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