1// SPDX-License-Identifier: GPL-2.0-or-later
2/*******************************************************************************
3 * This file contains the iSCSI Target DataIN value generation functions.
4 *
5 * (c) Copyright 2007-2013 Datera, Inc.
6 *
7 * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
8 *
9 ******************************************************************************/
10
11#include <linux/slab.h>
12#include <scsi/iscsi_proto.h>
13#include <target/iscsi/iscsi_target_core.h>
14#include "iscsi_target_seq_pdu_list.h"
15#include "iscsi_target_erl1.h"
16#include "iscsi_target_util.h"
17#include "iscsi_target.h"
18#include "iscsi_target_datain_values.h"
19
20struct iscsi_datain_req *iscsit_allocate_datain_req(void)
21{
22	struct iscsi_datain_req *dr;
23
24	dr = kmem_cache_zalloc(lio_dr_cache, GFP_ATOMIC);
25	if (!dr) {
26		pr_err("Unable to allocate memory for"
27				" struct iscsi_datain_req\n");
28		return NULL;
29	}
30	INIT_LIST_HEAD(&dr->cmd_datain_node);
31
32	return dr;
33}
34
35void iscsit_attach_datain_req(struct iscsit_cmd *cmd, struct iscsi_datain_req *dr)
36{
37	spin_lock(&cmd->datain_lock);
38	list_add_tail(&dr->cmd_datain_node, &cmd->datain_list);
39	spin_unlock(&cmd->datain_lock);
40}
41
42void iscsit_free_datain_req(struct iscsit_cmd *cmd, struct iscsi_datain_req *dr)
43{
44	spin_lock(&cmd->datain_lock);
45	list_del(&dr->cmd_datain_node);
46	spin_unlock(&cmd->datain_lock);
47
48	kmem_cache_free(lio_dr_cache, dr);
49}
50
51void iscsit_free_all_datain_reqs(struct iscsit_cmd *cmd)
52{
53	struct iscsi_datain_req *dr, *dr_tmp;
54
55	spin_lock(&cmd->datain_lock);
56	list_for_each_entry_safe(dr, dr_tmp, &cmd->datain_list, cmd_datain_node) {
57		list_del(&dr->cmd_datain_node);
58		kmem_cache_free(lio_dr_cache, dr);
59	}
60	spin_unlock(&cmd->datain_lock);
61}
62
63struct iscsi_datain_req *iscsit_get_datain_req(struct iscsit_cmd *cmd)
64{
65	if (list_empty(&cmd->datain_list)) {
66		pr_err("cmd->datain_list is empty for ITT:"
67			" 0x%08x\n", cmd->init_task_tag);
68		return NULL;
69	}
70
71	return list_first_entry(&cmd->datain_list, struct iscsi_datain_req,
72				cmd_datain_node);
73}
74
75/*
76 *	For Normal and Recovery DataSequenceInOrder=Yes and DataPDUInOrder=Yes.
77 */
78static struct iscsi_datain_req *iscsit_set_datain_values_yes_and_yes(
79	struct iscsit_cmd *cmd,
80	struct iscsi_datain *datain)
81{
82	u32 next_burst_len, read_data_done, read_data_left;
83	struct iscsit_conn *conn = cmd->conn;
84	struct iscsi_datain_req *dr;
85
86	dr = iscsit_get_datain_req(cmd);
87	if (!dr)
88		return NULL;
89
90	if (dr->recovery && dr->generate_recovery_values) {
91		if (iscsit_create_recovery_datain_values_datasequenceinorder_yes(
92					cmd, dr) < 0)
93			return NULL;
94
95		dr->generate_recovery_values = 0;
96	}
97
98	next_burst_len = (!dr->recovery) ?
99			cmd->next_burst_len : dr->next_burst_len;
100	read_data_done = (!dr->recovery) ?
