xref: /linux/drivers/target/iscsi/iscsi_target_util.c (revision e58e871becec2d3b04ed91c0c16fe8deac9c9dfa)
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 <net/ipv6.h>         /* ipv6_addr_equal() */
22 #include <scsi/scsi_tcq.h>
23 #include <scsi/iscsi_proto.h>
24 #include <target/target_core_base.h>
25 #include <target/target_core_fabric.h>
26 #include <target/iscsi/iscsi_transport.h>
27 
28 #include <target/iscsi/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_util.h"
37 #include "iscsi_target.h"
38 
39 #define PRINT_BUFF(buff, len)					\
40 {								\
41 	int zzz;						\
42 								\
43 	pr_debug("%d:\n", __LINE__);				\
44 	for (zzz = 0; zzz < len; zzz++) {			\
45 		if (zzz % 16 == 0) {				\
46 			if (zzz)				\
47 				pr_debug("\n");			\
48 			pr_debug("%4i: ", zzz);			\
49 		}						\
50 		pr_debug("%02x ", (unsigned char) (buff)[zzz]);	\
51 	}							\
52 	if ((len + 1) % 16)					\
53 		pr_debug("\n");					\
54 }
55 
56 extern struct list_head g_tiqn_list;
57 extern spinlock_t tiqn_lock;
58 
59 /*
60  *	Called with cmd->r2t_lock held.
61  */
62 int iscsit_add_r2t_to_list(
63 	struct iscsi_cmd *cmd,
64 	u32 offset,
65 	u32 xfer_len,
66 	int recovery,
67 	u32 r2t_sn)
68 {
69 	struct iscsi_r2t *r2t;
70 
71 	r2t = kmem_cache_zalloc(lio_r2t_cache, GFP_ATOMIC);
72 	if (!r2t) {
73 		pr_err("Unable to allocate memory for struct iscsi_r2t.\n");
74 		return -1;
75 	}
76 	INIT_LIST_HEAD(&r2t->r2t_list);
77 
78 	r2t->recovery_r2t = recovery;
79 	r2t->r2t_sn = (!r2t_sn) ? cmd->r2t_sn++ : r2t_sn;
80 	r2t->offset = offset;
81 	r2t->xfer_len = xfer_len;
82 	list_add_tail(&r2t->r2t_list, &cmd->cmd_r2t_list);
83 	spin_unlock_bh(&cmd->r2t_lock);
84 
85 	iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, ISTATE_SEND_R2T);
86 
87 	spin_lock_bh(&cmd->r2t_lock);
88 	return 0;
89 }
90 
91 struct iscsi_r2t *iscsit_get_r2t_for_eos(
92 	struct iscsi_cmd *cmd,
93 	u32 offset,
94 	u32 length)
95 {
96 	struct iscsi_r2t *r2t;
97 
98 	spin_lock_bh(&cmd->r2t_lock);
99 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
100 		if ((r2t->offset <= offset) &&
101 		    (r2t->offset + r2t->xfer_len) >= (offset + length)) {
102 			spin_unlock_bh(&cmd->r2t_lock);
103 			return r2t;
104 		}
105 	}
106 	spin_unlock_bh(&cmd->r2t_lock);
107 
108 	pr_err("Unable to locate R2T for Offset: %u, Length:"
109 			" %u\n", offset, length);
110 	return NULL;
111 }
112 
113 struct iscsi_r2t *iscsit_get_r2t_from_list(struct iscsi_cmd *cmd)
114 {
115 	struct iscsi_r2t *r2t;
116 
117 	spin_lock_bh(&cmd->r2t_lock);
118 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
119 		if (!r2t->sent_r2t) {
120 			spin_unlock_bh(&cmd->r2t_lock);
121 			return r2t;
122 		}
123 	}
124 	spin_unlock_bh(&cmd->r2t_lock);
125 
126 	pr_err("Unable to locate next R2T to send for ITT:"
127 			" 0x%08x.\n", cmd->init_task_tag);
128 	return NULL;
129 }
130 
131 /*
132  *	Called with cmd->r2t_lock held.
133  */
134 void iscsit_free_r2t(struct iscsi_r2t *r2t, struct iscsi_cmd *cmd)
135 {
136 	list_del(&r2t->r2t_list);
137 	kmem_cache_free(lio_r2t_cache, r2t);
138 }
139 
140 void iscsit_free_r2ts_from_list(struct iscsi_cmd *cmd)
141 {
142 	struct iscsi_r2t *r2t, *r2t_tmp;
143 
144 	spin_lock_bh(&cmd->r2t_lock);
145 	list_for_each_entry_safe(r2t, r2t_tmp, &cmd->cmd_r2t_list, r2t_list)
146 		iscsit_free_r2t(r2t, cmd);
147 	spin_unlock_bh(&cmd->r2t_lock);
148 }
149 
150 /*
151  * May be called from software interrupt (timer) context for allocating
152  * iSCSI NopINs.
