.data_length = data;
1369 	c.type = ISCSI_TX_DATA;
1370 
1371 	return iscsit_do_tx_data(conn, &c);
1372 }
1373 
1374 void iscsit_collect_login_stats(
1375 	struct iscsi_conn *conn,
1376 	u8 status_class,
1377 	u8 status_detail)
1378 {
1379 	struct iscsi_param *intrname = NULL;
1380 	struct iscsi_tiqn *tiqn;
1381 	struct iscsi_login_stats *ls;
1382 
1383 	tiqn = iscsit_snmp_get_tiqn(conn);
1384 	if (!tiqn)
1385 		return;
1386 
1387 	ls = &tiqn->login_stats;
1388 
1389 	spin_lock(&ls->lock);
1390 	if (!strcmp(conn->login_ip, ls->last_intr_fail_ip_addr) &&
1391 	    ((get_jiffies_64() - ls->last_fail_time) < 10)) {
1392 		/* We already have the failure info for this login */
1393 		spin_unlock(&ls->lock);
1394 		return;
1395 	}
1396 
1397 	if (status_class == ISCSI_STATUS_CLS_SUCCESS)
1398 		ls->accepts++;
1399 	else if (status_class == ISCSI_STATUS_CLS_REDIRECT) {
1400 		ls->redirects++;
1401 		ls->last_fail_type = ISCSI_LOGIN_FAIL_REDIRECT;
1402 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1403 		 (status_detail == ISCSI_LOGIN_STATUS_AUTH_FAILED)) {
1404 		ls->authenticate_fails++;
1405 		ls->last_fail_type =  ISCSI_LOGIN_FAIL_AUTHENTICATE;
1406 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1407 		 (status_detail == ISCSI_LOGIN_STATUS_TGT_FORBIDDEN)) {
1408 		ls->authorize_fails++;
1409 		ls->last_fail_type = ISCSI_LOGIN_FAIL_AUTHORIZE;
1410 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR) &&
1411 		 (status_detail == ISCSI_LOGIN_STATUS_INIT_ERR)) {
1412 		ls->negotiate_fails++;
1413 		ls->last_fail_type = ISCSI_LOGIN_FAIL_NEGOTIATE;
1414 	} else {
1415 		ls->other_fails++;
1416 		ls->last_fail_type = ISCSI_LOGIN_FAIL_OTHER;
1417 	}
1418 
1419 	/* Save initiator name, ip address and time, if it is a failed login */
1420 	if (status_class != ISCSI_STATUS_CLS_SUCCESS) {
1421 		if (conn->param_list)
1422 			intrname = iscsi_find_param_from_key(INITIATORNAME,
1423 							     conn->param_list);
1424 		strlcpy(ls->last_intr_fail_name,
1425 		       (intrname ? intrname->value : "Unknown"),
1426 		       sizeof(ls->last_intr_fail_name));
1427 
1428 		ls->last_intr_fail_ip_family = conn->login_family;
1429 
1430 		snprintf(ls->last_intr_fail_ip_addr, IPV6_ADDRESS_SPACE,
1431 				"%s", conn->login_ip);
1432 		ls->last_fail_time = get_jiffies_64();
1433 	}
1434 
1435 	spin_unlock(&ls->lock);
1436 }
1437 
1438 struct iscsi_tiqn *iscsit_snmp_get_tiqn(struct iscsi_conn *conn)
1439 {
1440 	struct iscsi_portal_group *tpg;
1441 
1442 	if (!conn || !conn->sess)
1443 		return NULL;
1444 
1445 	tpg = conn->sess->tpg;
1446 	if (!tpg)
1447 		return NULL;
1448 
1449 	if (!tpg->tpg_tiqn)
1450 		return NULL;
1451 
1452 	return tpg->tpg_tiqn;
1453 }
1454