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[SCSI] iscsi: don't switch states when just cleaning up
[mirror_ubuntu-zesty-kernel.git] / drivers / scsi / libiscsi.c
CommitLineData
7996a778
MC		 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/mutex.h>
26#include <linux/kfifo.h>
27#include <linux/delay.h>
28#include <net/tcp.h>
29#include <scsi/scsi_cmnd.h>
30#include <scsi/scsi_device.h>
31#include <scsi/scsi_eh.h>
32#include <scsi/scsi_tcq.h>
33#include <scsi/scsi_host.h>
34#include <scsi/scsi.h>
35#include <scsi/iscsi_proto.h>
36#include <scsi/scsi_transport.h>
37#include <scsi/scsi_transport_iscsi.h>
38#include <scsi/libiscsi.h>
39
40struct iscsi_session *
41class_to_transport_session(struct iscsi_cls_session *cls_session)
42{
43 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
44 return iscsi_hostdata(shost->hostdata);
45}
46EXPORT_SYMBOL_GPL(class_to_transport_session);
47
48#define INVALID_SN_DELTA 0xffff
49
50int
51iscsi_check_assign_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
52{
53 uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
54 uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);
55
56 if (max_cmdsn < exp_cmdsn -1 &&
57 max_cmdsn > exp_cmdsn - INVALID_SN_DELTA)
58 return ISCSI_ERR_MAX_CMDSN;
59 if (max_cmdsn > session->max_cmdsn ||
60 max_cmdsn < session->max_cmdsn - INVALID_SN_DELTA)
61 session->max_cmdsn = max_cmdsn;
62 if (exp_cmdsn > session->exp_cmdsn ||
63 exp_cmdsn < session->exp_cmdsn - INVALID_SN_DELTA)
64 session->exp_cmdsn = exp_cmdsn;
65
66 return 0;
67}
68EXPORT_SYMBOL_GPL(iscsi_check_assign_cmdsn);
69
70void iscsi_prep_unsolicit_data_pdu(struct iscsi_cmd_task *ctask,
71 struct iscsi_data *hdr,
72 int transport_data_cnt)
73{
74 struct iscsi_conn *conn = ctask->conn;
75
76 memset(hdr, 0, sizeof(struct iscsi_data));
77 hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
78 hdr->datasn = cpu_to_be32(ctask->unsol_datasn);
79 ctask->unsol_datasn++;
80 hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
81 memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
82
83 hdr->itt = ctask->hdr->itt;
84 hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
85
86 hdr->offset = cpu_to_be32(ctask->total_length -
87 transport_data_cnt -
88 ctask->unsol_count);
89
90 if (ctask->unsol_count > conn->max_xmit_dlength) {
91 hton24(hdr->dlength, conn->max_xmit_dlength);
92 ctask->data_count = conn->max_xmit_dlength;
93 hdr->flags = 0;
94 } else {
95 hton24(hdr->dlength, ctask->unsol_count);
96 ctask->data_count = ctask->unsol_count;
97 hdr->flags = ISCSI_FLAG_CMD_FINAL;
98 }
99}
100EXPORT_SYMBOL_GPL(iscsi_prep_unsolicit_data_pdu);
101
102/**
103 * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
104 * @ctask: iscsi cmd task
105 *
106 * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
107 * fields like dlength or final based on how much data it sends
108 */
109static void iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
110{
111 struct iscsi_conn *conn = ctask->conn;
112 struct iscsi_session *session = conn->session;
113 struct iscsi_cmd *hdr = ctask->hdr;
114 struct scsi_cmnd *sc = ctask->sc;
115
116 hdr->opcode = ISCSI_OP_SCSI_CMD;
117 hdr->flags = ISCSI_ATTR_SIMPLE;
118 int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
119 hdr->itt = ctask->itt | (conn->id << ISCSI_CID_SHIFT) |
120 (session->age << ISCSI_AGE_SHIFT);
121 hdr->data_length = cpu_to_be32(sc->request_bufflen);
122 hdr->cmdsn = cpu_to_be32(session->cmdsn);
123 session->cmdsn++;
124 hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
125 memcpy(hdr->cdb, sc->cmnd, sc->cmd_len);
126 memset(&hdr->cdb[sc->cmd_len], 0, MAX_COMMAND_SIZE - sc->cmd_len);
127
128 if (sc->sc_data_direction == DMA_TO_DEVICE) {
129 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
130 /*
131 * Write counters:
132 *
133 * imm_count bytes to be sent right after
134 * SCSI PDU Header
135 *
136 * unsol_count bytes(as Data-Out) to be sent
137 * without R2T ack right after
138 * immediate data
139 *
140 * r2t_data_count bytes to be sent via R2T ack's
141 *
142 * pad_count bytes to be sent as zero-padding
143 */
144 ctask->imm_count = 0;
145 ctask->unsol_count = 0;
146 ctask->unsol_datasn = 0;
147
148 if (session->imm_data_en) {
149 if (ctask->total_length >= session->first_burst)
150 ctask->imm_count = min(session->first_burst,
151 conn->max_xmit_dlength);
152 else
153 ctask->imm_count = min(ctask->total_length,
154 conn->max_xmit_dlength);
155 hton24(ctask->hdr->dlength, ctask->imm_count);
156 } else
157 zero_data(ctask->hdr->dlength);
158
159 if (!session->initial_r2t_en)
160 ctask->unsol_count = min(session->first_burst,
161 ctask->total_length) - ctask->imm_count;
162 if (!ctask->unsol_count)
163 /* No unsolicit Data-Out's */
164 ctask->hdr->flags |= ISCSI_FLAG_CMD_FINAL;
165 } else {
166 ctask->datasn = 0;
167 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
168 zero_data(hdr->dlength);
169
170 if (sc->sc_data_direction == DMA_FROM_DEVICE)
171 hdr->flags |= ISCSI_FLAG_CMD_READ;
172 }
173
174 conn->scsicmd_pdus_cnt++;
175}
176EXPORT_SYMBOL_GPL(iscsi_prep_scsi_cmd_pdu);
177
178/**
179 * iscsi_complete_command - return command back to scsi-ml
180 * @session: iscsi session
181 * @ctask: iscsi cmd task
182 *
183 * Must be called with session lock.
184 * This function returns the scsi command to scsi-ml and returns
185 * the cmd task to the pool of available cmd tasks.
186 */
187static void iscsi_complete_command(struct iscsi_session *session,
188 struct iscsi_cmd_task *ctask)
189{
190 struct scsi_cmnd *sc = ctask->sc;
191
192 ctask->sc = NULL;
193 list_del_init(&ctask->running);
194 __kfifo_put(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
195 sc->scsi_done(sc);
196}
197
198/**
199 * iscsi_cmd_rsp - SCSI Command Response processing
200 * @conn: iscsi connection
201 * @hdr: iscsi header
202 * @ctask: scsi command task
203 * @data: cmd data buffer
204 * @datalen: len of buffer
205 *
206 * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
207 * then completes the command and task.
