1/*
2 * iSCSI lib functions
3 *
4 * Copyright (C) 2006 Red Hat, Inc. All rights reserved.
5 * Copyright (C) 2004 - 2006 Mike Christie
6 * Copyright (C) 2004 - 2005 Dmitry Yusupov
7 * Copyright (C) 2004 - 2005 Alex Aizman
8 * maintained by open-iscsi@googlegroups.com
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23 */
24#include <linux/types.h>
25#include <linux/kfifo.h>
26#include <linux/delay.h>
27#include <linux/log2.h>
28#include <linux/slab.h>
29#include <linux/sched/signal.h>
30#include <linux/module.h>
31#include <asm/unaligned.h>
32#include <net/tcp.h>
33#include <scsi/scsi_cmnd.h>
34#include <scsi/scsi_device.h>
35#include <scsi/scsi_eh.h>
36#include <scsi/scsi_tcq.h>
37#include <scsi/scsi_host.h>
38#include <scsi/scsi.h>
39#include <scsi/iscsi_proto.h>
40#include <scsi/scsi_transport.h>
41#include <scsi/scsi_transport_iscsi.h>
42#include <scsi/libiscsi.h>
43#include <trace/events/iscsi.h>
44
45static int iscsi_dbg_lib_conn;
46module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
47 S_IRUGO | S_IWUSR);
48MODULE_PARM_DESC(debug_libiscsi_conn,
49 "Turn on debugging for connections in libiscsi module. "
50 "Set to 1 to turn on, and zero to turn off. Default is off.");
51
52static int iscsi_dbg_lib_session;
53module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
54 S_IRUGO | S_IWUSR);
55MODULE_PARM_DESC(debug_libiscsi_session,
56 "Turn on debugging for sessions in libiscsi module. "
57 "Set to 1 to turn on, and zero to turn off. Default is off.");
58
59static int iscsi_dbg_lib_eh;
60module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
61 S_IRUGO | S_IWUSR);
62MODULE_PARM_DESC(debug_libiscsi_eh,
63 "Turn on debugging for error handling in libiscsi module. "
64 "Set to 1 to turn on, and zero to turn off. Default is off.");
65
66#define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...) \
67 do { \
68 if (iscsi_dbg_lib_conn) \
69 iscsi_conn_printk(KERN_INFO, _conn, \
70 "%s " dbg_fmt, \
71 __func__, ##arg); \
72 iscsi_dbg_trace(trace_iscsi_dbg_conn, \
73 &(_conn)->cls_conn->dev, \
74 "%s " dbg_fmt, __func__, ##arg);\
75 } while (0);
76
77#define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...) \
78 do { \
79 if (iscsi_dbg_lib_session) \
80 iscsi_session_printk(KERN_INFO, _session, \
81 "%s " dbg_fmt, \
82 __func__, ##arg); \
83 iscsi_dbg_trace(trace_iscsi_dbg_session, \
84 &(_session)->cls_session->dev, \
85 "%s " dbg_fmt, __func__, ##arg); \
86 } while (0);
87
88#define ISCSI_DBG_EH(_session, dbg_fmt, arg...) \
89 do { \
90 if (iscsi_dbg_lib_eh) \
91 iscsi_session_printk(KERN_INFO, _session, \
92 "%s " dbg_fmt, \
93 __func__, ##arg); \
94 iscsi_dbg_trace(trace_iscsi_dbg_eh, \
95 &(_session)->cls_session->dev, \
96 "%s " dbg_fmt, __func__, ##arg); \
97 } while (0);
98
99inline void iscsi_conn_queue_work(struct iscsi_conn *conn)
100{
101 struct Scsi_Host *shost = conn->session->host;
102 struct iscsi_host *ihost = shost_priv(shost);
103
104 if (ihost->workq)
105 queue_work(ihost->workq, &conn->xmitwork);
106}
107EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
108
109static void __iscsi_update_cmdsn(struct iscsi_session *session,
110 uint32_t exp_cmdsn, uint32_t max_cmdsn)
111{
112 /*
113 * standard specifies this check for when to update expected and
114 * max sequence numbers
115 */
116 if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
117 return;
118
119 if (exp_cmdsn != session->exp_cmdsn &&
120 !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
121 session->exp_cmdsn = exp_cmdsn;
122
123 if (max_cmdsn != session->max_cmdsn &&
124 !iscsi_sna_lt(max_cmdsn, session->max_cmdsn))
125 session->max_cmdsn = max_cmdsn;
126}
127
128void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
129{
130 __iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
131 be32_to_cpu(hdr->max_cmdsn));
132}
133EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
134
135/**
136 * iscsi_prep_data_out_pdu - initialize Data-Out
137 * @task: scsi command task
138 * @r2t: R2T info
139 * @hdr: iscsi data in pdu
140 *
141 * Notes:
142 * Initialize Data-Out within this R2T sequence and finds
143 * proper data_offset within this SCSI command.
144 *
145 * This function is called with connection lock taken.
146 **/
147void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
148 struct iscsi_data *hdr)
149{
150 struct iscsi_conn *conn = task->conn;
151 unsigned int left = r2t->data_length - r2t->sent;
152
153 task->hdr_len = sizeof(struct iscsi_data);
154
155 memset(hdr, 0, sizeof(struct iscsi_data));
156 hdr->ttt = r2t->ttt;
157 hdr->datasn = cpu_to_be32(r2t->datasn);
158 r2t->datasn++;
159 hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
160 hdr->lun = task->lun;
161 hdr->itt = task->hdr_itt;
162 hdr->exp_statsn = r2t->exp_statsn;
163 hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
164 if (left > conn->max_xmit_dlength) {
165 hton24(hdr->dlength, conn->max_xmit_dlength);
166 r2t->data_count = conn->max_xmit_dlength;
167 hdr->flags = 0;
168 } else {
169 hton24(hdr->dlength, left);
170 r2t->data_count = left;
171 hdr->flags = ISCSI_FLAG_CMD_FINAL;
172 }
173 conn->dataout_pdus_cnt++;
174}
175EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
176
177static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
178{
179 unsigned exp_len = task->hdr_len + len;
180
181 if (exp_len > task->hdr_max) {
182 WARN_ON(1);
183 return -EINVAL;
184 }
185
186 WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
187 task->hdr_len = exp_len;
188 return 0;
189}
190
191/*
192 * make an extended cdb AHS
193 */
194static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
195{
196 struct scsi_cmnd *cmd = task->sc;
197 unsigned rlen, pad_len;
198 unsigned short ahslength;
199 struct iscsi_ecdb_ahdr *ecdb_ahdr;
200 int rc;
201
202 ecdb_ahdr = iscsi_next_hdr(task);
203 rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
204
205 BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
206 ahslength = rlen + sizeof(ecdb_ahdr->reserved);
207
208 pad_len = iscsi_padding(rlen);
209
210 rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
211 sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
212 if (rc)
213 return rc;
214
215 if (pad_len)
216 memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
217
218 ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
219 ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
220 ecdb_ahdr->reserved = 0;
221 memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
222
223 ISCSI_DBG_SESSION(task->conn->session,
224 "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
225 "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
226 "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
227 task->hdr_len);
228 return 0;
229}
230
231/**
232 * iscsi_check_tmf_restrictions - check if a task is affected by TMF
233 * @task: iscsi task
234 * @opcode: opcode to check for
235 *
236 * During TMF a task has to be checked if it's affected.
237 * All unrelated I/O can be passed through, but I/O to the
238 * affected LUN should be restricted.
239 * If 'fast_abort' is set we won't be sending any I/O to the
240 * affected LUN.
241 * Otherwise the target is waiting for all TTTs to be completed,
242 * so we have to send all outstanding Data-Out PDUs to the target.
243 */
244static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
245{
246 struct iscsi_conn *conn = task->conn;
247 struct iscsi_tm *tmf = &conn->tmhdr;
248 u64 hdr_lun;
249
250 if (conn->tmf_state == TMF_INITIAL)
251 return 0;
252
253 if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
254 return 0;
255
256 switch (ISCSI_TM_FUNC_VALUE(tmf)) {
257 case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
258 /*
259 * Allow PDUs for unrelated LUNs
260 */
261 hdr_lun = scsilun_to_int(&tmf->lun);
262 if (hdr_lun != task->sc->device->lun)
263 return 0;
264 /* fall through */
265 case ISCSI_TM_FUNC_TARGET_WARM_RESET:
266 /*
267 * Fail all SCSI cmd PDUs
268 */
269 if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
270 iscsi_conn_printk(KERN_INFO, conn,
271 "task [op %x itt "
272 "0x%x/0x%x] "
273 "rejected.\n",
274 opcode, task->itt,
275 task->hdr_itt);
276 return -EACCES;
277 }
278 /*
279 * And also all data-out PDUs in response to R2T
280 * if fast_abort is set.
281 */
282 if (conn->session->fast_abort) {
283 iscsi_conn_printk(KERN_INFO, conn,
284 "task [op %x itt "
285 "0x%x/0x%x] fast abort.\n",
286 opcode, task->itt,
287 task->hdr_itt);
288 return -EACCES;
289 }
290 break;
291 case ISCSI_TM_FUNC_ABORT_TASK:
292 /*
293 * the caller has already checked if the task
294 * they want to abort was in the pending queue so if
295 * we are here the cmd pdu has gone out already, and
296 * we will only hit this for data-outs
297 */
298 if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
299 task->hdr_itt == tmf->rtt) {
300 ISCSI_DBG_SESSION(conn->session,
301 "Preventing task %x/%x from sending "
302 "data-out due to abort task in "
303 "progress\n", task->itt,
304 task->hdr_itt);
305 return -EACCES;
306 }
307 break;
308 }
309
310 return 0;
311}
312
313/**
314 * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
315 * @task: iscsi task
316 *
317 * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
318 * fields like dlength or final based on how much data it sends
319 */
320static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
321{
322 struct iscsi_conn *conn = task->conn;
323 struct iscsi_session *session = conn->session;
324 struct scsi_cmnd *sc = task->sc;
325 struct iscsi_scsi_req *hdr;
326 unsigned hdrlength, cmd_len, transfer_length;
327 itt_t itt;
328 int rc;
329
330 rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
331 if (rc)
332 return rc;
333
334 if (conn->session->tt->alloc_pdu) {
335 rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
336 if (rc)
337 return rc;
338 }
339 hdr = (struct iscsi_scsi_req *)task->hdr;
340 itt = hdr->itt;
341 memset(hdr, 0, sizeof(*hdr));
342
343 if (session->tt->parse_pdu_itt)
344 hdr->itt = task->hdr_itt = itt;
345 else
346 hdr->itt = task->hdr_itt = build_itt(task->itt,
347 task->conn->session->age);
348 task->hdr_len = 0;
349 rc = iscsi_add_hdr(task, sizeof(*hdr));
350 if (rc)
351 return rc;
352 hdr->opcode = ISCSI_OP_SCSI_CMD;
353 hdr->flags = ISCSI_ATTR_SIMPLE;
354 int_to_scsilun(sc->device->lun, &hdr->lun);
355 task->lun = hdr->lun;
356 hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
357 cmd_len = sc->cmd_len;
358 if (cmd_len < ISCSI_CDB_SIZE)
359 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
360 else if (cmd_len > ISCSI_CDB_SIZE) {
361 rc = iscsi_prep_ecdb_ahs(task);
362 if (rc)
363 return rc;
364 cmd_len = ISCSI_CDB_SIZE;
365 }
366 memcpy(hdr->cdb, sc->cmnd, cmd_len);
367
368 task->imm_count = 0;
369 if (scsi_get_prot_op(sc) != SCSI_PROT_NORMAL)
370 task->protected = true;
371
372 transfer_length = scsi_transfer_length(sc);
373 hdr->data_length = cpu_to_be32(transfer_length);
374 if (sc->sc_data_direction == DMA_TO_DEVICE) {
375 struct iscsi_r2t_info *r2t = &task->unsol_r2t;
376
377 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
378 /*
379 * Write counters:
380 *
381 * imm_count bytes to be sent right after
382 * SCSI PDU Header
383 *
384 * unsol_count bytes(as Data-Out) to be sent
385 * without R2T ack right after
386 * immediate data
387 *
388 * r2t data_length bytes to be sent via R2T ack's
389 *
390 * pad_count bytes to be sent as zero-padding
391 */
392 memset(r2t, 0, sizeof(*r2t));
393
394 if (session->imm_data_en) {
395 if (transfer_length >= session->first_burst)
396 task->imm_count = min(session->first_burst,
397 conn->max_xmit_dlength);
398 else
399 task->imm_count = min(transfer_length,
400 conn->max_xmit_dlength);
401 hton24(hdr->dlength, task->imm_count);
402 } else
403 zero_data(hdr->dlength);
404
405 if (!session->initial_r2t_en) {
406 r2t->data_length = min(session->first_burst,
407 transfer_length) -
408 task->imm_count;
409 r2t->data_offset = task->imm_count;
410 r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
411 r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
412 }
413
414 if (!task->unsol_r2t.data_length)
415 /* No unsolicit Data-Out's */
416 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
417 } else {
418 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
419 zero_data(hdr->dlength);
420
421 if (sc->sc_data_direction == DMA_FROM_DEVICE)
422 hdr->flags |= ISCSI_FLAG_CMD_READ;
423 }
424
425 /* calculate size of additional header segments (AHSs) */
426 hdrlength = task->hdr_len - sizeof(*hdr);
427
428 WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
429 hdrlength /= ISCSI_PAD_LEN;
430
431 WARN_ON(hdrlength >= 256);
432 hdr->hlength = hdrlength & 0xFF;
433 hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
434
435 if (session->tt->init_task && session->tt->init_task(task))
436 return -EIO;
437
438 task->state = ISCSI_TASK_RUNNING;
439 session->cmdsn++;
440
441 conn->scsicmd_pdus_cnt++;
442 ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
443 "itt 0x%x len %d cmdsn %d win %d]\n",
444 sc->sc_data_direction == DMA_TO_DEVICE ?