101			cmd->read_data_done : dr->read_data_done;
102
103	read_data_left = (cmd->se_cmd.data_length - read_data_done);
104	if (!read_data_left) {
105		pr_err("ITT: 0x%08x read_data_left is zero!\n",
106				cmd->init_task_tag);
107		return NULL;
108	}
109
110	if ((read_data_left <= conn->conn_ops->MaxRecvDataSegmentLength) &&
111	    (read_data_left <= (conn->sess->sess_ops->MaxBurstLength -
112	     next_burst_len))) {
113		datain->length = read_data_left;
114
115		datain->flags |= (ISCSI_FLAG_CMD_FINAL | ISCSI_FLAG_DATA_STATUS);
116		if (conn->sess->sess_ops->ErrorRecoveryLevel > 0)
117			datain->flags |= ISCSI_FLAG_DATA_ACK;
118	} else {
119		if ((next_burst_len +
120		     conn->conn_ops->MaxRecvDataSegmentLength) <
121		     conn->sess->sess_ops->MaxBurstLength) {
122			datain->length =
123				conn->conn_ops->MaxRecvDataSegmentLength;
124			next_burst_len += datain->length;
125		} else {
126			datain->length = (conn->sess->sess_ops->MaxBurstLength -
127					  next_burst_len);
128			next_burst_len = 0;
129
130			datain->flags |= ISCSI_FLAG_CMD_FINAL;
131			if (conn->sess->sess_ops->ErrorRecoveryLevel > 0)
132				datain->flags |= ISCSI_FLAG_DATA_ACK;
133		}
134	}
135
136	datain->data_sn = (!dr->recovery) ? cmd->data_sn++ : dr->data_sn++;
137	datain->offset = read_data_done;
138
139	if (!dr->recovery) {
140		cmd->next_burst_len = next_burst_len;
141		cmd->read_data_done += datain->length;
142	} else {
143		dr->next_burst_len = next_burst_len;
144		dr->read_data_done += datain->length;
145	}
146
147	if (!dr->recovery) {
148		if (datain->flags & ISCSI_FLAG_DATA_STATUS)
149			dr->dr_complete = DATAIN_COMPLETE_NORMAL;
150
151		return dr;
152	}
153
154	if (!dr->runlength) {
155		if (datain->flags & ISCSI_FLAG_DATA_STATUS) {
156			dr->dr_complete =
157			    (dr->recovery == DATAIN_WITHIN_COMMAND_RECOVERY) ?
158				DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY :
159				DATAIN_COMPLETE_CONNECTION_RECOVERY;
160		}
161	} else {
162		if ((dr->begrun + dr->runlength) == dr->data_sn) {
163			dr->dr_complete =
164			    (dr->recovery == DATAIN_WITHIN_COMMAND_RECOVERY) ?
165				DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY :
166				DATAIN_COMPLETE_CONNECTION_RECOVERY;
167		}
168	}
169
170	return dr;
171}
172
173/*
174 *	For Normal and Recovery DataSequenceInOrder=No and DataPDUInOrder=Yes.
175 */
176static struct iscsi_datain_req *iscsit_set_datain_values_no_and_yes(
177	struct iscsit_cmd *cmd,
178	struct iscsi_datain *datain)
179{
180	u32 offset, read_data_done, read_data_left, seq_send_order;
181	struct iscsit_conn *conn = cmd->conn;
182	struct iscsi_datain_req *dr;
183	struct iscsi_seq *seq;
184
185	dr = iscsit_get_datain_req(cmd);
186	if (!dr)
187		return NULL;
188
189	if (dr->recovery && dr->generate_recovery_values) {
190		if (iscsit_create_recovery_datain_values_datasequenceinorder_no(
191					cmd, dr) < 0)
192			return NULL;
193
194		dr->generate_recovery_values = 0;
195	}
196
197	read_data_done = (!dr->recovery) ?
198			cmd->read_data_done : dr->read_data_done;
199	seq_send_order = (!dr->recovery) ?