153  */
154 struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn *conn, int state)
155 {
156 	struct iscsi_cmd *cmd;
157 	struct se_session *se_sess = conn->sess->se_sess;
158 	int size, tag;
159 
160 	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, state);
161 	if (tag < 0)
162 		return NULL;
163 
164 	size = sizeof(struct iscsi_cmd) + conn->conn_transport->priv_size;
165 	cmd = (struct iscsi_cmd *)(se_sess->sess_cmd_map + (tag * size));
166 	memset(cmd, 0, size);
167 
168 	cmd->se_cmd.map_tag = tag;
169 	cmd->conn = conn;
170 	INIT_LIST_HEAD(&cmd->i_conn_node);
171 	INIT_LIST_HEAD(&cmd->datain_list);
172 	INIT_LIST_HEAD(&cmd->cmd_r2t_list);
173 	spin_lock_init(&cmd->datain_lock);
174 	spin_lock_init(&cmd->dataout_timeout_lock);
175 	spin_lock_init(&cmd->istate_lock);
176 	spin_lock_init(&cmd->error_lock);
177 	spin_lock_init(&cmd->r2t_lock);
178 
179 	return cmd;
180 }
181 EXPORT_SYMBOL(iscsit_allocate_cmd);
182 
183 struct iscsi_seq *iscsit_get_seq_holder_for_datain(
184 	struct iscsi_cmd *cmd,
185 	u32 seq_send_order)
186 {
187 	u32 i;
188 
189 	for (i = 0; i < cmd->seq_count; i++)
190 		if (cmd->seq_list[i].seq_send_order == seq_send_order)
191 			return &cmd->seq_list[i];
192 
193 	return NULL;
194 }
195 
196 struct iscsi_seq *iscsit_get_seq_holder_for_r2t(struct iscsi_cmd *cmd)
197 {
198 	u32 i;
199 
200 	if (!cmd->seq_list) {
201 		pr_err("struct iscsi_cmd->seq_list is NULL!\n");
202 		return NULL;
203 	}
204 
205 	for (i = 0; i < cmd->seq_count; i++) {
206 		if (cmd->seq_list[i].type != SEQTYPE_NORMAL)
207 			continue;
208 		if (cmd->seq_list[i].seq_send_order == cmd->seq_send_order) {
209 			cmd->seq_send_order++;
210 			return &cmd->seq_list[i];
211 		}
212 	}
213 
214 	return NULL;
215 }
216 
217 struct iscsi_r2t *iscsit_get_holder_for_r2tsn(
218 	struct iscsi_cmd *cmd,
219 	u32 r2t_sn)
220 {
221 	struct iscsi_r2t *r2t;
222 
223 	spin_lock_bh(&cmd->r2t_lock);
224 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
225 		if (r2t->r2t_sn == r2t_sn) {
226 			spin_unlock_bh(&cmd->r2t_lock);
227 			return r2t;
228 		}
229 	}
230 	spin_unlock_bh(&cmd->r2t_lock);
231 
232 	return NULL;
233 }
234 
235 static inline int iscsit_check_received_cmdsn(struct iscsi_session *sess, u32 cmdsn)
236 {
237 	u32 max_cmdsn;
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 	max_cmdsn = atomic_read(&sess->max_cmd_sn);
247 	if (iscsi_sna_gt(cmdsn, max_cmdsn)) {
248 		pr_err("Received CmdSN: 0x%08x is greater than"
249 		       " MaxCmdSN: 0x%08x, ignoring.\n", cmdsn, max_cmdsn);
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 EXPORT_SYMBOL(iscsit_find_cmd_from_itt);
394 
395 struct iscsi_cmd *iscsit_find_cmd_from_itt_or_dump(
396 	struct iscsi_conn *conn,
397 	itt_t init_task_tag,
398 	u32 length)
399 {
400 	struct iscsi_cmd *cmd;
401 
402 	spin_lock_bh(&conn->cmd_lock);
403 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
404 		if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT)
405 			continue;
406 		if (cmd->init_task_tag == init_task_tag) {
407 			spin_unlock_bh(&conn->cmd_lock);
408 			return cmd;
409 		}
410 	}
411 	spin_unlock_bh(&conn->cmd_lock);
412 
413 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu,"
414 			" dumping payload\n", init_task_tag, conn->cid);
415 	if (length)
416 		iscsit_dump_data_payload(conn, length, 1);
417 
418 	return NULL;
419 }
420 EXPORT_SYMBOL(iscsit_find_cmd_from_itt_or_dump);
421 
422 struct iscsi_cmd *iscsit_find_cmd_from_ttt(
423 	struct iscsi_conn *conn,
424 	u32 targ_xfer_tag)
425 {
426 	struct iscsi_cmd *cmd = NULL;
427 
428 	spin_lock_bh(&conn->cmd_lock);
429 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
430 		if (cmd->targ_xfer_tag == targ_xfer_tag) {
431 			spin_unlock_bh(&conn->cmd_lock);
432 			return cmd;
433 		}
434 	}
435 	spin_unlock_bh(&conn->cmd_lock);
436 
437 	pr_err("Unable to locate TTT: 0x%08x on CID: %hu\n",
438 			targ_xfer_tag, conn->cid);
439 	return NULL;
440 }
441 
442 int iscsit_find_cmd_for_recovery(
443 	struct iscsi_session *sess,
444 	struct iscsi_cmd **cmd_ptr,
445 	struct iscsi_conn_recovery **cr_ptr,
446 	itt_t init_task_tag)
447 {
448 	struct iscsi_cmd *cmd = NULL;
449 	struct iscsi_conn_recovery *cr;
450 	/*
451 	 * Scan through the inactive connection recovery list's command list.
452 	 * If init_task_tag matches the command is still alligent.
453 	 */
454 	spin_lock(&sess->cr_i_lock);
455 	list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
456 		spin_lock(&cr->conn_recovery_cmd_lock);
457 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
458 			if (cmd->init_task_tag == init_task_tag) {
459 				spin_unlock(&cr->conn_recovery_cmd_lock);
460 				spin_unlock(&sess->cr_i_lock);
461 
462 				*cr_ptr = cr;
463 				*cmd_ptr = cmd;
464 				return -2;
465 			}
466 		}
467 		spin_unlock(&cr->conn_recovery_cmd_lock);
468 	}
469 	spin_unlock(&sess->cr_i_lock);
470 	/*
471 	 * Scan through the active connection recovery list's command list.
472 	 * If init_task_tag matches the command is ready to be reassigned.