445 "write" : "read", conn->id, sc, sc->cmnd[0],
446 task->itt, transfer_length,
447 session->cmdsn,
448 session->max_cmdsn - session->exp_cmdsn + 1);
449 return 0;
450}
451
452/**
453 * iscsi_free_task - free a task
454 * @task: iscsi cmd task
455 *
456 * Must be called with session back_lock.
457 * This function returns the scsi command to scsi-ml or cleans
458 * up mgmt tasks then returns the task to the pool.
459 */
460static void iscsi_free_task(struct iscsi_task *task)
461{
462 struct iscsi_conn *conn = task->conn;
463 struct iscsi_session *session = conn->session;
464 struct scsi_cmnd *sc = task->sc;
465 int oldstate = task->state;
466
467 ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
468 task->itt, task->state, task->sc);
469
470 session->tt->cleanup_task(task);
471 task->state = ISCSI_TASK_FREE;
472 task->sc = NULL;
473 /*
474 * login task is preallocated so do not free
475 */
476 if (conn->login_task == task)
477 return;
478
479 kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
480
481 if (sc) {
482 /* SCSI eh reuses commands to verify us */
483 sc->SCp.ptr = NULL;
484 /*
485 * queue command may call this to free the task, so
486 * it will decide how to return sc to scsi-ml.
487 */
488 if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
489 sc->scsi_done(sc);
490 }
491}
492
493void __iscsi_get_task(struct iscsi_task *task)
494{
495 refcount_inc(&task->refcount);
496}
497EXPORT_SYMBOL_GPL(__iscsi_get_task);
498
499void __iscsi_put_task(struct iscsi_task *task)
500{
501 if (refcount_dec_and_test(&task->refcount))
502 iscsi_free_task(task);
503}
504EXPORT_SYMBOL_GPL(__iscsi_put_task);
505
506void iscsi_put_task(struct iscsi_task *task)
507{
508 struct iscsi_session *session = task->conn->session;
509
510 /* regular RX path uses back_lock */
511 spin_lock_bh(&session->back_lock);
512 __iscsi_put_task(task);
513 spin_unlock_bh(&session->back_lock);
514}
515EXPORT_SYMBOL_GPL(iscsi_put_task);
516
517/**
518 * iscsi_complete_task - finish a task
519 * @task: iscsi cmd task
520 * @state: state to complete task with
521 *
522 * Must be called with session back_lock.
523 */
524static void iscsi_complete_task(struct iscsi_task *task, int state)
525{
526 struct iscsi_conn *conn = task->conn;
527
528 ISCSI_DBG_SESSION(conn->session,
529 "complete task itt 0x%x state %d sc %p\n",
530 task->itt, task->state, task->sc);
531 if (task->state == ISCSI_TASK_COMPLETED ||
532 task->state == ISCSI_TASK_ABRT_TMF ||
533 task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
534 task->state == ISCSI_TASK_REQUEUE_SCSIQ)
535 return;
536 WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
537 task->state = state;
538
539 spin_lock_bh(&conn->taskqueuelock);
540 if (!list_empty(&task->running)) {
541 pr_debug_once("%s while task on list", __func__);
542 list_del_init(&task->running);
543 }
544 spin_unlock_bh(&conn->taskqueuelock);
545
546 if (conn->task == task)
547 conn->task = NULL;
548
549 if (conn->ping_task == task)
550 conn->ping_task = NULL;
551
552 /* release get from queueing */
553 __iscsi_put_task(task);
554}
555
556/**
557 * iscsi_complete_scsi_task - finish scsi task normally
558 * @task: iscsi task for scsi cmd
559 * @exp_cmdsn: expected cmd sn in cpu format
560 * @max_cmdsn: max cmd sn in cpu format
561 *
562 * This is used when drivers do not need or cannot perform
563 * lower level pdu processing.
564 *
565 * Called with session back_lock
566 */
567void iscsi_complete_scsi_task(struct iscsi_task *task,
568 uint32_t exp_cmdsn, uint32_t max_cmdsn)
569{
570 struct iscsi_conn *conn = task->conn;
571
572 ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
573
574 conn->last_recv = jiffies;
575 __iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
576 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
577}
578EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
579
580
581/*
582 * session back_lock must be held and if not called for a task that is
583 * still pending or from the xmit thread, then xmit thread must
584 * be suspended.
585 */
586static void fail_scsi_task(struct iscsi_task *task, int err)
587{
588 struct iscsi_conn *conn = task->conn;
589 struct scsi_cmnd *sc;
590 int state;
591
592 /*
593 * if a command completes and we get a successful tmf response
594 * we will hit this because the scsi eh abort code does not take
595 * a ref to the task.
596 */
597 sc = task->sc;
598 if (!sc)
599 return;
600
601 if (task->state == ISCSI_TASK_PENDING) {
602 /*
603 * cmd never made it to the xmit thread, so we should not count
604 * the cmd in the sequencing
605 */
606 conn->session->queued_cmdsn--;
607 /* it was never sent so just complete like normal */
608 state = ISCSI_TASK_COMPLETED;
609 } else if (err == DID_TRANSPORT_DISRUPTED)
610 state = ISCSI_TASK_ABRT_SESS_RECOV;
611 else
612 state = ISCSI_TASK_ABRT_TMF;
613
614 sc->result = err << 16;
615 scsi_set_resid(sc, scsi_bufflen(sc));
616
617 /* regular RX path uses back_lock */
618 spin_lock_bh(&conn->session->back_lock);
619 iscsi_complete_task(task, state);
620 spin_unlock_bh(&conn->session->back_lock);
621}
622
623static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
624 struct iscsi_task *task)
625{
626 struct iscsi_session *session = conn->session;
627 struct iscsi_hdr *hdr = task->hdr;
628 struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
629 uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
630
631 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
632 return -ENOTCONN;
633
634 if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
635 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
636 /*
637 * pre-format CmdSN for outgoing PDU.
638 */
639 nop->cmdsn = cpu_to_be32(session->cmdsn);
640 if (hdr->itt != RESERVED_ITT) {
641 /*
642 * TODO: We always use immediate for normal session pdus.
643 * If we start to send tmfs or nops as non-immediate then
644 * we should start checking the cmdsn numbers for mgmt tasks.
645 *
646 * During discovery sessions iscsid sends TEXT as non immediate,
647 * but we always only send one PDU at a time.
648 */
649 if (conn->c_stage == ISCSI_CONN_STARTED &&
650 !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
651 session->queued_cmdsn++;
652 session->cmdsn++;
653 }
654 }
655
656 if (session->tt->init_task && session->tt->init_task(task))
657 return -EIO;
658
659 if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
660 session->state = ISCSI_STATE_LOGGING_OUT;
661
662 task->state = ISCSI_TASK_RUNNING;
663 ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
664 "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
665 hdr->itt, task->data_count);
666 return 0;
667}
668
669static struct iscsi_task *
670__iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
671 char *data, uint32_t data_size)
672{
673 struct iscsi_session *session = conn->session;
674 struct iscsi_host *ihost = shost_priv(session->host);
675 uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
676 struct iscsi_task *task;
677 itt_t itt;
678
679 if (session->state == ISCSI_STATE_TERMINATE)
680 return NULL;
681
682 if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
683 /*
684 * Login and Text are sent serially, in
685 * request-followed-by-response sequence.
686 * Same task can be used. Same ITT must be used.
687 * Note that login_task is preallocated at conn_create().
688 */
689 if (conn->login_task->state != ISCSI_TASK_FREE) {
690 iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
691 "progress. Cannot start new task.\n");
692 return NULL;
693 }
694
695 if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
696 iscsi_conn_printk(KERN_ERR, conn, "Invalid buffer len of %u for login task. Max len is %u\n", data_size, ISCSI_DEF_MAX_RECV_SEG_LEN);
697 return NULL;
698 }
699
700 task = conn->login_task;
701 } else {
702 if (session->state != ISCSI_STATE_LOGGED_IN)
703 return NULL;
704
705 if (data_size != 0) {
706 iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
707 return NULL;
708 }
709
710 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
711 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
712
713 if (!kfifo_out(&session->cmdpool.queue,
714 (void*)&task, sizeof(void*)))
715 return NULL;
716 }
717 /*
718 * released in complete pdu for task we expect a response for, and
719 * released by the lld when it has transmitted the task for
720 * pdus we do not expect a response for.
721 */
722 refcount_set(&task->refcount, 1);
723 task->conn = conn;
724 task->sc = NULL;
725 INIT_LIST_HEAD(&task->running);
726 task->state = ISCSI_TASK_PENDING;
727
728 if (data_size) {
729 memcpy(task->data, data, data_size);
730 task->data_count = data_size;
731 } else
732 task->data_count = 0;
733
734 if (conn->session->tt->alloc_pdu) {
735 if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
736 iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
737 "pdu for mgmt task.\n");
738 goto free_task;
739 }
740 }
741
742 itt = task->hdr->itt;
743 task->hdr_len = sizeof(struct iscsi_hdr);
744 memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
745
746 if (hdr->itt != RESERVED_ITT) {
747 if (session->tt->parse_pdu_itt)
748 task->hdr->itt = itt;
749 else
750 task->hdr->itt = build_itt(task->itt,
751 task->conn->session->age);
752 }
753
754 if (!ihost->workq) {
755 if (iscsi_prep_mgmt_task(conn, task))
756 goto free_task;
757
758 if (session->tt->xmit_task(task))
759 goto free_task;
760 } else {
761 spin_lock_bh(&conn->taskqueuelock);
762 list_add_tail(&task->running, &conn->mgmtqueue);
763 spin_unlock_bh(&conn->taskqueuelock);
764 iscsi_conn_queue_work(conn);
765 }
766
767 return task;
768
769free_task:
770 /* regular RX path uses back_lock */
771 spin_lock(&session->back_lock);
772 __iscsi_put_task(task);
773 spin_unlock(&session->back_lock);
774 return NULL;
775}
776
777int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
778 char *data, uint32_t data_size)
779{
780 struct iscsi_conn *conn = cls_conn->dd_data;
781 struct iscsi_session *session = conn->session;
782 int err = 0;
783
784 spin_lock_bh(&session->frwd_lock);
785 if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
786 err = -EPERM;
787 spin_unlock_bh(&session->frwd_lock);
788 return err;
789}
790EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
791
792/**
793 * iscsi_cmd_rsp - SCSI Command Response processing
794 * @conn: iscsi connection
795 * @hdr: iscsi header
796 * @task: scsi command task
797 * @data: cmd data buffer
798 * @datalen: len of buffer
799 *
800 * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
801 * then completes the command and task. called under back_lock
802 **/
803static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
804 struct iscsi_task *task, char *data,
805 int datalen)
806{
807 struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
808 struct iscsi_session *session = conn->session;
809 struct scsi_cmnd *sc = task->sc;
810
811 iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
812 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
813
814 sc->result = (DID_OK << 16) | rhdr->cmd_status;
815
816 if (task->protected) {
817 sector_t sector;
818 u8 ascq;
819
820 /**
821 * Transports that didn't implement check_protection
822 * callback but still published T10-PI support to scsi-mid
823 * deserve this BUG_ON.
