1/*******************************************************************************
2 * This file contains the iSCSI Target DataIN value generation 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 <scsi/iscsi_proto.h>
20
21#include <target/iscsi/iscsi_target_core.h>
22#include "iscsi_target_seq_pdu_list.h"
23#include "iscsi_target_erl1.h"
24#include "iscsi_target_util.h"
25#include "iscsi_target.h"
26#include "iscsi_target_datain_values.h"
27
28struct iscsi_datain_req *iscsit_allocate_datain_req(void)
29{
30	struct iscsi_datain_req *dr;
31
32	dr = kmem_cache_zalloc(lio_dr_cache, GFP_ATOMIC);
33	if (!dr) {
34		pr_err("Unable to allocate memory for"
35				" struct iscsi_datain_req\n");
36		return NULL;
37	}
38	INIT_LIST_HEAD(&dr->cmd_datain_node);
39
40	return dr;
41}
42
43void iscsit_attach_datain_req(struct iscsi_cmd *cmd, struct iscsi_datain_req *dr)
44{
45	spin_lock(&cmd->datain_lock);
46	list_add_tail(&dr->cmd_datain_node, &cmd->datain_list);
47	spin_unlock(&cmd->datain_lock);
48}
49
50void iscsit_free_datain_req(struct iscsi_cmd *cmd, struct iscsi_datain_req *dr)
51{
52	spin_lock(&cmd->datain_lock);
53	list_del(&dr->cmd_datain_node);
54	spin_unlock(&cmd->datain_lock);
55
56	kmem_cache_free(lio_dr_cache, dr);
57}
58
59void iscsit_free_all_datain_reqs(struct iscsi_cmd *cmd)
60{
61	struct iscsi_datain_req *dr, *dr_tmp;
62
63	spin_lock(&cmd->datain_lock);
64	list_for_each_entry_safe(dr, dr_tmp, &cmd->datain_list, cmd_datain_node) {
65		list_del(&dr->cmd_datain_node);
66		kmem_cache_free(lio_dr_cache, dr);
67	}
68	spin_unlock(&cmd->datain_lock);
69}
70
71struct iscsi_datain_req *iscsit_get_datain_req(struct iscsi_cmd *cmd)
72{
73	if (list_empty(&cmd->datain_list)) {
74		pr_err("cmd->datain_list is empty for ITT:"
75			" 0x%08x\n", cmd->init_task_tag);
76		return NULL;
77	}
78
79	return list_first_entry(&cmd->datain_list, struct iscsi_datain_req,
80				cmd_datain_node);
81}
82
83/*
84 *	For Normal and Recovery DataSequenceInOrder=Yes and DataPDUInOrder=Yes.
85 */
86static struct iscsi_datain_req *iscsit_set_datain_values_yes_and_yes(
87	struct iscsi_cmd *cmd,
88	struct iscsi_datain *datain)
89{
90	u32 next_burst_len, read_data_done, read_data_left;
91	struct iscsi_conn *conn = cmd->conn;
92	struct iscsi_datain_req *dr;
93
94	dr = iscsit_get_datain_req(cmd);
95	if (!dr)
96		return NULL;
97
98	if (dr->recovery && dr->generate_recovery_values) {
99		if (iscsit_create_recovery_datain_values_datasequenceinorder_yes(
100					cmd, dr) < 0)
101			return NULL;
102
103		dr->generate_recovery_values = 0;
104	}
105
106	next_burst_len = (!dr->recovery) ?
107			cmd->next_burst_len : dr->next_burst_len;
108	read_data_done = (!dr->recovery) ?
