1 /*******************************************************************************
2 * This file contains error recovery level two functions used by
3 * the iSCSI Target driver.
4 *
5 * (c) Copyright 2007-2013 Datera, Inc.
6 *
7 * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 ******************************************************************************/
19
20 #include <linux/slab.h>
21 #include <scsi/iscsi_proto.h>
22 #include <target/target_core_base.h>
23 #include <target/target_core_fabric.h>
24
25 #include <target/iscsi/iscsi_target_core.h>
26 #include "iscsi_target_datain_values.h"
27 #include "iscsi_target_util.h"
28 #include "iscsi_target_erl0.h"
29 #include "iscsi_target_erl1.h"
30 #include "iscsi_target_erl2.h"
31 #include "iscsi_target.h"
32
33 /*
34 * FIXME: Does RData SNACK apply here as well?
35 */
iscsit_create_conn_recovery_datain_values(struct iscsi_cmd * cmd,__be32 exp_data_sn)36 void iscsit_create_conn_recovery_datain_values(
37 struct iscsi_cmd *cmd,
38 __be32 exp_data_sn)
39 {
40 u32 data_sn = 0;
41 struct iscsi_conn *conn = cmd->conn;
42
43 cmd->next_burst_len = 0;
44 cmd->read_data_done = 0;
45
46 while (be32_to_cpu(exp_data_sn) > data_sn) {
47 if ((cmd->next_burst_len +
48 conn->conn_ops->MaxRecvDataSegmentLength) <
49 conn->sess->sess_ops->MaxBurstLength) {
50 cmd->read_data_done +=
51 conn->conn_ops->MaxRecvDataSegmentLength;
52 cmd->next_burst_len +=
53 conn->conn_ops->MaxRecvDataSegmentLength;
54 } else {
55 cmd->read_data_done +=
56 (conn->sess->sess_ops->MaxBurstLength -
57 cmd->next_burst_len);
58 cmd->next_burst_len = 0;
59 }
60 data_sn++;
61 }
62 }
63
iscsit_create_conn_recovery_dataout_values(struct iscsi_cmd * cmd)64 void iscsit_create_conn_recovery_dataout_values(
65 struct iscsi_cmd *cmd)
66 {
67 u32 write_data_done = 0;
68 struct iscsi_conn *conn = cmd->conn;
69
70 cmd->data_sn = 0;
71 cmd->next_burst_len = 0;
72
73 while (cmd->write_data_done > write_data_done) {
74 if ((write_data_done + conn->sess->sess_ops->MaxBurstLength) <=
75 cmd->write_data_done)
76 write_data_done += conn->sess->sess_ops->MaxBurstLength;
77 else
78 break;
79 }
80
81 cmd->write_data_done = write_data_done;
82 }
83
iscsit_attach_active_connection_recovery_entry(struct iscsi_session * sess,struct iscsi_conn_recovery * cr)84 static int iscsit_attach_active_connection_recovery_entry(
85 struct iscsi_session *sess,
86 struct iscsi_conn_recovery *cr)
87 {
88 spin_lock(&sess->cr_a_lock);
89 list_add_tail(&cr->cr_list, &sess->cr_active_list);
90 spin_unlock(&sess->cr_a_lock);
91
92 return 0;
93 }
94
iscsit_attach_inactive_connection_recovery_entry(struct iscsi_session * sess,struct iscsi_conn_recovery * cr)95 static int iscsit_attach_inactive_connection_recovery_entry(
96 struct iscsi_session *sess,
97 struct iscsi_conn_recovery *cr)
98 {
99 spin_lock(&sess->cr_i_lock);
100 list_add_tail(&cr->cr_list, &sess->cr_inactive_list);
101
102 sess->conn_recovery_count++;
103 pr_debug("Incremented connection recovery count to %u for"
104 " SID: %u\n", sess->conn_recovery_count, sess->sid);