824 **/
825 BUG_ON(!session->tt->check_protection);
826
827 ascq = session->tt->check_protection(task, &sector);
828 if (ascq) {
829 sc->result = DRIVER_SENSE << 24 |
830 SAM_STAT_CHECK_CONDITION;
831 scsi_build_sense_buffer(1, sc->sense_buffer,
832 ILLEGAL_REQUEST, 0x10, ascq);
833 scsi_set_sense_information(sc->sense_buffer,
834 SCSI_SENSE_BUFFERSIZE,
835 sector);
836 goto out;
837 }
838 }
839
840 if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
841 sc->result = DID_ERROR << 16;
842 goto out;
843 }
844
845 if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
846 uint16_t senselen;
847
848 if (datalen < 2) {
849invalid_datalen:
850 iscsi_conn_printk(KERN_ERR, conn,
851 "Got CHECK_CONDITION but invalid data "
852 "buffer size of %d\n", datalen);
853 sc->result = DID_BAD_TARGET << 16;
854 goto out;
855 }
856
857 senselen = get_unaligned_be16(data);
858 if (datalen < senselen)
859 goto invalid_datalen;
860
861 memcpy(sc->sense_buffer, data + 2,
862 min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
863 ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
864 min_t(uint16_t, senselen,
865 SCSI_SENSE_BUFFERSIZE));
866 }
867
868 if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
869 ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
870 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
871 }
872
873 if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
874 ISCSI_FLAG_CMD_OVERFLOW)) {
875 int res_count = be32_to_cpu(rhdr->residual_count);
876
877 if (res_count > 0 &&
878 (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
879 res_count <= scsi_bufflen(sc)))
880 /* write side for bidi or uni-io set_resid */
881 scsi_set_resid(sc, res_count);
882 else
883 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
884 }
885out:
886 ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
887 sc, sc->result, task->itt);
888 conn->scsirsp_pdus_cnt++;
889 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
890}
891
892/**
893 * iscsi_data_in_rsp - SCSI Data-In Response processing
894 * @conn: iscsi connection
895 * @hdr: iscsi pdu
896 * @task: scsi command task
897 *
898 * iscsi_data_in_rsp sets up the scsi_cmnd fields based on the data received
899 * then completes the command and task. called under back_lock
900 **/
901static void
902iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
903 struct iscsi_task *task)
904{
905 struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
906 struct scsi_cmnd *sc = task->sc;
907
908 if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
909 return;
910
911 iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
912 sc->result = (DID_OK << 16) | rhdr->cmd_status;
913 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
914 if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
915 ISCSI_FLAG_DATA_OVERFLOW)) {
916 int res_count = be32_to_cpu(rhdr->residual_count);
917
918 if (res_count > 0 &&
919 (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
920 res_count <= sc->sdb.length))
921 scsi_set_resid(sc, res_count);
922 else
923 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
924 }
925
926 ISCSI_DBG_SESSION(conn->session, "data in with status done "
927 "[sc %p res %d itt 0x%x]\n",
928 sc, sc->result, task->itt);
929 conn->scsirsp_pdus_cnt++;
930 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
931}
932
933static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
934{
935 struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
936
937 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
938 conn->tmfrsp_pdus_cnt++;
939
940 if (conn->tmf_state != TMF_QUEUED)
941 return;
942
943 if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
944 conn->tmf_state = TMF_SUCCESS;
945 else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
946 conn->tmf_state = TMF_NOT_FOUND;
947 else
948 conn->tmf_state = TMF_FAILED;
949 wake_up(&conn->ehwait);
950}
951
952static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
953{
954 struct iscsi_nopout hdr;
955 struct iscsi_task *task;
956
957 if (!rhdr && conn->ping_task)
958 return -EINVAL;
959
960 memset(&hdr, 0, sizeof(struct iscsi_nopout));
961 hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
962 hdr.flags = ISCSI_FLAG_CMD_FINAL;
963
964 if (rhdr) {
965 hdr.lun = rhdr->lun;
966 hdr.ttt = rhdr->ttt;
967 hdr.itt = RESERVED_ITT;
968 } else
969 hdr.ttt = RESERVED_ITT;
970
971 task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
972 if (!task) {
973 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
974 return -EIO;
975 } else if (!rhdr) {
976 /* only track our nops */
977 conn->ping_task = task;
978 conn->last_ping = jiffies;
979 }
980
981 return 0;
982}
983
984/**
985 * iscsi_nop_out_rsp - SCSI NOP Response processing
986 * @task: scsi command task
987 * @nop: the nop structure
988 * @data: where to put the data
989 * @datalen: length of data
990 *
991 * iscsi_nop_out_rsp handles nop response from use or
992 * from user space. called under back_lock
993 **/
994static int iscsi_nop_out_rsp(struct iscsi_task *task,
995 struct iscsi_nopin *nop, char *data, int datalen)
996{
997 struct iscsi_conn *conn = task->conn;
998 int rc = 0;
999
1000 if (conn->ping_task != task) {
1001 /*
1002 * If this is not in response to one of our
1003 * nops then it must be from userspace.
1004 */
1005 if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
1006 data, datalen))
1007 rc = ISCSI_ERR_CONN_FAILED;
1008 } else
1009 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1010 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1011 return rc;
1012}
1013
1014static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1015 char *data, int datalen)
1016{
1017 struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1018 struct iscsi_hdr rejected_pdu;
1019 int opcode, rc = 0;
1020
1021 conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1022
1023 if (ntoh24(reject->dlength) > datalen ||
1024 ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1025 iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1026 "pdu. Invalid data length (pdu dlength "
1027 "%u, datalen %d\n", ntoh24(reject->dlength),
1028 datalen);
1029 return ISCSI_ERR_PROTO;
1030 }
1031 memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1032 opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1033
1034 switch (reject->reason) {
1035 case ISCSI_REASON_DATA_DIGEST_ERROR:
1036 iscsi_conn_printk(KERN_ERR, conn,
1037 "pdu (op 0x%x itt 0x%x) rejected "
1038 "due to DataDigest error.\n",
1039 opcode, rejected_pdu.itt);
1040 break;
1041 case ISCSI_REASON_IMM_CMD_REJECT:
1042 iscsi_conn_printk(KERN_ERR, conn,
1043 "pdu (op 0x%x itt 0x%x) rejected. Too many "
1044 "immediate commands.\n",
1045 opcode, rejected_pdu.itt);
1046 /*
1047 * We only send one TMF at a time so if the target could not
1048 * handle it, then it should get fixed (RFC mandates that
1049 * a target can handle one immediate TMF per conn).
1050 *
1051 * For nops-outs, we could have sent more than one if
1052 * the target is sending us lots of nop-ins
1053 */
1054 if (opcode != ISCSI_OP_NOOP_OUT)
1055 return 0;
1056
1057 if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1058 /*
1059 * nop-out in response to target's nop-out rejected.
1060 * Just resend.
1061 */
1062 /* In RX path we are under back lock */
1063 spin_unlock(&conn->session->back_lock);
1064 spin_lock(&conn->session->frwd_lock);
1065 iscsi_send_nopout(conn,
1066 (struct iscsi_nopin*)&rejected_pdu);
1067 spin_unlock(&conn->session->frwd_lock);
1068 spin_lock(&conn->session->back_lock);
1069 } else {
1070 struct iscsi_task *task;
1071 /*
1072 * Our nop as ping got dropped. We know the target
1073 * and transport are ok so just clean up
1074 */
1075 task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1076 if (!task) {
1077 iscsi_conn_printk(KERN_ERR, conn,
1078 "Invalid pdu reject. Could "
1079 "not lookup rejected task.\n");
1080 rc = ISCSI_ERR_BAD_ITT;
1081 } else
1082 rc = iscsi_nop_out_rsp(task,
1083 (struct iscsi_nopin*)&rejected_pdu,
1084 NULL, 0);
1085 }
1086 break;
1087 default:
1088 iscsi_conn_printk(KERN_ERR, conn,
1089 "pdu (op 0x%x itt 0x%x) rejected. Reason "
1090 "code 0x%x\n", rejected_pdu.opcode,
1091 rejected_pdu.itt, reject->reason);
1092 break;
1093 }
1094 return rc;
1095}
1096
1097/**
1098 * iscsi_itt_to_task - look up task by itt
1099 * @conn: iscsi connection
1100 * @itt: itt
1101 *
1102 * This should be used for mgmt tasks like login and nops, or if
1103 * the LDD's itt space does not include the session age.
1104 *
1105 * The session back_lock must be held.
1106 */
1107struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1108{
1109 struct iscsi_session *session = conn->session;
1110 int i;
1111
1112 if (itt == RESERVED_ITT)
1113 return NULL;
1114
1115 if (session->tt->parse_pdu_itt)
1116 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1117 else
1118 i = get_itt(itt);
1119 if (i >= session->cmds_max)
1120 return NULL;
1121
1122 return session->cmds[i];
1123}
1124EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1125
1126/**
1127 * __iscsi_complete_pdu - complete pdu
1128 * @conn: iscsi conn
1129 * @hdr: iscsi header
1130 * @data: data buffer
1131 * @datalen: len of data buffer
1132 *
1133 * Completes pdu processing by freeing any resources allocated at
1134 * queuecommand or send generic. session back_lock must be held and verify
1135 * itt must have been called.
1136 */
1137int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1138 char *data, int datalen)
1139{
1140 struct iscsi_session *session = conn->session;
1141 int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1142 struct iscsi_task *task;
1143 uint32_t itt;
1144
1145 conn->last_recv = jiffies;
1146 rc = iscsi_verify_itt(conn, hdr->itt);
1147 if (rc)
1148 return rc;
1149
1150 if (hdr->itt != RESERVED_ITT)
1151 itt = get_itt(hdr->itt);
1152 else
1153 itt = ~0U;
1154
1155 ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1156 opcode, conn->id, itt, datalen);
1157
1158 if (itt == ~0U) {
1159 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1160
1161 switch(opcode) {
1162 case ISCSI_OP_NOOP_IN:
1163 if (datalen) {
1164 rc = ISCSI_ERR_PROTO;
1165 break;
1166 }
1167
1168 if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1169 break;
1170
1171 /* In RX path we are under back lock */
1172 spin_unlock(&session->back_lock);
1173 spin_lock(&session->frwd_lock);
1174 iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1175 spin_unlock(&session->frwd_lock);
1176 spin_lock(&session->back_lock);
1177 break;
1178 case ISCSI_OP_REJECT:
1179 rc = iscsi_handle_reject(conn, hdr, data, datalen);
1180 break;
1181 case ISCSI_OP_ASYNC_EVENT:
1182 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1183 if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1184 rc = ISCSI_ERR_CONN_FAILED;
1185 break;
1186 default:
1187 rc = ISCSI_ERR_BAD_OPCODE;
1188 break;
1189 }
1190 goto out;
1191 }
1192
1193 switch(opcode) {
1194 case ISCSI_OP_SCSI_CMD_RSP:
1195 case ISCSI_OP_SCSI_DATA_IN:
1196 task = iscsi_itt_to_ctask(conn, hdr->itt);
1197 if (!task)
1198 return ISCSI_ERR_BAD_ITT;
1199 task->last_xfer = jiffies;
1200 break;
1201 case ISCSI_OP_R2T:
1202 /*
1203 * LLD handles R2Ts if they need to.
