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Linux 3.11-rc3
[cris-mirror.git] / drivers / target / iscsi / iscsi_target_erl2.c
blob45a5afd5ea13b2eda8bfb11de4f6f238e3996219
1 /*******************************************************************************
2 * This file contains error recovery level two functions used by
3 * the iSCSI Target driver.
4 *
5 * \u00a9 Copyright 2007-2011 RisingTide Systems LLC.
6 *
7 * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
8 *
9 * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 ******************************************************************************/
21
22 #include <scsi/iscsi_proto.h>
23 #include <target/target_core_base.h>
24 #include <target/target_core_fabric.h>
25
26 #include "iscsi_target_core.h"
27 #include "iscsi_target_datain_values.h"
28 #include "iscsi_target_util.h"
29 #include "iscsi_target_erl0.h"
30 #include "iscsi_target_erl1.h"
31 #include "iscsi_target_erl2.h"
32 #include "iscsi_target.h"
33
34 /*
35 * FIXME: Does RData SNACK apply here as well?
36 */
37 void iscsit_create_conn_recovery_datain_values(
38 struct iscsi_cmd *cmd,
39 __be32 exp_data_sn)
40 {
41 u32 data_sn = 0;
42 struct iscsi_conn *conn = cmd->conn;
43
44 cmd->next_burst_len = 0;
45 cmd->read_data_done = 0;
46
47 while (be32_to_cpu(exp_data_sn) > data_sn) {
48 if ((cmd->next_burst_len +
49 conn->conn_ops->MaxRecvDataSegmentLength) <
50 conn->sess->sess_ops->MaxBurstLength) {
51 cmd->read_data_done +=
52 conn->conn_ops->MaxRecvDataSegmentLength;
53 cmd->next_burst_len +=
54 conn->conn_ops->MaxRecvDataSegmentLength;
55 } else {
56 cmd->read_data_done +=
57 (conn->sess->sess_ops->MaxBurstLength -
58 cmd->next_burst_len);
59 cmd->next_burst_len = 0;
60 }
61 data_sn++;
62 }
63 }
64
65 void iscsit_create_conn_recovery_dataout_values(
66 struct iscsi_cmd *cmd)
67 {
68 u32 write_data_done = 0;
69 struct iscsi_conn *conn = cmd->conn;
70
71 cmd->data_sn = 0;
72 cmd->next_burst_len = 0;
73
74 while (cmd->write_data_done > write_data_done) {
75 if ((write_data_done + conn->sess->sess_ops->MaxBurstLength) <=
76 cmd->write_data_done)
77 write_data_done += conn->sess->sess_ops->MaxBurstLength;
78 else
79 break;
80 }
81
82 cmd->write_data_done = write_data_done;
83 }
84
85 static int iscsit_attach_active_connection_recovery_entry(
86 struct iscsi_session *sess,
87 struct iscsi_conn_recovery *cr)
88 {
89 spin_lock(&sess->cr_a_lock);
90 list_add_tail(&cr->cr_list, &sess->cr_active_list);
91 spin_unlock(&sess->cr_a_lock);
92
93 return 0;
94 }
95
96 static int iscsit_attach_inactive_connection_recovery_entry(
97 struct iscsi_session *sess,
98 struct iscsi_conn_recovery *cr)
99 {
100 spin_lock(&sess->cr_i_lock);
101 list_add_tail(&cr->cr_list, &sess->cr_inactive_list);
102
103 sess->conn_recovery_count++;