473 	 */
474 	spin_lock(&sess->cr_a_lock);
475 	list_for_each_entry(cr, &sess->cr_active_list, cr_list) {
476 		spin_lock(&cr->conn_recovery_cmd_lock);
477 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
478 			if (cmd->init_task_tag == init_task_tag) {
479 				spin_unlock(&cr->conn_recovery_cmd_lock);
480 				spin_unlock(&sess->cr_a_lock);
481 
482 				*cr_ptr = cr;
483 				*cmd_ptr = cmd;
484 				return 0;
485 			}
486 		}
487 		spin_unlock(&cr->conn_recovery_cmd_lock);
488 	}
489 	spin_unlock(&sess->cr_a_lock);
490 
491 	return -1;
492 }
493 
494 void iscsit_add_cmd_to_immediate_queue(
495 	struct iscsi_cmd *cmd,
496 	struct iscsi_conn *conn,
497 	u8 state)
498 {
499 	struct iscsi_queue_req *qr;
500 
501 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
502 	if (!qr) {
503 		pr_err("Unable to allocate memory for"
504 				" struct iscsi_queue_req\n");
505 		return;
506 	}
507 	INIT_LIST_HEAD(&qr->qr_list);
508 	qr->cmd = cmd;
509 	qr->state = state;
510 
511 	spin_lock_bh(&conn->immed_queue_lock);
512 	list_add_tail(&qr->qr_list, &conn->immed_queue_list);
513 	atomic_inc(&cmd->immed_queue_count);
514 	atomic_set(&conn->check_immediate_queue, 1);
515 	spin_unlock_bh(&conn->immed_queue_lock);
516 
517 	wake_up(&conn->queues_wq);
518 }
519 EXPORT_SYMBOL(iscsit_add_cmd_to_immediate_queue);
520 
521 struct iscsi_queue_req *iscsit_get_cmd_from_immediate_queue(struct iscsi_conn *conn)
522 {
523 	struct iscsi_queue_req *qr;
524 
525 	spin_lock_bh(&conn->immed_queue_lock);
526 	if (list_empty(&conn->immed_queue_list)) {
527 		spin_unlock_bh(&conn->immed_queue_lock);
528 		return NULL;
529 	}
530 	qr = list_first_entry(&conn->immed_queue_list,
531 			      struct iscsi_queue_req, qr_list);
532 
533 	list_del(&qr->qr_list);
534 	if (qr->cmd)
535 		atomic_dec(&qr->cmd->immed_queue_count);
536 	spin_unlock_bh(&conn->immed_queue_lock);
537 
538 	return qr;
539 }
540 
541 static void iscsit_remove_cmd_from_immediate_queue(
542 	struct iscsi_cmd *cmd,
543 	struct iscsi_conn *conn)
544 {
545 	struct iscsi_queue_req *qr, *qr_tmp;
546 
547 	spin_lock_bh(&conn->immed_queue_lock);
548 	if (!atomic_read(&cmd->immed_queue_count)) {
549 		spin_unlock_bh(&conn->immed_queue_lock);
550 		return;
551 	}
552 
553 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
554 		if (qr->cmd != cmd)
555 			continue;
556 
557 		atomic_dec(&qr->cmd->immed_queue_count);
558 		list_del(&qr->qr_list);
559 		kmem_cache_free(lio_qr_cache, qr);
560 	}
561 	spin_unlock_bh(&conn->immed_queue_lock);
562 
563 	if (atomic_read(&cmd->immed_queue_count)) {
564 		pr_err("ITT: 0x%08x immed_queue_count: %d\n",
565 			cmd->init_task_tag,
566 			atomic_read(&cmd->immed_queue_count));
567 	}
568 }
569 
570 int iscsit_add_cmd_to_response_queue(
571 	struct iscsi_cmd *cmd,
572 	struct iscsi_conn *conn,
573 	u8 state)
574 {
575 	struct iscsi_queue_req *qr;
576 
577 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
578 	if (!qr) {
579 		pr_err("Unable to allocate memory for"
580 			" struct iscsi_queue_req\n");
581 		return -ENOMEM;
582 	}
583 	INIT_LIST_HEAD(&qr->qr_list);
584 	qr->cmd = cmd;
585 	qr->state = state;
586 
587 	spin_lock_bh(&conn->response_queue_lock);
588 	list_add_tail(&qr->qr_list, &conn->response_queue_list);
589 	atomic_inc(&cmd->response_queue_count);
590 	spin_unlock_bh(&conn->response_queue_lock);
591 
592 	wake_up(&conn->queues_wq);
593 	return 0;
594 }
595 
596 struct iscsi_queue_req *iscsit_get_cmd_from_response_queue(struct iscsi_conn *conn)
597 {
598 	struct iscsi_queue_req *qr;
599 
600 	spin_lock_bh(&conn->response_queue_lock);
601 	if (list_empty(&conn->response_queue_list)) {
602 		spin_unlock_bh(&conn->response_queue_lock);
603 		return NULL;
604 	}
605 
606 	qr = list_first_entry(&conn->response_queue_list,
607 			      struct iscsi_queue_req, qr_list);
608 
609 	list_del(&qr->qr_list);
610 	if (qr->cmd)
611 		atomic_dec(&qr->cmd->response_queue_count);
612 	spin_unlock_bh(&conn->response_queue_lock);
613 
614 	return qr;
615 }
616 
617 static void iscsit_remove_cmd_from_response_queue(
618 	struct iscsi_cmd *cmd,
619 	struct iscsi_conn *conn)
620 {