1204 */
1205 return 0;
1206 case ISCSI_OP_LOGOUT_RSP:
1207 case ISCSI_OP_LOGIN_RSP:
1208 case ISCSI_OP_TEXT_RSP:
1209 case ISCSI_OP_SCSI_TMFUNC_RSP:
1210 case ISCSI_OP_NOOP_IN:
1211 task = iscsi_itt_to_task(conn, hdr->itt);
1212 if (!task)
1213 return ISCSI_ERR_BAD_ITT;
1214 break;
1215 default:
1216 return ISCSI_ERR_BAD_OPCODE;
1217 }
1218
1219 switch(opcode) {
1220 case ISCSI_OP_SCSI_CMD_RSP:
1221 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1222 break;
1223 case ISCSI_OP_SCSI_DATA_IN:
1224 iscsi_data_in_rsp(conn, hdr, task);
1225 break;
1226 case ISCSI_OP_LOGOUT_RSP:
1227 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1228 if (datalen) {
1229 rc = ISCSI_ERR_PROTO;
1230 break;
1231 }
1232 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1233 goto recv_pdu;
1234 case ISCSI_OP_LOGIN_RSP:
1235 case ISCSI_OP_TEXT_RSP:
1236 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1237 /*
1238 * login related PDU's exp_statsn is handled in
1239 * userspace
1240 */
1241 goto recv_pdu;
1242 case ISCSI_OP_SCSI_TMFUNC_RSP:
1243 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1244 if (datalen) {
1245 rc = ISCSI_ERR_PROTO;
1246 break;
1247 }
1248
1249 iscsi_tmf_rsp(conn, hdr);
1250 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1251 break;
1252 case ISCSI_OP_NOOP_IN:
1253 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1254 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1255 rc = ISCSI_ERR_PROTO;
1256 break;
1257 }
1258 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1259
1260 rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1261 data, datalen);
1262 break;
1263 default:
1264 rc = ISCSI_ERR_BAD_OPCODE;
1265 break;
1266 }
1267
1268out:
1269 return rc;
1270recv_pdu:
1271 if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1272 rc = ISCSI_ERR_CONN_FAILED;
1273 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1274 return rc;
1275}
1276EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1277
1278int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1279 char *data, int datalen)
1280{
1281 int rc;
1282
1283 spin_lock(&conn->session->back_lock);
1284 rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1285 spin_unlock(&conn->session->back_lock);
1286 return rc;
1287}
1288EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1289
1290int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1291{
1292 struct iscsi_session *session = conn->session;
1293 int age = 0, i = 0;
1294
1295 if (itt == RESERVED_ITT)
1296 return 0;
1297
1298 if (session->tt->parse_pdu_itt)
1299 session->tt->parse_pdu_itt(conn, itt, &i, &age);
1300 else {
1301 i = get_itt(itt);
1302 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1303 }
1304
1305 if (age != session->age) {
1306 iscsi_conn_printk(KERN_ERR, conn,
1307 "received itt %x expected session age (%x)\n",
1308 (__force u32)itt, session->age);
1309 return ISCSI_ERR_BAD_ITT;
1310 }
1311
1312 if (i >= session->cmds_max) {
1313 iscsi_conn_printk(KERN_ERR, conn,
1314 "received invalid itt index %u (max cmds "
1315 "%u.\n", i, session->cmds_max);
1316 return ISCSI_ERR_BAD_ITT;
1317 }
1318 return 0;
1319}
1320EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1321
1322/**
1323 * iscsi_itt_to_ctask - look up ctask by itt
1324 * @conn: iscsi connection
1325 * @itt: itt
1326 *
1327 * This should be used for cmd tasks.
1328 *
1329 * The session back_lock must be held.
1330 */
1331struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1332{
1333 struct iscsi_task *task;
1334
1335 if (iscsi_verify_itt(conn, itt))
1336 return NULL;
1337
1338 task = iscsi_itt_to_task(conn, itt);
1339 if (!task || !task->sc)
1340 return NULL;
1341
1342 if (task->sc->SCp.phase != conn->session->age) {
1343 iscsi_session_printk(KERN_ERR, conn->session,
1344 "task's session age %d, expected %d\n",
1345 task->sc->SCp.phase, conn->session->age);
1346 return NULL;
1347 }
1348
1349 return task;
1350}
1351EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1352
1353void iscsi_session_failure(struct iscsi_session *session,
1354 enum iscsi_err err)
1355{
1356 struct iscsi_conn *conn;
1357 struct device *dev;
1358
1359 spin_lock_bh(&session->frwd_lock);
1360 conn = session->leadconn;
1361 if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1362 spin_unlock_bh(&session->frwd_lock);
1363 return;
1364 }
1365
1366 dev = get_device(&conn->cls_conn->dev);
1367 spin_unlock_bh(&session->frwd_lock);
1368 if (!dev)
1369 return;
1370 /*
1371 * if the host is being removed bypass the connection
1372 * recovery initialization because we are going to kill
1373 * the session.
1374 */
1375 if (err == ISCSI_ERR_INVALID_HOST)
1376 iscsi_conn_error_event(conn->cls_conn, err);
1377 else
1378 iscsi_conn_failure(conn, err);
1379 put_device(dev);
1380}
1381EXPORT_SYMBOL_GPL(iscsi_session_failure);
1382
1383void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1384{
1385 struct iscsi_session *session = conn->session;
1386
1387 spin_lock_bh(&session->frwd_lock);
1388 if (session->state == ISCSI_STATE_FAILED) {
1389 spin_unlock_bh(&session->frwd_lock);
1390 return;
1391 }
1392
1393 if (conn->stop_stage == 0)
1394 session->state = ISCSI_STATE_FAILED;
1395 spin_unlock_bh(&session->frwd_lock);
1396
1397 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1398 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1399 iscsi_conn_error_event(conn->cls_conn, err);
1400}
1401EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1402
1403static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1404{
1405 struct iscsi_session *session = conn->session;
1406
1407 /*
1408 * Check for iSCSI window and take care of CmdSN wrap-around
1409 */
1410 if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1411 ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1412 "%u MaxCmdSN %u CmdSN %u/%u\n",
1413 session->exp_cmdsn, session->max_cmdsn,
1414 session->cmdsn, session->queued_cmdsn);
1415 return -ENOSPC;
1416 }
1417 return 0;
1418}
1419
1420static int iscsi_xmit_task(struct iscsi_conn *conn)
1421{
1422 struct iscsi_task *task = conn->task;
1423 int rc;
1424
1425 if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
1426 return -ENODATA;
1427
1428 spin_lock_bh(&conn->session->back_lock);
1429 if (conn->task == NULL) {
1430 spin_unlock_bh(&conn->session->back_lock);
1431 return -ENODATA;
1432 }
1433 __iscsi_get_task(task);
1434 spin_unlock_bh(&conn->session->back_lock);
1435 spin_unlock_bh(&conn->session->frwd_lock);
1436 rc = conn->session->tt->xmit_task(task);
1437 spin_lock_bh(&conn->session->frwd_lock);
1438 if (!rc) {
1439 /* done with this task */
1440 task->last_xfer = jiffies;
1441 conn->task = NULL;
1442 }
1443 /* regular RX path uses back_lock */
1444 spin_lock(&conn->session->back_lock);
1445 __iscsi_put_task(task);
1446 spin_unlock(&conn->session->back_lock);
1447 return rc;
1448}
1449
1450/**
1451 * iscsi_requeue_task - requeue task to run from session workqueue
1452 * @task: task to requeue
1453 *
1454 * LLDs that need to run a task from the session workqueue should call
1455 * this. The session frwd_lock must be held. This should only be called
1456 * by software drivers.
1457 */
1458void iscsi_requeue_task(struct iscsi_task *task)
1459{
1460 struct iscsi_conn *conn = task->conn;
1461
1462 /*
1463 * this may be on the requeue list already if the xmit_task callout
1464 * is handling the r2ts while we are adding new ones
1465 */
1466 spin_lock_bh(&conn->taskqueuelock);
1467 if (list_empty(&task->running))
1468 list_add_tail(&task->running, &conn->requeue);
1469 spin_unlock_bh(&conn->taskqueuelock);
1470 iscsi_conn_queue_work(conn);
1471}
1472EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1473
1474/**
1475 * iscsi_data_xmit - xmit any command into the scheduled connection
1476 * @conn: iscsi connection
1477 *
1478 * Notes:
1479 * The function can return -EAGAIN in which case the caller must
1480 * re-schedule it again later or recover. '0' return code means
1481 * successful xmit.
1482 **/
1483static int iscsi_data_xmit(struct iscsi_conn *conn)
1484{
1485 struct iscsi_task *task;
1486 int rc = 0;
1487
1488 spin_lock_bh(&conn->session->frwd_lock);
1489 if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1490 ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1491 spin_unlock_bh(&conn->session->frwd_lock);
1492 return -ENODATA;
1493 }
1494
1495 if (conn->task) {
1496 rc = iscsi_xmit_task(conn);
1497 if (rc)
1498 goto done;
1499 }
1500
1501 /*
1502 * process mgmt pdus like nops before commands since we should
1503 * only have one nop-out as a ping from us and targets should not
1504 * overflow us with nop-ins
1505 */
1506 spin_lock_bh(&conn->taskqueuelock);
1507check_mgmt:
1508 while (!list_empty(&conn->mgmtqueue)) {
1509 conn->task = list_entry(conn->mgmtqueue.next,
1510 struct iscsi_task, running);
1511 list_del_init(&conn->task->running);
1512 spin_unlock_bh(&conn->taskqueuelock);
1513 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1514 /* regular RX path uses back_lock */
1515 spin_lock_bh(&conn->session->back_lock);
1516 __iscsi_put_task(conn->task);
1517 spin_unlock_bh(&conn->session->back_lock);
1518 conn->task = NULL;
1519 spin_lock_bh(&conn->taskqueuelock);
1520 continue;
1521 }
1522 rc = iscsi_xmit_task(conn);
1523 if (rc)
1524 goto done;
1525 spin_lock_bh(&conn->taskqueuelock);
1526 }
1527
1528 /* process pending command queue */
1529 while (!list_empty(&conn->cmdqueue)) {
1530 conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1531 running);
1532 list_del_init(&conn->task->running);
1533 spin_unlock_bh(&conn->taskqueuelock);
1534 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1535 fail_scsi_task(conn->task, DID_IMM_RETRY);
1536 spin_lock_bh(&conn->taskqueuelock);
1537 continue;
1538 }
1539 rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1540 if (rc) {
1541 if (rc == -ENOMEM || rc == -EACCES) {
1542 spin_lock_bh(&conn->taskqueuelock);
1543 list_add_tail(&conn->task->running,
1544 &conn->cmdqueue);
1545 conn->task = NULL;
1546 spin_unlock_bh(&conn->taskqueuelock);
1547 goto done;
1548 } else
1549 fail_scsi_task(conn->task, DID_ABORT);
1550 spin_lock_bh(&conn->taskqueuelock);
1551 continue;
1552 }
1553 rc = iscsi_xmit_task(conn);
1554 if (rc)
1555 goto done;
1556 /*
1557 * we could continuously get new task requests so
1558 * we need to check the mgmt queue for nops that need to
1559 * be sent to aviod starvation
1560 */
1561 spin_lock_bh(&conn->taskqueuelock);
1562 if (!list_empty(&conn->mgmtqueue))
1563 goto check_mgmt;
1564 }
1565
1566 while (!list_empty(&conn->requeue)) {
1567 /*
1568 * we always do fastlogout - conn stop code will clean up.
1569 */
1570 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1571 break;
1572
1573 task = list_entry(conn->requeue.next, struct iscsi_task,
1574 running);
1575 if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1576 break;
1577
1578 conn->task = task;
1579 list_del_init(&conn->task->running);
1580 conn->task->state = ISCSI_TASK_RUNNING;
1581 spin_unlock_bh(&conn->taskqueuelock);
1582 rc = iscsi_xmit_task(conn);
1583 if (rc)
1584 goto done;
1585 spin_lock_bh(&conn->taskqueuelock);
1586 if (!list_empty(&conn->mgmtqueue))
1587 goto check_mgmt;
1588 }
1589 spin_unlock_bh(&conn->taskqueuelock);
1590 spin_unlock_bh(&conn->session->frwd_lock);
1591 return -ENODATA;
1592
1593done:
1594 spin_unlock_bh(&conn->session->frwd_lock);
1595 return rc;
1596}
1597
1598static void iscsi_xmitworker(struct work_struct *work)
1599{
1600 struct iscsi_conn *conn =
1601 container_of(work, struct iscsi_conn, xmitwork);
1602 int rc;
1603 /*
1604 * serialize Xmit worker on a per-connection basis.
