Merge gregkh@master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6
[linux-2.6.git] / drivers / scsi / libiscsi.c
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
40 struct iscsi_session *
41 class_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 }
46 EXPORT_SYMBOL_GPL(class_to_transport_session);
47
48 #define INVALID_SN_DELTA        0xffff
49
50 int
51 iscsi_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 }
68 EXPORT_SYMBOL_GPL(iscsi_check_assign_cmdsn);
69
70 void 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 }
100 EXPORT_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  */
109 static 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 }
176 EXPORT_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  */
187 static 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->state = ISCSI_TASK_COMPLETED;
193         ctask->sc = NULL;
194         list_del_init(&ctask->running);
195         __kfifo_put(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
196         sc->scsi_done(sc);
197 }
198
199 /**
200  * iscsi_cmd_rsp - SCSI Command Response processing
201  * @conn: iscsi connection
202  * @hdr: iscsi header
203  * @ctask: scsi command task
204  * @data: cmd data buffer
205  * @datalen: len of buffer
206  *
207  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
208  * then completes the command and task.
209  **/
210 static int iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
211                               struct iscsi_cmd_task *ctask, char *data,
212                               int datalen)
213 {
214         int rc;
215         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
216         struct iscsi_session *session = conn->session;
217         struct scsi_cmnd *sc = ctask->sc;
218
219         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
220         if (rc) {
221                 sc->result = DID_ERROR << 16;
222                 goto out;
223         }
224
225         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
226
227         sc->result = (DID_OK << 16) | rhdr->cmd_status;
228
229         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
230                 sc->result = DID_ERROR << 16;
231                 goto out;
232         }
233
234         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
235                 int senselen;
236
237                 if (datalen < 2) {
238 invalid_datalen:
239                         printk(KERN_ERR "iscsi: Got CHECK_CONDITION but "
240                                "invalid data buffer size of %d\n", datalen);
241                         sc->result = DID_BAD_TARGET << 16;
242                         goto out;
243                 }
244
245                 senselen = (data[0] << 8) | data[1];
246                 if (datalen < senselen)
247                         goto invalid_datalen;
248
249                 memcpy(sc->sense_buffer, data + 2,
250                        min(senselen, SCSI_SENSE_BUFFERSIZE));
251                 debug_scsi("copied %d bytes of sense\n",
252                            min(senselen, SCSI_SENSE_BUFFERSIZE));
253         }
254
255         if (sc->sc_data_direction == DMA_TO_DEVICE)
256                 goto out;
257
258         if (rhdr->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
259                 int res_count = be32_to_cpu(rhdr->residual_count);
260
261                 if (res_count > 0 && res_count <= sc->request_bufflen)
262                         sc->resid = res_count;
263                 else
264                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
265         } else if (rhdr->flags & ISCSI_FLAG_CMD_BIDI_UNDERFLOW)
266                 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
267         else if (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW)
268                 sc->resid = be32_to_cpu(rhdr->residual_count);
269
270 out:
271         debug_scsi("done [sc %lx res %d itt 0x%x]\n",
272                    (long)sc, sc->result, ctask->itt);
273         conn->scsirsp_pdus_cnt++;
274
275         iscsi_complete_command(conn->session, ctask);
276         return rc;
277 }
278
279 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
280 {
281         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
282
283         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
284         conn->tmfrsp_pdus_cnt++;
285
286         if (conn->tmabort_state != TMABORT_INITIAL)
287                 return;
288
289         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
290                 conn->tmabort_state = TMABORT_SUCCESS;
291         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
292                 conn->tmabort_state = TMABORT_NOT_FOUND;
293         else
294                 conn->tmabort_state = TMABORT_FAILED;
295         wake_up(&conn->ehwait);
296 }
297
298 /**
299  * __iscsi_complete_pdu - complete pdu
300  * @conn: iscsi conn
301  * @hdr: iscsi header
302  * @data: data buffer
303  * @datalen: len of data buffer
304  *
305  * Completes pdu processing by freeing any resources allocated at
306  * queuecommand or send generic. session lock must be held and verify
307  * itt must have been called.
308  */
309 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
310                          char *data, int datalen)
311 {
312         struct iscsi_session *session = conn->session;
313         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
314         struct iscsi_cmd_task *ctask;
315         struct iscsi_mgmt_task *mtask;
316         uint32_t itt;
317
318         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG))
319                 itt = hdr->itt & ISCSI_ITT_MASK;
320         else
321                 itt = hdr->itt;
322
323         if (itt < session->cmds_max) {
324                 ctask = session->cmds[itt];
325
326                 debug_scsi("cmdrsp [op 0x%x cid %d itt 0x%x len %d]\n",
327                            opcode, conn->id, ctask->itt, datalen);
328
329                 switch(opcode) {
330                 case ISCSI_OP_SCSI_CMD_RSP:
331                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
332                         rc = iscsi_scsi_cmd_rsp(conn, hdr, ctask, data,
333                                                 datalen);
334                         break;
335                 case ISCSI_OP_SCSI_DATA_IN:
336                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
337                         if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
338                                 conn->scsirsp_pdus_cnt++;
339                                 iscsi_complete_command(session, ctask);
340                         }
341                         break;
342                 case ISCSI_OP_R2T:
343                         /* LLD handles this for now */
344                         break;
345                 default:
346                         rc = ISCSI_ERR_BAD_OPCODE;
347                         break;
348                 }
349         } else if (itt >= ISCSI_MGMT_ITT_OFFSET &&
350                    itt < ISCSI_MGMT_ITT_OFFSET + session->mgmtpool_max) {
351                 mtask = session->mgmt_cmds[itt - ISCSI_MGMT_ITT_OFFSET];
352
353                 debug_scsi("immrsp [op 0x%x cid %d itt 0x%x len %d]\n",
354                            opcode, conn->id, mtask->itt, datalen);
355
356                 rc = iscsi_check_assign_cmdsn(session,
357                                               (struct iscsi_nopin*)hdr);
358                 if (rc)
359                         goto done;
360
361                 switch(opcode) {
362                 case ISCSI_OP_LOGOUT_RSP:
363                         if (datalen) {
364                                 rc = ISCSI_ERR_PROTO;
365                                 break;
366                         }
367                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
368                         /* fall through */
369                 case ISCSI_OP_LOGIN_RSP:
370                 case ISCSI_OP_TEXT_RSP:
371                         /*
372                          * login related PDU's exp_statsn is handled in
373                          * userspace
374                          */
375                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
376                                 rc = ISCSI_ERR_CONN_FAILED;
377                         list_del(&mtask->running);
378                         if (conn->login_mtask != mtask)
379                                 __kfifo_put(session->mgmtpool.queue,
380                                             (void*)&mtask, sizeof(void*));
381                         break;
382                 case ISCSI_OP_SCSI_TMFUNC_RSP:
383                         if (datalen) {
384                                 rc = ISCSI_ERR_PROTO;
385                                 break;
386                         }
387
388                         iscsi_tmf_rsp(conn, hdr);
389                         break;
390                 case ISCSI_OP_NOOP_IN:
391                         if (hdr->ttt != ISCSI_RESERVED_TAG || datalen) {
392                                 rc = ISCSI_ERR_PROTO;
393                                 break;
394                         }
395                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
396
397                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
398                                 rc = ISCSI_ERR_CONN_FAILED;
399                         list_del(&mtask->running);
400                         if (conn->login_mtask != mtask)
401                                 __kfifo_put(session->mgmtpool.queue,