208 **/
209static int iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
210 struct iscsi_cmd_task *ctask, char *data,
211 int datalen)
212{
213 int rc;
214 struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
215 struct iscsi_session *session = conn->session;
216 struct scsi_cmnd *sc = ctask->sc;
217
218 rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
219 if (rc) {
220 sc->result = DID_ERROR << 16;
221 goto out;
222 }
223
224 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
225
226 sc->result = (DID_OK << 16) | rhdr->cmd_status;
227
228 if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
229 sc->result = DID_ERROR << 16;
230 goto out;
231 }
232
233 if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
234 int senselen;
235
236 if (datalen < 2) {
237invalid_datalen:
be2df72e
OG		 238 printk(KERN_ERR "iscsi: Got CHECK_CONDITION but "
239 "invalid data buffer size of %d\n", datalen);
7996a778
MC		 240 sc->result = DID_BAD_TARGET << 16;
241 goto out;
242 }
243
244 senselen = (data[0] << 8) | data[1];
245 if (datalen < senselen)
246 goto invalid_datalen;
247
248 memcpy(sc->sense_buffer, data + 2,
249 min(senselen, SCSI_SENSE_BUFFERSIZE));
250 debug_scsi("copied %d bytes of sense\n",
251 min(senselen, SCSI_SENSE_BUFFERSIZE));
252 }
253
254 if (sc->sc_data_direction == DMA_TO_DEVICE)
255 goto out;
256
257 if (rhdr->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
258 int res_count = be32_to_cpu(rhdr->residual_count);
259
260 if (res_count > 0 && res_count <= sc->request_bufflen)
261 sc->resid = res_count;
262 else
263 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
264 } else if (rhdr->flags & ISCSI_FLAG_CMD_BIDI_UNDERFLOW)
265 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
266 else if (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW)
267 sc->resid = be32_to_cpu(rhdr->residual_count);
268
269out:
270 debug_scsi("done [sc %lx res %d itt 0x%x]\n",
271 (long)sc, sc->result, ctask->itt);
272 conn->scsirsp_pdus_cnt++;
273
274 iscsi_complete_command(conn->session, ctask);
275 return rc;
276}
277
278/**
279 * __iscsi_complete_pdu - complete pdu
280 * @conn: iscsi conn
281 * @hdr: iscsi header
282 * @data: data buffer
283 * @datalen: len of data buffer
284 *
285 * Completes pdu processing by freeing any resources allocated at
286 * queuecommand or send generic. session lock must be held and verify
287 * itt must have been called.
288 */
289int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
290 char *data, int datalen)
291{
292 struct iscsi_session *session = conn->session;
293 int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
294 struct iscsi_cmd_task *ctask;
295 struct iscsi_mgmt_task *mtask;
296 uint32_t itt;
297
298 if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG))
299 itt = hdr->itt & ISCSI_ITT_MASK;
300 else
301 itt = hdr->itt;
302
303 if (itt < session->cmds_max) {
304 ctask = session->cmds[itt];
305
306 debug_scsi("cmdrsp [op 0x%x cid %d itt 0x%x len %d]\n",
307 opcode, conn->id, ctask->itt, datalen);
308
309 switch(opcode) {
310 case ISCSI_OP_SCSI_CMD_RSP:
311 BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
312 rc = iscsi_scsi_cmd_rsp(conn, hdr, ctask, data,
313 datalen);
314 break;
315 case ISCSI_OP_SCSI_DATA_IN:
316 BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
317 if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
318 conn->scsirsp_pdus_cnt++;
319 iscsi_complete_command(session, ctask);
320 }
321 break;
322 case ISCSI_OP_R2T:
323 /* LLD handles this for now */
324 break;
325 default:
326 rc = ISCSI_ERR_BAD_OPCODE;
327 break;
328 }
329 } else if (itt >= ISCSI_MGMT_ITT_OFFSET &&
330 itt < ISCSI_MGMT_ITT_OFFSET + session->mgmtpool_max) {
331 mtask = session->mgmt_cmds[itt - ISCSI_MGMT_ITT_OFFSET];
332
333 debug_scsi("immrsp [op 0x%x cid %d itt 0x%x len %d]\n",
334 opcode, conn->id, mtask->itt, datalen);
335
8d2860b3
MC		 336 rc = iscsi_check_assign_cmdsn(session,
337 (struct iscsi_nopin*)hdr);
338 if (rc)
339 goto done;
340
7996a778 341 switch(opcode) {
8d2860b3
MC		 342 case ISCSI_OP_LOGOUT_RSP:
343 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
344 /* fall through */
7996a778
MC		 345 case ISCSI_OP_LOGIN_RSP:
346 case ISCSI_OP_TEXT_RSP:
8d2860b3
MC		 347 /*
348 * login related PDU's exp_statsn is handled in
349 * userspace
350 */
7996a778
MC		 351 rc = iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen);
352 list_del(&mtask->running);
353 if (conn->login_mtask != mtask)
354 __kfifo_put(session->mgmtpool.queue,
355 (void*)&mtask, sizeof(void*));
356 break;
357 case ISCSI_OP_SCSI_TMFUNC_RSP:
7996a778
MC		 358 if (datalen) {
359 rc = ISCSI_ERR_PROTO;
360 break;
361 }
8d2860b3
MC		 362
363 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
7996a778
MC		 364 conn->tmfrsp_pdus_cnt++;
365 if (conn->tmabort_state == TMABORT_INITIAL) {
366 conn->tmabort_state =
367 ((struct iscsi_tm_rsp *)hdr)->
368 response == ISCSI_TMF_RSP_COMPLETE ?
369 TMABORT_SUCCESS:TMABORT_FAILED;
370 /* unblock eh_abort() */
371 wake_up(&conn->ehwait);
372 }
373 break;
374 case ISCSI_OP_NOOP_IN:
375 if (hdr->ttt != ISCSI_RESERVED_TAG) {
376 rc = ISCSI_ERR_PROTO;
377 break;
378 }
7996a778
MC		 379 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
380
381 rc = iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen);
382 list_del(&mtask->running);
383 if (conn->login_mtask != mtask)
384 __kfifo_put(session->mgmtpool.queue,
385 (void*)&mtask, sizeof(void*));
386 break;
387 default:
388 rc = ISCSI_ERR_BAD_OPCODE;
389 break;
390 }
391 } else if (itt == ISCSI_RESERVED_TAG) {
392 switch(opcode) {
393 case ISCSI_OP_NOOP_IN:
394 if (!datalen) {
395 rc = iscsi_check_assign_cmdsn(session,
396 (struct iscsi_nopin*)hdr);
397 if (!rc && hdr->ttt != ISCSI_RESERVED_TAG)