1605 */
1606 do {
1607 rc = iscsi_data_xmit(conn);
1608 } while (rc >= 0 || rc == -EAGAIN);
1609}
1610
1611static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1612 struct scsi_cmnd *sc)
1613{
1614 struct iscsi_task *task;
1615
1616 if (!kfifo_out(&conn->session->cmdpool.queue,
1617 (void *) &task, sizeof(void *)))
1618 return NULL;
1619
1620 sc->SCp.phase = conn->session->age;
1621 sc->SCp.ptr = (char *) task;
1622
1623 refcount_set(&task->refcount, 1);
1624 task->state = ISCSI_TASK_PENDING;
1625 task->conn = conn;
1626 task->sc = sc;
1627 task->have_checked_conn = false;
1628 task->last_timeout = jiffies;
1629 task->last_xfer = jiffies;
1630 task->protected = false;
1631 INIT_LIST_HEAD(&task->running);
1632 return task;
1633}
1634
1635enum {
1636 FAILURE_BAD_HOST = 1,
1637 FAILURE_SESSION_FAILED,
1638 FAILURE_SESSION_FREED,
1639 FAILURE_WINDOW_CLOSED,
1640 FAILURE_OOM,
1641 FAILURE_SESSION_TERMINATE,
1642 FAILURE_SESSION_IN_RECOVERY,
1643 FAILURE_SESSION_RECOVERY_TIMEOUT,
1644 FAILURE_SESSION_LOGGING_OUT,
1645 FAILURE_SESSION_NOT_READY,
1646};
1647
1648int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1649{
1650 struct iscsi_cls_session *cls_session;
1651 struct iscsi_host *ihost;
1652 int reason = 0;
1653 struct iscsi_session *session;
1654 struct iscsi_conn *conn;
1655 struct iscsi_task *task = NULL;
1656
1657 sc->result = 0;
1658 sc->SCp.ptr = NULL;
1659
1660 ihost = shost_priv(host);
1661
1662 cls_session = starget_to_session(scsi_target(sc->device));
1663 session = cls_session->dd_data;
1664 spin_lock_bh(&session->frwd_lock);
1665
1666 reason = iscsi_session_chkready(cls_session);
1667 if (reason) {
1668 sc->result = reason;
1669 goto fault;
1670 }
1671
1672 if (session->state != ISCSI_STATE_LOGGED_IN) {
1673 /*
1674 * to handle the race between when we set the recovery state
1675 * and block the session we requeue here (commands could
1676 * be entering our queuecommand while a block is starting
1677 * up because the block code is not locked)
1678 */
1679 switch (session->state) {
1680 case ISCSI_STATE_FAILED:
1681 /*
1682 * cmds should fail during shutdown, if the session
1683 * state is bad, allowing completion to happen
1684 */
1685 if (unlikely(system_state != SYSTEM_RUNNING)) {
1686 reason = FAILURE_SESSION_FAILED;
1687 sc->result = DID_NO_CONNECT << 16;
1688 break;
1689 }
1690 /* fall through */
1691 case ISCSI_STATE_IN_RECOVERY:
1692 reason = FAILURE_SESSION_IN_RECOVERY;
1693 sc->result = DID_IMM_RETRY << 16;
1694 break;
1695 case ISCSI_STATE_LOGGING_OUT:
1696 reason = FAILURE_SESSION_LOGGING_OUT;
1697 sc->result = DID_IMM_RETRY << 16;
1698 break;
1699 case ISCSI_STATE_RECOVERY_FAILED:
1700 reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1701 sc->result = DID_TRANSPORT_FAILFAST << 16;
1702 break;
1703 case ISCSI_STATE_TERMINATE:
1704 reason = FAILURE_SESSION_TERMINATE;
1705 sc->result = DID_NO_CONNECT << 16;
1706 break;
1707 default:
1708 reason = FAILURE_SESSION_FREED;
1709 sc->result = DID_NO_CONNECT << 16;
1710 }
1711 goto fault;
1712 }
1713
1714 conn = session->leadconn;
1715 if (!conn) {
1716 reason = FAILURE_SESSION_FREED;
1717 sc->result = DID_NO_CONNECT << 16;
1718 goto fault;
1719 }
1720
1721 if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1722 reason = FAILURE_SESSION_IN_RECOVERY;
1723 sc->result = DID_REQUEUE << 16;
1724 goto fault;
1725 }
1726
1727 if (iscsi_check_cmdsn_window_closed(conn)) {
1728 reason = FAILURE_WINDOW_CLOSED;
1729 goto reject;
1730 }
1731
1732 task = iscsi_alloc_task(conn, sc);
1733 if (!task) {
1734 reason = FAILURE_OOM;
1735 goto reject;
1736 }
1737
1738 if (!ihost->workq) {
1739 reason = iscsi_prep_scsi_cmd_pdu(task);
1740 if (reason) {
1741 if (reason == -ENOMEM || reason == -EACCES) {
1742 reason = FAILURE_OOM;
1743 goto prepd_reject;
1744 } else {
1745 sc->result = DID_ABORT << 16;
1746 goto prepd_fault;
1747 }
1748 }
1749 if (session->tt->xmit_task(task)) {
1750 session->cmdsn--;
1751 reason = FAILURE_SESSION_NOT_READY;
1752 goto prepd_reject;
1753 }
1754 } else {
1755 spin_lock_bh(&conn->taskqueuelock);
1756 list_add_tail(&task->running, &conn->cmdqueue);
1757 spin_unlock_bh(&conn->taskqueuelock);
1758 iscsi_conn_queue_work(conn);
1759 }
1760
1761 session->queued_cmdsn++;
1762 spin_unlock_bh(&session->frwd_lock);
1763 return 0;
1764
1765prepd_reject:
1766 spin_lock_bh(&session->back_lock);
1767 iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1768 spin_unlock_bh(&session->back_lock);
1769reject:
1770 spin_unlock_bh(&session->frwd_lock);
1771 ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1772 sc->cmnd[0], reason);
1773 return SCSI_MLQUEUE_TARGET_BUSY;
1774
1775prepd_fault:
1776 spin_lock_bh(&session->back_lock);
1777 iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1778 spin_unlock_bh(&session->back_lock);
1779fault:
1780 spin_unlock_bh(&session->frwd_lock);
1781 ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1782 sc->cmnd[0], reason);
1783 scsi_set_resid(sc, scsi_bufflen(sc));
1784 sc->scsi_done(sc);
1785 return 0;
1786}
1787EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1788
1789int iscsi_target_alloc(struct scsi_target *starget)
1790{
1791 struct iscsi_cls_session *cls_session = starget_to_session(starget);
1792 struct iscsi_session *session = cls_session->dd_data;
1793
1794 starget->can_queue = session->scsi_cmds_max;
1795 return 0;
1796}
1797EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1798
1799static void iscsi_tmf_timedout(struct timer_list *t)
1800{
1801 struct iscsi_conn *conn = from_timer(conn, t, tmf_timer);
1802 struct iscsi_session *session = conn->session;
1803
1804 spin_lock(&session->frwd_lock);
1805 if (conn->tmf_state == TMF_QUEUED) {
1806 conn->tmf_state = TMF_TIMEDOUT;
1807 ISCSI_DBG_EH(session, "tmf timedout\n");
1808 /* unblock eh_abort() */
1809 wake_up(&conn->ehwait);
1810 }
1811 spin_unlock(&session->frwd_lock);
1812}
1813
1814static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1815 struct iscsi_tm *hdr, int age,
1816 int timeout)
1817 __must_hold(&session->frwd_lock)
1818{
1819 struct iscsi_session *session = conn->session;
1820 struct iscsi_task *task;
1821
1822 task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1823 NULL, 0);
1824 if (!task) {
1825 spin_unlock_bh(&session->frwd_lock);
1826 iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1827 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1828 spin_lock_bh(&session->frwd_lock);
1829 return -EPERM;
1830 }
1831 conn->tmfcmd_pdus_cnt++;
1832 conn->tmf_timer.expires = timeout * HZ + jiffies;
1833 add_timer(&conn->tmf_timer);
1834 ISCSI_DBG_EH(session, "tmf set timeout\n");
1835
1836 spin_unlock_bh(&session->frwd_lock);
1837 mutex_unlock(&session->eh_mutex);
1838
1839 /*
1840 * block eh thread until:
1841 *
1842 * 1) tmf response
1843 * 2) tmf timeout
1844 * 3) session is terminated or restarted or userspace has
1845 * given up on recovery
1846 */
1847 wait_event_interruptible(conn->ehwait, age != session->age ||
1848 session->state != ISCSI_STATE_LOGGED_IN ||
1849 conn->tmf_state != TMF_QUEUED);
1850 if (signal_pending(current))
1851 flush_signals(current);
1852 del_timer_sync(&conn->tmf_timer);
1853
1854 mutex_lock(&session->eh_mutex);
1855 spin_lock_bh(&session->frwd_lock);
1856 /* if the session drops it will clean up the task */
1857 if (age != session->age ||
1858 session->state != ISCSI_STATE_LOGGED_IN)
1859 return -ENOTCONN;
1860 return 0;
1861}
1862
1863/*
1864 * Fail commands. session lock held and recv side suspended and xmit
1865 * thread flushed
1866 */
1867static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
1868{
1869 struct iscsi_task *task;
1870 int i;
1871
1872 for (i = 0; i < conn->session->cmds_max; i++) {
1873 task = conn->session->cmds[i];
1874 if (!task->sc || task->state == ISCSI_TASK_FREE)
1875 continue;
1876
1877 if (lun != -1 && lun != task->sc->device->lun)
1878 continue;
1879
1880 ISCSI_DBG_SESSION(conn->session,
1881 "failing sc %p itt 0x%x state %d\n",
1882 task->sc, task->itt, task->state);
1883 fail_scsi_task(task, error);
1884 }
1885}
1886
1887/**
1888 * iscsi_suspend_queue - suspend iscsi_queuecommand
1889 * @conn: iscsi conn to stop queueing IO on
1890 *
1891 * This grabs the session frwd_lock to make sure no one is in
1892 * xmit_task/queuecommand, and then sets suspend to prevent
1893 * new commands from being queued. This only needs to be called
1894 * by offload drivers that need to sync a path like ep disconnect
1895 * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1896 * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1897 */
1898void iscsi_suspend_queue(struct iscsi_conn *conn)
1899{
1900 spin_lock_bh(&conn->session->frwd_lock);
1901 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1902 spin_unlock_bh(&conn->session->frwd_lock);
1903}
1904EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1905
1906/**
1907 * iscsi_suspend_tx - suspend iscsi_data_xmit
1908 * @conn: iscsi conn tp stop processing IO on.
1909 *
1910 * This function sets the suspend bit to prevent iscsi_data_xmit
1911 * from sending new IO, and if work is queued on the xmit thread
1912 * it will wait for it to be completed.
1913 */
1914void iscsi_suspend_tx(struct iscsi_conn *conn)
1915{
1916 struct Scsi_Host *shost = conn->session->host;
1917 struct iscsi_host *ihost = shost_priv(shost);
1918
1919 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1920 if (ihost->workq)
1921 flush_workqueue(ihost->workq);
1922}
1923EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1924
1925static void iscsi_start_tx(struct iscsi_conn *conn)
1926{
1927 clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1928 iscsi_conn_queue_work(conn);
1929}
1930
1931/*
1932 * We want to make sure a ping is in flight. It has timed out.
1933 * And we are not busy processing a pdu that is making
1934 * progress but got started before the ping and is taking a while
1935 * to complete so the ping is just stuck behind it in a queue.
1936 */
1937static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1938{
1939 if (conn->ping_task &&
1940 time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1941 (conn->ping_timeout * HZ), jiffies))
1942 return 1;
1943 else
1944 return 0;
1945}
1946
1947enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1948{
1949 enum blk_eh_timer_return rc = BLK_EH_DONE;
1950 struct iscsi_task *task = NULL, *running_task;
1951 struct iscsi_cls_session *cls_session;
1952 struct iscsi_session *session;
1953 struct iscsi_conn *conn;
1954 int i;
1955
1956 cls_session = starget_to_session(scsi_target(sc->device));
1957 session = cls_session->dd_data;
1958
1959 ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1960
1961 spin_lock(&session->frwd_lock);
1962 task = (struct iscsi_task *)sc->SCp.ptr;
1963 if (!task) {
1964 /*
1965 * Raced with completion. Blk layer has taken ownership
1966 * so let timeout code complete it now.
1967 */
1968 rc = BLK_EH_DONE;
1969 goto done;
1970 }
1971
1972 if (session->state != ISCSI_STATE_LOGGED_IN) {
1973 /*
1974 * During shutdown, if session is prematurely disconnected,
1975 * recovery won't happen and there will be hung cmds. Not
1976 * handling cmds would trigger EH, also bad in this case.
1977 * Instead, handle cmd, allow completion to happen and let
1978 * upper layer to deal with the result.
1979 */
1980 if (unlikely(system_state != SYSTEM_RUNNING)) {
1981 sc->result = DID_NO_CONNECT << 16;
1982 ISCSI_DBG_EH(session, "sc on shutdown, handled\n");
1983 rc = BLK_EH_DONE;
1984 goto done;
1985 }
1986 /*
1987 * We are probably in the middle of iscsi recovery so let
1988 * that complete and handle the error.
1989 */
1990 rc = BLK_EH_RESET_TIMER;
1991 goto done;
1992 }
1993
1994 conn = session->leadconn;
1995 if (!conn) {
1996 /* In the middle of shuting down */
1997 rc = BLK_EH_RESET_TIMER;
1998 goto done;
1999 }
2000
2001 /*
2002 * If we have sent (at least queued to the network layer) a pdu or
2003 * recvd one for the task since the last timeout ask for
2004 * more time. If on the next timeout we have not made progress
2005 * we can check if it is the task or connection when we send the
2006 * nop as a ping.