105 spin_unlock(&sess->cr_i_lock);
106
107 return 0;
108 }
109
iscsit_get_inactive_connection_recovery_entry(struct iscsi_session * sess,u16 cid)110 struct iscsi_conn_recovery *iscsit_get_inactive_connection_recovery_entry(
111 struct iscsi_session *sess,
112 u16 cid)
113 {
114 struct iscsi_conn_recovery *cr;
115
116 spin_lock(&sess->cr_i_lock);
117 list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
118 if (cr->cid == cid) {
119 spin_unlock(&sess->cr_i_lock);
120 return cr;
121 }
122 }
123 spin_unlock(&sess->cr_i_lock);
124
125 return NULL;
126 }
127
iscsit_free_connection_recovery_entires(struct iscsi_session * sess)128 void iscsit_free_connection_recovery_entires(struct iscsi_session *sess)
129 {
130 struct iscsi_cmd *cmd, *cmd_tmp;
131 struct iscsi_conn_recovery *cr, *cr_tmp;
132
133 spin_lock(&sess->cr_a_lock);
134 list_for_each_entry_safe(cr, cr_tmp, &sess->cr_active_list, cr_list) {
135 list_del(&cr->cr_list);
136 spin_unlock(&sess->cr_a_lock);
137
138 spin_lock(&cr->conn_recovery_cmd_lock);
139 list_for_each_entry_safe(cmd, cmd_tmp,
140 &cr->conn_recovery_cmd_list, i_conn_node) {
141
142 list_del_init(&cmd->i_conn_node);
143 cmd->conn = NULL;
144 spin_unlock(&cr->conn_recovery_cmd_lock);
145 iscsit_free_cmd(cmd, true);
146 spin_lock(&cr->conn_recovery_cmd_lock);
147 }
148 spin_unlock(&cr->conn_recovery_cmd_lock);
149 spin_lock(&sess->cr_a_lock);
150
151 kfree(cr);
152 }
153 spin_unlock(&sess->cr_a_lock);
154
155 spin_lock(&sess->cr_i_lock);
156 list_for_each_entry_safe(cr, cr_tmp, &sess->cr_inactive_list, cr_list) {
157 list_del(&cr->cr_list);
158 spin_unlock(&sess->cr_i_lock);
159
160 spin_lock(&cr->conn_recovery_cmd_lock);
161 list_for_each_entry_safe(cmd, cmd_tmp,
162 &cr->conn_recovery_cmd_list, i_conn_node) {
163
164 list_del_init(&cmd->i_conn_node);
165 cmd->conn = NULL;
166 spin_unlock(&cr->conn_recovery_cmd_lock);
167 iscsit_free_cmd(cmd, true);
168 spin_lock(&cr->conn_recovery_cmd_lock);
169 }
170 spin_unlock(&cr->conn_recovery_cmd_lock);
171 spin_lock(&sess->cr_i_lock);
172
173 kfree(cr);
174 }
175 spin_unlock(&sess->cr_i_lock);
176 }
177
iscsit_remove_active_connection_recovery_entry(struct iscsi_conn_recovery * cr,struct iscsi_session * sess)178 int iscsit_remove_active_connection_recovery_entry(
179 struct iscsi_conn_recovery *cr,
180 struct iscsi_session *sess)
181 {
182 spin_lock(&sess->cr_a_lock);
183 list_del(&cr->cr_list);
184
185 sess->conn_recovery_count--;
186 pr_debug("Decremented connection recovery count to %u for"
187 " SID: %u\n", sess->conn_recovery_count, sess->sid);
188 spin_unlock(&sess->cr_a_lock);
189
190 kfree(cr);
191
192 return 0;
193 }
194
iscsit_remove_inactive_connection_recovery_entry(struct iscsi_conn_recovery * cr,struct iscsi_session * sess)195 static void iscsit_remove_inactive_connection_recovery_entry(
196 struct iscsi_conn_recovery *cr,
197 struct iscsi_session *sess)
198 {
199 spin_lock(&sess->cr_i_lock);
200 list_del(&cr->cr_list);
201 spin_unlock(&sess->cr_i_lock);
202 }
203
204 /*
205 * Called with cr->conn_recovery_cmd_lock help.