104 pr_debug("Incremented connection recovery count to %u for"
105 " SID: %u\n", sess->conn_recovery_count, sess->sid);
106 spin_unlock(&sess->cr_i_lock);
107
108 return 0;
109 }
110
111 struct iscsi_conn_recovery *iscsit_get_inactive_connection_recovery_entry(
112 struct iscsi_session *sess,
113 u16 cid)
114 {
115 struct iscsi_conn_recovery *cr;
116
117 spin_lock(&sess->cr_i_lock);
118 list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
119 if (cr->cid == cid) {
120 spin_unlock(&sess->cr_i_lock);
121 return cr;
122 }
123 }
124 spin_unlock(&sess->cr_i_lock);
125
126 return NULL;
127 }
128
129 void iscsit_free_connection_recovery_entires(struct iscsi_session *sess)
130 {
131 struct iscsi_cmd *cmd, *cmd_tmp;
132 struct iscsi_conn_recovery *cr, *cr_tmp;
133
134 spin_lock(&sess->cr_a_lock);
135 list_for_each_entry_safe(cr, cr_tmp, &sess->cr_active_list, cr_list) {
136 list_del(&cr->cr_list);
137 spin_unlock(&sess->cr_a_lock);
138
139 spin_lock(&cr->conn_recovery_cmd_lock);
140 list_for_each_entry_safe(cmd, cmd_tmp,
141 &cr->conn_recovery_cmd_list, i_conn_node) {
142
143 list_del(&cmd->i_conn_node);
144 cmd->conn = NULL;
145 spin_unlock(&cr->conn_recovery_cmd_lock);
146 iscsit_free_cmd(cmd, true);
147 spin_lock(&cr->conn_recovery_cmd_lock);
148 }
149 spin_unlock(&cr->conn_recovery_cmd_lock);
150 spin_lock(&sess->cr_a_lock);
151
152 kfree(cr);
153 }
154 spin_unlock(&sess->cr_a_lock);
155
156 spin_lock(&sess->cr_i_lock);
157 list_for_each_entry_safe(cr, cr_tmp, &sess->cr_inactive_list, cr_list) {
158 list_del(&cr->cr_list);
159 spin_unlock(&sess->cr_i_lock);
160
161 spin_lock(&cr->conn_recovery_cmd_lock);
162 list_for_each_entry_safe(cmd, cmd_tmp,
163 &cr->conn_recovery_cmd_list, i_conn_node) {
164
165 list_del(&cmd->i_conn_node);
166 cmd->conn = NULL;
167 spin_unlock(&cr->conn_recovery_cmd_lock);
168 iscsit_free_cmd(cmd, true);
169 spin_lock(&cr->conn_recovery_cmd_lock);
170 }
171 spin_unlock(&cr->conn_recovery_cmd_lock);
172 spin_lock(&sess->cr_i_lock);
173
174 kfree(cr);
175 }
176 spin_unlock(&sess->cr_i_lock);
177 }
178
179 int iscsit_remove_active_connection_recovery_entry(
180 struct iscsi_conn_recovery *cr,
181 struct iscsi_session *sess)
182 {
183 spin_lock(&sess->cr_a_lock);
184 list_del(&cr->cr_list);
185
186 sess->conn_recovery_count--;
187 pr_debug("Decremented connection recovery count to %u for"
188 " SID: %u\n", sess->conn_recovery_count, sess->sid);
189 spin_unlock(&sess->cr_a_lock);
190
191 kfree(cr);
192
193 return 0;
194 }
195
196 static void iscsit_remove_inactive_connection_recovery_entry(
197 struct iscsi_conn_recovery *cr,
198 struct iscsi_session *sess)
199 {
200 spin_lock(&sess->cr_i_lock);
201 list_del(&cr->cr_list);
202 spin_unlock(&sess->cr_i_lock);
203 }
204
205 /*
206 * Called with cr->conn_recovery_cmd_lock help.