2007 */
2008 if (time_after(task->last_xfer, task->last_timeout)) {
2009 ISCSI_DBG_EH(session, "Command making progress. Asking "
2010 "scsi-ml for more time to complete. "
2011 "Last data xfer at %lu. Last timeout was at "
2012 "%lu\n.", task->last_xfer, task->last_timeout);
2013 task->have_checked_conn = false;
2014 rc = BLK_EH_RESET_TIMER;
2015 goto done;
2016 }
2017
2018 if (!conn->recv_timeout && !conn->ping_timeout)
2019 goto done;
2020 /*
2021 * if the ping timedout then we are in the middle of cleaning up
2022 * and can let the iscsi eh handle it
2023 */
2024 if (iscsi_has_ping_timed_out(conn)) {
2025 rc = BLK_EH_RESET_TIMER;
2026 goto done;
2027 }
2028
2029 for (i = 0; i < conn->session->cmds_max; i++) {
2030 running_task = conn->session->cmds[i];
2031 if (!running_task->sc || running_task == task ||
2032 running_task->state != ISCSI_TASK_RUNNING)
2033 continue;
2034
2035 /*
2036 * Only check if cmds started before this one have made
2037 * progress, or this could never fail
2038 */
2039 if (time_after(running_task->sc->jiffies_at_alloc,
2040 task->sc->jiffies_at_alloc))
2041 continue;
2042
2043 if (time_after(running_task->last_xfer, task->last_timeout)) {
2044 /*
2045 * This task has not made progress, but a task
2046 * started before us has transferred data since
2047 * we started/last-checked. We could be queueing
2048 * too many tasks or the LU is bad.
2049 *
2050 * If the device is bad the cmds ahead of us on
2051 * other devs will complete, and this loop will
2052 * eventually fail starting the scsi eh.
2053 */
2054 ISCSI_DBG_EH(session, "Command has not made progress "
2055 "but commands ahead of it have. "
2056 "Asking scsi-ml for more time to "
2057 "complete. Our last xfer vs running task "
2058 "last xfer %lu/%lu. Last check %lu.\n",
2059 task->last_xfer, running_task->last_xfer,
2060 task->last_timeout);
2061 rc = BLK_EH_RESET_TIMER;
2062 goto done;
2063 }
2064 }
2065
2066 /* Assumes nop timeout is shorter than scsi cmd timeout */
2067 if (task->have_checked_conn)
2068 goto done;
2069
2070 /*
2071 * Checking the transport already or nop from a cmd timeout still
2072 * running
2073 */
2074 if (conn->ping_task) {
2075 task->have_checked_conn = true;
2076 rc = BLK_EH_RESET_TIMER;
2077 goto done;
2078 }
2079
2080 /* Make sure there is a transport check done */
2081 iscsi_send_nopout(conn, NULL);
2082 task->have_checked_conn = true;
2083 rc = BLK_EH_RESET_TIMER;
2084
2085done:
2086 if (task)
2087 task->last_timeout = jiffies;
2088 spin_unlock(&session->frwd_lock);
2089 ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2090 "timer reset" : "shutdown or nh");
2091 return rc;
2092}
2093EXPORT_SYMBOL_GPL(iscsi_eh_cmd_timed_out);
2094
2095static void iscsi_check_transport_timeouts(struct timer_list *t)
2096{
2097 struct iscsi_conn *conn = from_timer(conn, t, transport_timer);
2098 struct iscsi_session *session = conn->session;
2099 unsigned long recv_timeout, next_timeout = 0, last_recv;
2100
2101 spin_lock(&session->frwd_lock);
2102 if (session->state != ISCSI_STATE_LOGGED_IN)
2103 goto done;
2104
2105 recv_timeout = conn->recv_timeout;
2106 if (!recv_timeout)
2107 goto done;
2108
2109 recv_timeout *= HZ;
2110 last_recv = conn->last_recv;
2111
2112 if (iscsi_has_ping_timed_out(conn)) {
2113 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2114 "expired, recv timeout %d, last rx %lu, "
2115 "last ping %lu, now %lu\n",
2116 conn->ping_timeout, conn->recv_timeout,
2117 last_recv, conn->last_ping, jiffies);
2118 spin_unlock(&session->frwd_lock);
2119 iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2120 return;
2121 }
2122
2123 if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2124 /* send a ping to try to provoke some traffic */
2125 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2126 if (iscsi_send_nopout(conn, NULL))
2127 next_timeout = jiffies + (1 * HZ);
2128 else
2129 next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2130 } else
2131 next_timeout = last_recv + recv_timeout;
2132
2133 ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2134 mod_timer(&conn->transport_timer, next_timeout);
2135done:
2136 spin_unlock(&session->frwd_lock);
2137}
2138
2139static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2140 struct iscsi_tm *hdr)
2141{
2142 memset(hdr, 0, sizeof(*hdr));
2143 hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2144 hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2145 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2146 hdr->lun = task->lun;
2147 hdr->rtt = task->hdr_itt;
2148 hdr->refcmdsn = task->cmdsn;
2149}
2150
2151int iscsi_eh_abort(struct scsi_cmnd *sc)
2152{
2153 struct iscsi_cls_session *cls_session;
2154 struct iscsi_session *session;
2155 struct iscsi_conn *conn;
2156 struct iscsi_task *task;
2157 struct iscsi_tm *hdr;
2158 int age;
2159
2160 cls_session = starget_to_session(scsi_target(sc->device));
2161 session = cls_session->dd_data;
2162
2163 ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2164
2165 mutex_lock(&session->eh_mutex);
2166 spin_lock_bh(&session->frwd_lock);
2167 /*
2168 * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2169 * got the command.
2170 */
2171 if (!sc->SCp.ptr) {
2172 ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2173 "it completed.\n");
2174 spin_unlock_bh(&session->frwd_lock);
2175 mutex_unlock(&session->eh_mutex);
2176 return SUCCESS;
2177 }
2178
2179 /*
2180 * If we are not logged in or we have started a new session
2181 * then let the host reset code handle this
2182 */
2183 if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2184 sc->SCp.phase != session->age) {
2185 spin_unlock_bh(&session->frwd_lock);
2186 mutex_unlock(&session->eh_mutex);
2187 ISCSI_DBG_EH(session, "failing abort due to dropped "
2188 "session.\n");
2189 return FAILED;
2190 }
2191
2192 conn = session->leadconn;
2193 conn->eh_abort_cnt++;
2194 age = session->age;
2195
2196 task = (struct iscsi_task *)sc->SCp.ptr;
2197 ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2198 sc, task->itt);
2199
2200 /* task completed before time out */
2201 if (!task->sc) {
2202 ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2203 goto success;
2204 }
2205
2206 if (task->state == ISCSI_TASK_PENDING) {
2207 fail_scsi_task(task, DID_ABORT);
2208 goto success;
2209 }
2210
2211 /* only have one tmf outstanding at a time */
2212 if (conn->tmf_state != TMF_INITIAL)
2213 goto failed;
2214 conn->tmf_state = TMF_QUEUED;
2215
2216 hdr = &conn->tmhdr;
2217 iscsi_prep_abort_task_pdu(task, hdr);
2218
2219 if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout))
2220 goto failed;
2221
2222 switch (conn->tmf_state) {
2223 case TMF_SUCCESS:
2224 spin_unlock_bh(&session->frwd_lock);
2225 /*
2226 * stop tx side incase the target had sent a abort rsp but
2227 * the initiator was still writing out data.
2228 */
2229 iscsi_suspend_tx(conn);
2230 /*
2231 * we do not stop the recv side because targets have been
2232 * good and have never sent us a successful tmf response
2233 * then sent more data for the cmd.
2234 */
2235 spin_lock_bh(&session->frwd_lock);
2236 fail_scsi_task(task, DID_ABORT);
2237 conn->tmf_state = TMF_INITIAL;
2238 memset(hdr, 0, sizeof(*hdr));
2239 spin_unlock_bh(&session->frwd_lock);
2240 iscsi_start_tx(conn);
2241 goto success_unlocked;
2242 case TMF_TIMEDOUT:
2243 spin_unlock_bh(&session->frwd_lock);
2244 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2245 goto failed_unlocked;
2246 case TMF_NOT_FOUND:
2247 if (!sc->SCp.ptr) {
2248 conn->tmf_state = TMF_INITIAL;
2249 memset(hdr, 0, sizeof(*hdr));
2250 /* task completed before tmf abort response */
2251 ISCSI_DBG_EH(session, "sc completed while abort in "
2252 "progress\n");
2253 goto success;
2254 }
2255 /* fall through */
2256 default:
2257 conn->tmf_state = TMF_INITIAL;
2258 goto failed;
2259 }
2260
2261success:
2262 spin_unlock_bh(&session->frwd_lock);
2263success_unlocked:
2264 ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2265 sc, task->itt);
2266 mutex_unlock(&session->eh_mutex);
2267 return SUCCESS;
2268
2269failed:
2270 spin_unlock_bh(&session->frwd_lock);
2271failed_unlocked:
2272 ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2273 task ? task->itt : 0);
2274 mutex_unlock(&session->eh_mutex);
2275 return FAILED;
2276}
2277EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2278
2279static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2280{
2281 memset(hdr, 0, sizeof(*hdr));
2282 hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2283 hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2284 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2285 int_to_scsilun(sc->device->lun, &hdr->lun);
2286 hdr->rtt = RESERVED_ITT;
2287}
2288
2289int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2290{
2291 struct iscsi_cls_session *cls_session;
2292 struct iscsi_session *session;
2293 struct iscsi_conn *conn;
2294 struct iscsi_tm *hdr;
2295 int rc = FAILED;
2296
2297 cls_session = starget_to_session(scsi_target(sc->device));
2298 session = cls_session->dd_data;
2299
2300 ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2301 sc->device->lun);
2302
2303 mutex_lock(&session->eh_mutex);
2304 spin_lock_bh(&session->frwd_lock);
2305 /*
2306 * Just check if we are not logged in. We cannot check for
2307 * the phase because the reset could come from a ioctl.
2308 */
2309 if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2310 goto unlock;
2311 conn = session->leadconn;
2312
2313 /* only have one tmf outstanding at a time */
2314 if (conn->tmf_state != TMF_INITIAL)
2315 goto unlock;
2316 conn->tmf_state = TMF_QUEUED;
2317
2318 hdr = &conn->tmhdr;
2319 iscsi_prep_lun_reset_pdu(sc, hdr);
2320
2321 if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2322 session->lu_reset_timeout)) {
2323 rc = FAILED;
2324 goto unlock;
2325 }
2326
2327 switch (conn->tmf_state) {
2328 case TMF_SUCCESS:
2329 break;
2330 case TMF_TIMEDOUT:
2331 spin_unlock_bh(&session->frwd_lock);
2332 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2333 goto done;
2334 default:
2335 conn->tmf_state = TMF_INITIAL;
2336 goto unlock;
2337 }
2338
2339 rc = SUCCESS;
2340 spin_unlock_bh(&session->frwd_lock);
2341
2342 iscsi_suspend_tx(conn);
2343
2344 spin_lock_bh(&session->frwd_lock);
2345 memset(hdr, 0, sizeof(*hdr));
2346 fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2347 conn->tmf_state = TMF_INITIAL;
2348 spin_unlock_bh(&session->frwd_lock);
2349
2350 iscsi_start_tx(conn);
2351 goto done;
2352
2353unlock:
2354 spin_unlock_bh(&session->frwd_lock);
2355done:
2356 ISCSI_DBG_EH(session, "dev reset result = %s\n",
2357 rc == SUCCESS ? "SUCCESS" : "FAILED");
2358 mutex_unlock(&session->eh_mutex);
2359 return rc;
2360}
2361EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2362
2363void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2364{
2365 struct iscsi_session *session = cls_session->dd_data;
2366
2367 spin_lock_bh(&session->frwd_lock);
2368 if (session->state != ISCSI_STATE_LOGGED_IN) {
2369 session->state = ISCSI_STATE_RECOVERY_FAILED;
2370 if (session->leadconn)
2371 wake_up(&session->leadconn->ehwait);
2372 }
2373 spin_unlock_bh(&session->frwd_lock);
2374}
2375EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2376
2377/**
2378 * iscsi_eh_session_reset - drop session and attempt relogin
2379 * @sc: scsi command
2380 *
2381 * This function will wait for a relogin, session termination from
2382 * userspace, or a recovery/replacement timeout.