402                                             (void*)&mtask, sizeof(void*));
403                         break;
404                 default:
405                         rc = ISCSI_ERR_BAD_OPCODE;
406                         break;
407                 }
408         } else if (itt == ISCSI_RESERVED_TAG) {
409                 switch(opcode) {
410                 case ISCSI_OP_NOOP_IN:
411                         if (datalen) {
412                                 rc = ISCSI_ERR_PROTO;
413                                 break;
414                         }
415
416                         rc = iscsi_check_assign_cmdsn(session,
417                                                  (struct iscsi_nopin*)hdr);
418                         if (rc)
419                                 break;
420
421                         if (hdr->ttt == ISCSI_RESERVED_TAG)
422                                 break;
423
424                         if (iscsi_recv_pdu(conn->cls_conn, hdr, NULL, 0))
425                                 rc = ISCSI_ERR_CONN_FAILED;
426                         break;
427                 case ISCSI_OP_REJECT:
428                         /* we need sth like iscsi_reject_rsp()*/
429                 case ISCSI_OP_ASYNC_EVENT:
430                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
431                         /* we need sth like iscsi_async_event_rsp() */
432                         rc = ISCSI_ERR_BAD_OPCODE;
433                         break;
434                 default:
435                         rc = ISCSI_ERR_BAD_OPCODE;
436                         break;
437                 }
438         } else
439                 rc = ISCSI_ERR_BAD_ITT;
440
441 done:
442         return rc;
443 }
444 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
445
446 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
447                        char *data, int datalen)
448 {
449         int rc;
450
451         spin_lock(&conn->session->lock);
452         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
453         spin_unlock(&conn->session->lock);
454         return rc;
455 }
456 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
457
458 /* verify itt (itt encoding: age+cid+itt) */
459 int iscsi_verify_itt(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
460                      uint32_t *ret_itt)
461 {
462         struct iscsi_session *session = conn->session;
463         struct iscsi_cmd_task *ctask;
464         uint32_t itt;
465
466         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
467                 if ((hdr->itt & ISCSI_AGE_MASK) !=
468                     (session->age << ISCSI_AGE_SHIFT)) {
469                         printk(KERN_ERR "iscsi: received itt %x expected "
470                                 "session age (%x)\n", hdr->itt,
471                                 session->age & ISCSI_AGE_MASK);
472                         return ISCSI_ERR_BAD_ITT;
473                 }
474
475                 if ((hdr->itt & ISCSI_CID_MASK) !=
476                     (conn->id << ISCSI_CID_SHIFT)) {
477                         printk(KERN_ERR "iscsi: received itt %x, expected "
478                                 "CID (%x)\n", hdr->itt, conn->id);
479                         return ISCSI_ERR_BAD_ITT;
480                 }
481                 itt = hdr->itt & ISCSI_ITT_MASK;
482         } else
483                 itt = hdr->itt;
484
485         if (itt < session->cmds_max) {
486                 ctask = session->cmds[itt];
487
488                 if (!ctask->sc) {
489                         printk(KERN_INFO "iscsi: dropping ctask with "
490                                "itt 0x%x\n", ctask->itt);
491                         /* force drop */
492                         return ISCSI_ERR_NO_SCSI_CMD;
493                 }
494
495                 if (ctask->sc->SCp.phase != session->age) {
496                         printk(KERN_ERR "iscsi: ctask's session age %d, "
497                                 "expected %d\n", ctask->sc->SCp.phase,
498                                 session->age);
499                         return ISCSI_ERR_SESSION_FAILED;
500                 }
501         }
502
503         *ret_itt = itt;
504         return 0;
505 }
506 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
507
508 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
509 {
510         struct iscsi_session *session = conn->session;
511         unsigned long flags;
512
513         spin_lock_irqsave(&session->lock, flags);
514         if (session->state == ISCSI_STATE_FAILED) {
515                 spin_unlock_irqrestore(&session->lock, flags);
516                 return;
517         }
518
519         if (conn->stop_stage == 0)
520                 session->state = ISCSI_STATE_FAILED;
521         spin_unlock_irqrestore(&session->lock, flags);
522         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
523         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
524         iscsi_conn_error(conn->cls_conn, err);
525 }
526 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
527
528 /**
529  * iscsi_data_xmit - xmit any command into the scheduled connection
530  * @conn: iscsi connection
531  *
532  * Notes:
533  *      The function can return -EAGAIN in which case the caller must
534  *      re-schedule it again later or recover. '0' return code means
535  *      successful xmit.
536  **/
537 static int iscsi_data_xmit(struct iscsi_conn *conn)
538 {
539         struct iscsi_transport *tt;
540         int rc = 0;
541
542         if (unlikely(conn->suspend_tx)) {
543                 debug_scsi("conn %d Tx suspended!\n", conn->id);
544                 return -ENODATA;
545         }
546         tt = conn->session->tt;
547
548         /*
549          * Transmit in the following order:
550          *
551          * 1) un-finished xmit (ctask or mtask)
552          * 2) immediate control PDUs
553          * 3) write data
554          * 4) SCSI commands
555          * 5) non-immediate control PDUs
556          *
557          * No need to lock around __kfifo_get as long as
558          * there's one producer and one consumer.
559          */
560
561         BUG_ON(conn->ctask && conn->mtask);
562
563         if (conn->ctask) {
564                 rc = tt->xmit_cmd_task(conn, conn->ctask);
565                 if (rc)
566                         goto again;
567                 /* done with this in-progress ctask */
568                 conn->ctask = NULL;
569         }
570         if (conn->mtask) {
571                 rc = tt->xmit_mgmt_task(conn, conn->mtask);
572                 if (rc)
573                         goto again;
574                 /* done with this in-progress mtask */
575                 conn->mtask = NULL;
576         }
577
578         /* process immediate first */
579         if (unlikely(__kfifo_len(conn->immqueue))) {
580                 while (__kfifo_get(conn->immqueue, (void*)&conn->mtask,
581                                    sizeof(void*))) {
582                         spin_lock_bh(&conn->session->lock);
583                         list_add_tail(&conn->mtask->running,
584                                       &conn->mgmt_run_list);
585                         spin_unlock_bh(&conn->session->lock);
586                         rc = tt->xmit_mgmt_task(conn, conn->mtask);
587                         if (rc)
588                                 goto again;
589                 }
590                 /* done with this mtask */
591                 conn->mtask = NULL;
592         }
593
594         /* process command queue */
595         spin_lock_bh(&conn->session->lock);
596         while (!list_empty(&conn->xmitqueue)) {
597                 /*
598                  * iscsi tcp may readd the task to the xmitqueue to send
599                  * write data
600                  */
601                 conn->ctask = list_entry(conn->xmitqueue.next,
602                                          struct iscsi_cmd_task, running);
603                 conn->ctask->state = ISCSI_TASK_RUNNING;
604                 list_move_tail(conn->xmitqueue.next, &conn->run_list);
605                 spin_unlock_bh(&conn->session->lock);
606
607                 rc = tt->xmit_cmd_task(conn, conn->ctask);
608                 if (rc)
609                         goto again;
610                 spin_lock_bh(&conn->session->lock);
611         }
612         spin_unlock_bh(&conn->session->lock);
613         /* done with this ctask */
614         conn->ctask = NULL;
615
616         /* process the rest control plane PDUs, if any */
617         if (unlikely(__kfifo_len(conn->mgmtqueue))) {
618                 while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask,
619                                    sizeof(void*))) {
620                         spin_lock_bh(&conn->session->lock);
621                         list_add_tail(&conn->mtask->running,
622                                       &conn->mgmt_run_list);
623                         spin_unlock_bh(&conn->session->lock);
624                         rc = tt->xmit_mgmt_task(conn, conn->mtask);
625                         if (rc)
626                                 goto again;
627                 }
628                 /* done with this mtask */
629                 conn->mtask = NULL;
630         }
631
632         return -ENODATA;
633
634 again:
635         if (unlikely(conn->suspend_tx))
636                 return -ENODATA;
637
638         return rc;
639 }
640
641 static void iscsi_xmitworker(void *data)
642 {
643         struct iscsi_conn *conn = data;
644         int rc;
645         /*
646          * serialize Xmit worker on a per-connection basis.
