Merge branch 'master' into upstream
[linux-2.6] / 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 {
73         struct iscsi_conn *conn = ctask->conn;
74
75         memset(hdr, 0, sizeof(struct iscsi_data));
76         hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
77         hdr->datasn = cpu_to_be32(ctask->unsol_datasn);
78         ctask->unsol_datasn++;
79         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
80         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
81
82         hdr->itt = ctask->hdr->itt;
83         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
84         hdr->offset = cpu_to_be32(ctask->unsol_offset);
85
86         if (ctask->unsol_count > conn->max_xmit_dlength) {
87                 hton24(hdr->dlength, conn->max_xmit_dlength);
88                 ctask->data_count = conn->max_xmit_dlength;
89                 ctask->unsol_offset += ctask->data_count;
90                 hdr->flags = 0;
91         } else {
92                 hton24(hdr->dlength, ctask->unsol_count);
93                 ctask->data_count = ctask->unsol_count;
94                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
95         }
96 }
97 EXPORT_SYMBOL_GPL(iscsi_prep_unsolicit_data_pdu);
98
99 /**
100  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
101  * @ctask: iscsi cmd task
102  *
103  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
104  * fields like dlength or final based on how much data it sends
105  */
106 static void iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
107 {
108         struct iscsi_conn *conn = ctask->conn;
109         struct iscsi_session *session = conn->session;
110         struct iscsi_cmd *hdr = ctask->hdr;
111         struct scsi_cmnd *sc = ctask->sc;
112
113         hdr->opcode = ISCSI_OP_SCSI_CMD;
114         hdr->flags = ISCSI_ATTR_SIMPLE;
115         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
116         hdr->itt = ctask->itt | (conn->id << ISCSI_CID_SHIFT) |
117                          (session->age << ISCSI_AGE_SHIFT);
118         hdr->data_length = cpu_to_be32(sc->request_bufflen);
119         hdr->cmdsn = cpu_to_be32(session->cmdsn);
120         session->cmdsn++;
121         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
122         memcpy(hdr->cdb, sc->cmnd, sc->cmd_len);
123         memset(&hdr->cdb[sc->cmd_len], 0, MAX_COMMAND_SIZE - sc->cmd_len);
124
125         ctask->data_count = 0;
126         if (sc->sc_data_direction == DMA_TO_DEVICE) {
127                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
128                 /*
129                  * Write counters:
130                  *
131                  *      imm_count       bytes to be sent right after
132                  *                      SCSI PDU Header
133                  *
134                  *      unsol_count     bytes(as Data-Out) to be sent
135                  *                      without R2T ack right after
136                  *                      immediate data
137                  *
138                  *      r2t_data_count  bytes to be sent via R2T ack's
139                  *
140                  *      pad_count       bytes to be sent as zero-padding
141                  */
142                 ctask->imm_count = 0;
143                 ctask->unsol_count = 0;
144                 ctask->unsol_offset = 0;
145                 ctask->unsol_datasn = 0;
146
147                 if (session->imm_data_en) {
148                         if (ctask->total_length >= session->first_burst)
149                                 ctask->imm_count = min(session->first_burst,
150                                                         conn->max_xmit_dlength);
151                         else
152                                 ctask->imm_count = min(ctask->total_length,
153                                                         conn->max_xmit_dlength);
154                         hton24(ctask->hdr->dlength, ctask->imm_count);
155                 } else
156                         zero_data(ctask->hdr->dlength);
157
158                 if (!session->initial_r2t_en) {
159                         ctask->unsol_count = min(session->first_burst,
160                                 ctask->total_length) - ctask->imm_count;
161                         ctask->unsol_offset = ctask->imm_count;
162                 }
163
164                 if (!ctask->unsol_count)
165                         /* No unsolicit Data-Out's */
166                         ctask->hdr->flags |= ISCSI_FLAG_CMD_FINAL;
167         } else {
168                 ctask->datasn = 0;
169                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
170                 zero_data(hdr->dlength);
171
172                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
173                         hdr->flags |= ISCSI_FLAG_CMD_READ;
174         }
175
176         conn->scsicmd_pdus_cnt++;
177 }
178 EXPORT_SYMBOL_GPL(iscsi_prep_scsi_cmd_pdu);
179
180 /**
181  * iscsi_complete_command - return command back to scsi-ml
182  * @ctask: iscsi cmd task
183  *
184  * Must be called with session lock.
185  * This function returns the scsi command to scsi-ml and returns
186  * the cmd task to the pool of available cmd tasks.