2383 */
2384int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2385{
2386 struct iscsi_cls_session *cls_session;
2387 struct iscsi_session *session;
2388 struct iscsi_conn *conn;
2389
2390 cls_session = starget_to_session(scsi_target(sc->device));
2391 session = cls_session->dd_data;
2392 conn = session->leadconn;
2393
2394 mutex_lock(&session->eh_mutex);
2395 spin_lock_bh(&session->frwd_lock);
2396 if (session->state == ISCSI_STATE_TERMINATE) {
2397failed:
2398 ISCSI_DBG_EH(session,
2399 "failing session reset: Could not log back into "
2400 "%s [age %d]\n", session->targetname,
2401 session->age);
2402 spin_unlock_bh(&session->frwd_lock);
2403 mutex_unlock(&session->eh_mutex);
2404 return FAILED;
2405 }
2406
2407 spin_unlock_bh(&session->frwd_lock);
2408 mutex_unlock(&session->eh_mutex);
2409 /*
2410 * we drop the lock here but the leadconn cannot be destoyed while
2411 * we are in the scsi eh
2412 */
2413 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2414
2415 ISCSI_DBG_EH(session, "wait for relogin\n");
2416 wait_event_interruptible(conn->ehwait,
2417 session->state == ISCSI_STATE_TERMINATE ||
2418 session->state == ISCSI_STATE_LOGGED_IN ||
2419 session->state == ISCSI_STATE_RECOVERY_FAILED);
2420 if (signal_pending(current))
2421 flush_signals(current);
2422
2423 mutex_lock(&session->eh_mutex);
2424 spin_lock_bh(&session->frwd_lock);
2425 if (session->state == ISCSI_STATE_LOGGED_IN) {
2426 ISCSI_DBG_EH(session,
2427 "session reset succeeded for %s,%s\n",
2428 session->targetname, conn->persistent_address);
2429 } else
2430 goto failed;
2431 spin_unlock_bh(&session->frwd_lock);
2432 mutex_unlock(&session->eh_mutex);
2433 return SUCCESS;
2434}
2435EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2436
2437static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2438{
2439 memset(hdr, 0, sizeof(*hdr));
2440 hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2441 hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2442 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2443 hdr->rtt = RESERVED_ITT;
2444}
2445
2446/**
2447 * iscsi_eh_target_reset - reset target
2448 * @sc: scsi command
2449 *
2450 * This will attempt to send a warm target reset.
2451 */
2452static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2453{
2454 struct iscsi_cls_session *cls_session;
2455 struct iscsi_session *session;
2456 struct iscsi_conn *conn;
2457 struct iscsi_tm *hdr;
2458 int rc = FAILED;
2459
2460 cls_session = starget_to_session(scsi_target(sc->device));
2461 session = cls_session->dd_data;
2462
2463 ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2464 session->targetname);
2465
2466 mutex_lock(&session->eh_mutex);
2467 spin_lock_bh(&session->frwd_lock);
2468 /*
2469 * Just check if we are not logged in. We cannot check for
2470 * the phase because the reset could come from a ioctl.
2471 */
2472 if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2473 goto unlock;
2474 conn = session->leadconn;
2475
2476 /* only have one tmf outstanding at a time */
2477 if (conn->tmf_state != TMF_INITIAL)
2478 goto unlock;
2479 conn->tmf_state = TMF_QUEUED;
2480
2481 hdr = &conn->tmhdr;
2482 iscsi_prep_tgt_reset_pdu(sc, hdr);
2483
2484 if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2485 session->tgt_reset_timeout)) {
2486 rc = FAILED;
2487 goto unlock;
2488 }
2489
2490 switch (conn->tmf_state) {
2491 case TMF_SUCCESS:
2492 break;
2493 case TMF_TIMEDOUT:
2494 spin_unlock_bh(&session->frwd_lock);
2495 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2496 goto done;
2497 default:
2498 conn->tmf_state = TMF_INITIAL;
2499 goto unlock;
2500 }
2501
2502 rc = SUCCESS;
2503 spin_unlock_bh(&session->frwd_lock);
2504
2505 iscsi_suspend_tx(conn);
2506
2507 spin_lock_bh(&session->frwd_lock);
2508 memset(hdr, 0, sizeof(*hdr));
2509 fail_scsi_tasks(conn, -1, DID_ERROR);
2510 conn->tmf_state = TMF_INITIAL;
2511 spin_unlock_bh(&session->frwd_lock);
2512
2513 iscsi_start_tx(conn);
2514 goto done;
2515
2516unlock:
2517 spin_unlock_bh(&session->frwd_lock);
2518done:
2519 ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2520 rc == SUCCESS ? "SUCCESS" : "FAILED");
2521 mutex_unlock(&session->eh_mutex);
2522 return rc;
2523}
2524
2525/**
2526 * iscsi_eh_recover_target - reset target and possibly the session
2527 * @sc: scsi command
2528 *
2529 * This will attempt to send a warm target reset. If that fails,
2530 * we will escalate to ERL0 session recovery.
2531 */
2532int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2533{
2534 int rc;
2535
2536 rc = iscsi_eh_target_reset(sc);
2537 if (rc == FAILED)
2538 rc = iscsi_eh_session_reset(sc);
2539 return rc;
2540}
2541EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2542
2543/*
2544 * Pre-allocate a pool of @max items of @item_size. By default, the pool
2545 * should be accessed via kfifo_{get,put} on q->queue.
2546 * Optionally, the caller can obtain the array of object pointers
2547 * by passing in a non-NULL @items pointer
2548 */
2549int
2550iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2551{
2552 int i, num_arrays = 1;
2553
2554 memset(q, 0, sizeof(*q));
2555
2556 q->max = max;
2557
2558 /* If the user passed an items pointer, he wants a copy of
2559 * the array. */
2560 if (items)
2561 num_arrays++;
2562 q->pool = kvcalloc(num_arrays * max, sizeof(void *), GFP_KERNEL);
2563 if (q->pool == NULL)
2564 return -ENOMEM;
2565
2566 kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2567
2568 for (i = 0; i < max; i++) {
2569 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2570 if (q->pool[i] == NULL) {
2571 q->max = i;
2572 goto enomem;
2573 }
2574 kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2575 }
2576
2577 if (items) {
2578 *items = q->pool + max;
2579 memcpy(*items, q->pool, max * sizeof(void *));
2580 }
2581
2582 return 0;
2583
2584enomem:
2585 iscsi_pool_free(q);
2586 return -ENOMEM;
2587}
2588EXPORT_SYMBOL_GPL(iscsi_pool_init);
2589
2590void iscsi_pool_free(struct iscsi_pool *q)
2591{
2592 int i;
2593
2594 for (i = 0; i < q->max; i++)
2595 kfree(q->pool[i]);
2596 kvfree(q->pool);
2597}
2598EXPORT_SYMBOL_GPL(iscsi_pool_free);
2599
2600/**
2601 * iscsi_host_add - add host to system
2602 * @shost: scsi host
2603 * @pdev: parent device
2604 *
2605 * This should be called by partial offload and software iscsi drivers
2606 * to add a host to the system.
2607 */
2608int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2609{
2610 if (!shost->can_queue)
2611 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2612
2613 if (!shost->cmd_per_lun)
2614 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2615
2616 return scsi_add_host(shost, pdev);
2617}
2618EXPORT_SYMBOL_GPL(iscsi_host_add);
2619
2620/**
2621 * iscsi_host_alloc - allocate a host and driver data
2622 * @sht: scsi host template
2623 * @dd_data_size: driver host data size
2624 * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2625 *
2626 * This should be called by partial offload and software iscsi drivers.
2627 * To access the driver specific memory use the iscsi_host_priv() macro.
2628 */
2629struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2630 int dd_data_size, bool xmit_can_sleep)
2631{
2632 struct Scsi_Host *shost;
2633 struct iscsi_host *ihost;
2634
2635 shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2636 if (!shost)
2637 return NULL;
2638 ihost = shost_priv(shost);
2639
2640 if (xmit_can_sleep) {
2641 snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2642 "iscsi_q_%d", shost->host_no);
2643 ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2644 if (!ihost->workq)
2645 goto free_host;
2646 }
2647
2648 spin_lock_init(&ihost->lock);
2649 ihost->state = ISCSI_HOST_SETUP;
2650 ihost->num_sessions = 0;
2651 init_waitqueue_head(&ihost->session_removal_wq);
2652 return shost;
2653
2654free_host:
2655 scsi_host_put(shost);
2656 return NULL;
2657}
2658EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2659
2660static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2661{
2662 iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2663}
2664
2665/**
2666 * iscsi_host_remove - remove host and sessions
2667 * @shost: scsi host
2668 *
2669 * If there are any sessions left, this will initiate the removal and wait
2670 * for the completion.
2671 */
2672void iscsi_host_remove(struct Scsi_Host *shost)
2673{
2674 struct iscsi_host *ihost = shost_priv(shost);
2675 unsigned long flags;
2676
2677 spin_lock_irqsave(&ihost->lock, flags);
2678 ihost->state = ISCSI_HOST_REMOVED;
2679 spin_unlock_irqrestore(&ihost->lock, flags);
2680
2681 iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2682 wait_event_interruptible(ihost->session_removal_wq,
2683 ihost->num_sessions == 0);
2684 if (signal_pending(current))
2685 flush_signals(current);
2686
2687 scsi_remove_host(shost);
2688 if (ihost->workq)
2689 destroy_workqueue(ihost->workq);
2690}
2691EXPORT_SYMBOL_GPL(iscsi_host_remove);
2692
2693void iscsi_host_free(struct Scsi_Host *shost)
2694{
2695 struct iscsi_host *ihost = shost_priv(shost);
2696
2697 kfree(ihost->netdev);
2698 kfree(ihost->hwaddress);
2699 kfree(ihost->initiatorname);
2700 scsi_host_put(shost);
2701}
2702EXPORT_SYMBOL_GPL(iscsi_host_free);
2703
2704static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2705{
2706 struct iscsi_host *ihost = shost_priv(shost);
2707 unsigned long flags;
2708
2709 shost = scsi_host_get(shost);
2710 if (!shost) {
2711 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2712 "of session teardown event because host already "
2713 "removed.\n");
2714 return;
2715 }
2716
2717 spin_lock_irqsave(&ihost->lock, flags);
2718 ihost->num_sessions--;
2719 if (ihost->num_sessions == 0)
2720 wake_up(&ihost->session_removal_wq);
2721 spin_unlock_irqrestore(&ihost->lock, flags);
2722 scsi_host_put(shost);
2723}
2724
2725/**
2726 * iscsi_session_setup - create iscsi cls session and host and session
2727 * @iscsit: iscsi transport template
2728 * @shost: scsi host
2729 * @cmds_max: session can queue
2730 * @dd_size: private driver data size, added to session allocation size
2731 * @cmd_task_size: LLD task private data size
2732 * @initial_cmdsn: initial CmdSN
2733 * @id: target ID to add to this session
2734 *
2735 * This can be used by software iscsi_transports that allocate
2736 * a session per scsi host.
2737 *
2738 * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2739 * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2740 * for nop handling and login/logout requests.
2741 */
2742struct iscsi_cls_session *
2743iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2744 uint16_t cmds_max, int dd_size, int cmd_task_size,
2745 uint32_t initial_cmdsn, unsigned int id)
2746{
2747 struct iscsi_host *ihost = shost_priv(shost);
2748 struct iscsi_session *session;
2749 struct iscsi_cls_session *cls_session;
2750 int cmd_i, scsi_cmds, total_cmds = cmds_max;
2751 unsigned long flags;
2752
2753 spin_lock_irqsave(&ihost->lock, flags);
2754 if (ihost->state == ISCSI_HOST_REMOVED) {
2755 spin_unlock_irqrestore(&ihost->lock, flags);
2756 return NULL;
2757 }
2758 ihost->num_sessions++;
2759 spin_unlock_irqrestore(&ihost->lock, flags);
2760
2761 if (!total_cmds)
2762 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2763 /*
2764 * The iscsi layer needs some tasks for nop handling and tmfs,
2765 * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2766 * + 1 command for scsi IO.