647          */
648         mutex_lock(&conn->xmitmutex);
649         do {
650                 rc = iscsi_data_xmit(conn);
651         } while (rc >= 0 || rc == -EAGAIN);
652         mutex_unlock(&conn->xmitmutex);
653 }
654
655 enum {
656         FAILURE_BAD_HOST = 1,
657         FAILURE_SESSION_FAILED,
658         FAILURE_SESSION_FREED,
659         FAILURE_WINDOW_CLOSED,
660         FAILURE_SESSION_TERMINATE,
661         FAILURE_SESSION_IN_RECOVERY,
662         FAILURE_SESSION_RECOVERY_TIMEOUT,
663 };
664
665 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
666 {
667         struct Scsi_Host *host;
668         int reason = 0;
669         struct iscsi_session *session;
670         struct iscsi_conn *conn;
671         struct iscsi_cmd_task *ctask = NULL;
672
673         sc->scsi_done = done;
674         sc->result = 0;
675
676         host = sc->device->host;
677         session = iscsi_hostdata(host->hostdata);
678
679         spin_lock(&session->lock);
680
681         /*
682          * ISCSI_STATE_FAILED is a temp. state. The recovery
683          * code will decide what is best to do with command queued
684          * during this time
685          */
686         if (session->state != ISCSI_STATE_LOGGED_IN &&
687             session->state != ISCSI_STATE_FAILED) {
688                 /*
689                  * to handle the race between when we set the recovery state
690                  * and block the session we requeue here (commands could
691                  * be entering our queuecommand while a block is starting
692                  * up because the block code is not locked)
693                  */
694                 if (session->state == ISCSI_STATE_IN_RECOVERY) {
695                         reason = FAILURE_SESSION_IN_RECOVERY;
696                         goto reject;
697                 }
698
699                 if (session->state == ISCSI_STATE_RECOVERY_FAILED)
700                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
701                 else if (session->state == ISCSI_STATE_TERMINATE)
702                         reason = FAILURE_SESSION_TERMINATE;
703                 else
704                         reason = FAILURE_SESSION_FREED;
705                 goto fault;
706         }
707
708         /*
709          * Check for iSCSI window and take care of CmdSN wrap-around
710          */
711         if ((int)(session->max_cmdsn - session->cmdsn) < 0) {
712                 reason = FAILURE_WINDOW_CLOSED;
713                 goto reject;
714         }
715
716         conn = session->leadconn;
717
718         __kfifo_get(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
719         sc->SCp.phase = session->age;
720         sc->SCp.ptr = (char *)ctask;
721
722         ctask->state = ISCSI_TASK_PENDING;
723         ctask->mtask = NULL;
724         ctask->conn = conn;
725         ctask->sc = sc;
726         INIT_LIST_HEAD(&ctask->running);
727         ctask->total_length = sc->request_bufflen;
728         iscsi_prep_scsi_cmd_pdu(ctask);
729
730         session->tt->init_cmd_task(ctask);
731
732         list_add_tail(&ctask->running, &conn->xmitqueue);
733         debug_scsi(
734                "ctask enq [%s cid %d sc %lx itt 0x%x len %d cmdsn %d win %d]\n",
735                 sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
736                 conn->id, (long)sc, ctask->itt, sc->request_bufflen,
737                 session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
738         spin_unlock(&session->lock);
739
740         scsi_queue_work(host, &conn->xmitwork);
741         return 0;
742
743 reject:
744         spin_unlock(&session->lock);
745         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
746         return SCSI_MLQUEUE_HOST_BUSY;
747
748 fault:
749         spin_unlock(&session->lock);
750         printk(KERN_ERR "iscsi: cmd 0x%x is not queued (%d)\n",
751                sc->cmnd[0], reason);
752         sc->result = (DID_NO_CONNECT << 16);
753         sc->resid = sc->request_bufflen;
754         sc->scsi_done(sc);
755         return 0;
756 }
757 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
758
759 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
760 {
761         if (depth > ISCSI_MAX_CMD_PER_LUN)
762                 depth = ISCSI_MAX_CMD_PER_LUN;
763         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
764         return sdev->queue_depth;
765 }
766 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
767
768 static int
769 iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
770                         char *data, uint32_t data_size)
771 {
772         struct iscsi_session *session = conn->session;
773         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
774         struct iscsi_mgmt_task *mtask;
775
776         spin_lock_bh(&session->lock);
777         if (session->state == ISCSI_STATE_TERMINATE) {
778                 spin_unlock_bh(&session->lock);
779                 return -EPERM;
780         }
781         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
782             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
783                 /*
784                  * Login and Text are sent serially, in
785                  * request-followed-by-response sequence.
786                  * Same mtask can be used. Same ITT must be used.
787                  * Note that login_mtask is preallocated at conn_create().
788                  */
789                 mtask = conn->login_mtask;
790         else {
791                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
792                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
793
794                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
795                 if (!__kfifo_get(session->mgmtpool.queue,
796                                  (void*)&mtask, sizeof(void*))) {
797                         spin_unlock_bh(&session->lock);
798                         return -ENOSPC;
799                 }
800         }
801
802         /*
803          * pre-format CmdSN for outgoing PDU.