200			cmd->seq_send_order : dr->seq_send_order;
201
202	read_data_left = (cmd->se_cmd.data_length - read_data_done);
203	if (!read_data_left) {
204		pr_err("ITT: 0x%08x read_data_left is zero!\n",
205				cmd->init_task_tag);
206		return NULL;
207	}
208
209	seq = iscsit_get_seq_holder_for_datain(cmd, seq_send_order);
210	if (!seq)
211		return NULL;
212
213	seq->sent = 1;
214
215	if (!dr->recovery && !seq->next_burst_len)
216		seq->first_datasn = cmd->data_sn;
217
218	offset = (seq->offset + seq->next_burst_len);
219
220	if ((offset + conn->conn_ops->MaxRecvDataSegmentLength) >=
221	     cmd->se_cmd.data_length) {
222		datain->length = (cmd->se_cmd.data_length - offset);
223		datain->offset = offset;
224
225		datain->flags |= ISCSI_FLAG_CMD_FINAL;
226		if (conn->sess->sess_ops->ErrorRecoveryLevel > 0)
227			datain->flags |= ISCSI_FLAG_DATA_ACK;
228
229		seq->next_burst_len = 0;
230		seq_send_order++;
231	} else {
232		if ((seq->next_burst_len +
233		     conn->conn_ops->MaxRecvDataSegmentLength) <
234		     conn->sess->sess_ops->MaxBurstLength) {
235			datain->length =
236				conn->conn_ops->MaxRecvDataSegmentLength;
237			datain->offset = (seq->offset + seq->next_burst_len);
238
239			seq->next_burst_len += datain->length;
240		} else {
241			datain->length = (conn->sess->sess_ops->MaxBurstLength -
242					  seq->next_burst_len);
243			datain->offset = (seq->offset + seq->next_burst_len);
244
245			datain->flags |= ISCSI_FLAG_CMD_FINAL;
246			if (conn->sess->sess_ops->ErrorRecoveryLevel > 0)
247				datain->flags |= ISCSI_FLAG_DATA_ACK;
248
249			seq->next_burst_len = 0;
250			seq_send_order++;
251		}
252	}
253
254	if ((read_data_done + datain->length) == cmd->se_cmd.data_length)
255		datain->flags |= ISCSI_FLAG_DATA_STATUS;
256
257	datain->data_sn = (!dr->recovery) ? cmd->data_sn++ : dr->data_sn++;
258	if (!dr->recovery) {
259		cmd->seq_send_order = seq_send_order;
260		cmd->read_data_done += datain->length;
261	} else {
262		dr->seq_send_order = seq_send_order;
263		dr->read_data_done += datain->length;
264	}
265
266	if (!dr->recovery) {
267		if (datain->flags & ISCSI_FLAG_CMD_FINAL)
268			seq->last_datasn = datain->data_sn;
269		if (datain->flags & ISCSI_FLAG_DATA_STATUS)
270			dr->dr_complete = DATAIN_COMPLETE_NORMAL;
271
272		return dr;
273	}
274
275	if (!dr->runlength) {
276		if (datain->flags & ISCSI_FLAG_DATA_STATUS) {
277			dr->dr_complete =
278			    (dr->recovery == DATAIN_WITHIN_COMMAND_RECOVERY) ?
279				DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY :
280				DATAIN_COMPLETE_CONNECTION_RECOVERY;
281		}
282	} else {
283		if ((dr->begrun + dr->runlength) == dr->data_sn) {
284			dr->dr_complete =
285			    (dr->recovery == DATAIN_WITHIN_COMMAND_RECOVERY) ?
286				DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY :
287				DATAIN_COMPLETE_CONNECTION_RECOVERY;
288		}
289	}
290
291	return dr;
292}
293
294/*
295 *	For Normal and Recovery DataSequenceInOrder=Yes and DataPDUInOrder=No.
296 */
297static struct iscsi_datain_req *iscsit_set_datain_values_yes_and_no(
298	struct iscsit_cmd *cmd,
299	struct iscsi_datain *datain)
300{
301	u32 next_burst_len, read_data_done, read_data_left;
302	struct iscsit_conn *conn = cmd->conn;
303	struct iscsi_datain_req *dr;
304	struct iscsi_pdu *pdu;
305
306	dr = iscsit_get_datain_req(cmd);
307	if (!dr)
308		return NULL;
309
310	if (dr->recovery && dr->generate_recovery_values) {
311		if (iscsit_create_recovery_datain_values_datasequenceinorder_yes(
312					cmd, dr) < 0)
313			return NULL;
314
315		dr->generate_recovery_values = 0;
316	}
317
318	next_burst_len = (!dr->recovery) ?