2767 */
2768 if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2769 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2770 "must be a power of two that is at least %d.\n",
2771 total_cmds, ISCSI_TOTAL_CMDS_MIN);
2772 goto dec_session_count;
2773 }
2774
2775 if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2776 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2777 "must be a power of 2 less than or equal to %d.\n",
2778 cmds_max, ISCSI_TOTAL_CMDS_MAX);
2779 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2780 }
2781
2782 if (!is_power_of_2(total_cmds)) {
2783 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2784 "must be a power of 2.\n", total_cmds);
2785 total_cmds = rounddown_pow_of_two(total_cmds);
2786 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2787 return NULL;
2788 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2789 total_cmds);
2790 }
2791 scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2792
2793 cls_session = iscsi_alloc_session(shost, iscsit,
2794 sizeof(struct iscsi_session) +
2795 dd_size);
2796 if (!cls_session)
2797 goto dec_session_count;
2798 session = cls_session->dd_data;
2799 session->cls_session = cls_session;
2800 session->host = shost;
2801 session->state = ISCSI_STATE_FREE;
2802 session->fast_abort = 1;
2803 session->tgt_reset_timeout = 30;
2804 session->lu_reset_timeout = 15;
2805 session->abort_timeout = 10;
2806 session->scsi_cmds_max = scsi_cmds;
2807 session->cmds_max = total_cmds;
2808 session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2809 session->exp_cmdsn = initial_cmdsn + 1;
2810 session->max_cmdsn = initial_cmdsn + 1;
2811 session->max_r2t = 1;
2812 session->tt = iscsit;
2813 session->dd_data = cls_session->dd_data + sizeof(*session);
2814
2815 mutex_init(&session->eh_mutex);
2816 spin_lock_init(&session->frwd_lock);
2817 spin_lock_init(&session->back_lock);
2818
2819 /* initialize SCSI PDU commands pool */
2820 if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2821 (void***)&session->cmds,
2822 cmd_task_size + sizeof(struct iscsi_task)))
2823 goto cmdpool_alloc_fail;
2824
2825 /* pre-format cmds pool with ITT */
2826 for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2827 struct iscsi_task *task = session->cmds[cmd_i];
2828
2829 if (cmd_task_size)
2830 task->dd_data = &task[1];
2831 task->itt = cmd_i;
2832 task->state = ISCSI_TASK_FREE;
2833 INIT_LIST_HEAD(&task->running);
2834 }
2835
2836 if (!try_module_get(iscsit->owner))
2837 goto module_get_fail;
2838
2839 if (iscsi_add_session(cls_session, id))
2840 goto cls_session_fail;
2841
2842 return cls_session;
2843
2844cls_session_fail:
2845 module_put(iscsit->owner);
2846module_get_fail:
2847 iscsi_pool_free(&session->cmdpool);
2848cmdpool_alloc_fail:
2849 iscsi_free_session(cls_session);
2850dec_session_count:
2851 iscsi_host_dec_session_cnt(shost);
2852 return NULL;
2853}
2854EXPORT_SYMBOL_GPL(iscsi_session_setup);
2855
2856/**
2857 * iscsi_session_teardown - destroy session, host, and cls_session
2858 * @cls_session: iscsi session
2859 */
2860void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2861{
2862 struct iscsi_session *session = cls_session->dd_data;
2863 struct module *owner = cls_session->transport->owner;
2864 struct Scsi_Host *shost = session->host;
2865
2866 iscsi_pool_free(&session->cmdpool);
2867
2868 iscsi_remove_session(cls_session);
2869
2870 kfree(session->password);
2871 kfree(session->password_in);
2872 kfree(session->username);
2873 kfree(session->username_in);
2874 kfree(session->targetname);
2875 kfree(session->targetalias);
2876 kfree(session->initiatorname);
2877 kfree(session->boot_root);
2878 kfree(session->boot_nic);
2879 kfree(session->boot_target);
2880 kfree(session->ifacename);
2881 kfree(session->portal_type);
2882 kfree(session->discovery_parent_type);
2883
2884 iscsi_free_session(cls_session);
2885
2886 iscsi_host_dec_session_cnt(shost);
2887 module_put(owner);
2888}
2889EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2890
2891/**
2892 * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2893 * @cls_session: iscsi_cls_session
2894 * @dd_size: private driver data size
2895 * @conn_idx: cid
2896 */
2897struct iscsi_cls_conn *
2898iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2899 uint32_t conn_idx)
2900{
2901 struct iscsi_session *session = cls_session->dd_data;
2902 struct iscsi_conn *conn;
2903 struct iscsi_cls_conn *cls_conn;
2904 char *data;
2905
2906 cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2907 conn_idx);
2908 if (!cls_conn)
2909 return NULL;
2910 conn = cls_conn->dd_data;
2911 memset(conn, 0, sizeof(*conn) + dd_size);
2912
2913 conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2914 conn->session = session;
2915 conn->cls_conn = cls_conn;
2916 conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2917 conn->id = conn_idx;
2918 conn->exp_statsn = 0;
2919 conn->tmf_state = TMF_INITIAL;
2920
2921 timer_setup(&conn->transport_timer, iscsi_check_transport_timeouts, 0);
2922
2923 INIT_LIST_HEAD(&conn->mgmtqueue);
2924 INIT_LIST_HEAD(&conn->cmdqueue);
2925 INIT_LIST_HEAD(&conn->requeue);
2926 spin_lock_init(&conn->taskqueuelock);
2927 INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2928
2929 /* allocate login_task used for the login/text sequences */
2930 spin_lock_bh(&session->frwd_lock);
2931 if (!kfifo_out(&session->cmdpool.queue,
2932 (void*)&conn->login_task,
2933 sizeof(void*))) {
2934 spin_unlock_bh(&session->frwd_lock);
2935 goto login_task_alloc_fail;
2936 }
2937 spin_unlock_bh(&session->frwd_lock);
2938
2939 data = (char *) __get_free_pages(GFP_KERNEL,
2940 get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2941 if (!data)
2942 goto login_task_data_alloc_fail;
2943 conn->login_task->data = conn->data = data;
2944
2945 timer_setup(&conn->tmf_timer, iscsi_tmf_timedout, 0);
2946 init_waitqueue_head(&conn->ehwait);
2947
2948 return cls_conn;
2949
2950login_task_data_alloc_fail:
2951 kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2952 sizeof(void*));
2953login_task_alloc_fail:
2954 iscsi_destroy_conn(cls_conn);
2955 return NULL;
2956}
2957EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2958
2959/**
2960 * iscsi_conn_teardown - teardown iscsi connection
2961 * @cls_conn: iscsi class connection
2962 *
2963 * TODO: we may need to make this into a two step process
2964 * like scsi-mls remove + put host
2965 */
2966void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2967{
2968 struct iscsi_conn *conn = cls_conn->dd_data;
2969 struct iscsi_session *session = conn->session;
2970
2971 del_timer_sync(&conn->transport_timer);
2972
2973 mutex_lock(&session->eh_mutex);
2974 spin_lock_bh(&session->frwd_lock);
2975 conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2976 if (session->leadconn == conn) {
2977 /*
2978 * leading connection? then give up on recovery.
2979 */
2980 session->state = ISCSI_STATE_TERMINATE;
2981 wake_up(&conn->ehwait);
2982 }
2983 spin_unlock_bh(&session->frwd_lock);
2984
2985 /* flush queued up work because we free the connection below */
2986 iscsi_suspend_tx(conn);
2987
2988 spin_lock_bh(&session->frwd_lock);
2989 free_pages((unsigned long) conn->data,
2990 get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2991 kfree(conn->persistent_address);
2992 kfree(conn->local_ipaddr);
2993 /* regular RX path uses back_lock */
2994 spin_lock_bh(&session->back_lock);
2995 kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2996 sizeof(void*));
2997 spin_unlock_bh(&session->back_lock);
2998 if (session->leadconn == conn)
2999 session->leadconn = NULL;
3000 spin_unlock_bh(&session->frwd_lock);
3001 mutex_unlock(&session->eh_mutex);
3002
3003 iscsi_destroy_conn(cls_conn);
3004}
3005EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
3006
3007int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
3008{
3009 struct iscsi_conn *conn = cls_conn->dd_data;
3010 struct iscsi_session *session = conn->session;
3011
3012 if (!session) {
3013 iscsi_conn_printk(KERN_ERR, conn,
3014 "can't start unbound connection\n");
3015 return -EPERM;
3016 }
3017
3018 if ((session->imm_data_en || !session->initial_r2t_en) &&
3019 session->first_burst > session->max_burst) {
3020 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
3021 "first_burst %d max_burst %d\n",
3022 session->first_burst, session->max_burst);
3023 return -EINVAL;
3024 }
3025
3026 if (conn->ping_timeout && !conn->recv_timeout) {
3027 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3028 "zero. Using 5 seconds\n.");
3029 conn->recv_timeout = 5;
3030 }
3031
3032 if (conn->recv_timeout && !conn->ping_timeout) {
3033 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3034 "zero. Using 5 seconds.\n");
3035 conn->ping_timeout = 5;
3036 }
3037
3038 spin_lock_bh(&session->frwd_lock);
3039 conn->c_stage = ISCSI_CONN_STARTED;
3040 session->state = ISCSI_STATE_LOGGED_IN;
3041 session->queued_cmdsn = session->cmdsn;
3042
3043 conn->last_recv = jiffies;
3044 conn->last_ping = jiffies;
3045 if (conn->recv_timeout && conn->ping_timeout)
3046 mod_timer(&conn->transport_timer,
3047 jiffies + (conn->recv_timeout * HZ));
3048
3049 switch(conn->stop_stage) {
3050 case STOP_CONN_RECOVER:
3051 /*
3052 * unblock eh_abort() if it is blocked. re-try all
3053 * commands after successful recovery
3054 */
3055 conn->stop_stage = 0;
3056 conn->tmf_state = TMF_INITIAL;
3057 session->age++;
3058 if (session->age == 16)
3059 session->age = 0;
3060 break;
3061 case STOP_CONN_TERM:
3062 conn->stop_stage = 0;
3063 break;
3064 default:
3065 break;
3066 }
3067 spin_unlock_bh(&session->frwd_lock);
3068
3069 iscsi_unblock_session(session->cls_session);
3070 wake_up(&conn->ehwait);
3071 return 0;
3072}
3073EXPORT_SYMBOL_GPL(iscsi_conn_start);
3074
3075static void
3076fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3077{
3078 struct iscsi_task *task;
3079 int i, state;
3080
3081 for (i = 0; i < conn->session->cmds_max; i++) {
3082 task = conn->session->cmds[i];
3083 if (task->sc)
3084 continue;
3085
3086 if (task->state == ISCSI_TASK_FREE)
3087 continue;
3088
3089 ISCSI_DBG_SESSION(conn->session,
3090 "failing mgmt itt 0x%x state %d\n",
3091 task->itt, task->state);
3092 state = ISCSI_TASK_ABRT_SESS_RECOV;
3093 if (task->state == ISCSI_TASK_PENDING)
3094 state = ISCSI_TASK_COMPLETED;
3095 spin_lock_bh(&session->back_lock);
3096 iscsi_complete_task(task, state);
3097 spin_unlock_bh(&session->back_lock);
3098 }
3099}
3100
3101static void iscsi_start_session_recovery(struct iscsi_session *session,
3102 struct iscsi_conn *conn, int flag)
3103{
3104 int old_stop_stage;
3105
3106 mutex_lock(&session->eh_mutex);
3107 spin_lock_bh(&session->frwd_lock);
3108 if (conn->stop_stage == STOP_CONN_TERM) {
3109 spin_unlock_bh(&session->frwd_lock);
3110 mutex_unlock(&session->eh_mutex);
3111 return;
3112 }
3113
3114 /*
3115 * When this is called for the in_login state, we only want to clean
3116 * up the login task and connection. We do not need to block and set
3117 * the recovery state again
3118 */
3119 if (flag == STOP_CONN_TERM)
3120 session->state = ISCSI_STATE_TERMINATE;
3121 else if (conn->stop_stage != STOP_CONN_RECOVER)
3122 session->state = ISCSI_STATE_IN_RECOVERY;
3123
3124 old_stop_stage = conn->stop_stage;
3125 conn->stop_stage = flag;
3126 spin_unlock_bh(&session->frwd_lock);
3127
3128 del_timer_sync(&conn->transport_timer);
3129 iscsi_suspend_tx(conn);
3130
3131 spin_lock_bh(&session->frwd_lock);
3132 conn->c_stage = ISCSI_CONN_STOPPED;
3133 spin_unlock_bh(&session->frwd_lock);
3134
3135 /*
3136 * for connection level recovery we should not calculate
3137 * header digest. conn->hdr_size used for optimization
3138 * in hdr_extract() and will be re-negotiated at
3139 * set_param() time.
3140 */
3141 if (flag == STOP_CONN_RECOVER) {
3142 conn->hdrdgst_en = 0;
3143 conn->datadgst_en = 0;
3144 if (session->state == ISCSI_STATE_IN_RECOVERY &&
3145 old_stop_stage != STOP_CONN_RECOVER) {
3146 ISCSI_DBG_SESSION(session, "blocking session\n");
3147 iscsi_block_session(session->cls_session);
3148 }
3149 }
3150
3151 /*
3152 * flush queues.
3153 */
3154 spin_lock_bh(&session->frwd_lock);
3155 fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3156 fail_mgmt_tasks(session, conn);
3157 memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3158 spin_unlock_bh(&session->frwd_lock);
3159 mutex_unlock(&session->eh_mutex);
3160}
3161
3162void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3163{
3164 struct iscsi_conn *conn = cls_conn->dd_data;
3165 struct iscsi_session *session = conn->session;
3166
3167 switch (flag) {
3168 case STOP_CONN_RECOVER:
3169 case STOP_CONN_TERM:
3170 iscsi_start_session_recovery(session, conn, flag);
3171 break;
3172 default:
3173 iscsi_conn_printk(KERN_ERR, conn,
3174 "invalid stop flag %d\n", flag);
3175 }
3176}
3177