398 rc = iscsi_recv_pdu(conn->cls_conn,
399 hdr, NULL, 0);
400 } else
401 rc = ISCSI_ERR_PROTO;
402 break;
403 case ISCSI_OP_REJECT:
404 /* we need sth like iscsi_reject_rsp()*/
405 case ISCSI_OP_ASYNC_EVENT:
8d2860b3 406 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
7996a778
MC		 407 /* we need sth like iscsi_async_event_rsp() */
408 rc = ISCSI_ERR_BAD_OPCODE;
409 break;
410 default:
411 rc = ISCSI_ERR_BAD_OPCODE;
412 break;
413 }
414 } else
415 rc = ISCSI_ERR_BAD_ITT;
416
8d2860b3 417done:
7996a778
MC		 418 return rc;
419}
420EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
421
422int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
423 char *data, int datalen)
424{
425 int rc;
426
427 spin_lock(&conn->session->lock);
428 rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
429 spin_unlock(&conn->session->lock);
430 return rc;
431}
432EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
433
434/* verify itt (itt encoding: age+cid+itt) */
435int iscsi_verify_itt(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
436 uint32_t *ret_itt)
437{
438 struct iscsi_session *session = conn->session;
439 struct iscsi_cmd_task *ctask;
440 uint32_t itt;
441
442 if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
443 if ((hdr->itt & ISCSI_AGE_MASK) !=
444 (session->age << ISCSI_AGE_SHIFT)) {
be2df72e 445 printk(KERN_ERR "iscsi: received itt %x expected "
7996a778
MC		 446 "session age (%x)\n", hdr->itt,
447 session->age & ISCSI_AGE_MASK);
448 return ISCSI_ERR_BAD_ITT;
449 }
450
451 if ((hdr->itt & ISCSI_CID_MASK) !=
452 (conn->id << ISCSI_CID_SHIFT)) {
be2df72e 453 printk(KERN_ERR "iscsi: received itt %x, expected "
7996a778
MC		 454 "CID (%x)\n", hdr->itt, conn->id);
455 return ISCSI_ERR_BAD_ITT;
456 }
457 itt = hdr->itt & ISCSI_ITT_MASK;
458 } else
459 itt = hdr->itt;
460
461 if (itt < session->cmds_max) {
462 ctask = session->cmds[itt];
463
464 if (!ctask->sc) {
be2df72e 465 printk(KERN_INFO "iscsi: dropping ctask with "
7996a778
MC		 466 "itt 0x%x\n", ctask->itt);
467 /* force drop */
468 return ISCSI_ERR_NO_SCSI_CMD;
469 }
470
471 if (ctask->sc->SCp.phase != session->age) {
be2df72e 472 printk(KERN_ERR "iscsi: ctask's session age %d, "
7996a778
MC		 473 "expected %d\n", ctask->sc->SCp.phase,
474 session->age);
475 return ISCSI_ERR_SESSION_FAILED;
476 }
477 }
478
479 *ret_itt = itt;
480 return 0;
481}
482EXPORT_SYMBOL_GPL(iscsi_verify_itt);
483
484void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
485{
486 struct iscsi_session *session = conn->session;
487 unsigned long flags;
488
489 spin_lock_irqsave(&session->lock, flags);
656cffc9
MC		 490 if (session->state == ISCSI_STATE_FAILED) {
491 spin_unlock_irqrestore(&session->lock, flags);
492 return;
493 }
494
67a61114 495 if (conn->stop_stage == 0)
7996a778
MC		 496 session->state = ISCSI_STATE_FAILED;
497 spin_unlock_irqrestore(&session->lock, flags);
498 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
499 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
500 iscsi_conn_error(conn->cls_conn, err);
501}
502EXPORT_SYMBOL_GPL(iscsi_conn_failure);
503
504/**
505 * iscsi_data_xmit - xmit any command into the scheduled connection
506 * @conn: iscsi connection
507 *
508 * Notes:
509 * The function can return -EAGAIN in which case the caller must
510 * re-schedule it again later or recover. '0' return code means
511 * successful xmit.
512 **/
513static int iscsi_data_xmit(struct iscsi_conn *conn)
514{
515 struct iscsi_transport *tt;
516
517 if (unlikely(conn->suspend_tx)) {
518 debug_scsi("conn %d Tx suspended!\n", conn->id);
519 return 0;
520 }
521 tt = conn->session->tt;
522
523 /*
524 * Transmit in the following order:
525 *
526 * 1) un-finished xmit (ctask or mtask)
527 * 2) immediate control PDUs
528 * 3) write data
529 * 4) SCSI commands
530 * 5) non-immediate control PDUs
531 *
532 * No need to lock around __kfifo_get as long as
533 * there's one producer and one consumer.
534 */
535
536 BUG_ON(conn->ctask && conn->mtask);
537
538 if (conn->ctask) {
539 if (tt->xmit_cmd_task(conn, conn->ctask))
540 goto again;
541 /* done with this in-progress ctask */
542 conn->ctask = NULL;
543 }
544 if (conn->mtask) {
545 if (tt->xmit_mgmt_task(conn, conn->mtask))
546 goto again;
547 /* done with this in-progress mtask */
548 conn->mtask = NULL;
549 }
550
551 /* process immediate first */
552 if (unlikely(__kfifo_len(conn->immqueue))) {
553 while (__kfifo_get(conn->immqueue, (void*)&conn->mtask,
554 sizeof(void*))) {
555 list_add_tail(&conn->mtask->running,
556 &conn->mgmt_run_list);
557 if (tt->xmit_mgmt_task(conn, conn->mtask))
558 goto again;
559 }
560 /* done with this mtask */
561 conn->mtask = NULL;
562 }
563
564 /* process command queue */
565 while (__kfifo_get(conn->xmitqueue, (void*)&conn->ctask,
566 sizeof(void*))) {
567 /*
568 * iscsi tcp may readd the task to the xmitqueue to send
569 * write data
570 */
571 if (list_empty(&conn->ctask->running))
572 list_add_tail(&conn->ctask->running, &conn->run_list);
573 if (tt->xmit_cmd_task(conn, conn->ctask))
574 goto again;
575 }
576 /* done with this ctask */
577 conn->ctask = NULL;
578
579 /* process the rest control plane PDUs, if any */
580 if (unlikely(__kfifo_len(conn->mgmtqueue))) {
581 while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask,
582 sizeof(void*))) {
583 list_add_tail(&conn->mtask->running,
584 &conn->mgmt_run_list);
585 if (tt->xmit_mgmt_task(conn, conn->mtask))
586 goto again;
587 }
588 /* done with this mtask */
589 conn->mtask = NULL;
590 }
591
592 return 0;
593
594again:
595 if (unlikely(conn->suspend_tx))
596 return 0;
597
598 return -EAGAIN;
599}
600
601static void iscsi_xmitworker(void *data)
602{
603 struct iscsi_conn *conn = data;
604
605 /*
606 * serialize Xmit worker on a per-connection basis.
