1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*******************************************************************************
3 * This file contains error recovery level two functions used by
4 * the iSCSI Target driver.
5 *
6 * (c) Copyright 2007-2013 Datera, Inc.
7 *
8 * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
9 *
10 ******************************************************************************/
11
12 #include <linux/slab.h>
13 #include <scsi/iscsi_proto.h>
14 #include <target/target_core_base.h>
15 #include <target/target_core_fabric.h>
16
17 #include <target/iscsi/iscsi_target_core.h>
18 #include "iscsi_target_datain_values.h"
19 #include "iscsi_target_util.h"
20 #include "iscsi_target_erl0.h"
21 #include "iscsi_target_erl1.h"
22 #include "iscsi_target_erl2.h"
23 #include "iscsi_target.h"
24
25 /*
26 * FIXME: Does RData SNACK apply here as well?
27 */
iscsit_create_conn_recovery_datain_values(struct iscsi_cmd * cmd,__be32 exp_data_sn)28 void iscsit_create_conn_recovery_datain_values(
29 struct iscsi_cmd *cmd,
30 __be32 exp_data_sn)
31 {
32 u32 data_sn = 0;
33 struct iscsi_conn *conn = cmd->conn;
34
35 cmd->next_burst_len = 0;
36 cmd->read_data_done = 0;
37
38 while (be32_to_cpu(exp_data_sn) > data_sn) {
39 if ((cmd->next_burst_len +
40 conn->conn_ops->MaxRecvDataSegmentLength) <
41 conn->sess->sess_ops->MaxBurstLength) {
42 cmd->read_data_done +=
43 conn->conn_ops->MaxRecvDataSegmentLength;
44 cmd->next_burst_len +=
45 conn->conn_ops->MaxRecvDataSegmentLength;
46 } else {
47 cmd->read_data_done +=
48 (conn->sess->sess_ops->MaxBurstLength -
49 cmd->next_burst_len);
50 cmd->next_burst_len = 0;
51 }
52 data_sn++;
53 }
54 }
55
iscsit_create_conn_recovery_dataout_values(struct iscsi_cmd * cmd)56 void iscsit_create_conn_recovery_dataout_values(
57 struct iscsi_cmd *cmd)
58 {
59 u32 write_data_done = 0;
60 struct iscsi_conn *conn = cmd->conn;
61
62 cmd->data_sn = 0;
63 cmd->next_burst_len = 0;
64
65 while (cmd->write_data_done > write_data_done) {
66 if ((write_data_done + conn->sess->sess_ops->MaxBurstLength) <=
67 cmd->write_data_done)
68 write_data_done += conn->sess->sess_ops->MaxBurstLength;
69 else
70 break;
71 }
72
73 cmd->write_data_done = write_data_done;
74 }
75
iscsit_attach_active_connection_recovery_entry(struct iscsi_session * sess,struct iscsi_conn_recovery * cr)76 static int iscsit_attach_active_connection_recovery_entry(
77 struct iscsi_session *sess,
78 struct iscsi_conn_recovery *cr)
79 {
80 spin_lock(&sess->cr_a_lock);
81 list_add_tail(&cr->cr_list, &sess->cr_active_list);
82 spin_unlock(&sess->cr_a_lock);
83
84 return 0;
85 }
86
iscsit_attach_inactive_connection_recovery_entry(struct iscsi_session * sess,struct iscsi_conn_recovery * cr)87 static int iscsit_attach_inactive_connection_recovery_entry(
88 struct iscsi_session *sess,
89 struct iscsi_conn_recovery *cr)
90 {
91 spin_lock(&sess->cr_i_lock);
92 list_add_tail(&cr->cr_list, &sess->cr_inactive_list);
93
94 sess->conn_recovery_count++;
95 pr_debug("Incremented connection recovery count to %u for"
96 " SID: %u\n", sess->conn_recovery_count, sess->sid);