621 	struct iscsi_queue_req *qr, *qr_tmp;
622 
623 	spin_lock_bh(&conn->response_queue_lock);
624 	if (!atomic_read(&cmd->response_queue_count)) {
625 		spin_unlock_bh(&conn->response_queue_lock);
626 		return;
627 	}
628 
629 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
630 				qr_list) {
631 		if (qr->cmd != cmd)
632 			continue;
633 
634 		atomic_dec(&qr->cmd->response_queue_count);
635 		list_del(&qr->qr_list);
636 		kmem_cache_free(lio_qr_cache, qr);
637 	}
638 	spin_unlock_bh(&conn->response_queue_lock);
639 
640 	if (atomic_read(&cmd->response_queue_count)) {
641 		pr_err("ITT: 0x%08x response_queue_count: %d\n",
642 			cmd->init_task_tag,
643 			atomic_read(&cmd->response_queue_count));
644 	}
645 }
646 
647 bool iscsit_conn_all_queues_empty(struct iscsi_conn *conn)
648 {
649 	bool empty;
650 
651 	spin_lock_bh(&conn->immed_queue_lock);
652 	empty = list_empty(&conn->immed_queue_list);
653 	spin_unlock_bh(&conn->immed_queue_lock);
654 
655 	if (!empty)
656 		return empty;
657 
658 	spin_lock_bh(&conn->response_queue_lock);
659 	empty = list_empty(&conn->response_queue_list);
660 	spin_unlock_bh(&conn->response_queue_lock);
661 
662 	return empty;
663 }
664 
665 void iscsit_free_queue_reqs_for_conn(struct iscsi_conn *conn)
666 {
667 	struct iscsi_queue_req *qr, *qr_tmp;
668 
669 	spin_lock_bh(&conn->immed_queue_lock);
670 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
671 		list_del(&qr->qr_list);
672 		if (qr->cmd)
673 			atomic_dec(&qr->cmd->immed_queue_count);
674 
675 		kmem_cache_free(lio_qr_cache, qr);
676 	}
677 	spin_unlock_bh(&conn->immed_queue_lock);
678 
679 	spin_lock_bh(&conn->response_queue_lock);
680 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
681 			qr_list) {
682 		list_del(&qr->qr_list);
683 		if (qr->cmd)
684 			atomic_dec(&qr->cmd->response_queue_count);
685 
686 		kmem_cache_free(lio_qr_cache, qr);
687 	}
688 	spin_unlock_bh(&conn->response_queue_lock);
689 }
690 
691 void iscsit_release_cmd(struct iscsi_cmd *cmd)
692 {
693 	struct iscsi_session *sess;
694 	struct se_cmd *se_cmd = &cmd->se_cmd;
695 
696 	if (cmd->conn)
697 		sess = cmd->conn->sess;
698 	else
699 		sess = cmd->sess;
700 
701 	BUG_ON(!sess || !sess->se_sess);
702 
703 	kfree(cmd->buf_ptr);
704 	kfree(cmd->pdu_list);
705 	kfree(cmd->seq_list);
706 	kfree(cmd->tmr_req);
707 	kfree(cmd->iov_data);
708 	kfree(cmd->text_in_ptr);
709 
710 	percpu_ida_free(&sess->se_sess->sess_tag_pool, se_cmd->map_tag);
711 }
712 EXPORT_SYMBOL(iscsit_release_cmd);
713 
714 void __iscsit_free_cmd(struct iscsi_cmd *cmd, bool scsi_cmd,
715 		       bool check_queues)
716 {
717 	struct iscsi_conn *conn = cmd->conn;
718 
719 	if (scsi_cmd) {
720 		if (cmd->data_direction == DMA_TO_DEVICE) {
721 			iscsit_stop_dataout_timer(cmd);
722 			iscsit_free_r2ts_from_list(cmd);
723 		}
724 		if (cmd->data_direction == DMA_FROM_DEVICE)
725 			iscsit_free_all_datain_reqs(cmd);
726 	}
727 
728 	if (conn && check_queues) {
729 		iscsit_remove_cmd_from_immediate_queue(cmd, conn);
730 		iscsit_remove_cmd_from_response_queue(cmd, conn);
731 	}
732 
733 	if (conn && conn->conn_transport->iscsit_release_cmd)
734 		conn->conn_transport->iscsit_release_cmd(conn, cmd);
735 }
736 
737 void iscsit_free_cmd(struct iscsi_cmd *cmd, bool shutdown)
738 {
739 	struct se_cmd *se_cmd = NULL;
740 	int rc;
741 	bool op_scsi = false;
742 	/*
743 	 * Determine if a struct se_cmd is associated with
744 	 * this struct iscsi_cmd.
745 	 */
746 	switch (cmd->iscsi_opcode) {
747 	case ISCSI_OP_SCSI_CMD:
748 		op_scsi = true;
749 		/*
750 		 * Fallthrough
751 		 */
752 	case ISCSI_OP_SCSI_TMFUNC:
753 		se_cmd = &cmd->se_cmd;
754 		__iscsit_free_cmd(cmd, op_scsi, shutdown);
755 		rc = transport_generic_free_cmd(se_cmd, shutdown);
756 		if (!rc && shutdown && se_cmd->se_sess) {
757 			__iscsit_free_cmd(cmd, op_scsi, shutdown);
758 			target_put_sess_cmd(se_cmd);
759 		}
760 		break;
761 	case ISCSI_OP_REJECT:
762 		/*
763 		 * Handle special case for REJECT when iscsi_add_reject*() has
764 		 * overwritten the original iscsi_opcode assignment, and the
765 		 * associated cmd->se_cmd needs to be released.