206 */
iscsit_remove_cmd_from_connection_recovery(struct iscsi_cmd * cmd,struct iscsi_session * sess)207 int iscsit_remove_cmd_from_connection_recovery(
208 struct iscsi_cmd *cmd,
209 struct iscsi_session *sess)
210 {
211 struct iscsi_conn_recovery *cr;
212
213 if (!cmd->cr) {
214 pr_err("struct iscsi_conn_recovery pointer for ITT: 0x%08x"
215 " is NULL!\n", cmd->init_task_tag);
216 BUG();
217 }
218 cr = cmd->cr;
219
220 list_del_init(&cmd->i_conn_node);
221 return --cr->cmd_count;
222 }
223
iscsit_discard_cr_cmds_by_expstatsn(struct iscsi_conn_recovery * cr,u32 exp_statsn)224 void iscsit_discard_cr_cmds_by_expstatsn(
225 struct iscsi_conn_recovery *cr,
226 u32 exp_statsn)
227 {
228 u32 dropped_count = 0;
229 struct iscsi_cmd *cmd, *cmd_tmp;
230 struct iscsi_session *sess = cr->sess;
231
232 spin_lock(&cr->conn_recovery_cmd_lock);
233 list_for_each_entry_safe(cmd, cmd_tmp,
234 &cr->conn_recovery_cmd_list, i_conn_node) {
235
236 if (((cmd->deferred_i_state != ISTATE_SENT_STATUS) &&
237 (cmd->deferred_i_state != ISTATE_REMOVE)) ||
238 (cmd->stat_sn >= exp_statsn)) {
239 continue;
240 }
241
242 dropped_count++;
243 pr_debug("Dropping Acknowledged ITT: 0x%08x, StatSN:"
244 " 0x%08x, CID: %hu.\n", cmd->init_task_tag,
245 cmd->stat_sn, cr->cid);
246
247 iscsit_remove_cmd_from_connection_recovery(cmd, sess);
248
249 spin_unlock(&cr->conn_recovery_cmd_lock);
250 iscsit_free_cmd(cmd, true);
251 spin_lock(&cr->conn_recovery_cmd_lock);
252 }
253 spin_unlock(&cr->conn_recovery_cmd_lock);
254
255 pr_debug("Dropped %u total acknowledged commands on"
256 " CID: %hu less than old ExpStatSN: 0x%08x\n",
257 dropped_count, cr->cid, exp_statsn);
258
259 if (!cr->cmd_count) {
260 pr_debug("No commands to be reassigned for failed"
261 " connection CID: %hu on SID: %u\n",
262 cr->cid, sess->sid);
263 iscsit_remove_inactive_connection_recovery_entry(cr, sess);
264 iscsit_attach_active_connection_recovery_entry(sess, cr);
265 pr_debug("iSCSI connection recovery successful for CID:"
266 " %hu on SID: %u\n", cr->cid, sess->sid);
267 iscsit_remove_active_connection_recovery_entry(cr, sess);
268 } else {
269 iscsit_remove_inactive_connection_recovery_entry(cr, sess);
270 iscsit_attach_active_connection_recovery_entry(sess, cr);
271 }
272 }
273
iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(struct iscsi_conn * conn)274 int iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(struct iscsi_conn *conn)
275 {
276 u32 dropped_count = 0;
277 struct iscsi_cmd *cmd, *cmd_tmp;
278 struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
279 struct iscsi_session *sess = conn->sess;
280
281 mutex_lock(&sess->cmdsn_mutex);
282 list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
283 &sess->sess_ooo_cmdsn_list, ooo_list) {
284
285 if (ooo_cmdsn->cid != conn->cid)
286 continue;
287
288 dropped_count++;
289 pr_debug("Dropping unacknowledged CmdSN:"
290 " 0x%08x during connection recovery on CID: %hu\n",
291 ooo_cmdsn->cmdsn, conn->cid);
292 iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
293 }
294 mutex_unlock(&sess->cmdsn_mutex);
295
296 spin_lock_bh(&conn->cmd_lock);
297 list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_conn_node) {
298 if (!(cmd->cmd_flags & ICF_OOO_CMDSN))
299 continue;
300
301 list_del_init(&cmd->i_conn_node);
302
303 spin_unlock_bh(&conn->cmd_lock);
304 iscsit_free_cmd(cmd, true);
305 spin_lock_bh(&conn->cmd_lock);
306 }
307 spin_unlock_bh(&conn->cmd_lock);
308
309 pr_debug("Dropped %u total unacknowledged commands on CID:"
310 " %hu for ExpCmdSN: 0x%08x.\n", dropped_count, conn->cid,
311 sess->exp_cmd_sn);
312 return 0;
313 }
314
iscsit_prepare_cmds_for_reallegiance(struct iscsi_conn * conn)315 int iscsit_prepare_cmds_for_reallegiance(struct iscsi_conn *conn)
316 {
317 u32 cmd_count = 0;
318 struct iscsi_cmd *cmd, *cmd_tmp;
319 struct iscsi_conn_recovery *cr;
320
321 /*
322 * Allocate an struct iscsi_conn_recovery for this connection.
323 * Each struct iscsi_cmd contains an struct iscsi_conn_recovery pointer
324 * (struct iscsi_cmd->cr) so we need to allocate this before preparing the
325 * connection's command list for connection recovery.
326 */
327 cr = kzalloc(sizeof(struct iscsi_conn_recovery), GFP_KERNEL);
328 if (!cr) {
329 pr_err("Unable to allocate memory for"
330 " struct iscsi_conn_recovery.\n");
331 return -1;
332 }
333 INIT_LIST_HEAD(&cr->cr_list);
334 INIT_LIST_HEAD(&cr->conn_recovery_cmd_list);
335 spin_lock_init(&cr->conn_recovery_cmd_lock);
336 /*
337 * Only perform connection recovery on ISCSI_OP_SCSI_CMD or
338 * ISCSI_OP_NOOP_OUT opcodes. For all other opcodes call
339 * list_del_init(&cmd->i_conn_node); to release the command to the
340 * session pool and remove it from the connection's list.