97 spin_unlock(&sess->cr_i_lock);
98
99 return 0;
100 }
101
iscsit_get_inactive_connection_recovery_entry(struct iscsi_session * sess,u16 cid)102 struct iscsi_conn_recovery *iscsit_get_inactive_connection_recovery_entry(
103 struct iscsi_session *sess,
104 u16 cid)
105 {
106 struct iscsi_conn_recovery *cr;
107
108 spin_lock(&sess->cr_i_lock);
109 list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
110 if (cr->cid == cid) {
111 spin_unlock(&sess->cr_i_lock);
112 return cr;
113 }
114 }
115 spin_unlock(&sess->cr_i_lock);
116
117 return NULL;
118 }
119
iscsit_free_connection_recovery_entries(struct iscsi_session * sess)120 void iscsit_free_connection_recovery_entries(struct iscsi_session *sess)
121 {
122 struct iscsi_cmd *cmd, *cmd_tmp;
123 struct iscsi_conn_recovery *cr, *cr_tmp;
124
125 spin_lock(&sess->cr_a_lock);
126 list_for_each_entry_safe(cr, cr_tmp, &sess->cr_active_list, cr_list) {
127 list_del(&cr->cr_list);
128 spin_unlock(&sess->cr_a_lock);
129
130 spin_lock(&cr->conn_recovery_cmd_lock);
131 list_for_each_entry_safe(cmd, cmd_tmp,
132 &cr->conn_recovery_cmd_list, i_conn_node) {
133
134 list_del_init(&cmd->i_conn_node);
135 cmd->conn = NULL;
136 spin_unlock(&cr->conn_recovery_cmd_lock);
137 iscsit_free_cmd(cmd, true);
138 spin_lock(&cr->conn_recovery_cmd_lock);
139 }
140 spin_unlock(&cr->conn_recovery_cmd_lock);
141 spin_lock(&sess->cr_a_lock);
142
143 kfree(cr);
144 }
145 spin_unlock(&sess->cr_a_lock);
146
147 spin_lock(&sess->cr_i_lock);
148 list_for_each_entry_safe(cr, cr_tmp, &sess->cr_inactive_list, cr_list) {
149 list_del(&cr->cr_list);
150 spin_unlock(&sess->cr_i_lock);
151
152 spin_lock(&cr->conn_recovery_cmd_lock);
153 list_for_each_entry_safe(cmd, cmd_tmp,
154 &cr->conn_recovery_cmd_list, i_conn_node) {
155
156 list_del_init(&cmd->i_conn_node);
157 cmd->conn = NULL;
158 spin_unlock(&cr->conn_recovery_cmd_lock);
159 iscsit_free_cmd(cmd, true);
160 spin_lock(&cr->conn_recovery_cmd_lock);
161 }
162 spin_unlock(&cr->conn_recovery_cmd_lock);
163 spin_lock(&sess->cr_i_lock);
164
165 kfree(cr);
166 }
167 spin_unlock(&sess->cr_i_lock);
168 }
169
iscsit_remove_active_connection_recovery_entry(struct iscsi_conn_recovery * cr,struct iscsi_session * sess)170 int iscsit_remove_active_connection_recovery_entry(
171 struct iscsi_conn_recovery *cr,
172 struct iscsi_session *sess)
173 {
174 spin_lock(&sess->cr_a_lock);
175 list_del(&cr->cr_list);
176
177 sess->conn_recovery_count--;
178 pr_debug("Decremented connection recovery count to %u for"
179 " SID: %u\n", sess->conn_recovery_count, sess->sid);
180 spin_unlock(&sess->cr_a_lock);
181
182 kfree(cr);
183
184 return 0;
185 }
186
iscsit_remove_inactive_connection_recovery_entry(struct iscsi_conn_recovery * cr,struct iscsi_session * sess)187 static void iscsit_remove_inactive_connection_recovery_entry(
188 struct iscsi_conn_recovery *cr,
189 struct iscsi_session *sess)
190 {
191 spin_lock(&sess->cr_i_lock);
192 list_del(&cr->cr_list);
193 spin_unlock(&sess->cr_i_lock);
194 }
195
196 /*
197 * Called with cr->conn_recovery_cmd_lock help.