109			cmd->read_data_done : dr->read_data_done;
110
111	read_data_left = (cmd->se_cmd.data_length - read_data_done);
112	if (!read_data_left) {
113		pr_err("ITT: 0x%08x read_data_left is zero!\n",
114				cmd->init_task_tag);
115		return NULL;
116	}
117
118	if ((read_data_left <= conn->conn_ops->MaxRecvDataSegmentLength) &&
119	    (read_data_left <= (conn->sess->sess_ops->MaxBurstLength -
120	     next_burst_len))) {
121		datain->length = read_data_left;
122
123		datain->flags |= (ISCSI_FLAG_CMD_FINAL | ISCSI_FLAG_DATA_STATUS);
124		if (conn->sess->sess_ops->ErrorRecoveryLevel > 0)
125			datain->flags |= ISCSI_FLAG_DATA_ACK;
126	} else {
127		if ((next_burst_len +
128		     conn->conn_ops->MaxRecvDataSegmentLength) <
129		     conn->sess->sess_ops->MaxBurstLength) {
130			datain->length =
131				conn->conn_ops->MaxRecvDataSegmentLength;
132			next_burst_len += datain->length;
133		} else {
134			datain->length = (conn->sess->sess_ops->MaxBurstLength -
135					  next_burst_len);
136			next_burst_len = 0;
137
138			datain->flags |= ISCSI_FLAG_CMD_FINAL;
139			if (conn->sess->sess_ops->ErrorRecoveryLevel > 0)
140				datain->flags |= ISCSI_FLAG_DATA_ACK;
141		}
142	}
143
144	datain->data_sn = (!dr->recovery) ? cmd->data_sn++ : dr->data_sn++;
145	datain->offset = read_data_done;
146
147	if (!dr->recovery) {
148		cmd->next_burst_len = next_burst_len;
149		cmd->read_data_done += datain->length;
150	} else {
151		dr->next_burst_len = next_burst_len;
152		dr->read_data_done += datain->length;
153	}
154
155	if (!dr->recovery) {
156		if (datain->flags & ISCSI_FLAG_DATA_STATUS)
157			dr->dr_complete = DATAIN_COMPLETE_NORMAL;
158
159		return dr;
160	}
161
162	if (!dr->runlength) {
163		if (datain->flags & ISCSI_FLAG_DATA_STATUS) {
164			dr->dr_complete =
165			    (dr->recovery == DATAIN_WITHIN_COMMAND_RECOVERY) ?
166				DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY :
167				DATAIN_COMPLETE_CONNECTION_RECOVERY;
168		}
169	} else {
170		if ((dr->begrun + dr->runlength) == dr->data_sn) {
171			dr->dr_complete =
172			    (dr->recovery == DATAIN_WITHIN_COMMAND_RECOVERY) ?
173				DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY :
174				DATAIN_COMPLETE_CONNECTION_RECOVERY;
175		}
176	}
177
178	return dr;
179}
180
181/*
182 *	For Normal and Recovery DataSequenceInOrder=No and DataPDUInOrder=Yes.
183 */
184static struct iscsi_datain_req *iscsit_set_datain_values_no_and_yes(
185	struct iscsi_cmd *cmd,
186	struct iscsi_datain *datain)
187{
188	u32 offset, read_data_done, read_data_left, seq_send_order;
189	struct iscsi_conn *conn = cmd->conn;
190	struct iscsi_datain_req *dr;
191	struct iscsi_seq *seq;
192
193	dr = iscsit_get_datain_req(cmd);
194	if (!dr)
195		return NULL;
196
197	if (dr->recovery && dr->generate_recovery_values) {
198		if (iscsit_create_recovery_datain_values_datasequenceinorder_no(
199					cmd, dr) < 0)
200			return NULL;
201
202		dr->generate_recovery_values = 0;
203	}
204
205	read_data_done = (!dr->recovery) ?
206			cmd->read_data_done : dr->read_data_done;
207	seq_send_order = (!dr->recovery) ?