804          */
805         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
806                 hdr->itt = mtask->itt | (conn->id << ISCSI_CID_SHIFT) |
807                            (session->age << ISCSI_AGE_SHIFT);
808                 nop->cmdsn = cpu_to_be32(session->cmdsn);
809                 if (conn->c_stage == ISCSI_CONN_STARTED &&
810                     !(hdr->opcode & ISCSI_OP_IMMEDIATE))
811                         session->cmdsn++;
812         } else
813                 /* do not advance CmdSN */
814                 nop->cmdsn = cpu_to_be32(session->cmdsn);
815
816         if (data_size) {
817                 memcpy(mtask->data, data, data_size);
818                 mtask->data_count = data_size;
819         } else
820                 mtask->data_count = 0;
821
822         INIT_LIST_HEAD(&mtask->running);
823         memcpy(mtask->hdr, hdr, sizeof(struct iscsi_hdr));
824         if (session->tt->init_mgmt_task)
825                 session->tt->init_mgmt_task(conn, mtask, data, data_size);
826         spin_unlock_bh(&session->lock);
827
828         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
829                    hdr->opcode, hdr->itt, data_size);
830
831         /*
832          * since send_pdu() could be called at least from two contexts,
833          * we need to serialize __kfifo_put, so we don't have to take
834          * additional lock on fast data-path
835          */
836         if (hdr->opcode & ISCSI_OP_IMMEDIATE)
837                 __kfifo_put(conn->immqueue, (void*)&mtask, sizeof(void*));
838         else
839                 __kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*));
840
841         scsi_queue_work(session->host, &conn->xmitwork);
842         return 0;
843 }
844
845 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
846                         char *data, uint32_t data_size)
847 {
848         struct iscsi_conn *conn = cls_conn->dd_data;
849         int rc;
850
851         mutex_lock(&conn->xmitmutex);
852         rc = iscsi_conn_send_generic(conn, hdr, data, data_size);
853         mutex_unlock(&conn->xmitmutex);
854
855         return rc;
856 }
857 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
858
859 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
860 {
861         struct iscsi_session *session = class_to_transport_session(cls_session);
862         struct iscsi_conn *conn = session->leadconn;
863
864         spin_lock_bh(&session->lock);
865         if (session->state != ISCSI_STATE_LOGGED_IN) {
866                 session->state = ISCSI_STATE_RECOVERY_FAILED;
867                 if (conn)
868                         wake_up(&conn->ehwait);
869         }
870         spin_unlock_bh(&session->lock);
871 }
872 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
873
874 int iscsi_eh_host_reset(struct scsi_cmnd *sc)
875 {
876         struct Scsi_Host *host = sc->device->host;
877         struct iscsi_session *session = iscsi_hostdata(host->hostdata);
878         struct iscsi_conn *conn = session->leadconn;
879         int fail_session = 0;
880
881         spin_lock_bh(&session->lock);
882         if (session->state == ISCSI_STATE_TERMINATE) {
883 failed:
884                 debug_scsi("failing host reset: session terminated "
885                            "[CID %d age %d]", conn->id, session->age);
886                 spin_unlock_bh(&session->lock);
887                 return FAILED;
888         }
889
890         if (sc->SCp.phase == session->age) {
891                 debug_scsi("failing connection CID %d due to SCSI host reset",
892                            conn->id);
893                 fail_session = 1;
894         }
895         spin_unlock_bh(&session->lock);
896
897         /*
898          * we drop the lock here but the leadconn cannot be destoyed while
899          * we are in the scsi eh
900          */
901         if (fail_session)
902                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
903
904         debug_scsi("iscsi_eh_host_reset wait for relogin\n");
905         wait_event_interruptible(conn->ehwait,
906                                  session->state == ISCSI_STATE_TERMINATE ||
907                                  session->state == ISCSI_STATE_LOGGED_IN ||
908                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
909         if (signal_pending(current))
910                 flush_signals(current);
911
912         spin_lock_bh(&session->lock);
913         if (session->state == ISCSI_STATE_LOGGED_IN)
914                 printk(KERN_INFO "iscsi: host reset succeeded\n");
915         else
916                 goto failed;
917         spin_unlock_bh(&session->lock);
918
919         return SUCCESS;
920 }
921 EXPORT_SYMBOL_GPL(iscsi_eh_host_reset);
922
923 static void iscsi_tmabort_timedout(unsigned long data)
924 {
925         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)data;
926         struct iscsi_conn *conn = ctask->conn;
927         struct iscsi_session *session = conn->session;
928
929         spin_lock(&session->lock);
930         if (conn->tmabort_state == TMABORT_INITIAL) {
931                 conn->tmabort_state = TMABORT_TIMEDOUT;
932                 debug_scsi("tmabort timedout [sc %p itt 0x%x]\n",
933                         ctask->sc, ctask->itt);
934                 /* unblock eh_abort() */
935                 wake_up(&conn->ehwait);
936         }
937         spin_unlock(&session->lock);
938 }
939
940 /* must be called with the mutex lock */
941 static int iscsi_exec_abort_task(struct scsi_cmnd *sc,
942                                  struct iscsi_cmd_task *ctask)
943 {
944         struct iscsi_conn *conn = ctask->conn;
945         struct iscsi_session *session = conn->session;
946         struct iscsi_tm *hdr = &conn->tmhdr;
947         int rc;
948
949         /*
950          * ctask timed out but session is OK requests must be serialized.
951          */
952         memset(hdr, 0, sizeof(struct iscsi_tm));
953         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
954         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK;
955         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
956         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
957         hdr->rtt = ctask->hdr->itt;
958         hdr->refcmdsn = ctask->hdr->cmdsn;
959
960         rc = iscsi_conn_send_generic(conn, (struct iscsi_hdr *)hdr,
961                                      NULL, 0);
962         if (rc) {
963                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
964                 debug_scsi("abort sent failure [itt 0x%x] %d", ctask->itt, rc);
965                 return rc;
966         }
967
968         debug_scsi("abort sent [itt 0x%x]\n", ctask->itt);
969
970         spin_lock_bh(&session->lock);
971         ctask->mtask = (struct iscsi_mgmt_task *)
972                         session->mgmt_cmds[(hdr->itt & ISCSI_ITT_MASK) -
973                                         ISCSI_MGMT_ITT_OFFSET];
974
975         if (conn->tmabort_state == TMABORT_INITIAL) {
976                 conn->tmfcmd_pdus_cnt++;
977                 conn->tmabort_timer.expires = 10*HZ + jiffies;
978                 conn->tmabort_timer.function = iscsi_tmabort_timedout;
979                 conn->tmabort_timer.data = (unsigned long)ctask;
980                 add_timer(&conn->tmabort_timer);
981                 debug_scsi("abort set timeout [itt 0x%x]", ctask->itt);
982         }
983         spin_unlock_bh(&session->lock);
984         mutex_unlock(&conn->xmitmutex);
985
986         /*
987          * block eh thread until:
988          *
989          * 1) abort response
990          * 2) abort timeout
991          * 3) session is terminated or restarted or userspace has
992          * given up on recovery
993          */
994         wait_event_interruptible(conn->ehwait,
995                                  sc->SCp.phase != session->age ||
996                                  session->state != ISCSI_STATE_LOGGED_IN ||
997                                  conn->tmabort_state != TMABORT_INITIAL);
998         if (signal_pending(current))
999                 flush_signals(current);
1000         del_timer_sync(&conn->tmabort_timer);
1001
1002         mutex_lock(&conn->xmitmutex);
1003         return 0;