198 */
iscsit_remove_cmd_from_connection_recovery(struct iscsi_cmd * cmd,struct iscsi_session * sess)199 int iscsit_remove_cmd_from_connection_recovery(
200 struct iscsi_cmd *cmd,
201 struct iscsi_session *sess)
202 {
203 struct iscsi_conn_recovery *cr;
204
205 if (!cmd->cr) {
206 pr_err("struct iscsi_conn_recovery pointer for ITT: 0x%08x"
207 " is NULL!\n", cmd->init_task_tag);
208 BUG();
209 }
210 cr = cmd->cr;
211
212 list_del_init(&cmd->i_conn_node);
213 return --cr->cmd_count;
214 }
215
iscsit_discard_cr_cmds_by_expstatsn(struct iscsi_conn_recovery * cr,u32 exp_statsn)216 void iscsit_discard_cr_cmds_by_expstatsn(
217 struct iscsi_conn_recovery *cr,
218 u32 exp_statsn)
219 {
220 u32 dropped_count = 0;
221 struct iscsi_cmd *cmd, *cmd_tmp;
222 struct iscsi_session *sess = cr->sess;
223
224 spin_lock(&cr->conn_recovery_cmd_lock);
225 list_for_each_entry_safe(cmd, cmd_tmp,
226 &cr->conn_recovery_cmd_list, i_conn_node) {
227
228 if (((cmd->deferred_i_state != ISTATE_SENT_STATUS) &&
229 (cmd->deferred_i_state != ISTATE_REMOVE)) ||
230 (cmd->stat_sn >= exp_statsn)) {
231 continue;
232 }
233
234 dropped_count++;
235 pr_debug("Dropping Acknowledged ITT: 0x%08x, StatSN:"
236 " 0x%08x, CID: %hu.\n", cmd->init_task_tag,
237 cmd->stat_sn, cr->cid);
238
239 iscsit_remove_cmd_from_connection_recovery(cmd, sess);
240
241 spin_unlock(&cr->conn_recovery_cmd_lock);
242 iscsit_free_cmd(cmd, true);
243 spin_lock(&cr->conn_recovery_cmd_lock);
244 }
245 spin_unlock(&cr->conn_recovery_cmd_lock);
246
247 pr_debug("Dropped %u total acknowledged commands on"
248 " CID: %hu less than old ExpStatSN: 0x%08x\n",
249 dropped_count, cr->cid, exp_statsn);
250
251 if (!cr->cmd_count) {
252 pr_debug("No commands to be reassigned for failed"
253 " connection CID: %hu on SID: %u\n",
254 cr->cid, sess->sid);
255 iscsit_remove_inactive_connection_recovery_entry(cr, sess);
256 iscsit_attach_active_connection_recovery_entry(sess, cr);
257 pr_debug("iSCSI connection recovery successful for CID:"
258 " %hu on SID: %u\n", cr->cid, sess->sid);
259 iscsit_remove_active_connection_recovery_entry(cr, sess);
260 } else {
261 iscsit_remove_inactive_connection_recovery_entry(cr, sess);
262 iscsit_attach_active_connection_recovery_entry(sess, cr);
263 }
264 }
265
iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(struct iscsi_conn * conn)266 int iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(struct iscsi_conn *conn)
267 {
268 u32 dropped_count = 0;
269 struct iscsi_cmd *cmd, *cmd_tmp;
270 struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
271 struct iscsi_session *sess = conn->sess;
272
273 mutex_lock(&sess->cmdsn_mutex);
274 list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
275 &sess->sess_ooo_cmdsn_list, ooo_list) {
276
277 if (ooo_cmdsn->cid != conn->cid)
278 continue;
279
280 dropped_count++;
281 pr_debug("Dropping unacknowledged CmdSN:"
282 " 0x%08x during connection recovery on CID: %hu\n",
283 ooo_cmdsn->cmdsn, conn->cid);
284 iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
285 }
286 mutex_unlock(&sess->cmdsn_mutex);
287
288 spin_lock_bh(&conn->cmd_lock);
289 list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_conn_node) {
290 if (!(cmd->cmd_flags & ICF_OOO_CMDSN))
291 continue;
292
293 list_del_init(&cmd->i_conn_node);
294
295 spin_unlock_bh(&conn->cmd_lock);
296 iscsit_free_cmd(cmd, true);
297 spin_lock_bh(&conn->cmd_lock);
298 }
299 spin_unlock_bh(&conn->cmd_lock);
300
301 pr_debug("Dropped %u total unacknowledged commands on CID:"
302 " %hu for ExpCmdSN: 0x%08x.\n", dropped_count, conn->cid,
303 sess->exp_cmd_sn);
304 return 0;
305 }
306
iscsit_prepare_cmds_for_reallegiance(struct iscsi_conn * conn)307 int iscsit_prepare_cmds_for_reallegiance(struct iscsi_conn *conn)
308 {
309 u32 cmd_count = 0;
310 struct iscsi_cmd *cmd, *cmd_tmp;
311 struct iscsi_conn_recovery *cr;
312
313 /*
314 * Allocate an struct iscsi_conn_recovery for this connection.
315 * Each struct iscsi_cmd contains an struct iscsi_conn_recovery pointer
316 * (struct iscsi_cmd->cr) so we need to allocate this before preparing the
317 * connection's command list for connection recovery.
318 */
319 cr = kzalloc(sizeof(struct iscsi_conn_recovery), GFP_KERNEL);
320 if (!cr) {
321 pr_err("Unable to allocate memory for"
322 " struct iscsi_conn_recovery.\n");
323 return -1;
324 }
325 INIT_LIST_HEAD(&cr->cr_list);
326 INIT_LIST_HEAD(&cr->conn_recovery_cmd_list);
327 spin_lock_init(&cr->conn_recovery_cmd_lock);
328 /*
329 * Only perform connection recovery on ISCSI_OP_SCSI_CMD or
330 * ISCSI_OP_NOOP_OUT opcodes. For all other opcodes call
331 * list_del_init(&cmd->i_conn_node); to release the command to the
332 * session pool and remove it from the connection's list.