208			cmd->seq_send_order : dr->seq_send_order;
209
210	read_data_left = (cmd->se_cmd.data_length - read_data_done);
211	if (!read_data_left) {
212		pr_err("ITT: 0x%08x read_data_left is zero!\n",
213				cmd->init_task_tag);
214		return NULL;
215	}
216
217	seq = iscsit_get_seq_holder_for_datain(cmd, seq_send_order);
218	if (!seq)
219		return NULL;
220
221	seq->sent = 1;
222
223	if (!dr->recovery && !seq->next_burst_len)
224		seq->first_datasn = cmd->data_sn;
225
226	offset = (seq->offset + seq->next_burst_len);
227
228	if ((offset + conn->conn_ops->MaxRecvDataSegmentLength) >=
229	     cmd->se_cmd.data_length) {
230		datain->length = (cmd->se_cmd.data_length - offset);
231		datain->offset = offset;
232
233		datain->flags |= ISCSI_FLAG_CMD_FINAL;
234		if (conn->sess->sess_ops->ErrorRecoveryLevel > 0)
235			datain->flags |= ISCSI_FLAG_DATA_ACK;
236
237		seq->next_burst_len = 0;
238		seq_send_order++;
239	} else {
240		if ((seq->next_burst_len +
241		     conn->conn_ops->MaxRecvDataSegmentLength) <
242		     conn->sess->sess_ops->MaxBurstLength) {
243			datain->length =
244				conn->conn_ops->MaxRecvDataSegmentLength;
245			datain->offset = (seq->offset + seq->next_burst_len);
246
247			seq->next_burst_len += datain->length;
248		} else {
249			datain->length = (conn->sess->sess_ops->MaxBurstLength -
250					  seq->next_burst_len);
251			datain->offset = (seq->offset + seq->next_burst_len);
252
253			datain->flags |= ISCSI_FLAG_CMD_FINAL;
254			if (conn->sess->sess_ops->ErrorRecoveryLevel > 0)
255				datain->flags |= ISCSI_FLAG_DATA_ACK;
256
257			seq->next_burst_len = 0;
258			seq_send_order++;
259		}
260	}
261
262	if ((read_data_done + datain->length) == cmd->se_cmd.data_length)
263		datain->flags |= ISCSI_FLAG_DATA_STATUS;
264
265	datain->data_sn = (!dr->recovery) ? cmd->data_sn++ : dr->data_sn++;
266	if (!dr->recovery) {
267		cmd->seq_send_order = seq_send_order;
268		cmd->read_data_done += datain->length;
269	} else {
270		dr->seq_send_order = seq_send_order;
271		dr->read_data_done += datain->length;
272	}
273
274	if (!dr->recovery) {
275		if (datain->flags & ISCSI_FLAG_CMD_FINAL)
276			seq->last_datasn = datain->data_sn;
277		if (datain->flags & ISCSI_FLAG_DATA_STATUS)
278			dr->dr_complete = DATAIN_COMPLETE_NORMAL;
279
280		return dr;
281	}
282
283	if (!dr->runlength) {
284		if (datain->flags & ISCSI_FLAG_DATA_STATUS) {
285			dr->dr_complete =
286			    (dr->recovery == DATAIN_WITHIN_COMMAND_RECOVERY) ?
287				DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY :
288				DATAIN_COMPLETE_CONNECTION_RECOVERY;
289		}
290	} else {
291		if ((dr->begrun + dr->runlength) == dr->data_sn) {
292			dr->dr_complete =
293			    (dr->recovery == DATAIN_WITHIN_COMMAND_RECOVERY) ?
294				DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY :
295				DATAIN_COMPLETE_CONNECTION_RECOVERY;
296		}
297	}
298
299	return dr;
300}
301
302/*
303 *	For Normal and Recovery DataSequenceInOrder=Yes and DataPDUInOrder=No.
304 */
305static struct iscsi_datain_req *iscsit_set_datain_values_yes_and_no(
306	struct iscsi_cmd *cmd,
307	struct iscsi_datain *datain)
308{
309	u32 next_burst_len, read_data_done, read_data_left;
310	struct iscsi_conn *conn = cmd->conn;
311	struct iscsi_datain_req *dr;
312	struct iscsi_pdu *pdu;
313
314	dr = iscsit_get_datain_req(cmd);
315	if (!dr)
316		return NULL;
317
318	if (dr->recovery && dr->generate_recovery_values) {
319		if (iscsit_create_recovery_datain_values_datasequenceinorder_yes(
320					cmd, dr) < 0)
321			return NULL;
322
323		dr->generate_recovery_values = 0;
324	}
325
326	next_burst_len = (!dr->recovery) ?