607 */
608 mutex_lock(&conn->xmitmutex);
609 if (iscsi_data_xmit(conn))
610 scsi_queue_work(conn->session->host, &conn->xmitwork);
611 mutex_unlock(&conn->xmitmutex);
612}
613
614enum {
615 FAILURE_BAD_HOST = 1,
616 FAILURE_SESSION_FAILED,
617 FAILURE_SESSION_FREED,
618 FAILURE_WINDOW_CLOSED,
619 FAILURE_SESSION_TERMINATE,
656cffc9 620 FAILURE_SESSION_IN_RECOVERY,
7996a778
MC		 621 FAILURE_SESSION_RECOVERY_TIMEOUT,
622};
623
624int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
625{
626 struct Scsi_Host *host;
627 int reason = 0;
628 struct iscsi_session *session;
629 struct iscsi_conn *conn;
630 struct iscsi_cmd_task *ctask = NULL;
631
632 sc->scsi_done = done;
633 sc->result = 0;
634
635 host = sc->device->host;
636 session = iscsi_hostdata(host->hostdata);
637
638 spin_lock(&session->lock);
639
656cffc9
MC		 640 /*
641 * ISCSI_STATE_FAILED is a temp. state. The recovery
642 * code will decide what is best to do with command queued
643 * during this time
644 */
645 if (session->state != ISCSI_STATE_LOGGED_IN &&
646 session->state != ISCSI_STATE_FAILED) {
647 /*
648 * to handle the race between when we set the recovery state
649 * and block the session we requeue here (commands could
650 * be entering our queuecommand while a block is starting
651 * up because the block code is not locked)
652 */
653 if (session->state == ISCSI_STATE_IN_RECOVERY) {
654 reason = FAILURE_SESSION_IN_RECOVERY;
67a61114 655 goto reject;
7996a778 656 }
656cffc9
MC		 657
658 if (session->state == ISCSI_STATE_RECOVERY_FAILED)
659 reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
660 else if (session->state == ISCSI_STATE_TERMINATE)
661 reason = FAILURE_SESSION_TERMINATE;
662 else
663 reason = FAILURE_SESSION_FREED;
7996a778
MC		 664 goto fault;
665 }
666
667 /*
668 * Check for iSCSI window and take care of CmdSN wrap-around
669 */
670 if ((int)(session->max_cmdsn - session->cmdsn) < 0) {
671 reason = FAILURE_WINDOW_CLOSED;
672 goto reject;
673 }
674
675 conn = session->leadconn;
676
677 __kfifo_get(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
678 sc->SCp.phase = session->age;
679 sc->SCp.ptr = (char *)ctask;
680
681 ctask->mtask = NULL;
682 ctask->conn = conn;
683 ctask->sc = sc;
684 INIT_LIST_HEAD(&ctask->running);
685 ctask->total_length = sc->request_bufflen;
686 iscsi_prep_scsi_cmd_pdu(ctask);
687
688 session->tt->init_cmd_task(ctask);
689
690 __kfifo_put(conn->xmitqueue, (void*)&ctask, sizeof(void*));
691 debug_scsi(
692 "ctask enq [%s cid %d sc %lx itt 0x%x len %d cmdsn %d win %d]\n",
693 sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
694 conn->id, (long)sc, ctask->itt, sc->request_bufflen,
695 session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
696 spin_unlock(&session->lock);
697
698 scsi_queue_work(host, &conn->xmitwork);
699 return 0;
700
701reject:
702 spin_unlock(&session->lock);
703 debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
704 return SCSI_MLQUEUE_HOST_BUSY;
705
706fault:
707 spin_unlock(&session->lock);
be2df72e 708 printk(KERN_ERR "iscsi: cmd 0x%x is not queued (%d)\n",
7996a778
MC		 709 sc->cmnd[0], reason);
710 sc->result = (DID_NO_CONNECT << 16);
711 sc->resid = sc->request_bufflen;
712 sc->scsi_done(sc);
713 return 0;
714}
715EXPORT_SYMBOL_GPL(iscsi_queuecommand);
716
717int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
718{
719 if (depth > ISCSI_MAX_CMD_PER_LUN)
720 depth = ISCSI_MAX_CMD_PER_LUN;
721 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
722 return sdev->queue_depth;
723}
724EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
725
726static int
727iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
728 char *data, uint32_t data_size)
729{
730 struct iscsi_session *session = conn->session;
731 struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
732 struct iscsi_mgmt_task *mtask;
733
734 spin_lock_bh(&session->lock);
735 if (session->state == ISCSI_STATE_TERMINATE) {
736 spin_unlock_bh(&session->lock);
737 return -EPERM;
738 }
739 if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
740 hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
741 /*
742 * Login and Text are sent serially, in
743 * request-followed-by-response sequence.
744 * Same mtask can be used. Same ITT must be used.
745 * Note that login_mtask is preallocated at conn_create().
746 */
747 mtask = conn->login_mtask;
748 else {
656cffc9
MC		 749 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
750 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
7996a778 751
8d2860b3 752 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
7996a778
MC		 753 if (!__kfifo_get(session->mgmtpool.queue,
754 (void*)&mtask, sizeof(void*))) {
755 spin_unlock_bh(&session->lock);
756 return -ENOSPC;
757 }
758 }
759
760 /*
8d2860b3 761 * pre-format CmdSN for outgoing PDU.
7996a778
MC		 762 */
763 if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
764 hdr->itt = mtask->itt | (conn->id << ISCSI_CID_SHIFT) |
765 (session->age << ISCSI_AGE_SHIFT);
766 nop->cmdsn = cpu_to_be32(session->cmdsn);
767 if (conn->c_stage == ISCSI_CONN_STARTED &&
768 !(hdr->opcode & ISCSI_OP_IMMEDIATE))
769 session->cmdsn++;
770 } else
771 /* do not advance CmdSN */
772 nop->cmdsn = cpu_to_be32(session->cmdsn);
773
7996a778
MC		 774 if (data_size) {
775 memcpy(mtask->data, data, data_size);
776 mtask->data_count = data_size;
777 } else
778 mtask->data_count = 0;
779
780 INIT_LIST_HEAD(&mtask->running);
781 memcpy(mtask->hdr, hdr, sizeof(struct iscsi_hdr));
782 if (session->tt->init_mgmt_task)
783 session->tt->init_mgmt_task(conn, mtask, data, data_size);
784 spin_unlock_bh(&session->lock);
785
786 debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
787 hdr->opcode, hdr->itt, data_size);
788
789 /*
790 * since send_pdu() could be called at least from two contexts,
791 * we need to serialize __kfifo_put, so we don't have to take
792 * additional lock on fast data-path
793 */
794 if (hdr->opcode & ISCSI_OP_IMMEDIATE)
795 __kfifo_put(conn->immqueue, (void*)&mtask, sizeof(void*));
796 else
797 __kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*));
798
799 scsi_queue_work(session->host, &conn->xmitwork);
800 return 0;
801}
802
803int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
804 char *data, uint32_t data_size)
805{
806 struct iscsi_conn *conn = cls_conn->dd_data;
807 int rc;
808
809 mutex_lock(&conn->xmitmutex);
810 rc = iscsi_conn_send_generic(conn, hdr, data, data_size);
811 mutex_unlock(&conn->xmitmutex);
812
813 return rc;
814}
815EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
816
817void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
818{
819 struct iscsi_session *session = class_to_transport_session(cls_session);
820 struct iscsi_conn *conn = session->leadconn;
821
822 spin_lock_bh(&session->lock);
823 if (session->state != ISCSI_STATE_LOGGED_IN) {
656cffc9 824 session->state = ISCSI_STATE_RECOVERY_FAILED;
7996a778
MC		 825 if (conn)
826 wake_up(&conn->ehwait);
827 }
828 spin_unlock_bh(&session->lock);
829}
830EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
831
832int iscsi_eh_host_reset(struct scsi_cmnd *sc)
833{
834 struct Scsi_Host *host = sc->device->host;
835 struct iscsi_session *session = iscsi_hostdata(host->hostdata);
836 struct iscsi_conn *conn = session->leadconn;
837 int fail_session = 0;
838
839 spin_lock_bh(&session->lock);
840 if (session->state == ISCSI_STATE_TERMINATE) {
841failed:
842 debug_scsi("failing host reset: session terminated "
843 "[CID %d age %d]", conn->id, session->age);
844 spin_unlock_bh(&session->lock);
845 return FAILED;
846 }
847
848 if (sc->SCp.phase == session->age) {
849 debug_scsi("failing connection CID %d due to SCSI host reset",
850 conn->id);
851 fail_session = 1;
852 }
853 spin_unlock_bh(&session->lock);
854
855 /*
856 * we drop the lock here but the leadconn cannot be destoyed while
857 * we are in the scsi eh
858 */
656cffc9 859 if (fail_session)
7996a778 860 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
7996a778
MC		 861
862 debug_scsi("iscsi_eh_host_reset wait for relogin\n");
863 wait_event_interruptible(conn->ehwait,
864 session->state == ISCSI_STATE_TERMINATE ||
865 session->state == ISCSI_STATE_LOGGED_IN ||
656cffc9 866 session->state == ISCSI_STATE_RECOVERY_FAILED);
7996a778
MC		 867 if (signal_pending(current))
868 flush_signals(current);
869
870 spin_lock_bh(&session->lock);
871 if (session->state == ISCSI_STATE_LOGGED_IN)
be2df72e 872 printk(KERN_INFO "iscsi: host reset succeeded\n");
7996a778
MC		 873 else
874 goto failed;
875 spin_unlock_bh(&session->lock);
876
877 return SUCCESS;
878}
879EXPORT_SYMBOL_GPL(iscsi_eh_host_reset);
880
881static void iscsi_tmabort_timedout(unsigned long data)
882{
883 struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)data;
884 struct iscsi_conn *conn = ctask->conn;
885 struct iscsi_session *session = conn->session;
886
887 spin_lock(&session->lock);
888 if (conn->tmabort_state == TMABORT_INITIAL) {
889 conn->tmabort_state = TMABORT_TIMEDOUT;
890 debug_scsi("tmabort timedout [sc %p itt 0x%x]\n",
891 ctask->sc, ctask->itt);
892 /* unblock eh_abort() */
893 wake_up(&conn->ehwait);
894 }
895 spin_unlock(&session->lock);
896}
897
898/* must be called with the mutex lock */
899static int iscsi_exec_abort_task(struct scsi_cmnd *sc,
900 struct iscsi_cmd_task *ctask)
901{
902 struct iscsi_conn *conn = ctask->conn;
903 struct iscsi_session *session = conn->session;
904 struct iscsi_tm *hdr = &conn->tmhdr;
905 int rc;
906
907 /*
908 * ctask timed out but session is OK requests must be serialized.