333 *
334 * Also stop the DataOUT timer, which will be restarted after
335 * sending the TMR response.
336 */
337 spin_lock_bh(&conn->cmd_lock);
338 list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_conn_node) {
339
340 if ((cmd->iscsi_opcode != ISCSI_OP_SCSI_CMD) &&
341 (cmd->iscsi_opcode != ISCSI_OP_NOOP_OUT)) {
342 pr_debug("Not performing reallegiance on"
343 " Opcode: 0x%02x, ITT: 0x%08x, CmdSN: 0x%08x,"
344 " CID: %hu\n", cmd->iscsi_opcode,
345 cmd->init_task_tag, cmd->cmd_sn, conn->cid);
346
347 list_del_init(&cmd->i_conn_node);
348 spin_unlock_bh(&conn->cmd_lock);
349 iscsit_free_cmd(cmd, true);
350 spin_lock_bh(&conn->cmd_lock);
351 continue;
352 }
353
354 /*
355 * Special case where commands greater than or equal to
356 * the session's ExpCmdSN are attached to the connection
357 * list but not to the out of order CmdSN list. The one
358 * obvious case is when a command with immediate data
359 * attached must only check the CmdSN against ExpCmdSN
360 * after the data is received. The special case below
361 * is when the connection fails before data is received,
362 * but also may apply to other PDUs, so it has been
363 * made generic here.
364 */
365 if (!(cmd->cmd_flags & ICF_OOO_CMDSN) && !cmd->immediate_cmd &&
366 iscsi_sna_gte(cmd->cmd_sn, conn->sess->exp_cmd_sn)) {
367 list_del_init(&cmd->i_conn_node);
368 spin_unlock_bh(&conn->cmd_lock);
369 iscsit_free_cmd(cmd, true);
370 spin_lock_bh(&conn->cmd_lock);
371 continue;
372 }
373
374 cmd_count++;
375 pr_debug("Preparing Opcode: 0x%02x, ITT: 0x%08x,"
376 " CmdSN: 0x%08x, StatSN: 0x%08x, CID: %hu for"
377 " reallegiance.\n", cmd->iscsi_opcode,
378 cmd->init_task_tag, cmd->cmd_sn, cmd->stat_sn,
379 conn->cid);
380
381 cmd->deferred_i_state = cmd->i_state;
382 cmd->i_state = ISTATE_IN_CONNECTION_RECOVERY;
383
384 if (cmd->data_direction == DMA_TO_DEVICE)
385 iscsit_stop_dataout_timer(cmd);
386
387 cmd->sess = conn->sess;
388
389 list_del_init(&cmd->i_conn_node);
390 spin_unlock_bh(&conn->cmd_lock);
391
392 iscsit_free_all_datain_reqs(cmd);
393
394 transport_wait_for_tasks(&cmd->se_cmd);
395 /*
396 * Add the struct iscsi_cmd to the connection recovery cmd list
397 */
398 spin_lock(&cr->conn_recovery_cmd_lock);
399 list_add_tail(&cmd->i_conn_node, &cr->conn_recovery_cmd_list);
400 spin_unlock(&cr->conn_recovery_cmd_lock);
401
402 spin_lock_bh(&conn->cmd_lock);
403 cmd->cr = cr;
404 cmd->conn = NULL;
405 }
406 spin_unlock_bh(&conn->cmd_lock);
407 /*
408 * Fill in the various values in the preallocated struct iscsi_conn_recovery.
409 */
410 cr->cid = conn->cid;
411 cr->cmd_count = cmd_count;
412 cr->maxrecvdatasegmentlength = conn->conn_ops->MaxRecvDataSegmentLength;
413 cr->maxxmitdatasegmentlength = conn->conn_ops->MaxXmitDataSegmentLength;
414 cr->sess = conn->sess;
415
416 iscsit_attach_inactive_connection_recovery_entry(conn->sess, cr);
417
418 return 0;
419 }
420
iscsit_connection_recovery_transport_reset(struct iscsi_conn * conn)421 int iscsit_connection_recovery_transport_reset(struct iscsi_conn *conn)
422 {
423 atomic_set(&conn->connection_recovery, 1);
424
425 if (iscsit_close_connection(conn) < 0)
426 return -1;
427
428 return 0;
429 }
430