187  */
188 static void iscsi_complete_command(struct iscsi_cmd_task *ctask)
189 {
190         struct iscsi_session *session = ctask->conn->session;
191         struct scsi_cmnd *sc = ctask->sc;
192
193         ctask->state = ISCSI_TASK_COMPLETED;
194         ctask->sc = NULL;
195         /* SCSI eh reuses commands to verify us */
196         sc->SCp.ptr = NULL;
197         list_del_init(&ctask->running);
198         __kfifo_put(session->cmdpool.queue, (void*)&ctask, sizeof(void*));
199         sc->scsi_done(sc);
200 }
201
202 static void __iscsi_get_ctask(struct iscsi_cmd_task *ctask)
203 {
204         atomic_inc(&ctask->refcount);
205 }
206
207 static void iscsi_get_ctask(struct iscsi_cmd_task *ctask)
208 {
209         spin_lock_bh(&ctask->conn->session->lock);
210         __iscsi_get_ctask(ctask);
211         spin_unlock_bh(&ctask->conn->session->lock);
212 }
213
214 static void __iscsi_put_ctask(struct iscsi_cmd_task *ctask)
215 {
216         if (atomic_dec_and_test(&ctask->refcount))
217                 iscsi_complete_command(ctask);
218 }
219
220 static void iscsi_put_ctask(struct iscsi_cmd_task *ctask)
221 {
222         spin_lock_bh(&ctask->conn->session->lock);
223         __iscsi_put_ctask(ctask);
224         spin_unlock_bh(&ctask->conn->session->lock);
225 }
226
227 /**
228  * iscsi_cmd_rsp - SCSI Command Response processing
229  * @conn: iscsi connection
230  * @hdr: iscsi header
231  * @ctask: scsi command task
232  * @data: cmd data buffer
233  * @datalen: len of buffer
234  *
235  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
236  * then completes the command and task.
237  **/
238 static int iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
239                               struct iscsi_cmd_task *ctask, char *data,
240                               int datalen)
241 {
242         int rc;
243         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
244         struct iscsi_session *session = conn->session;
245         struct scsi_cmnd *sc = ctask->sc;
246
247         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
248         if (rc) {
249                 sc->result = DID_ERROR << 16;
250                 goto out;
251         }
252
253         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
254
255         sc->result = (DID_OK << 16) | rhdr->cmd_status;
256
257         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
258                 sc->result = DID_ERROR << 16;
259                 goto out;
260         }
261
262         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
263                 int senselen;
264
265                 if (datalen < 2) {
266 invalid_datalen:
267                         printk(KERN_ERR "iscsi: Got CHECK_CONDITION but "
268                                "invalid data buffer size of %d\n", datalen);
269                         sc->result = DID_BAD_TARGET << 16;
270                         goto out;
271                 }
272
273                 senselen = (data[0] << 8) | data[1];
274                 if (datalen < senselen)
275                         goto invalid_datalen;
276
277                 memcpy(sc->sense_buffer, data + 2,
278                        min(senselen, SCSI_SENSE_BUFFERSIZE));
279                 debug_scsi("copied %d bytes of sense\n",
280                            min(senselen, SCSI_SENSE_BUFFERSIZE));
281         }
282
283         if (sc->sc_data_direction == DMA_TO_DEVICE)
284                 goto out;
285
286         if (rhdr->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
287                 int res_count = be32_to_cpu(rhdr->residual_count);
288
289                 if (res_count > 0 && res_count <= sc->request_bufflen)
290                         sc->resid = res_count;
291                 else
292                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
293         } else if (rhdr->flags & ISCSI_FLAG_CMD_BIDI_UNDERFLOW)
294                 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
295         else if (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW)
296                 sc->resid = be32_to_cpu(rhdr->residual_count);
297
298 out:
299         debug_scsi("done [sc %lx res %d itt 0x%x]\n",
300                    (long)sc, sc->result, ctask->itt);
301         conn->scsirsp_pdus_cnt++;
302
303         __iscsi_put_ctask(ctask);
304         return rc;
305 }
306
307 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
308 {
309         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
310
311         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
312         conn->tmfrsp_pdus_cnt++;
313
314         if (conn->tmabort_state != TMABORT_INITIAL)
315                 return;
316
317         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
318                 conn->tmabort_state = TMABORT_SUCCESS;
319         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
320                 conn->tmabort_state = TMABORT_NOT_FOUND;
321         else
322                 conn->tmabort_state = TMABORT_FAILED;
323         wake_up(&conn->ehwait);
324 }
325
326 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
327                                char *data, int datalen)
328 {
329         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
330         struct iscsi_hdr rejected_pdu;
331         uint32_t itt;
332
333         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
334
335         if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
336                 if (ntoh24(reject->dlength) > datalen)
337                         return ISCSI_ERR_PROTO;
338
339                 if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
340                         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
341                         itt = rejected_pdu.itt & ISCSI_ITT_MASK;
342                         printk(KERN_ERR "itt 0x%x had pdu (op 0x%x) rejected "
343                                 "due to DataDigest error.\n", itt,
344                                 rejected_pdu.opcode);
345                 }
346         }
347         return 0;
348 }
349
350 /**
351  * __iscsi_complete_pdu - complete pdu
352  * @conn: iscsi conn
353  * @hdr: iscsi header
354  * @data: data buffer
355  * @datalen: len of data buffer
356  *
357  * Completes pdu processing by freeing any resources allocated at
358  * queuecommand or send generic. session lock must be held and verify
359  * itt must have been called.