909 */
910 memset(hdr, 0, sizeof(struct iscsi_tm));
911 hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
912 hdr->flags = ISCSI_TM_FUNC_ABORT_TASK;
913 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
914 memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
915 hdr->rtt = ctask->hdr->itt;
916 hdr->refcmdsn = ctask->hdr->cmdsn;
917
918 rc = iscsi_conn_send_generic(conn, (struct iscsi_hdr *)hdr,
919 NULL, 0);
920 if (rc) {
921 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
922 debug_scsi("abort sent failure [itt 0x%x] %d", ctask->itt, rc);
923 return rc;
924 }
925
926 debug_scsi("abort sent [itt 0x%x]\n", ctask->itt);
927
928 spin_lock_bh(&session->lock);
929 ctask->mtask = (struct iscsi_mgmt_task *)
930 session->mgmt_cmds[(hdr->itt & ISCSI_ITT_MASK) -
931 ISCSI_MGMT_ITT_OFFSET];
932
933 if (conn->tmabort_state == TMABORT_INITIAL) {
934 conn->tmfcmd_pdus_cnt++;
935 conn->tmabort_timer.expires = 10*HZ + jiffies;
936 conn->tmabort_timer.function = iscsi_tmabort_timedout;
937 conn->tmabort_timer.data = (unsigned long)ctask;
938 add_timer(&conn->tmabort_timer);
939 debug_scsi("abort set timeout [itt 0x%x]", ctask->itt);
940 }
941 spin_unlock_bh(&session->lock);
942 mutex_unlock(&conn->xmitmutex);
943
944 /*
945 * block eh thread until:
946 *
947 * 1) abort response
948 * 2) abort timeout
949 * 3) session is terminated or restarted or userspace has
950 * given up on recovery
951 */
952 wait_event_interruptible(conn->ehwait,
953 sc->SCp.phase != session->age ||
954 session->state != ISCSI_STATE_LOGGED_IN ||
656cffc9 955 conn->tmabort_state != TMABORT_INITIAL);
7996a778
MC		 956 if (signal_pending(current))
957 flush_signals(current);
958 del_timer_sync(&conn->tmabort_timer);
959
960 mutex_lock(&conn->xmitmutex);
961 return 0;
962}
963
964/*
965 * xmit mutex and session lock must be held
966 */
967#define iscsi_remove_task(tasktype) \
968static struct iscsi_##tasktype * \
969iscsi_remove_##tasktype(struct kfifo *fifo, uint32_t itt) \
970{ \
971 int i, nr_tasks = __kfifo_len(fifo) / sizeof(void*); \
972 struct iscsi_##tasktype *task; \
973 \
974 debug_scsi("searching %d tasks\n", nr_tasks); \
975 \
976 for (i = 0; i < nr_tasks; i++) { \
977 __kfifo_get(fifo, (void*)&task, sizeof(void*)); \
978 debug_scsi("check task %u\n", task->itt); \
979 \
980 if (task->itt == itt) { \
981 debug_scsi("matched task\n"); \
982 break; \
983 } \
984 \
985 __kfifo_put(fifo, (void*)&task, sizeof(void*)); \
986 } \
987 return NULL; \
988}
989
990iscsi_remove_task(mgmt_task);
991iscsi_remove_task(cmd_task);
992
993static int iscsi_ctask_mtask_cleanup(struct iscsi_cmd_task *ctask)
994{
995 struct iscsi_conn *conn = ctask->conn;
996 struct iscsi_session *session = conn->session;
997
998 if (!ctask->mtask)
999 return -EINVAL;
1000
1001 if (!iscsi_remove_mgmt_task(conn->immqueue, ctask->mtask->itt))
1002 list_del(&ctask->mtask->running);
1003 __kfifo_put(session->mgmtpool.queue, (void*)&ctask->mtask,
1004 sizeof(void*));
1005 ctask->mtask = NULL;
1006 return 0;
1007}
1008
1009/*
1010 * session lock and xmitmutex must be held
1011 */
1012static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1013 int err)
1014{
1015 struct scsi_cmnd *sc;
1016
1017 conn->session->tt->cleanup_cmd_task(conn, ctask);
1018 iscsi_ctask_mtask_cleanup(ctask);
1019
1020 sc = ctask->sc;
1021 if (!sc)
1022 return;
1023 sc->result = err;
1024 sc->resid = sc->request_bufflen;
1025 iscsi_complete_command(conn->session, ctask);
1026}
1027
1028int iscsi_eh_abort(struct scsi_cmnd *sc)
1029{
1030 struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
1031 struct iscsi_conn *conn = ctask->conn;
1032 struct iscsi_session *session = conn->session;
1033 struct iscsi_cmd_task *pending_ctask;
1034 int rc;
1035
1036 conn->eh_abort_cnt++;
1037 debug_scsi("aborting [sc %p itt 0x%x]\n", sc, ctask->itt);
1038
1039 mutex_lock(&conn->xmitmutex);
1040 spin_lock_bh(&session->lock);
1041
1042 /*
1043 * If we are not logged in or we have started a new session
1044 * then let the host reset code handle this
1045 */
1046 if (session->state != ISCSI_STATE_LOGGED_IN ||
1047 sc->SCp.phase != session->age)
1048 goto failed;
1049
1050 /* ctask completed before time out */
1051 if (!ctask->sc)
1052 goto success;
1053
1054 /* what should we do here ? */
1055 if (conn->ctask == ctask) {
be2df72e
OG		 1056 printk(KERN_INFO "iscsi: sc %p itt 0x%x partially sent. "
1057 "Failing abort\n", sc, ctask->itt);
7996a778
MC		 1058 goto failed;
1059 }
1060
1061 /* check for the easy pending cmd abort */
1062 pending_ctask = iscsi_remove_cmd_task(conn->xmitqueue, ctask->itt);
1063 if (pending_ctask) {
1064 /* iscsi_tcp queues write transfers on the xmitqueue */
1065 if (list_empty(&pending_ctask->running)) {
1066 debug_scsi("found pending task\n");
1067 goto success;
1068 } else
1069 __kfifo_put(conn->xmitqueue, (void*)&pending_ctask,
1070 sizeof(void*));
1071 }
1072
1073 conn->tmabort_state = TMABORT_INITIAL;
1074
1075 spin_unlock_bh(&session->lock);
1076 rc = iscsi_exec_abort_task(sc, ctask);
1077 spin_lock_bh(&session->lock);
1078
1079 iscsi_ctask_mtask_cleanup(ctask);
1080 if (rc || sc->SCp.phase != session->age ||
1081 session->state != ISCSI_STATE_LOGGED_IN)
1082 goto failed;
1083
1084 /* ctask completed before tmf abort response */
1085 if (!ctask->sc) {
1086 debug_scsi("sc completed while abort in progress\n");
1087 goto success;
1088 }
1089
1090 if (conn->tmabort_state != TMABORT_SUCCESS) {
1091 spin_unlock_bh(&session->lock);
1092 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1093 spin_lock_bh(&session->lock);
1094 goto failed;
1095 }
1096
1097success:
1098 debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1099 spin_unlock_bh(&session->lock);
1100
1101 /*
1102 * clean up task if aborted. we have the xmitmutex so grab
1103 * the recv lock as a writer