341 *
342 * Also stop the DataOUT timer, which will be restarted after
343 * sending the TMR response.
344 */
345 spin_lock_bh(&conn->cmd_lock);
346 list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_conn_node) {
347
348 if ((cmd->iscsi_opcode != ISCSI_OP_SCSI_CMD) &&
349 (cmd->iscsi_opcode != ISCSI_OP_NOOP_OUT)) {
350 pr_debug("Not performing reallegiance on"
351 " Opcode: 0x%02x, ITT: 0x%08x, CmdSN: 0x%08x,"
352 " CID: %hu\n", cmd->iscsi_opcode,
353 cmd->init_task_tag, cmd->cmd_sn, conn->cid);
354
355 list_del_init(&cmd->i_conn_node);
356 spin_unlock_bh(&conn->cmd_lock);
357 iscsit_free_cmd(cmd, true);
358 spin_lock_bh(&conn->cmd_lock);
359 continue;
360 }
361
362 /*
363 * Special case where commands greater than or equal to
364 * the session's ExpCmdSN are attached to the connection
365 * list but not to the out of order CmdSN list. The one
366 * obvious case is when a command with immediate data
367 * attached must only check the CmdSN against ExpCmdSN
368 * after the data is received. The special case below
369 * is when the connection fails before data is received,
370 * but also may apply to other PDUs, so it has been
371 * made generic here.
372 */
373 if (!(cmd->cmd_flags & ICF_OOO_CMDSN) && !cmd->immediate_cmd &&
374 iscsi_sna_gte(cmd->cmd_sn, conn->sess->exp_cmd_sn)) {
375 list_del_init(&cmd->i_conn_node);
376 spin_unlock_bh(&conn->cmd_lock);
377 iscsit_free_cmd(cmd, true);
378 spin_lock_bh(&conn->cmd_lock);
379 continue;
380 }
381
382 cmd_count++;
383 pr_debug("Preparing Opcode: 0x%02x, ITT: 0x%08x,"
384 " CmdSN: 0x%08x, StatSN: 0x%08x, CID: %hu for"
385 " reallegiance.\n", cmd->iscsi_opcode,
386 cmd->init_task_tag, cmd->cmd_sn, cmd->stat_sn,
387 conn->cid);
388
389 cmd->deferred_i_state = cmd->i_state;
390 cmd->i_state = ISTATE_IN_CONNECTION_RECOVERY;
391
392 if (cmd->data_direction == DMA_TO_DEVICE)
393 iscsit_stop_dataout_timer(cmd);
394
395 cmd->sess = conn->sess;
396
397 list_del_init(&cmd->i_conn_node);
398 spin_unlock_bh(&conn->cmd_lock);
399
400 iscsit_free_all_datain_reqs(cmd);
401
402 transport_wait_for_tasks(&cmd->se_cmd);
403 /*
404 * Add the struct iscsi_cmd to the connection recovery cmd list
405 */
406 spin_lock(&cr->conn_recovery_cmd_lock);
407 list_add_tail(&cmd->i_conn_node, &cr->conn_recovery_cmd_list);
408 spin_unlock(&cr->conn_recovery_cmd_lock);
409
410 spin_lock_bh(&conn->cmd_lock);
411 cmd->cr = cr;
412 cmd->conn = NULL;
413 }
414 spin_unlock_bh(&conn->cmd_lock);
415 /*
416 * Fill in the various values in the preallocated struct iscsi_conn_recovery.
417 */
418 cr->cid = conn->cid;
419 cr->cmd_count = cmd_count;
420 cr->maxrecvdatasegmentlength = conn->conn_ops->MaxRecvDataSegmentLength;
421 cr->maxxmitdatasegmentlength = conn->conn_ops->MaxXmitDataSegmentLength;
422 cr->sess = conn->sess;
423
424 iscsit_attach_inactive_connection_recovery_entry(conn->sess, cr);
425
426 return 0;
427 }
428
iscsit_connection_recovery_transport_reset(struct iscsi_conn * conn)429 int iscsit_connection_recovery_transport_reset(struct iscsi_conn *conn)
430 {
431 atomic_set(&conn->connection_recovery, 1);
432
433 if (iscsit_close_connection(conn) < 0)
434 return -1;
435
436 return 0;
437 }
438