766 		 */
767 		if (cmd->se_cmd.se_tfo != NULL) {
768 			se_cmd = &cmd->se_cmd;
769 			__iscsit_free_cmd(cmd, true, shutdown);
770 
771 			rc = transport_generic_free_cmd(&cmd->se_cmd, shutdown);
772 			if (!rc && shutdown && se_cmd->se_sess) {
773 				__iscsit_free_cmd(cmd, true, shutdown);
774 				target_put_sess_cmd(se_cmd);
775 			}
776 			break;
777 		}
778 		/* Fall-through */
779 	default:
780 		__iscsit_free_cmd(cmd, false, shutdown);
781 		iscsit_release_cmd(cmd);
782 		break;
783 	}
784 }
785 EXPORT_SYMBOL(iscsit_free_cmd);
786 
787 int iscsit_check_session_usage_count(struct iscsi_session *sess)
788 {
789 	spin_lock_bh(&sess->session_usage_lock);
790 	if (sess->session_usage_count != 0) {
791 		sess->session_waiting_on_uc = 1;
792 		spin_unlock_bh(&sess->session_usage_lock);
793 		if (in_interrupt())
794 			return 2;
795 
796 		wait_for_completion(&sess->session_waiting_on_uc_comp);
797 		return 1;
798 	}
799 	spin_unlock_bh(&sess->session_usage_lock);
800 
801 	return 0;
802 }
803 
804 void iscsit_dec_session_usage_count(struct iscsi_session *sess)
805 {
806 	spin_lock_bh(&sess->session_usage_lock);
807 	sess->session_usage_count--;
808 
809 	if (!sess->session_usage_count && sess->session_waiting_on_uc)
810 		complete(&sess->session_waiting_on_uc_comp);
811 
812 	spin_unlock_bh(&sess->session_usage_lock);
813 }
814 
815 void iscsit_inc_session_usage_count(struct iscsi_session *sess)
816 {
817 	spin_lock_bh(&sess->session_usage_lock);
818 	sess->session_usage_count++;
819 	spin_unlock_bh(&sess->session_usage_lock);
820 }
821 
822 struct iscsi_conn *iscsit_get_conn_from_cid(struct iscsi_session *sess, u16 cid)
823 {
824 	struct iscsi_conn *conn;
825 
826 	spin_lock_bh(&sess->conn_lock);
827 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
828 		if ((conn->cid == cid) &&
829 		    (conn->conn_state == TARG_CONN_STATE_LOGGED_IN)) {
830 			iscsit_inc_conn_usage_count(conn);
831 			spin_unlock_bh(&sess->conn_lock);
832 			return conn;
833 		}
834 	}
835 	spin_unlock_bh(&sess->conn_lock);
836 
837 	return NULL;
838 }
839 
840 struct iscsi_conn *iscsit_get_conn_from_cid_rcfr(struct iscsi_session *sess, u16 cid)
841 {
842 	struct iscsi_conn *conn;
843 
844 	spin_lock_bh(&sess->conn_lock);
845 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
846 		if (conn->cid == cid) {
847 			iscsit_inc_conn_usage_count(conn);
848 			spin_lock(&conn->state_lock);
849 			atomic_set(&conn->connection_wait_rcfr, 1);
850 			spin_unlock(&conn->state_lock);
851 			spin_unlock_bh(&sess->conn_lock);
852 			return conn;
853 		}
854 	}
855 	spin_unlock_bh(&sess->conn_lock);
856 
857 	return NULL;
858 }
859 
860 void iscsit_check_conn_usage_count(struct iscsi_conn *conn)
861 {
862 	spin_lock_bh(&conn->conn_usage_lock);
863 	if (conn->conn_usage_count != 0) {
864 		conn->conn_waiting_on_uc = 1;
865 		spin_unlock_bh(&conn->conn_usage_lock);
866 
867 		wait_for_completion(&conn->conn_waiting_on_uc_comp);
868 		return;
869 	}
870 	spin_unlock_bh(&conn->conn_usage_lock);
871 }
872 
873 void iscsit_dec_conn_usage_count(struct iscsi_conn *conn)
874 {
875 	spin_lock_bh(&conn->conn_usage_lock);
876 	conn->conn_usage_count--;
877 
878 	if (!conn->conn_usage_count && conn->conn_waiting_on_uc)
879 		complete(&conn->conn_waiting_on_uc_comp);
880 
881 	spin_unlock_bh(&conn->conn_usage_lock);
882 }
883 
884 void iscsit_inc_conn_usage_count(struct iscsi_conn *conn)
885 {
886 	spin_lock_bh(&conn->conn_usage_lock);
887 	conn->conn_usage_count++;
888 	spin_unlock_bh(&conn->conn_usage_lock);
889 }
890 
891 static int iscsit_add_nopin(struct iscsi_conn *conn, int want_response)
892 {
893 	u8 state;
894 	struct iscsi_cmd *cmd;
895 
896 	cmd = iscsit_allocate_cmd(conn, TASK_RUNNING);
897 	if (!cmd)
898 		return -1;
899 
900 	cmd->iscsi_opcode = ISCSI_OP_NOOP_IN;
901 	state = (want_response) ? ISTATE_SEND_NOPIN_WANT_RESPONSE :
902 				ISTATE_SEND_NOPIN_NO_RESPONSE;
903 	cmd->init_task_tag = RESERVED_ITT;
904 	cmd->targ_xfer_tag = (want_response) ?
905 			     session_get_next_ttt(conn->sess) : 0xFFFFFFFF;
906 	spin_lock_bh(&conn->cmd_lock);
907 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
908 	spin_unlock_bh(&conn->cmd_lock);
909 
910 	if (want_response)
911 		iscsit_start_nopin_response_timer(conn);
912 	iscsit_add_cmd_to_immediate_queue(cmd, conn, state);
913 
914 	return 0;
915 }
916 
917 static void iscsit_handle_nopin_response_timeout(unsigned long data)
918 {
919 	struct iscsi_conn *conn = (struct iscsi_conn *) data;
920 
921 	iscsit_inc_conn_usage_count(conn);
922 
923 	spin_lock_bh(&conn->nopin_timer_lock);
924 	if (conn->nopin_response_timer_flags & ISCSI_TF_STOP) {
925 		spin_unlock_bh(&conn->nopin_timer_lock);
926 		iscsit_dec_conn_usage_count(conn);
927 		return;
928 	}
929 
930 	pr_debug("Did not receive response to NOPIN on CID: %hu on"
931 		" SID: %u, failing connection.\n", conn->cid,
932 			conn->sess->sid);
933 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
934 	spin_unlock_bh(&conn->nopin_timer_lock);
935 
936 	{
937 	struct iscsi_portal_group *tpg = conn->sess->tpg;
938 	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
939 
940 	if (tiqn) {
941 		spin_lock_bh(&tiqn->sess_err_stats.lock);
942 		strcpy(tiqn->sess_err_stats.last_sess_fail_rem_name,
943 				conn->sess->sess_ops->InitiatorName);
944 		tiqn->sess_err_stats.last_sess_failure_type =
945 				ISCSI_SESS_ERR_CXN_TIMEOUT;
946 		tiqn->sess_err_stats.cxn_timeout_errors++;
947 		atomic_long_inc(&conn->sess->conn_timeout_errors);
948 		spin_unlock_bh(&tiqn->sess_err_stats.lock);
949 	}
950 	}
951 
952 	iscsit_cause_connection_reinstatement(conn, 0);
953 	iscsit_dec_conn_usage_count(conn);
954 }
955 
956 void iscsit_mod_nopin_response_timer(struct iscsi_conn *conn)
957 {
958 	struct iscsi_session *sess = conn->sess;
959 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
960 
961 	spin_lock_bh(&conn->nopin_timer_lock);
962 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
963 		spin_unlock_bh(&conn->nopin_timer_lock);
964 		return;
965 	}
966 
967 	mod_timer(&conn->nopin_response_timer,
968 		(get_jiffies_64() + na->nopin_response_timeout * HZ));
969 	spin_unlock_bh(&conn->nopin_timer_lock);
970 }
971 
972 /*
973  *	Called with conn->nopin_timer_lock held.