319			cmd->next_burst_len : dr->next_burst_len;
320	read_data_done = (!dr->recovery) ?
321			cmd->read_data_done : dr->read_data_done;
322
323	read_data_left = (cmd->se_cmd.data_length - read_data_done);
324	if (!read_data_left) {
325		pr_err("ITT: 0x%08x read_data_left is zero!\n",
326				cmd->init_task_tag);
327		return dr;
328	}
329
330	pdu = iscsit_get_pdu_holder_for_seq(cmd, NULL);
331	if (!pdu)
332		return dr;
333
334	if ((read_data_done + pdu->length) == cmd->se_cmd.data_length) {
335		pdu->flags |= (ISCSI_FLAG_CMD_FINAL | ISCSI_FLAG_DATA_STATUS);
336		if (conn->sess->sess_ops->ErrorRecoveryLevel > 0)
337			pdu->flags |= ISCSI_FLAG_DATA_ACK;
338
339		next_burst_len = 0;
340	} else {
341		if ((next_burst_len + conn->conn_ops->MaxRecvDataSegmentLength) <
342		     conn->sess->sess_ops->MaxBurstLength)
343			next_burst_len += pdu->length;
344		else {
345			pdu->flags |= ISCSI_FLAG_CMD_FINAL;
346			if (conn->sess->sess_ops->ErrorRecoveryLevel > 0)
347				pdu->flags |= ISCSI_FLAG_DATA_ACK;
348
349			next_burst_len = 0;
350		}
351	}
352
353	pdu->data_sn = (!dr->recovery) ? cmd->data_sn++ : dr->data_sn++;
354	if (!dr->recovery) {
355		cmd->next_burst_len = next_burst_len;
356		cmd->read_data_done += pdu->length;
357	} else {
358		dr->next_burst_len = next_burst_len;
359		dr->read_data_done += pdu->length;
360	}
361
362	datain->flags = pdu->flags;
363	datain->length = pdu->length;
364	datain->offset = pdu->offset;
365	datain->data_sn = pdu->data_sn;
366
367	if (!dr->recovery) {
368		if (datain->flags & ISCSI_FLAG_DATA_STATUS)
369			dr->dr_complete = DATAIN_COMPLETE_NORMAL;
370
371		return dr;
372	}
373
374	if (!dr->runlength) {
375		if (datain->flags & ISCSI_FLAG_DATA_STATUS) {
376			dr->dr_complete =
377			    (dr->recovery == DATAIN_WITHIN_COMMAND_RECOVERY) ?
378				DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY :
379				DATAIN_COMPLETE_CONNECTION_RECOVERY;
380		}
381	} else {
382		if ((dr->begrun + dr->runlength) == dr->data_sn) {
383			dr->dr_complete =
384			    (dr->recovery == DATAIN_WITHIN_COMMAND_RECOVERY) ?
385				DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY :
386				DATAIN_COMPLETE_CONNECTION_RECOVERY;
387		}
388	}
389
390	return dr;
391}
392
393/*
394 *	For Normal and Recovery DataSequenceInOrder=No and DataPDUInOrder=No.
395 */
396static struct iscsi_datain_req *iscsit_set_datain_values_no_and_no(
397	struct iscsit_cmd *cmd,
398	struct iscsi_datain *datain)
399{
400	u32 read_data_done, read_data_left, seq_send_order;
401	struct iscsit_conn *conn = cmd->conn;
402	struct iscsi_datain_req *dr;
403	struct iscsi_pdu *pdu;
404	struct iscsi_seq *seq = NULL;
405
406	dr = iscsit_get_datain_req(cmd);
407	if (!dr)
408		return NULL;
409
410	if (dr->recovery && dr->generate_recovery_values) {
411		if (iscsit_create_recovery_datain_values_datasequenceinorder_no(
412					cmd, dr) < 0)
413			return NULL;
414
415		dr->generate_recovery_values = 0;
416	}
417
418	read_data_done = (!dr->recovery) ?
419			cmd->read_data_done : dr->read_data_done;
420	seq_send_order = (!dr->recovery) ?