1004 }
1005
1006 /*
1007  * xmit mutex and session lock must be held
1008  */
1009 static struct iscsi_mgmt_task *
1010 iscsi_remove_mgmt_task(struct kfifo *fifo, uint32_t itt)
1011 {
1012         int i, nr_tasks = __kfifo_len(fifo) / sizeof(void*);
1013         struct iscsi_mgmt_task *task;
1014
1015         debug_scsi("searching %d tasks\n", nr_tasks);
1016
1017         for (i = 0; i < nr_tasks; i++) {
1018                 __kfifo_get(fifo, (void*)&task, sizeof(void*));
1019                 debug_scsi("check task %u\n", task->itt);
1020
1021                 if (task->itt == itt) {
1022                         debug_scsi("matched task\n");
1023                         return task;
1024                 }
1025
1026                 __kfifo_put(fifo, (void*)&task, sizeof(void*));
1027         }
1028         return NULL;
1029 }
1030
1031 static int iscsi_ctask_mtask_cleanup(struct iscsi_cmd_task *ctask)
1032 {
1033         struct iscsi_conn *conn = ctask->conn;
1034         struct iscsi_session *session = conn->session;
1035
1036         if (!ctask->mtask)
1037                 return -EINVAL;
1038
1039         if (!iscsi_remove_mgmt_task(conn->immqueue, ctask->mtask->itt))
1040                 list_del(&ctask->mtask->running);
1041         __kfifo_put(session->mgmtpool.queue, (void*)&ctask->mtask,
1042                     sizeof(void*));
1043         ctask->mtask = NULL;
1044         return 0;
1045 }
1046
1047 /*
1048  * session lock and xmitmutex must be held
1049  */
1050 static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1051                          int err)
1052 {
1053         struct scsi_cmnd *sc;
1054
1055         sc = ctask->sc;
1056         if (!sc)
1057                 return;
1058
1059         conn->session->tt->cleanup_cmd_task(conn, ctask);
1060         iscsi_ctask_mtask_cleanup(ctask);
1061
1062         sc->result = err;
1063         sc->resid = sc->request_bufflen;
1064         iscsi_complete_command(conn->session, ctask);
1065 }
1066
1067 int iscsi_eh_abort(struct scsi_cmnd *sc)
1068 {
1069         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
1070         struct iscsi_conn *conn = ctask->conn;
1071         struct iscsi_session *session = conn->session;
1072         int rc;
1073
1074         conn->eh_abort_cnt++;
1075         debug_scsi("aborting [sc %p itt 0x%x]\n", sc, ctask->itt);
1076
1077         mutex_lock(&conn->xmitmutex);
1078         spin_lock_bh(&session->lock);
1079
1080         /*
1081          * If we are not logged in or we have started a new session
1082          * then let the host reset code handle this
1083          */
1084         if (session->state != ISCSI_STATE_LOGGED_IN ||
1085             sc->SCp.phase != session->age)
1086                 goto failed;
1087
1088         /* ctask completed before time out */
1089         if (!ctask->sc) {
1090                 spin_unlock_bh(&session->lock);
1091                 debug_scsi("sc completed while abort in progress\n");
1092                 goto success_rel_mutex;
1093         }
1094
1095         /* what should we do here ? */
1096         if (conn->ctask == ctask) {
1097                 printk(KERN_INFO "iscsi: sc %p itt 0x%x partially sent. "
1098                        "Failing abort\n", sc, ctask->itt);
1099                 goto failed;
1100         }
1101
1102         if (ctask->state == ISCSI_TASK_PENDING)
1103                 goto success_cleanup;
1104
1105         conn->tmabort_state = TMABORT_INITIAL;
1106
1107         spin_unlock_bh(&session->lock);
1108         rc = iscsi_exec_abort_task(sc, ctask);
1109         spin_lock_bh(&session->lock);
1110
1111         if (rc || sc->SCp.phase != session->age ||
1112             session->state != ISCSI_STATE_LOGGED_IN)
1113                 goto failed;
1114         iscsi_ctask_mtask_cleanup(ctask);
1115
1116         switch (conn->tmabort_state) {
1117         case TMABORT_SUCCESS:
1118                 goto success_cleanup;
1119         case TMABORT_NOT_FOUND:
1120                 if (!ctask->sc) {
1121                         /* ctask completed before tmf abort response */
1122                         spin_unlock_bh(&session->lock);
1123                         debug_scsi("sc completed while abort in progress\n");
1124                         goto success_rel_mutex;
1125                 }
1126                 /* fall through */
1127         default:
1128                 /* timedout or failed */
1129                 spin_unlock_bh(&session->lock);
1130                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1131                 spin_lock_bh(&session->lock);
1132                 goto failed;
1133         }
1134
1135 success_cleanup:
1136         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1137         spin_unlock_bh(&session->lock);
1138
1139         /*
1140          * clean up task if aborted. we have the xmitmutex so grab
1141          * the recv lock as a writer
1142          */
1143         write_lock_bh(conn->recv_lock);
1144         spin_lock(&session->lock);
1145         fail_command(conn, ctask, DID_ABORT << 16);
1146         spin_unlock(&session->lock);
1147         write_unlock_bh(conn->recv_lock);
1148
1149 success_rel_mutex:
1150         mutex_unlock(&conn->xmitmutex);
1151         return SUCCESS;
1152
1153 failed:
1154         spin_unlock_bh(&session->lock);
1155         mutex_unlock(&conn->xmitmutex);
1156
1157         debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1158         return FAILED;
1159 }
1160 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1161
1162 int
1163 iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
1164 {
1165         int i;
1166
1167         *items = kmalloc(max * sizeof(void*), GFP_KERNEL);
1168         if (*items == NULL)
1169                 return -ENOMEM;
1170
1171         q->max = max;
1172         q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL);
1173         if (q->pool == NULL) {
1174                 kfree(*items);
1175                 return -ENOMEM;
1176         }
1177
1178         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1179                               GFP_KERNEL, NULL);
1180         if (q->queue == ERR_PTR(-ENOMEM)) {
1181                 kfree(q->pool);
1182                 kfree(*items);
1183                 return -ENOMEM;
1184         }
1185
1186         for (i = 0; i < max; i++) {
1187                 q->pool[i] = kmalloc(item_size, GFP_KERNEL);
1188                 if (q->pool[i] == NULL) {
1189                         int j;
1190
1191                         for (j = 0; j < i; j++)
1192                                 kfree(q->pool[j]);
1193
1194                         kfifo_free(q->queue);
1195                         kfree(q->pool);
1196                         kfree(*items);
1197                         return -ENOMEM;
1198                 }
1199                 memset(q->pool[i], 0, item_size);
1200                 (*items)[i] = q->pool[i];
1201                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1202         }
1203         return 0;
1204 }
1205 EXPORT_SYMBOL_GPL(iscsi_pool_init);
1206
1207 void iscsi_pool_free(struct iscsi_queue *q, void **items)
1208 {
1209         int i;
1210
1211         for (i = 0; i < q->max; i++)
1212                 kfree(items[i]);
1213         kfree(q->pool);
1214         kfree(items);
1215 }
1216 EXPORT_SYMBOL_GPL(iscsi_pool_free);
1217
1218 /*
1219  * iSCSI Session's hostdata organization:
1220  *
1221  *    *------------------* <== hostdata_session(host->hostdata)
1222  *    | ptr to class sess|
1223  *    |------------------| <== iscsi_hostdata(host->hostdata)
1224  *    | iscsi_session    |
1225  *    *------------------*
1226  */
1227
1228 #define hostdata_privsize(_sz)  (sizeof(unsigned long) + _sz + \
1229                                  _sz % sizeof(unsigned long))
1230
1231 #define hostdata_session(_hostdata) (iscsi_ptr(*(unsigned long *)_hostdata))
1232
1233 /**
1234  * iscsi_session_setup - create iscsi cls session and host and session
1235  * @scsit: scsi transport template
1236  * @iscsit: iscsi transport template
1237  * @initial_cmdsn: initial CmdSN
1238  * @hostno: host no allocated
1239  *
1240  * This can be used by software iscsi_transports that allocate
1241  * a session per scsi host.