327			cmd->next_burst_len : dr->next_burst_len;
328	read_data_done = (!dr->recovery) ?
329			cmd->read_data_done : dr->read_data_done;
330
331	read_data_left = (cmd->se_cmd.data_length - read_data_done);
332	if (!read_data_left) {
333		pr_err("ITT: 0x%08x read_data_left is zero!\n",
334				cmd->init_task_tag);
335		return dr;
336	}
337
338	pdu = iscsit_get_pdu_holder_for_seq(cmd, NULL);
339	if (!pdu)
340		return dr;
341
342	if ((read_data_done + pdu->length) == cmd->se_cmd.data_length) {
343		pdu->flags |= (ISCSI_FLAG_CMD_FINAL | ISCSI_FLAG_DATA_STATUS);
344		if (conn->sess->sess_ops->ErrorRecoveryLevel > 0)
345			pdu->flags |= ISCSI_FLAG_DATA_ACK;
346
347		next_burst_len = 0;
348	} else {
349		if ((next_burst_len + conn->conn_ops->MaxRecvDataSegmentLength) <
350		     conn->sess->sess_ops->MaxBurstLength)
351			next_burst_len += pdu->length;
352		else {
353			pdu->flags |= ISCSI_FLAG_CMD_FINAL;
354			if (conn->sess->sess_ops->ErrorRecoveryLevel > 0)
355				pdu->flags |= ISCSI_FLAG_DATA_ACK;
356
357			next_burst_len = 0;
358		}
359	}
360
361	pdu->data_sn = (!dr->recovery) ? cmd->data_sn++ : dr->data_sn++;
362	if (!dr->recovery) {
363		cmd->next_burst_len = next_burst_len;
364		cmd->read_data_done += pdu->length;
365	} else {
366		dr->next_burst_len = next_burst_len;
367		dr->read_data_done += pdu->length;
368	}
369
370	datain->flags = pdu->flags;
371	datain->length = pdu->length;
372	datain->offset = pdu->offset;
373	datain->data_sn = pdu->data_sn;
374
375	if (!dr->recovery) {
376		if (datain->flags & ISCSI_FLAG_DATA_STATUS)
377			dr->dr_complete = DATAIN_COMPLETE_NORMAL;
378
379		return dr;
380	}
381
382	if (!dr->runlength) {
383		if (datain->flags & ISCSI_FLAG_DATA_STATUS) {
384			dr->dr_complete =
385			    (dr->recovery == DATAIN_WITHIN_COMMAND_RECOVERY) ?
386				DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY :
387				DATAIN_COMPLETE_CONNECTION_RECOVERY;
388		}
389	} else {
390		if ((dr->begrun + dr->runlength) == dr->data_sn) {
391			dr->dr_complete =
392			    (dr->recovery == DATAIN_WITHIN_COMMAND_RECOVERY) ?
393				DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY :
394				DATAIN_COMPLETE_CONNECTION_RECOVERY;
395		}
396	}
397
398	return dr;
399}
400
401/*
402 *	For Normal and Recovery DataSequenceInOrder=No and DataPDUInOrder=No.
403 */
404static struct iscsi_datain_req *iscsit_set_datain_values_no_and_no(
405	struct iscsi_cmd *cmd,
406	struct iscsi_datain *datain)
407{
408	u32 read_data_done, read_data_left, seq_send_order;
409	struct iscsi_conn *conn = cmd->conn;
410	struct iscsi_datain_req *dr;
411	struct iscsi_pdu *pdu;
412	struct iscsi_seq *seq = NULL;
413
414	dr = iscsit_get_datain_req(cmd);
415	if (!dr)
416		return NULL;
417
418	if (dr->recovery && dr->generate_recovery_values) {
419		if (iscsit_create_recovery_datain_values_datasequenceinorder_no(
420					cmd, dr) < 0)
421			return NULL;
422
423		dr->generate_recovery_values = 0;
424	}
425
426	read_data_done = (!dr->recovery) ?
427			cmd->read_data_done : dr->read_data_done;
428	seq_send_order = (!dr->recovery) ?