360  */
361 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
362                          char *data, int datalen)
363 {
364         struct iscsi_session *session = conn->session;
365         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
366         struct iscsi_cmd_task *ctask;
367         struct iscsi_mgmt_task *mtask;
368         uint32_t itt;
369
370         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG))
371                 itt = hdr->itt & ISCSI_ITT_MASK;
372         else
373                 itt = hdr->itt;
374
375         if (itt < session->cmds_max) {
376                 ctask = session->cmds[itt];
377
378                 debug_scsi("cmdrsp [op 0x%x cid %d itt 0x%x len %d]\n",
379                            opcode, conn->id, ctask->itt, datalen);
380
381                 switch(opcode) {
382                 case ISCSI_OP_SCSI_CMD_RSP:
383                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
384                         rc = iscsi_scsi_cmd_rsp(conn, hdr, ctask, data,
385                                                 datalen);
386                         break;
387                 case ISCSI_OP_SCSI_DATA_IN:
388                         BUG_ON((void*)ctask != ctask->sc->SCp.ptr);
389                         if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
390                                 conn->scsirsp_pdus_cnt++;
391                                 __iscsi_put_ctask(ctask);
392                         }
393                         break;
394                 case ISCSI_OP_R2T:
395                         /* LLD handles this for now */
396                         break;
397                 default:
398                         rc = ISCSI_ERR_BAD_OPCODE;
399                         break;
400                 }
401         } else if (itt >= ISCSI_MGMT_ITT_OFFSET &&
402                    itt < ISCSI_MGMT_ITT_OFFSET + session->mgmtpool_max) {
403                 mtask = session->mgmt_cmds[itt - ISCSI_MGMT_ITT_OFFSET];
404
405                 debug_scsi("immrsp [op 0x%x cid %d itt 0x%x len %d]\n",
406                            opcode, conn->id, mtask->itt, datalen);
407
408                 rc = iscsi_check_assign_cmdsn(session,
409                                               (struct iscsi_nopin*)hdr);
410                 if (rc)
411                         goto done;
412
413                 switch(opcode) {
414                 case ISCSI_OP_LOGOUT_RSP:
415                         if (datalen) {
416                                 rc = ISCSI_ERR_PROTO;
417                                 break;
418                         }
419                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
420                         /* fall through */
421                 case ISCSI_OP_LOGIN_RSP:
422                 case ISCSI_OP_TEXT_RSP:
423                         /*
424                          * login related PDU's exp_statsn is handled in
425                          * userspace
426                          */
427                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
428                                 rc = ISCSI_ERR_CONN_FAILED;
429                         list_del(&mtask->running);
430                         if (conn->login_mtask != mtask)
431                                 __kfifo_put(session->mgmtpool.queue,
432                                             (void*)&mtask, sizeof(void*));
433                         break;
434                 case ISCSI_OP_SCSI_TMFUNC_RSP:
435                         if (datalen) {
436                                 rc = ISCSI_ERR_PROTO;
437                                 break;
438                         }
439
440                         iscsi_tmf_rsp(conn, hdr);
441                         break;
442                 case ISCSI_OP_NOOP_IN:
443                         if (hdr->ttt != ISCSI_RESERVED_TAG || datalen) {
444                                 rc = ISCSI_ERR_PROTO;
445                                 break;
446                         }
447                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
448
449                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
450                                 rc = ISCSI_ERR_CONN_FAILED;
451                         list_del(&mtask->running);
452                         if (conn->login_mtask != mtask)
453                                 __kfifo_put(session->mgmtpool.queue,
454                                             (void*)&mtask, sizeof(void*));
455                         break;
456                 default:
457                         rc = ISCSI_ERR_BAD_OPCODE;
458                         break;
459                 }
460         } else if (itt == ISCSI_RESERVED_TAG) {
461                 rc = iscsi_check_assign_cmdsn(session,
462                                              (struct iscsi_nopin*)hdr);