1242  **/
1243 struct iscsi_cls_session *
1244 iscsi_session_setup(struct iscsi_transport *iscsit,
1245                     struct scsi_transport_template *scsit,
1246                     int cmd_task_size, int mgmt_task_size,
1247                     uint32_t initial_cmdsn, uint32_t *hostno)
1248 {
1249         struct Scsi_Host *shost;
1250         struct iscsi_session *session;
1251         struct iscsi_cls_session *cls_session;
1252         int cmd_i;
1253
1254         shost = scsi_host_alloc(iscsit->host_template,
1255                                 hostdata_privsize(sizeof(*session)));
1256         if (!shost)
1257                 return NULL;
1258
1259         shost->max_id = 1;
1260         shost->max_channel = 0;
1261         shost->max_lun = iscsit->max_lun;
1262         shost->max_cmd_len = iscsit->max_cmd_len;
1263         shost->transportt = scsit;
1264         shost->transportt->create_work_queue = 1;
1265         *hostno = shost->host_no;
1266
1267         session = iscsi_hostdata(shost->hostdata);
1268         memset(session, 0, sizeof(struct iscsi_session));
1269         session->host = shost;
1270         session->state = ISCSI_STATE_FREE;
1271         session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
1272         session->cmds_max = ISCSI_XMIT_CMDS_MAX;
1273         session->cmdsn = initial_cmdsn;
1274         session->exp_cmdsn = initial_cmdsn + 1;
1275         session->max_cmdsn = initial_cmdsn + 1;
1276         session->max_r2t = 1;
1277         session->tt = iscsit;
1278
1279         /* initialize SCSI PDU commands pool */
1280         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
1281                             (void***)&session->cmds,
1282                             cmd_task_size + sizeof(struct iscsi_cmd_task)))
1283                 goto cmdpool_alloc_fail;
1284
1285         /* pre-format cmds pool with ITT */
1286         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1287                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1288
1289                 if (cmd_task_size)
1290                         ctask->dd_data = &ctask[1];
1291                 ctask->itt = cmd_i;
1292                 INIT_LIST_HEAD(&ctask->running);
1293         }
1294
1295         spin_lock_init(&session->lock);
1296         INIT_LIST_HEAD(&session->connections);
1297
1298         /* initialize immediate command pool */
1299         if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max,
1300                            (void***)&session->mgmt_cmds,
1301                            mgmt_task_size + sizeof(struct iscsi_mgmt_task)))
1302                 goto mgmtpool_alloc_fail;
1303
1304
1305         /* pre-format immediate cmds pool with ITT */
1306         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
1307                 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
1308
1309                 if (mgmt_task_size)
1310                         mtask->dd_data = &mtask[1];
1311                 mtask->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i;
1312                 INIT_LIST_HEAD(&mtask->running);
1313         }
1314
1315         if (scsi_add_host(shost, NULL))
1316                 goto add_host_fail;
1317
1318         if (!try_module_get(iscsit->owner))
1319                 goto cls_session_fail;
1320
1321         cls_session = iscsi_create_session(shost, iscsit, 0);
1322         if (!cls_session)
1323                 goto module_put;
1324         *(unsigned long*)shost->hostdata = (unsigned long)cls_session;
1325
1326         return cls_session;
1327
1328 module_put:
1329         module_put(iscsit->owner);
1330 cls_session_fail:
1331         scsi_remove_host(shost);
1332 add_host_fail:
1333         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1334 mgmtpool_alloc_fail:
1335         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1336 cmdpool_alloc_fail:
1337         scsi_host_put(shost);
1338         return NULL;
1339 }
1340 EXPORT_SYMBOL_GPL(iscsi_session_setup);
1341
1342 /**
1343  * iscsi_session_teardown - destroy session, host, and cls_session
1344  * shost: scsi host
1345  *
1346  * This can be used by software iscsi_transports that allocate
1347  * a session per scsi host.
1348  **/
1349 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
1350 {
1351         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1352         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1353         struct module *owner = cls_session->transport->owner;
1354
1355         scsi_remove_host(shost);
1356
1357         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1358         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1359
1360         kfree(session->targetname);
1361
1362         iscsi_destroy_session(cls_session);
1363         scsi_host_put(shost);
1364         module_put(owner);
1365 }
1366 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
1367
1368 /**
1369  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
1370  * @cls_session: iscsi_cls_session
1371  * @conn_idx: cid
1372  **/
1373 struct iscsi_cls_conn *
1374 iscsi_conn_setup(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1375 {
1376         struct iscsi_session *session = class_to_transport_session(cls_session);
1377         struct iscsi_conn *conn;
1378         struct iscsi_cls_conn *cls_conn;
1379         char *data;
1380
1381         cls_conn = iscsi_create_conn(cls_session, conn_idx);
1382         if (!cls_conn)
1383                 return NULL;
1384         conn = cls_conn->dd_data;
1385         memset(conn, 0, sizeof(*conn));
1386
1387         conn->session = session;
1388         conn->cls_conn = cls_conn;
1389         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
1390         conn->id = conn_idx;
1391         conn->exp_statsn = 0;
1392         conn->tmabort_state = TMABORT_INITIAL;
1393         INIT_LIST_HEAD(&conn->run_list);
1394         INIT_LIST_HEAD(&conn->mgmt_run_list);
1395         INIT_LIST_HEAD(&conn->xmitqueue);
1396
1397         /* initialize general immediate & non-immediate PDU commands queue */
1398         conn->immqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
1399                                         GFP_KERNEL, NULL);
1400         if (conn->immqueue == ERR_PTR(-ENOMEM))
1401                 goto immqueue_alloc_fail;
1402
1403         conn->mgmtqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
1404                                         GFP_KERNEL, NULL);
1405         if (conn->mgmtqueue == ERR_PTR(-ENOMEM))
1406                 goto mgmtqueue_alloc_fail;
1407
1408         INIT_WORK(&conn->xmitwork, iscsi_xmitworker, conn);
1409
1410         /* allocate login_mtask used for the login/text sequences */
1411         spin_lock_bh(&session->lock);
1412         if (!__kfifo_get(session->mgmtpool.queue,
1413                          (void*)&conn->login_mtask,
1414                          sizeof(void*))) {
1415                 spin_unlock_bh(&session->lock);
1416                 goto login_mtask_alloc_fail;
1417         }
1418         spin_unlock_bh(&session->lock);
1419
1420         data = kmalloc(DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH, GFP_KERNEL);
1421         if (!data)
1422                 goto login_mtask_data_alloc_fail;
1423         conn->login_mtask->data = conn->data = data;
1424
1425         init_timer(&conn->tmabort_timer);
1426         mutex_init(&conn->xmitmutex);
1427         init_waitqueue_head(&conn->ehwait);
1428
1429         return cls_conn;
1430
1431 login_mtask_data_alloc_fail:
1432         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1433                     sizeof(void*));
1434 login_mtask_alloc_fail:
1435         kfifo_free(conn->mgmtqueue);
1436 mgmtqueue_alloc_fail:
1437         kfifo_free(conn->immqueue);
1438 immqueue_alloc_fail:
1439         iscsi_destroy_conn(cls_conn);
1440         return NULL;
1441 }
1442 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
1443
1444 /**
1445  * iscsi_conn_teardown - teardown iscsi connection
1446  * cls_conn: iscsi class connection
1447  *
1448  * TODO: we may need to make this into a two step process
1449  * like scsi-mls remove + put host
1450  */
1451 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
1452 {
1453         struct iscsi_conn *conn = cls_conn->dd_data;
1454         struct iscsi_session *session = conn->session;
1455         unsigned long flags;
1456
1457         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1458         mutex_lock(&conn->xmitmutex);
1459
1460         spin_lock_bh(&session->lock);
1461         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
1462         if (session->leadconn == conn) {
1463                 /*
1464                  * leading connection? then give up on recovery.
1465                  */
1466                 session->state = ISCSI_STATE_TERMINATE;
1467                 wake_up(&conn->ehwait);
1468         }
1469         spin_unlock_bh(&session->lock);
1470
1471         mutex_unlock(&conn->xmitmutex);
1472
1473         /*
1474          * Block until all in-progress commands for this connection
1475          * time out or fail.