974  */
975 void iscsit_start_nopin_response_timer(struct iscsi_conn *conn)
976 {
977 	struct iscsi_session *sess = conn->sess;
978 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
979 
980 	spin_lock_bh(&conn->nopin_timer_lock);
981 	if (conn->nopin_response_timer_flags & ISCSI_TF_RUNNING) {
982 		spin_unlock_bh(&conn->nopin_timer_lock);
983 		return;
984 	}
985 
986 	init_timer(&conn->nopin_response_timer);
987 	conn->nopin_response_timer.expires =
988 		(get_jiffies_64() + na->nopin_response_timeout * HZ);
989 	conn->nopin_response_timer.data = (unsigned long)conn;
990 	conn->nopin_response_timer.function = iscsit_handle_nopin_response_timeout;
991 	conn->nopin_response_timer_flags &= ~ISCSI_TF_STOP;
992 	conn->nopin_response_timer_flags |= ISCSI_TF_RUNNING;
993 	add_timer(&conn->nopin_response_timer);
994 
995 	pr_debug("Started NOPIN Response Timer on CID: %d to %u"
996 		" seconds\n", conn->cid, na->nopin_response_timeout);
997 	spin_unlock_bh(&conn->nopin_timer_lock);
998 }
999 
1000 void iscsit_stop_nopin_response_timer(struct iscsi_conn *conn)
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 	conn->nopin_response_timer_flags |= ISCSI_TF_STOP;
1008 	spin_unlock_bh(&conn->nopin_timer_lock);
1009 
1010 	del_timer_sync(&conn->nopin_response_timer);
1011 
1012 	spin_lock_bh(&conn->nopin_timer_lock);
1013 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
1014 	spin_unlock_bh(&conn->nopin_timer_lock);
1015 }
1016 
1017 static void iscsit_handle_nopin_timeout(unsigned long data)
1018 {
1019 	struct iscsi_conn *conn = (struct iscsi_conn *) data;
1020 
1021 	iscsit_inc_conn_usage_count(conn);
1022 
1023 	spin_lock_bh(&conn->nopin_timer_lock);
1024 	if (conn->nopin_timer_flags & ISCSI_TF_STOP) {
1025 		spin_unlock_bh(&conn->nopin_timer_lock);
1026 		iscsit_dec_conn_usage_count(conn);
1027 		return;
1028 	}
1029 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1030 	spin_unlock_bh(&conn->nopin_timer_lock);
1031 
1032 	iscsit_add_nopin(conn, 1);
1033 	iscsit_dec_conn_usage_count(conn);
1034 }
1035 
1036 /*
1037  * Called with conn->nopin_timer_lock held.
1038  */
1039 void __iscsit_start_nopin_timer(struct iscsi_conn *conn)
1040 {
1041 	struct iscsi_session *sess = conn->sess;
1042 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1043 	/*
1044 	* NOPIN timeout is disabled.
1045 	 */
1046 	if (!na->nopin_timeout)
1047 		return;
1048 
1049 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING)
1050 		return;
1051 
1052 	init_timer(&conn->nopin_timer);
1053 	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1054 	conn->nopin_timer.data = (unsigned long)conn;
1055 	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1056 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1057 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1058 	add_timer(&conn->nopin_timer);
1059 
1060 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1061 		" interval\n", conn->cid, na->nopin_timeout);
1062 }
1063 
1064 void iscsit_start_nopin_timer(struct iscsi_conn *conn)
1065 {
1066 	struct iscsi_session *sess = conn->sess;
1067 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1068 	/*
1069 	 * NOPIN timeout is disabled..
1070 	 */
1071 	if (!na->nopin_timeout)
1072 		return;
1073 
1074 	spin_lock_bh(&conn->nopin_timer_lock);
1075 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING) {
1076 		spin_unlock_bh(&conn->nopin_timer_lock);
1077 		return;
1078 	}
1079 
1080 	init_timer(&conn->nopin_timer);
1081 	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
1082 	conn->nopin_timer.data = (unsigned long)conn;
1083 	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
1084 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1085 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1086 	add_timer(&conn->nopin_timer);
1087 
1088 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1089 			" interval\n", conn->cid, na->nopin_timeout);
1090 	spin_unlock_bh(&conn->nopin_timer_lock);
1091 }
1092 
1093 void iscsit_stop_nopin_timer(struct iscsi_conn *conn)
1094 {
1095 	spin_lock_bh(&conn->nopin_timer_lock);
1096 	if (!(conn->nopin_timer_flags & ISCSI_TF_RUNNING)) {