207 */
208 int iscsit_remove_cmd_from_connection_recovery(
209 struct iscsi_cmd *cmd,
210 struct iscsi_session *sess)
211 {
212 struct iscsi_conn_recovery *cr;
213
214 if (!cmd->cr) {
215 pr_err("struct iscsi_conn_recovery pointer for ITT: 0x%08x"
216 " is NULL!\n", cmd->init_task_tag);
217 BUG();
218 }
219 cr = cmd->cr;
220
221 list_del(&cmd->i_conn_node);
222 return --cr->cmd_count;
223 }
224
225 void iscsit_discard_cr_cmds_by_expstatsn(
226 struct iscsi_conn_recovery *cr,
227 u32 exp_statsn)
228 {
229 u32 dropped_count = 0;
230 struct iscsi_cmd *cmd, *cmd_tmp;
231 struct iscsi_session *sess = cr->sess;
232
233 spin_lock(&cr->conn_recovery_cmd_lock);
234 list_for_each_entry_safe(cmd, cmd_tmp,
235 &cr->conn_recovery_cmd_list, i_conn_node) {
236
237 if (((cmd->deferred_i_state != ISTATE_SENT_STATUS) &&
238 (cmd->deferred_i_state != ISTATE_REMOVE)) ||
239 (cmd->stat_sn >= exp_statsn)) {
240 continue;
241 }
242
243 dropped_count++;
244 pr_debug("Dropping Acknowledged ITT: 0x%08x, StatSN:"
245 " 0x%08x, CID: %hu.\n", cmd->init_task_tag,
246 cmd->stat_sn, cr->cid);
247
248 iscsit_remove_cmd_from_connection_recovery(cmd, sess);
249
250 spin_unlock(&cr->conn_recovery_cmd_lock);
251 iscsit_free_cmd(cmd, true);
252 spin_lock(&cr->conn_recovery_cmd_lock);
253 }
254 spin_unlock(&cr->conn_recovery_cmd_lock);
255
256 pr_debug("Dropped %u total acknowledged commands on"
257 " CID: %hu less than old ExpStatSN: 0x%08x\n",
258 dropped_count, cr->cid, exp_statsn);
259
260 if (!cr->cmd_count) {
261 pr_debug("No commands to be reassigned for failed"
262 " connection CID: %hu on SID: %u\n",
263 cr->cid, sess->sid);
264 iscsit_remove_inactive_connection_recovery_entry(cr, sess);
265 iscsit_attach_active_connection_recovery_entry(sess, cr);
266 pr_debug("iSCSI connection recovery successful for CID:"
267 " %hu on SID: %u\n", cr->cid, sess->sid);
268 iscsit_remove_active_connection_recovery_entry(cr, sess);
269 } else {
270 iscsit_remove_inactive_connection_recovery_entry(cr, sess);
271 iscsit_attach_active_connection_recovery_entry(sess, cr);
272 }
273 }
274
275 int iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(struct iscsi_conn *conn)
276 {
277 u32 dropped_count = 0;
278 struct iscsi_cmd *cmd, *cmd_tmp;
279 struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
280 struct iscsi_session *sess = conn->sess;
281
282 mutex_lock(&sess->cmdsn_mutex);
283 list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
284 &sess->sess_ooo_cmdsn_list, ooo_list) {
285
286 if (ooo_cmdsn->cid != conn->cid)
287 continue;
288
289 dropped_count++;
290 pr_debug("Dropping unacknowledged CmdSN:"
291 " 0x%08x during connection recovery on CID: %hu\n",
292 ooo_cmdsn->cmdsn, conn->cid);
293 iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
294 }
295 mutex_unlock(&sess->cmdsn_mutex);
296
297 spin_lock_bh(&conn->cmd_lock);
298 list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_conn_node) {
299 if (!(cmd->cmd_flags & ICF_OOO_CMDSN))
300 continue;
301
302 list_del(&cmd->i_conn_node);
303
304 spin_unlock_bh(&conn->cmd_lock);
305 iscsit_free_cmd(cmd, true);
306 spin_lock_bh(&conn->cmd_lock);
307 }
308 spin_unlock_bh(&conn->cmd_lock);
309
310 pr_debug("Dropped %u total unacknowledged commands on CID:"
311 " %hu for ExpCmdSN: 0x%08x.\n", dropped_count, conn->cid,
312 sess->exp_cmd_sn);
313 return 0;
314 }
315
316 int iscsit_prepare_cmds_for_realligance(struct iscsi_conn *conn)
317 {
318 u32 cmd_count = 0;
319 struct iscsi_cmd *cmd, *cmd_tmp;
320 struct iscsi_conn_recovery *cr;
321
322 /*
323 * Allocate an struct iscsi_conn_recovery for this connection.
324 * Each struct iscsi_cmd contains an struct iscsi_conn_recovery pointer
325 * (struct iscsi_cmd->cr) so we need to allocate this before preparing the
326 * connection's command list for connection recovery.
327 */
328 cr = kzalloc(sizeof(struct iscsi_conn_recovery), GFP_KERNEL);
329 if (!cr) {
330 pr_err("Unable to allocate memory for"
331 " struct iscsi_conn_recovery.\n");
332 return -1;
333 }
334 INIT_LIST_HEAD(&cr->cr_list);
335 INIT_LIST_HEAD(&cr->conn_recovery_cmd_list);
336 spin_lock_init(&cr->conn_recovery_cmd_lock);
337 /*
338 * Only perform connection recovery on ISCSI_OP_SCSI_CMD or
339 * ISCSI_OP_NOOP_OUT opcodes. For all other opcodes call
340 * list_del(&cmd->i_conn_node); to release the command to the
341 * session pool and remove it from the connection's list.