1476          */
1477         for (;;) {
1478                 spin_lock_irqsave(session->host->host_lock, flags);
1479                 if (!session->host->host_busy) { /* OK for ERL == 0 */
1480                         spin_unlock_irqrestore(session->host->host_lock, flags);
1481                         break;
1482                 }
1483                 spin_unlock_irqrestore(session->host->host_lock, flags);
1484                 msleep_interruptible(500);
1485                 printk(KERN_INFO "iscsi: scsi conn_destroy(): host_busy %d "
1486                        "host_failed %d\n", session->host->host_busy,
1487                        session->host->host_failed);
1488                 /*
1489                  * force eh_abort() to unblock
1490                  */
1491                 wake_up(&conn->ehwait);
1492         }
1493
1494         spin_lock_bh(&session->lock);
1495         kfree(conn->data);
1496         kfree(conn->persistent_address);
1497         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1498                     sizeof(void*));
1499         list_del(&conn->item);
1500         if (list_empty(&session->connections))
1501                 session->leadconn = NULL;
1502         if (session->leadconn && session->leadconn == conn)
1503                 session->leadconn = container_of(session->connections.next,
1504                         struct iscsi_conn, item);
1505
1506         if (session->leadconn == NULL)
1507                 /* no connections exits.. reset sequencing */
1508                 session->cmdsn = session->max_cmdsn = session->exp_cmdsn = 1;
1509         spin_unlock_bh(&session->lock);
1510
1511         kfifo_free(conn->immqueue);
1512         kfifo_free(conn->mgmtqueue);
1513
1514         iscsi_destroy_conn(cls_conn);
1515 }
1516 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
1517
1518 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
1519 {
1520         struct iscsi_conn *conn = cls_conn->dd_data;
1521         struct iscsi_session *session = conn->session;
1522
1523         if (session == NULL) {
1524                 printk(KERN_ERR "iscsi: can't start unbound connection\n");
1525                 return -EPERM;
1526         }
1527
1528         spin_lock_bh(&session->lock);
1529         conn->c_stage = ISCSI_CONN_STARTED;
1530         session->state = ISCSI_STATE_LOGGED_IN;
1531
1532         switch(conn->stop_stage) {
1533         case STOP_CONN_RECOVER:
1534                 /*
1535                  * unblock eh_abort() if it is blocked. re-try all
1536                  * commands after successful recovery
1537                  */
1538                 conn->stop_stage = 0;
1539                 conn->tmabort_state = TMABORT_INITIAL;
1540                 session->age++;
1541                 spin_unlock_bh(&session->lock);
1542
1543                 iscsi_unblock_session(session_to_cls(session));
1544                 wake_up(&conn->ehwait);
1545                 return 0;
1546         case STOP_CONN_TERM:
1547                 conn->stop_stage = 0;
1548                 break;
1549         default:
1550                 break;
1551         }
1552         spin_unlock_bh(&session->lock);
1553
1554         return 0;
1555 }
1556 EXPORT_SYMBOL_GPL(iscsi_conn_start);
1557
1558 static void
1559 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
1560 {
1561         struct iscsi_mgmt_task *mtask, *tmp;
1562
1563         /* handle pending */
1564         while (__kfifo_get(conn->immqueue, (void*)&mtask, sizeof(void*)) ||
1565                __kfifo_get(conn->mgmtqueue, (void*)&mtask, sizeof(void*))) {
1566                 if (mtask == conn->login_mtask)
1567                         continue;
1568                 debug_scsi("flushing pending mgmt task itt 0x%x\n", mtask->itt);
1569                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1570                             sizeof(void*));
1571         }
1572
1573         /* handle running */
1574         list_for_each_entry_safe(mtask, tmp, &conn->mgmt_run_list, running) {
1575                 debug_scsi("flushing running mgmt task itt 0x%x\n", mtask->itt);
1576                 list_del(&mtask->running);
1577
1578                 if (mtask == conn->login_mtask)
1579                         continue;
1580                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1581                            sizeof(void*));
1582         }
1583
1584         conn->mtask = NULL;
1585 }
1586
1587 /* Fail commands. Mutex and session lock held and recv side suspended */
1588 static void fail_all_commands(struct iscsi_conn *conn)
1589 {
1590         struct iscsi_cmd_task *ctask, *tmp;
1591
1592         /* flush pending */
1593         list_for_each_entry_safe(ctask, tmp, &conn->xmitqueue, running) {
1594                 debug_scsi("failing pending sc %p itt 0x%x\n", ctask->sc,
1595                            ctask->itt);
1596                 fail_command(conn, ctask, DID_BUS_BUSY << 16);
1597         }
1598
1599         /* fail all other running */
1600         list_for_each_entry_safe(ctask, tmp, &conn->run_list, running) {
1601                 debug_scsi("failing in progress sc %p itt 0x%x\n",
1602                            ctask->sc, ctask->itt);
1603                 fail_command(conn, ctask, DID_BUS_BUSY << 16);
1604         }
1605
1606         conn->ctask = NULL;
1607 }
1608
1609 static void iscsi_start_session_recovery(struct iscsi_session *session,
1610                                          struct iscsi_conn *conn, int flag)
1611 {
1612         int old_stop_stage;
1613
1614         spin_lock_bh(&session->lock);
1615         if (conn->stop_stage == STOP_CONN_TERM) {
1616                 spin_unlock_bh(&session->lock);
1617                 return;
1618         }
1619
1620         /*
1621          * When this is called for the in_login state, we only want to clean
1622          * up the login task and connection. We do not need to block and set
1623          * the recovery state again
1624          */
1625         if (flag == STOP_CONN_TERM)
1626                 session->state = ISCSI_STATE_TERMINATE;
1627         else if (conn->stop_stage != STOP_CONN_RECOVER)
1628                 session->state = ISCSI_STATE_IN_RECOVERY;
1629
1630         old_stop_stage = conn->stop_stage;
1631         conn->stop_stage = flag;
1632         conn->c_stage = ISCSI_CONN_STOPPED;
1633         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1634         spin_unlock_bh(&session->lock);
1635
1636         write_lock_bh(conn->recv_lock);
1637         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1638         write_unlock_bh(conn->recv_lock);
1639
1640         mutex_lock(&conn->xmitmutex);
1641         /*
1642          * for connection level recovery we should not calculate
1643          * header digest. conn->hdr_size used for optimization
1644          * in hdr_extract() and will be re-negotiated at
1645          * set_param() time.
1646          */
1647         if (flag == STOP_CONN_RECOVER) {
1648                 conn->hdrdgst_en = 0;
1649                 conn->datadgst_en = 0;
1650                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
1651                     old_stop_stage != STOP_CONN_RECOVER) {
1652                         debug_scsi("blocking session\n");
1653                         iscsi_block_session(session_to_cls(session));
1654                 }
1655         }
1656
1657         /*
1658          * flush queues.
1659          */
1660         spin_lock_bh(&session->lock);
1661         fail_all_commands(conn);
1662         flush_control_queues(session, conn);
1663         spin_unlock_bh(&session->lock);
1664
1665         mutex_unlock(&conn->xmitmutex);
1666 }
1667
1668 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1669 {
1670         struct iscsi_conn *conn = cls_conn->dd_data;
1671         struct iscsi_session *session = conn->session;
1672
1673         switch (flag) {
1674         case STOP_CONN_RECOVER:
1675         case STOP_CONN_TERM:
1676                 iscsi_start_session_recovery(session, conn, flag);
1677                 break;
1678         default:
1679                 printk(KERN_ERR "iscsi: invalid stop flag %d\n", flag);
1680         }
1681 }
1682 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
1683
1684 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
1685                     struct iscsi_cls_conn *cls_conn, int is_leading)
1686 {
1687         struct iscsi_session *session = class_to_transport_session(cls_session);
1688         struct iscsi_conn *tmp = ERR_PTR(-EEXIST), *conn = cls_conn->dd_data;
1689
1690         /* lookup for existing connection */
1691         spin_lock_bh(&session->lock);
1692         list_for_each_entry(tmp, &session->connections, item) {
1693                 if (tmp == conn) {
1694                         if (conn->c_stage != ISCSI_CONN_STOPPED ||
1695                             conn->stop_stage == STOP_CONN_TERM) {
1696                                 printk(KERN_ERR "iscsi: can't bind "
1697                                        "non-stopped connection (%d:%d)\n",
1698                                        conn->c_stage, conn->stop_stage);
1699                                 spin_unlock_bh(&session->lock);
1700                                 return -EIO;
1701                         }
1702                         break;
1703                 }
1704         }
1705         if (tmp != conn) {
1706                 /* bind new iSCSI connection to session */
1707                 conn->session = session;
1708                 list_add(&conn->item, &session->connections);
1709         }
1710         spin_unlock_bh(&session->lock);
1711
1712         if (is_leading)
1713                 session->leadconn = conn;
1714
1715         /*
1716          * Unblock xmitworker(), Login Phase will pass through.