1097 		spin_unlock_bh(&conn->nopin_timer_lock);
1098 		return;
1099 	}
1100 	conn->nopin_timer_flags |= ISCSI_TF_STOP;
1101 	spin_unlock_bh(&conn->nopin_timer_lock);
1102 
1103 	del_timer_sync(&conn->nopin_timer);
1104 
1105 	spin_lock_bh(&conn->nopin_timer_lock);
1106 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1107 	spin_unlock_bh(&conn->nopin_timer_lock);
1108 }
1109 
1110 int iscsit_send_tx_data(
1111 	struct iscsi_cmd *cmd,
1112 	struct iscsi_conn *conn,
1113 	int use_misc)
1114 {
1115 	int tx_sent, tx_size;
1116 	u32 iov_count;
1117 	struct kvec *iov;
1118 
1119 send_data:
1120 	tx_size = cmd->tx_size;
1121 
1122 	if (!use_misc) {
1123 		iov = &cmd->iov_data[0];
1124 		iov_count = cmd->iov_data_count;
1125 	} else {
1126 		iov = &cmd->iov_misc[0];
1127 		iov_count = cmd->iov_misc_count;
1128 	}
1129 
1130 	tx_sent = tx_data(conn, &iov[0], iov_count, tx_size);
1131 	if (tx_size != tx_sent) {
1132 		if (tx_sent == -EAGAIN) {
1133 			pr_err("tx_data() returned -EAGAIN\n");
1134 			goto send_data;
1135 		} else
1136 			return -1;
1137 	}
1138 	cmd->tx_size = 0;
1139 
1140 	return 0;
1141 }
1142 
1143 int iscsit_fe_sendpage_sg(
1144 	struct iscsi_cmd *cmd,
1145 	struct iscsi_conn *conn)
1146 {
1147 	struct scatterlist *sg = cmd->first_data_sg;
1148 	struct kvec iov;
1149 	u32 tx_hdr_size, data_len;
1150 	u32 offset = cmd->first_data_sg_off;
1151 	int tx_sent, iov_off;
1152 
1153 send_hdr:
1154 	tx_hdr_size = ISCSI_HDR_LEN;
1155 	if (conn->conn_ops->HeaderDigest)
1156 		tx_hdr_size += ISCSI_CRC_LEN;
1157 
1158 	iov.iov_base = cmd->pdu;
1159 	iov.iov_len = tx_hdr_size;
1160 
1161 	tx_sent = tx_data(conn, &iov, 1, tx_hdr_size);
1162 	if (tx_hdr_size != tx_sent) {
1163 		if (tx_sent == -EAGAIN) {
1164 			pr_err("tx_data() returned -EAGAIN\n");
1165 			goto send_hdr;
1166 		}
1167 		return -1;
1168 	}
1169 
1170 	data_len = cmd->tx_size - tx_hdr_size - cmd->padding;
1171 	/*
1172 	 * Set iov_off used by padding and data digest tx_data() calls below
1173 	 * in order to determine proper offset into cmd->iov_data[]
1174 	 */
1175 	if (conn->conn_ops->DataDigest) {
1176 		data_len -= ISCSI_CRC_LEN;
1177 		if (cmd->padding)
1178 			iov_off = (cmd->iov_data_count - 2);
1179 		else
1180 			iov_off = (cmd->iov_data_count - 1);
1181 	} else {
1182 		iov_off = (cmd->iov_data_count - 1);
1183 	}
1184 	/*
1185 	 * Perform sendpage() for each page in the scatterlist
1186 	 */
1187 	while (data_len) {
1188 		u32 space = (sg->length - offset);
1189 		u32 sub_len = min_t(u32, data_len, space);
1190 send_pg:
1191 		tx_sent = conn->sock->ops->sendpage(conn->sock,
1192 					sg_page(sg), sg->offset + offset, sub_len, 0);
1193 		if (tx_sent != sub_len) {
1194 			if (tx_sent == -EAGAIN) {
1195 				pr_err("tcp_sendpage() returned"
1196 						" -EAGAIN\n");
1197 				goto send_pg;
1198 			}
1199 
1200 			pr_err("tcp_sendpage() failure: %d\n",
1201 					tx_sent);
1202 			return -1;
1203 		}
1204 
1205 		data_len -= sub_len;
1206 		offset = 0;
1207 		sg = sg_next(sg);
1208 	}
1209 
1210 send_padding:
1211 	if (cmd->padding) {
1212 		struct kvec *iov_p = &cmd->iov_data[iov_off++];
1213 
1214 		tx_sent = tx_data(conn, iov_p, 1, cmd->padding);
1215 		if (cmd->padding != tx_sent) {
1216 			if (tx_sent == -EAGAIN) {
1217 				pr_err("tx_data() returned -EAGAIN\n");
1218 				goto send_padding;
1219 			}
1220 			return -1;
1221 		}
1222 	}
1223 
1224 send_datacrc:
1225 	if (conn->conn_ops->DataDigest) {
1226 		struct kvec *iov_d = &cmd->iov_data[iov_off];
1227 
1228 		tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN);
1229 		if (ISCSI_CRC_LEN != tx_sent) {
1230 			if (tx_sent == -EAGAIN) {
1231 				pr_err("tx_data() returned -EAGAIN\n");
1232 				goto send_datacrc;
1233 			}
1234 			return -1;
1235 		}
1236 	}
1237 
1238 	return 0;
1239 }
1240 
1241 /*
1242  *      This function is used for mainly sending a ISCSI_TARG_LOGIN_RSP PDU
1243  *      back to the Initiator when an expection condition occurs with the
1244  *      errors set in status_class and status_detail.
1245  *
1246  *      Parameters:     iSCSI Connection, Status Class, Status Detail.
1247  *      Returns:        0 on success, -1 on error.