1104 */
1105 write_lock_bh(conn->recv_lock);
1106 spin_lock(&session->lock);
1107 fail_command(conn, ctask, DID_ABORT << 16);
1108 spin_unlock(&session->lock);
1109 write_unlock_bh(conn->recv_lock);
1110
1111 mutex_unlock(&conn->xmitmutex);
1112 return SUCCESS;
1113
1114failed:
1115 spin_unlock_bh(&session->lock);
1116 mutex_unlock(&conn->xmitmutex);
1117
1118 debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1119 return FAILED;
1120}
1121EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1122
1123int
1124iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
1125{
1126 int i;
1127
1128 *items = kmalloc(max * sizeof(void*), GFP_KERNEL);
1129 if (*items == NULL)
1130 return -ENOMEM;
1131
1132 q->max = max;
1133 q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL);
1134 if (q->pool == NULL) {
1135 kfree(*items);
1136 return -ENOMEM;
1137 }
1138
1139 q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1140 GFP_KERNEL, NULL);
1141 if (q->queue == ERR_PTR(-ENOMEM)) {
1142 kfree(q->pool);
1143 kfree(*items);
1144 return -ENOMEM;
1145 }
1146
1147 for (i = 0; i < max; i++) {
1148 q->pool[i] = kmalloc(item_size, GFP_KERNEL);
1149 if (q->pool[i] == NULL) {
1150 int j;
1151
1152 for (j = 0; j < i; j++)
1153 kfree(q->pool[j]);
1154
1155 kfifo_free(q->queue);
1156 kfree(q->pool);
1157 kfree(*items);
1158 return -ENOMEM;
1159 }
1160 memset(q->pool[i], 0, item_size);
1161 (*items)[i] = q->pool[i];
1162 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1163 }
1164 return 0;
1165}
1166EXPORT_SYMBOL_GPL(iscsi_pool_init);
1167
1168void iscsi_pool_free(struct iscsi_queue *q, void **items)
1169{
1170 int i;
1171
1172 for (i = 0; i < q->max; i++)
1173 kfree(items[i]);
1174 kfree(q->pool);
1175 kfree(items);
1176}
1177EXPORT_SYMBOL_GPL(iscsi_pool_free);
1178
1179/*
1180 * iSCSI Session's hostdata organization:
1181 *
1182 * *------------------* <== hostdata_session(host->hostdata)
1183 * | ptr to class sess|
1184 * |------------------| <== iscsi_hostdata(host->hostdata)
1185 * | iscsi_session |
1186 * *------------------*
1187 */
1188
1189#define hostdata_privsize(_sz) (sizeof(unsigned long) + _sz + \
1190 _sz % sizeof(unsigned long))
1191
1192#define hostdata_session(_hostdata) (iscsi_ptr(*(unsigned long *)_hostdata))
1193
1194/**
1195 * iscsi_session_setup - create iscsi cls session and host and session
1196 * @scsit: scsi transport template
1197 * @iscsit: iscsi transport template
1198 * @initial_cmdsn: initial CmdSN
1199 * @hostno: host no allocated
1200 *
1201 * This can be used by software iscsi_transports that allocate
1202 * a session per scsi host.
1203 **/
1204struct iscsi_cls_session *
1205iscsi_session_setup(struct iscsi_transport *iscsit,
1206 struct scsi_transport_template *scsit,
1207 int cmd_task_size, int mgmt_task_size,
1208 uint32_t initial_cmdsn, uint32_t *hostno)
1209{
1210 struct Scsi_Host *shost;
1211 struct iscsi_session *session;
1212 struct iscsi_cls_session *cls_session;
1213 int cmd_i;
1214
1215 shost = scsi_host_alloc(iscsit->host_template,
1216 hostdata_privsize(sizeof(*session)));
1217 if (!shost)
1218 return NULL;
1219
1220 shost->max_id = 1;
1221 shost->max_channel = 0;
1222 shost->max_lun = iscsit->max_lun;
1223 shost->max_cmd_len = iscsit->max_cmd_len;
1224 shost->transportt = scsit;
1225 shost->transportt->create_work_queue = 1;
1226 *hostno = shost->host_no;
1227
1228 session = iscsi_hostdata(shost->hostdata);
1229 memset(session, 0, sizeof(struct iscsi_session));
1230 session->host = shost;
1231 session->state = ISCSI_STATE_FREE;
1232 session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
1233 session->cmds_max = ISCSI_XMIT_CMDS_MAX;
1234 session->cmdsn = initial_cmdsn;
1235 session->exp_cmdsn = initial_cmdsn + 1;
1236 session->max_cmdsn = initial_cmdsn + 1;
1237 session->max_r2t = 1;
1238 session->tt = iscsit;
1239
1240 /* initialize SCSI PDU commands pool */
1241 if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
1242 (void***)&session->cmds,
1243 cmd_task_size + sizeof(struct iscsi_cmd_task)))
1244 goto cmdpool_alloc_fail;
1245
1246 /* pre-format cmds pool with ITT */
1247 for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1248 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1249
1250 if (cmd_task_size)
1251 ctask->dd_data = &ctask[1];
1252 ctask->itt = cmd_i;
1253 }
1254
1255 spin_lock_init(&session->lock);
1256 INIT_LIST_HEAD(&session->connections);
1257
1258 /* initialize immediate command pool */
1259 if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max,
1260 (void***)&session->mgmt_cmds,
1261 mgmt_task_size + sizeof(struct iscsi_mgmt_task)))
1262 goto mgmtpool_alloc_fail;
1263
1264
1265 /* pre-format immediate cmds pool with ITT */
1266 for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
1267 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
1268
1269 if (mgmt_task_size)
1270 mtask->dd_data = &mtask[1];
1271 mtask->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i;
7996a778
MC		 1272 }
1273
1274 if (scsi_add_host(shost, NULL))
1275 goto add_host_fail;
1276
1277 cls_session = iscsi_create_session(shost, iscsit, 0);
1278 if (!cls_session)
1279 goto cls_session_fail;
1280 *(unsigned long*)shost->hostdata = (unsigned long)cls_session;
1281
1282 return cls_session;
1283
1284cls_session_fail:
1285 scsi_remove_host(shost);
1286add_host_fail:
7996a778
MC		 1287 iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1288mgmtpool_alloc_fail:
1289 iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1290cmdpool_alloc_fail:
1291 scsi_host_put(shost);
1292 return NULL;
1293}
1294EXPORT_SYMBOL_GPL(iscsi_session_setup);
1295
1296/**
1297 * iscsi_session_teardown - destroy session, host, and cls_session
1298 * shost: scsi host
1299 *
1300 * This can be used by software iscsi_transports that allocate
1301 * a session per scsi host.