429			cmd->seq_send_order : dr->seq_send_order;
430
431	read_data_left = (cmd->se_cmd.data_length - read_data_done);
432	if (!read_data_left) {
433		pr_err("ITT: 0x%08x read_data_left is zero!\n",
434				cmd->init_task_tag);
435		return NULL;
436	}
437
438	seq = iscsit_get_seq_holder_for_datain(cmd, seq_send_order);
439	if (!seq)
440		return NULL;
441
442	seq->sent = 1;
443
444	if (!dr->recovery && !seq->next_burst_len)
445		seq->first_datasn = cmd->data_sn;
446
447	pdu = iscsit_get_pdu_holder_for_seq(cmd, seq);
448	if (!pdu)
449		return NULL;
450
451	if (seq->pdu_send_order == seq->pdu_count) {
452		pdu->flags |= ISCSI_FLAG_CMD_FINAL;
453		if (conn->sess->sess_ops->ErrorRecoveryLevel > 0)
454			pdu->flags |= ISCSI_FLAG_DATA_ACK;
455
456		seq->next_burst_len = 0;
457		seq_send_order++;
458	} else
459		seq->next_burst_len += pdu->length;
460
461	if ((read_data_done + pdu->length) == cmd->se_cmd.data_length)
462		pdu->flags |= ISCSI_FLAG_DATA_STATUS;
463
464	pdu->data_sn = (!dr->recovery) ? cmd->data_sn++ : dr->data_sn++;
465	if (!dr->recovery) {
466		cmd->seq_send_order = seq_send_order;
467		cmd->read_data_done += pdu->length;
468	} else {
469		dr->seq_send_order = seq_send_order;
470		dr->read_data_done += pdu->length;
471	}
472
473	datain->flags = pdu->flags;
474	datain->length = pdu->length;
475	datain->offset = pdu->offset;
476	datain->data_sn = pdu->data_sn;
477
478	if (!dr->recovery) {
479		if (datain->flags & ISCSI_FLAG_CMD_FINAL)
480			seq->last_datasn = datain->data_sn;
481		if (datain->flags & ISCSI_FLAG_DATA_STATUS)
482			dr->dr_complete = DATAIN_COMPLETE_NORMAL;
483
484		return dr;
485	}
486
487	if (!dr->runlength) {
488		if (datain->flags & ISCSI_FLAG_DATA_STATUS) {
489			dr->dr_complete =
490			    (dr->recovery == DATAIN_WITHIN_COMMAND_RECOVERY) ?
491				DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY :
492				DATAIN_COMPLETE_CONNECTION_RECOVERY;
493		}
494	} else {
495		if ((dr->begrun + dr->runlength) == dr->data_sn) {
496			dr->dr_complete =
497			    (dr->recovery == DATAIN_WITHIN_COMMAND_RECOVERY) ?
498				DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY :
499				DATAIN_COMPLETE_CONNECTION_RECOVERY;
500		}
501	}
502
503	return dr;
504}
505
506struct iscsi_datain_req *iscsit_get_datain_values(
507	struct iscsi_cmd *cmd,
508	struct iscsi_datain *datain)
509{
510	struct iscsi_conn *conn = cmd->conn;
511
512	if (conn->sess->sess_ops->DataSequenceInOrder &&
513	    conn->sess->sess_ops->DataPDUInOrder)
514		return iscsit_set_datain_values_yes_and_yes(cmd, datain);
515	else if (!conn->sess->sess_ops->DataSequenceInOrder &&
516		  conn->sess->sess_ops->DataPDUInOrder)
517		return iscsit_set_datain_values_no_and_yes(cmd, datain);
518	else if (conn->sess->sess_ops->DataSequenceInOrder &&
519		 !conn->sess->sess_ops->DataPDUInOrder)
520		return iscsit_set_datain_values_yes_and_no(cmd, datain);
521	else if (!conn->sess->sess_ops->DataSequenceInOrder &&
522		   !conn->sess->sess_ops->DataPDUInOrder)
523		return iscsit_set_datain_values_no_and_no(cmd, datain);
524
525	return NULL;
526}
527