1248  */
1249 int iscsit_tx_login_rsp(struct iscsi_conn *conn, u8 status_class, u8 status_detail)
1250 {
1251 	struct iscsi_login_rsp *hdr;
1252 	struct iscsi_login *login = conn->conn_login;
1253 
1254 	login->login_failed = 1;
1255 	iscsit_collect_login_stats(conn, status_class, status_detail);
1256 
1257 	memset(&login->rsp[0], 0, ISCSI_HDR_LEN);
1258 
1259 	hdr	= (struct iscsi_login_rsp *)&login->rsp[0];
1260 	hdr->opcode		= ISCSI_OP_LOGIN_RSP;
1261 	hdr->status_class	= status_class;
1262 	hdr->status_detail	= status_detail;
1263 	hdr->itt		= conn->login_itt;
1264 
1265 	return conn->conn_transport->iscsit_put_login_tx(conn, login, 0);
1266 }
1267 
1268 void iscsit_print_session_params(struct iscsi_session *sess)
1269 {
1270 	struct iscsi_conn *conn;
1271 
1272 	pr_debug("-----------------------------[Session Params for"
1273 		" SID: %u]-----------------------------\n", sess->sid);
1274 	spin_lock_bh(&sess->conn_lock);
1275 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
1276 		iscsi_dump_conn_ops(conn->conn_ops);
1277 	spin_unlock_bh(&sess->conn_lock);
1278 
1279 	iscsi_dump_sess_ops(sess->sess_ops);
1280 }
1281 
1282 static int iscsit_do_rx_data(
1283 	struct iscsi_conn *conn,
1284 	struct iscsi_data_count *count)
1285 {
1286 	int data = count->data_length, rx_loop = 0, total_rx = 0;
1287 	struct msghdr msg;
1288 
1289 	if (!conn || !conn->sock || !conn->conn_ops)
1290 		return -1;
1291 
1292 	memset(&msg, 0, sizeof(struct msghdr));
1293 	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC,
1294 		      count->iov, count->iov_count, data);
1295 
1296 	while (msg_data_left(&msg)) {
1297 		rx_loop = sock_recvmsg(conn->sock, &msg, MSG_WAITALL);
1298 		if (rx_loop <= 0) {
1299 			pr_debug("rx_loop: %d total_rx: %d\n",
1300 				rx_loop, total_rx);
1301 			return rx_loop;
1302 		}
1303 		total_rx += rx_loop;
1304 		pr_debug("rx_loop: %d, total_rx: %d, data: %d\n",
1305 				rx_loop, total_rx, data);
1306 	}
1307 
1308 	return total_rx;
1309 }
1310 
1311 int rx_data(
1312 	struct iscsi_conn *conn,
1313 	struct kvec *iov,
1314 	int iov_count,
1315 	int data)
1316 {
1317 	struct iscsi_data_count c;
1318 
1319 	if (!conn || !conn->sock || !conn->conn_ops)
1320 		return -1;
1321 
1322 	memset(&c, 0, sizeof(struct iscsi_data_count));
1323 	c.iov = iov;
1324 	c.iov_count = iov_count;
1325 	c.data_length = data;
1326 	c.type = ISCSI_RX_DATA;
1327 
1328 	return iscsit_do_rx_data(conn, &c);
1329 }
1330 
1331 int tx_data(
1332 	struct iscsi_conn *conn,
1333 	struct kvec *iov,
1334 	int iov_count,
1335 	int data)
1336 {
1337 	struct msghdr msg;
1338 	int total_tx = 0;
1339 
1340 	if (!conn || !conn->sock || !conn->conn_ops)
1341 		return -1;
1342 
1343 	if (data <= 0) {
1344 		pr_err("Data length is: %d\n", data);
1345 		return -1;
1346 	}
1347 
1348 	memset(&msg, 0, sizeof(struct msghdr));
1349 
1350 	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC,
1351 		      iov, iov_count, data);
1352 
1353 	while (msg_data_left(&msg)) {
1354 		int tx_loop = sock_sendmsg(conn->sock, &msg);
1355 		if (tx_loop <= 0) {
1356 			pr_debug("tx_loop: %d total_tx %d\n",
1357 				tx_loop, total_tx);
1358 			return tx_loop;
1359 		}
1360 		total_tx += tx_loop;
1361 		pr_debug("tx_loop: %d, total_tx: %d, data: %d\n",
1362 					tx_loop, total_tx, data);
1363 	}
1364 
1365 	return total_tx;
1366 }
1367 
1368 void iscsit_collect_login_stats(
1369 	struct iscsi_conn *conn,
1370 	u8 status_class,
1371 	u8 status_detail)
1372 {
1373 	struct iscsi_param *intrname = NULL;
1374 	struct iscsi_tiqn *tiqn;
1375 	struct iscsi_login_stats *ls;
1376 
1377 	tiqn = iscsit_snmp_get_tiqn(conn);
1378 	if (!tiqn)
1379 		return;
1380 
1381 	ls = &tiqn->login_stats;
1382 
1383 	spin_lock(&ls->lock);
1384 	if (status_class == ISCSI_STATUS_CLS_SUCCESS)
1385 		ls->accepts++;
1386 	else if (status_class == ISCSI_STATUS_CLS_REDIRECT) {
1387 		ls->redirects++;
1388 		ls->last_fail_type = ISCSI_LOGIN_FAIL_REDIRECT;
1389 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1390 		 (status_detail == ISCSI_LOGIN_STATUS_AUTH_FAILED)) {
1391 		ls->authenticate_fails++;
1392 		ls->last_fail_type =  ISCSI_LOGIN_FAIL_AUTHENTICATE;
1393 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1394 		 (status_detail == ISCSI_LOGIN_STATUS_TGT_FORBIDDEN)) {
1395 		ls->authorize_fails++;
1396 		ls->last_fail_type = ISCSI_LOGIN_FAIL_AUTHORIZE;
1397 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR) &&
1398 		 (status_detail == ISCSI_LOGIN_STATUS_INIT_ERR)) {
1399 		ls->negotiate_fails++;
1400 		ls->last_fail_type = ISCSI_LOGIN_FAIL_NEGOTIATE;
1401 	} else {
1402 		ls->other_fails++;
1403 		ls->last_fail_type = ISCSI_LOGIN_FAIL_OTHER;
1404 	}
1405 
1406 	/* Save initiator name, ip address and time, if it is a failed login */
1407 	if (status_class != ISCSI_STATUS_CLS_SUCCESS) {
1408 		if (conn->param_list)
1409 			intrname = iscsi_find_param_from_key(INITIATORNAME,
1410 							     conn->param_list);
1411 		strlcpy(ls->last_intr_fail_name,
1412 		       (intrname ? intrname->value : "Unknown"),
1413 		       sizeof(ls->last_intr_fail_name));
1414 
1415 		ls->last_intr_fail_ip_family = conn->login_family;
1416 
1417 		ls->last_intr_fail_sockaddr = conn->login_sockaddr;
1418 		ls->last_fail_time = get_jiffies_64();
1419 	}
1420 
1421 	spin_unlock(&ls->lock);
1422 }
1423 
1424 struct iscsi_tiqn *iscsit_snmp_get_tiqn(struct iscsi_conn *conn)
1425 {
1426 	struct iscsi_portal_group *tpg;
1427 
1428 	if (!conn)
1429 		return NULL;
1430 
1431 	tpg = conn->tpg;
1432 	if (!tpg)
1433 		return NULL;
1434 
1435 	if (!tpg->tpg_tiqn)
1436 		return NULL;
1437 
1438 	return tpg->tpg_tiqn;
1439 }
1440