1717          */
1718         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1719         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1720         return 0;
1721 }
1722 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
1723
1724
1725 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
1726                     enum iscsi_param param, char *buf, int buflen)
1727 {
1728         struct iscsi_conn *conn = cls_conn->dd_data;
1729         struct iscsi_session *session = conn->session;
1730         uint32_t value;
1731
1732         switch(param) {
1733         case ISCSI_PARAM_MAX_RECV_DLENGTH:
1734                 sscanf(buf, "%d", &conn->max_recv_dlength);
1735                 break;
1736         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
1737                 sscanf(buf, "%d", &conn->max_xmit_dlength);
1738                 break;
1739         case ISCSI_PARAM_HDRDGST_EN:
1740                 sscanf(buf, "%d", &conn->hdrdgst_en);
1741                 break;
1742         case ISCSI_PARAM_DATADGST_EN:
1743                 sscanf(buf, "%d", &conn->datadgst_en);
1744                 break;
1745         case ISCSI_PARAM_INITIAL_R2T_EN:
1746                 sscanf(buf, "%d", &session->initial_r2t_en);
1747                 break;
1748         case ISCSI_PARAM_MAX_R2T:
1749                 sscanf(buf, "%d", &session->max_r2t);
1750                 break;
1751         case ISCSI_PARAM_IMM_DATA_EN:
1752                 sscanf(buf, "%d", &session->imm_data_en);
1753                 break;
1754         case ISCSI_PARAM_FIRST_BURST:
1755                 sscanf(buf, "%d", &session->first_burst);
1756                 break;
1757         case ISCSI_PARAM_MAX_BURST:
1758                 sscanf(buf, "%d", &session->max_burst);
1759                 break;
1760         case ISCSI_PARAM_PDU_INORDER_EN:
1761                 sscanf(buf, "%d", &session->pdu_inorder_en);
1762                 break;
1763         case ISCSI_PARAM_DATASEQ_INORDER_EN:
1764                 sscanf(buf, "%d", &session->dataseq_inorder_en);
1765                 break;
1766         case ISCSI_PARAM_ERL:
1767                 sscanf(buf, "%d", &session->erl);
1768                 break;
1769         case ISCSI_PARAM_IFMARKER_EN:
1770                 sscanf(buf, "%d", &value);
1771                 BUG_ON(value);
1772                 break;
1773         case ISCSI_PARAM_OFMARKER_EN:
1774                 sscanf(buf, "%d", &value);
1775                 BUG_ON(value);
1776                 break;
1777         case ISCSI_PARAM_EXP_STATSN:
1778                 sscanf(buf, "%u", &conn->exp_statsn);
1779                 break;
1780         case ISCSI_PARAM_TARGET_NAME:
1781                 /* this should not change between logins */
1782                 if (session->targetname)
1783                         break;
1784
1785                 session->targetname = kstrdup(buf, GFP_KERNEL);
1786                 if (!session->targetname)
1787                         return -ENOMEM;
1788                 break;
1789         case ISCSI_PARAM_TPGT:
1790                 sscanf(buf, "%d", &session->tpgt);
1791                 break;
1792         case ISCSI_PARAM_PERSISTENT_PORT:
1793                 sscanf(buf, "%d", &conn->persistent_port);
1794                 break;
1795         case ISCSI_PARAM_PERSISTENT_ADDRESS:
1796                 /*
1797                  * this is the address returned in discovery so it should
1798                  * not change between logins.
1799                  */
1800                 if (conn->persistent_address)
1801                         break;
1802
1803                 conn->persistent_address = kstrdup(buf, GFP_KERNEL);
1804                 if (!conn->persistent_address)
1805                         return -ENOMEM;
1806                 break;
1807         default:
1808                 return -ENOSYS;
1809         }
1810
1811         return 0;
1812 }
1813 EXPORT_SYMBOL_GPL(iscsi_set_param);
1814
1815 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
1816                             enum iscsi_param param, char *buf)
1817 {
1818         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1819         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1820         int len;
1821
1822         switch(param) {
1823         case ISCSI_PARAM_INITIAL_R2T_EN:
1824                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
1825                 break;
1826         case ISCSI_PARAM_MAX_R2T:
1827                 len = sprintf(buf, "%hu\n", session->max_r2t);
1828                 break;
1829         case ISCSI_PARAM_IMM_DATA_EN:
1830                 len = sprintf(buf, "%d\n", session->imm_data_en);
1831                 break;
1832         case ISCSI_PARAM_FIRST_BURST:
1833                 len = sprintf(buf, "%u\n", session->first_burst);
1834                 break;
1835         case ISCSI_PARAM_MAX_BURST:
1836                 len = sprintf(buf, "%u\n", session->max_burst);
1837                 break;
1838         case ISCSI_PARAM_PDU_INORDER_EN:
1839                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
1840                 break;
1841         case ISCSI_PARAM_DATASEQ_INORDER_EN:
1842                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
1843                 break;
1844         case ISCSI_PARAM_ERL:
1845                 len = sprintf(buf, "%d\n", session->erl);
1846                 break;
1847         case ISCSI_PARAM_TARGET_NAME:
1848                 len = sprintf(buf, "%s\n", session->targetname);
1849                 break;
1850         case ISCSI_PARAM_TPGT:
1851                 len = sprintf(buf, "%d\n", session->tpgt);
1852                 break;
1853         default:
1854                 return -ENOSYS;
1855         }
1856
1857         return len;
1858 }
1859 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
1860
1861 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
1862                          enum iscsi_param param, char *buf)
1863 {
1864         struct iscsi_conn *conn = cls_conn->dd_data;
1865         int len;
1866
1867         switch(param) {
1868         case ISCSI_PARAM_MAX_RECV_DLENGTH:
1869                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
1870                 break;
1871         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
1872                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
1873                 break;
1874         case ISCSI_PARAM_HDRDGST_EN:
1875                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
1876                 break;
1877         case ISCSI_PARAM_DATADGST_EN:
1878                 len = sprintf(buf, "%d\n", conn->datadgst_en);
1879                 break;
1880         case ISCSI_PARAM_IFMARKER_EN:
1881                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
1882                 break;
1883         case ISCSI_PARAM_OFMARKER_EN:
1884                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
1885                 break;
1886         case ISCSI_PARAM_EXP_STATSN:
1887                 len = sprintf(buf, "%u\n", conn->exp_statsn);
1888                 break;
1889         case ISCSI_PARAM_PERSISTENT_PORT:
1890                 len = sprintf(buf, "%d\n", conn->persistent_port);
1891                 break;
1892         case ISCSI_PARAM_PERSISTENT_ADDRESS:
1893                 len = sprintf(buf, "%s\n", conn->persistent_address);
1894                 break;
1895         default:
1896                 return -ENOSYS;
1897         }
1898
1899         return len;
1900 }
1901 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
1902
1903 MODULE_AUTHOR("Mike Christie");
1904 MODULE_DESCRIPTION("iSCSI library functions");
1905 MODULE_LICENSE("GPL");