421			cmd->seq_send_order : dr->seq_send_order;
422
423	read_data_left = (cmd->se_cmd.data_length - read_data_done);
424	if (!read_data_left) {
425		pr_err("ITT: 0x%08x read_data_left is zero!\n",
426				cmd->init_task_tag);
427		return NULL;
428	}
429
430	seq = iscsit_get_seq_holder_for_datain(cmd, seq_send_order);
431	if (!seq)
432		return NULL;
433
434	seq->sent = 1;
435
436	if (!dr->recovery && !seq->next_burst_len)
437		seq->first_datasn = cmd->data_sn;
438
439	pdu = iscsit_get_pdu_holder_for_seq(cmd, seq);
440	if (!pdu)
441		return NULL;
442
443	if (seq->pdu_send_order == seq->pdu_count) {
444		pdu->flags |= ISCSI_FLAG_CMD_FINAL;
445		if (conn->sess->sess_ops->ErrorRecoveryLevel > 0)
446			pdu->flags |= ISCSI_FLAG_DATA_ACK;
447
448		seq->next_burst_len = 0;
449		seq_send_order++;
450	} else
451		seq->next_burst_len += pdu->length;
452
453	if ((read_data_done + pdu->length) == cmd->se_cmd.data_length)
454		pdu->flags |= ISCSI_FLAG_DATA_STATUS;
455
456	pdu->data_sn = (!dr->recovery) ? cmd->data_sn++ : dr->data_sn++;
457	if (!dr->recovery) {
458		cmd->seq_send_order = seq_send_order;
459		cmd->read_data_done += pdu->length;
460	} else {
461		dr->seq_send_order = seq_send_order;
462		dr->read_data_done += pdu->length;
463	}
464
465	datain->flags = pdu->flags;
466	datain->length = pdu->length;
467	datain->offset = pdu->offset;
468	datain->data_sn = pdu->data_sn;
469
470	if (!dr->recovery) {
471		if (datain->flags & ISCSI_FLAG_CMD_FINAL)
472			seq->last_datasn = datain->data_sn;
473		if (datain->flags & ISCSI_FLAG_DATA_STATUS)
474			dr->dr_complete = DATAIN_COMPLETE_NORMAL;
475
476		return dr;
477	}
478
479	if (!dr->runlength) {
480		if (datain->flags & ISCSI_FLAG_DATA_STATUS) {
481			dr->dr_complete =
482			    (dr->recovery == DATAIN_WITHIN_COMMAND_RECOVERY) ?
483				DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY :
484				DATAIN_COMPLETE_CONNECTION_RECOVERY;
485		}
486	} else {
487		if ((dr->begrun + dr->runlength) == dr->data_sn) {
488			dr->dr_complete =
489			    (dr->recovery == DATAIN_WITHIN_COMMAND_RECOVERY) ?
490				DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY :
491				DATAIN_COMPLETE_CONNECTION_RECOVERY;
492		}
493	}
494
495	return dr;
496}
497
498struct iscsi_datain_req *iscsit_get_datain_values(
499	struct iscsit_cmd *cmd,
500	struct iscsi_datain *datain)
501{
502	struct iscsit_conn *conn = cmd->conn;
503
504	if (conn->sess->sess_ops->DataSequenceInOrder &&
505	    conn->sess->sess_ops->DataPDUInOrder)
506		return iscsit_set_datain_values_yes_and_yes(cmd, datain);
507	else if (!conn->sess->sess_ops->DataSequenceInOrder &&
508		  conn->sess->sess_ops->DataPDUInOrder)
509		return iscsit_set_datain_values_no_and_yes(cmd, datain);
510	else if (conn->sess->sess_ops->DataSequenceInOrder &&
511		 !conn->sess->sess_ops->DataPDUInOrder)
512		return iscsit_set_datain_values_yes_and_no(cmd, datain);
513	else if (!conn->sess->sess_ops->DataSequenceInOrder &&
514		   !conn->sess->sess_ops->DataPDUInOrder)
515		return iscsit_set_datain_values_no_and_no(cmd, datain);
516
517	return NULL;
518}
519EXPORT_SYMBOL(iscsit_get_datain_values);
520