1302 **/
1303void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
1304{
1305 struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1306 struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
7996a778
MC		 1307
1308 scsi_remove_host(shost);
1309
7996a778
MC		 1310 iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1311 iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1312
1313 iscsi_destroy_session(cls_session);
1314 scsi_host_put(shost);
1315}
1316EXPORT_SYMBOL_GPL(iscsi_session_teardown);
1317
1318/**
1319 * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
1320 * @cls_session: iscsi_cls_session
1321 * @conn_idx: cid
1322 **/
1323struct iscsi_cls_conn *
1324iscsi_conn_setup(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1325{
1326 struct iscsi_session *session = class_to_transport_session(cls_session);
1327 struct iscsi_conn *conn;
1328 struct iscsi_cls_conn *cls_conn;
d36ab6f3 1329 char *data;
7996a778
MC		 1330
1331 cls_conn = iscsi_create_conn(cls_session, conn_idx);
1332 if (!cls_conn)
1333 return NULL;
1334 conn = cls_conn->dd_data;
1335 memset(conn, 0, sizeof(*conn));
1336
1337 conn->session = session;
1338 conn->cls_conn = cls_conn;
1339 conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
1340 conn->id = conn_idx;
1341 conn->exp_statsn = 0;
1342 conn->tmabort_state = TMABORT_INITIAL;
1343 INIT_LIST_HEAD(&conn->run_list);
1344 INIT_LIST_HEAD(&conn->mgmt_run_list);
1345
1346 /* initialize general xmit PDU commands queue */
1347 conn->xmitqueue = kfifo_alloc(session->cmds_max * sizeof(void*),
1348 GFP_KERNEL, NULL);
1349 if (conn->xmitqueue == ERR_PTR(-ENOMEM))
1350 goto xmitqueue_alloc_fail;
1351
1352 /* initialize general immediate & non-immediate PDU commands queue */
1353 conn->immqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
1354 GFP_KERNEL, NULL);
1355 if (conn->immqueue == ERR_PTR(-ENOMEM))
1356 goto immqueue_alloc_fail;
1357
1358 conn->mgmtqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
1359 GFP_KERNEL, NULL);
1360 if (conn->mgmtqueue == ERR_PTR(-ENOMEM))
1361 goto mgmtqueue_alloc_fail;
1362
1363 INIT_WORK(&conn->xmitwork, iscsi_xmitworker, conn);
1364
1365 /* allocate login_mtask used for the login/text sequences */
1366 spin_lock_bh(&session->lock);
1367 if (!__kfifo_get(session->mgmtpool.queue,
1368 (void*)&conn->login_mtask,
1369 sizeof(void*))) {
1370 spin_unlock_bh(&session->lock);
1371 goto login_mtask_alloc_fail;
1372 }
1373 spin_unlock_bh(&session->lock);
1374
d36ab6f3
MC		 1375 data = kmalloc(DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH, GFP_KERNEL);
1376 if (!data)
1377 goto login_mtask_data_alloc_fail;
1378 conn->login_mtask->data = data;
1379
7996a778
MC		 1380 init_timer(&conn->tmabort_timer);
1381 mutex_init(&conn->xmitmutex);
1382 init_waitqueue_head(&conn->ehwait);
1383
1384 return cls_conn;
1385
d36ab6f3
MC		 1386login_mtask_data_alloc_fail:
1387 __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1388 sizeof(void*));
7996a778
MC		 1389login_mtask_alloc_fail:
1390 kfifo_free(conn->mgmtqueue);
1391mgmtqueue_alloc_fail:
1392 kfifo_free(conn->immqueue);
1393immqueue_alloc_fail:
1394 kfifo_free(conn->xmitqueue);
1395xmitqueue_alloc_fail:
1396 iscsi_destroy_conn(cls_conn);
1397 return NULL;
1398}
1399EXPORT_SYMBOL_GPL(iscsi_conn_setup);
1400
1401/**
1402 * iscsi_conn_teardown - teardown iscsi connection
1403 * cls_conn: iscsi class connection
1404 *
1405 * TODO: we may need to make this into a two step process
1406 * like scsi-mls remove + put host
1407 */
1408void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
1409{
1410 struct iscsi_conn *conn = cls_conn->dd_data;
1411 struct iscsi_session *session = conn->session;
1412 unsigned long flags;
1413
7996a778 1414 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
67a61114 1415 mutex_lock(&conn->xmitmutex);
7996a778
MC		 1416 if (conn->c_stage == ISCSI_CONN_INITIAL_STAGE) {
1417 if (session->tt->suspend_conn_recv)
1418 session->tt->suspend_conn_recv(conn);
1419
1420 session->tt->terminate_conn(conn);
1421 }
1422
1423 spin_lock_bh(&session->lock);
1424 conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
1425 if (session->leadconn == conn) {
1426 /*
1427 * leading connection? then give up on recovery.
1428 */
1429 session->state = ISCSI_STATE_TERMINATE;
1430 wake_up(&conn->ehwait);
1431 }
1432 spin_unlock_bh(&session->lock);
1433
1434 mutex_unlock(&conn->xmitmutex);
1435
1436 /*
1437 * Block until all in-progress commands for this connection
1438 * time out or fail.
1439 */
1440 for (;;) {
1441 spin_lock_irqsave(session->host->host_lock, flags);
1442 if (!session->host->host_busy) { /* OK for ERL == 0 */
1443 spin_unlock_irqrestore(session->host->host_lock, flags);
1444 break;
1445 }
1446 spin_unlock_irqrestore(session->host->host_lock, flags);
1447 msleep_interruptible(500);
be2df72e
OG		 1448 printk(KERN_INFO "iscsi: scsi conn_destroy(): host_busy %d "
1449 "host_failed %d\n", session->host->host_busy,
1450 session->host->host_failed);
7996a778
MC		 1451 /*
1452 * force eh_abort() to unblock
1453 */
1454 wake_up(&conn->ehwait);
1455 }
1456
1457 spin_lock_bh(&session->lock);
d36ab6f3 1458 kfree(conn->login_mtask->data);
7996a778
MC		 1459 __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1460 sizeof(void*));
1461 list_del(&conn->item);
1462 if (list_empty(&session->connections))
1463 session->leadconn = NULL;
1464 if (session->leadconn && session->leadconn == conn)
1465 session->leadconn = container_of(session->connections.next,
1466 struct iscsi_conn, item);
1467
1468 if (session->leadconn == NULL)
1469 /* no connections exits.. reset sequencing */
1470 session->cmdsn = session->max_cmdsn = session->exp_cmdsn = 1;
1471 spin_unlock_bh(&session->lock);
1472
1473 kfifo_free(conn->xmitqueue);
1474 kfifo_free(conn->immqueue);
1475 kfifo_free(conn->mgmtqueue);
1476
1477 iscsi_destroy_conn(cls_conn);
1478}
1479EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
1480
1481int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
1482{
1483 struct iscsi_conn *conn = cls_conn->dd_data;
1484 struct iscsi_session *session = conn->session;
1485
1486 if (session == NULL) {
1487 printk(KERN_ERR "iscsi: can't start unbound connection\n");
1488 return -EPERM;
1489 }
1490
1491 spin_lock_bh(&session->lock);
1492 conn->c_stage = ISCSI_CONN_STARTED;
1493 session->state = ISCSI_STATE_LOGGED_IN;
1494