342 *
343 * Also stop the DataOUT timer, which will be restarted after
344 * sending the TMR response.
345 */
346 spin_lock_bh(&conn->cmd_lock);
347 list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_conn_node) {
348
349 if ((cmd->iscsi_opcode != ISCSI_OP_SCSI_CMD) &&
350 (cmd->iscsi_opcode != ISCSI_OP_NOOP_OUT)) {
351 pr_debug("Not performing realligence on"
352 " Opcode: 0x%02x, ITT: 0x%08x, CmdSN: 0x%08x,"
353 " CID: %hu\n", cmd->iscsi_opcode,
354 cmd->init_task_tag, cmd->cmd_sn, conn->cid);
355
356 list_del(&cmd->i_conn_node);
357 spin_unlock_bh(&conn->cmd_lock);
358 iscsit_free_cmd(cmd, true);
359 spin_lock_bh(&conn->cmd_lock);
360 continue;
361 }
362
363 /*
364 * Special case where commands greater than or equal to
365 * the session's ExpCmdSN are attached to the connection
366 * list but not to the out of order CmdSN list. The one
367 * obvious case is when a command with immediate data
368 * attached must only check the CmdSN against ExpCmdSN
369 * after the data is received. The special case below
370 * is when the connection fails before data is received,
371 * but also may apply to other PDUs, so it has been
372 * made generic here.
373 */
374 if (!(cmd->cmd_flags & ICF_OOO_CMDSN) && !cmd->immediate_cmd &&
375 iscsi_sna_gte(cmd->cmd_sn, conn->sess->exp_cmd_sn)) {
376 list_del(&cmd->i_conn_node);
377 spin_unlock_bh(&conn->cmd_lock);
378 iscsit_free_cmd(cmd, true);
379 spin_lock_bh(&conn->cmd_lock);
380 continue;
381 }
382
383 cmd_count++;
384 pr_debug("Preparing Opcode: 0x%02x, ITT: 0x%08x,"
385 " CmdSN: 0x%08x, StatSN: 0x%08x, CID: %hu for"
386 " realligence.\n", cmd->iscsi_opcode,
387 cmd->init_task_tag, cmd->cmd_sn, cmd->stat_sn,
388 conn->cid);
389
390 cmd->deferred_i_state = cmd->i_state;
391 cmd->i_state = ISTATE_IN_CONNECTION_RECOVERY;
392
393 if (cmd->data_direction == DMA_TO_DEVICE)
394 iscsit_stop_dataout_timer(cmd);
395
396 cmd->sess = conn->sess;
397
398 list_del(&cmd->i_conn_node);
399 spin_unlock_bh(&conn->cmd_lock);
400
401 iscsit_free_all_datain_reqs(cmd);
402
403 transport_wait_for_tasks(&cmd->se_cmd);
404 /*
405 * Add the struct iscsi_cmd to the connection recovery cmd list
406 */
407 spin_lock(&cr->conn_recovery_cmd_lock);
408 list_add_tail(&cmd->i_conn_node, &cr->conn_recovery_cmd_list);
409 spin_unlock(&cr->conn_recovery_cmd_lock);
410
411 spin_lock_bh(&conn->cmd_lock);
412 cmd->cr = cr;
413 cmd->conn = NULL;
414 }
415 spin_unlock_bh(&conn->cmd_lock);
416 /*
417 * Fill in the various values in the preallocated struct iscsi_conn_recovery.
418 */
419 cr->cid = conn->cid;
420 cr->cmd_count = cmd_count;
421 cr->maxrecvdatasegmentlength = conn->conn_ops->MaxRecvDataSegmentLength;
422 cr->maxxmitdatasegmentlength = conn->conn_ops->MaxXmitDataSegmentLength;
423 cr->sess = conn->sess;
424
425 iscsit_attach_inactive_connection_recovery_entry(conn->sess, cr);
426
427 return 0;
428 }
429
430 int iscsit_connection_recovery_transport_reset(struct iscsi_conn *conn)
431 {
432 atomic_set(&conn->connection_recovery, 1);
433
434 if (iscsit_close_connection(conn) < 0)
435 return -1;
436
437 return 0;
438 }
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