1495 switch(conn->stop_stage) {
1496 case STOP_CONN_RECOVER:
1497 /*
1498 * unblock eh_abort() if it is blocked. re-try all
1499 * commands after successful recovery
1500 */
7996a778
MC		 1501 conn->stop_stage = 0;
1502 conn->tmabort_state = TMABORT_INITIAL;
1503 session->age++;
7996a778
MC		 1504 spin_unlock_bh(&session->lock);
1505
1506 iscsi_unblock_session(session_to_cls(session));
1507 wake_up(&conn->ehwait);
1508 return 0;
1509 case STOP_CONN_TERM:
7996a778 1510 conn->stop_stage = 0;
7996a778
MC		 1511 break;
1512 default:
1513 break;
1514 }
1515 spin_unlock_bh(&session->lock);
1516
1517 return 0;
1518}
1519EXPORT_SYMBOL_GPL(iscsi_conn_start);
1520
1521static void
1522flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
1523{
1524 struct iscsi_mgmt_task *mtask, *tmp;
1525
1526 /* handle pending */
1527 while (__kfifo_get(conn->immqueue, (void*)&mtask, sizeof(void*)) ||
1528 __kfifo_get(conn->mgmtqueue, (void*)&mtask, sizeof(void*))) {
1529 if (mtask == conn->login_mtask)
1530 continue;
1531 debug_scsi("flushing pending mgmt task itt 0x%x\n", mtask->itt);
1532 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1533 sizeof(void*));
1534 }
1535
1536 /* handle running */
1537 list_for_each_entry_safe(mtask, tmp, &conn->mgmt_run_list, running) {
1538 debug_scsi("flushing running mgmt task itt 0x%x\n", mtask->itt);
ed2abc7f
MC		 1539 list_del(&mtask->running);
1540
7996a778
MC		 1541 if (mtask == conn->login_mtask)
1542 continue;
ed2abc7f 1543 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
7996a778
MC		 1544 sizeof(void*));
1545 }
1546
1547 conn->mtask = NULL;
1548}
1549
1550/* Fail commands. Mutex and session lock held and recv side suspended */
1551static void fail_all_commands(struct iscsi_conn *conn)
1552{
1553 struct iscsi_cmd_task *ctask, *tmp;
1554
1555 /* flush pending */
1556 while (__kfifo_get(conn->xmitqueue, (void*)&ctask, sizeof(void*))) {
1557 debug_scsi("failing pending sc %p itt 0x%x\n", ctask->sc,
1558 ctask->itt);
1559 fail_command(conn, ctask, DID_BUS_BUSY << 16);
1560 }
1561
1562 /* fail all other running */
1563 list_for_each_entry_safe(ctask, tmp, &conn->run_list, running) {
1564 debug_scsi("failing in progress sc %p itt 0x%x\n",
1565 ctask->sc, ctask->itt);
1566 fail_command(conn, ctask, DID_BUS_BUSY << 16);
1567 }
1568
1569 conn->ctask = NULL;
1570}
1571
656cffc9
MC		 1572static void iscsi_start_session_recovery(struct iscsi_session *session,
1573 struct iscsi_conn *conn, int flag)
7996a778 1574{
ed2abc7f
MC		 1575 int old_stop_stage;
1576
7996a778 1577 spin_lock_bh(&session->lock);
ed2abc7f 1578 if (conn->stop_stage == STOP_CONN_TERM) {
7996a778
MC		 1579 spin_unlock_bh(&session->lock);
1580 return;
1581 }
ed2abc7f
MC		 1582
1583 /*
1584 * When this is called for the in_login state, we only want to clean
67a61114
MC		 1585 * up the login task and connection. We do not need to block and set
1586 * the recovery state again
ed2abc7f 1587 */
67a61114
MC		 1588 if (flag == STOP_CONN_TERM)
1589 session->state = ISCSI_STATE_TERMINATE;
1590 else if (conn->stop_stage != STOP_CONN_RECOVER)
1591 session->state = ISCSI_STATE_IN_RECOVERY;
ed2abc7f
MC		 1592
1593 old_stop_stage = conn->stop_stage;
7996a778 1594 conn->stop_stage = flag;
67a61114
MC		 1595 conn->c_stage = ISCSI_CONN_STOPPED;
1596 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
7996a778
MC		 1597 spin_unlock_bh(&session->lock);
1598
1599 if (session->tt->suspend_conn_recv)
1600 session->tt->suspend_conn_recv(conn);
1601
1602 mutex_lock(&conn->xmitmutex);
7996a778
MC		 1603 /*
1604 * for connection level recovery we should not calculate
1605 * header digest. conn->hdr_size used for optimization
1606 * in hdr_extract() and will be re-negotiated at
1607 * set_param() time.
1608 */
1609 if (flag == STOP_CONN_RECOVER) {
1610 conn->hdrdgst_en = 0;
1611 conn->datadgst_en = 0;
656cffc9 1612 if (session->state == ISCSI_STATE_IN_RECOVERY &&
67a61114
MC		 1613 old_stop_stage != STOP_CONN_RECOVER) {
1614 debug_scsi("blocking session\n");
7996a778 1615 iscsi_block_session(session_to_cls(session));
67a61114 1616 }
7996a778 1617 }
656cffc9
MC		 1618
1619 session->tt->terminate_conn(conn);
1620 /*
1621 * flush queues.
1622 */
1623 spin_lock_bh(&session->lock);
1624 fail_all_commands(conn);
1625 flush_control_queues(session, conn);
1626 spin_unlock_bh(&session->lock);
1627
7996a778
MC		 1628 mutex_unlock(&conn->xmitmutex);
1629}
7996a778
MC		 1630
1631void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1632{
1633 struct iscsi_conn *conn = cls_conn->dd_data;
1634 struct iscsi_session *session = conn->session;
1635
1636 switch (flag) {
1637 case STOP_CONN_RECOVER:
1638 case STOP_CONN_TERM:
1639 iscsi_start_session_recovery(session, conn, flag);
8d2860b3 1640 break;
7996a778 1641 default:
be2df72e 1642 printk(KERN_ERR "iscsi: invalid stop flag %d\n", flag);
7996a778
MC		 1643 }
1644}
1645EXPORT_SYMBOL_GPL(iscsi_conn_stop);
1646
1647int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
1648 struct iscsi_cls_conn *cls_conn, int is_leading)
1649{
1650 struct iscsi_session *session = class_to_transport_session(cls_session);
1651 struct iscsi_conn *tmp = ERR_PTR(-EEXIST), *conn = cls_conn->dd_data;
1652
1653 /* lookup for existing connection */
1654 spin_lock_bh(&session->lock);
1655 list_for_each_entry(tmp, &session->connections, item) {
1656 if (tmp == conn) {
1657 if (conn->c_stage != ISCSI_CONN_STOPPED ||
1658 conn->stop_stage == STOP_CONN_TERM) {
be2df72e 1659 printk(KERN_ERR "iscsi: can't bind "
7996a778
MC		 1660 "non-stopped connection (%d:%d)\n",
1661 conn->c_stage, conn->stop_stage);
1662 spin_unlock_bh(&session->lock);
1663 return -EIO;
1664 }
1665 break;
1666 }
1667 }
1668 if (tmp != conn) {
1669 /* bind new iSCSI connection to session */
1670 conn->session = session;
1671 list_add(&conn->item, &session->connections);
1672 }
1673 spin_unlock_bh(&session->lock);
1674
1675 if (is_leading)
1676 session->leadconn = conn;
1677
1678 /*
1679 * Unblock xmitworker(), Login Phase will pass through.
1680 */
1681 clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1682 clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1683 return 0;
1684}
1685EXPORT_SYMBOL_GPL(iscsi_conn_bind);
1686
1687MODULE_AUTHOR("Mike Christie");
1688MODULE_DESCRIPTION("iSCSI library functions");
1689MODULE_LICENSE("GPL");
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