463                 if (rc)
464                         goto done;
465
466                 switch(opcode) {
467                 case ISCSI_OP_NOOP_IN:
468                         if (datalen) {
469                                 rc = ISCSI_ERR_PROTO;
470                                 break;
471                         }
472
473                         if (hdr->ttt == ISCSI_RESERVED_TAG)
474                                 break;
475
476                         if (iscsi_recv_pdu(conn->cls_conn, hdr, NULL, 0))
477                                 rc = ISCSI_ERR_CONN_FAILED;
478                         break;
479                 case ISCSI_OP_REJECT:
480                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
481                         break;
482                 case ISCSI_OP_ASYNC_EVENT:
483                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
484                         /* we need sth like iscsi_async_event_rsp() */
485                         rc = ISCSI_ERR_BAD_OPCODE;
486                         break;
487                 default:
488                         rc = ISCSI_ERR_BAD_OPCODE;
489                         break;
490                 }
491         } else
492                 rc = ISCSI_ERR_BAD_ITT;
493
494 done:
495         return rc;
496 }
497 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
498
499 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
500                        char *data, int datalen)
501 {
502         int rc;
503
504         spin_lock(&conn->session->lock);
505         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
506         spin_unlock(&conn->session->lock);
507         return rc;
508 }
509 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
510
511 /* verify itt (itt encoding: age+cid+itt) */
512 int iscsi_verify_itt(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
513                      uint32_t *ret_itt)
514 {
515         struct iscsi_session *session = conn->session;
516         struct iscsi_cmd_task *ctask;
517         uint32_t itt;
518
519         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
520                 if ((hdr->itt & ISCSI_AGE_MASK) !=
521                     (session->age << ISCSI_AGE_SHIFT)) {
522                         printk(KERN_ERR "iscsi: received itt %x expected "
523                                 "session age (%x)\n", hdr->itt,
524                                 session->age & ISCSI_AGE_MASK);
525                         return ISCSI_ERR_BAD_ITT;
526                 }
527
528                 if ((hdr->itt & ISCSI_CID_MASK) !=
529                     (conn->id << ISCSI_CID_SHIFT)) {
530                         printk(KERN_ERR "iscsi: received itt %x, expected "
531                                 "CID (%x)\n", hdr->itt, conn->id);
532                         return ISCSI_ERR_BAD_ITT;
533                 }
534                 itt = hdr->itt & ISCSI_ITT_MASK;
535         } else
536                 itt = hdr->itt;
537
538         if (itt < session->cmds_max) {
539                 ctask = session->cmds[itt];
540
541                 if (!ctask->sc) {
542                         printk(KERN_INFO "iscsi: dropping ctask with "
543                                "itt 0x%x\n", ctask->itt);
544                         /* force drop */
545                         return ISCSI_ERR_NO_SCSI_CMD;
546                 }
547
548                 if (ctask->sc->SCp.phase != session->age) {
549                         printk(KERN_ERR "iscsi: ctask's session age %d, "
550                                 "expected %d\n", ctask->sc->SCp.phase,
551                                 session->age);
552                         return ISCSI_ERR_SESSION_FAILED;
553                 }
554         }
555
556         *ret_itt = itt;
557         return 0;
558 }
559 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
560
561 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
562 {
563         struct iscsi_session *session = conn->session;
564         unsigned long flags;
565
566         spin_lock_irqsave(&session->lock, flags);
567         if (session->state == ISCSI_STATE_FAILED) {
568                 spin_unlock_irqrestore(&session->lock, flags);
569                 return;
570         }
571
572         if (conn->stop_stage == 0)
573                 session->state = ISCSI_STATE_FAILED;
574         spin_unlock_irqrestore(&session->lock, flags);
575         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
576         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
577         iscsi_conn_error(conn->cls_conn, err);
578 }
579 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
580
581 /**
582  * iscsi_data_xmit - xmit any command into the scheduled connection
583  * @conn: iscsi connection
584  *
585  * Notes:
586  *      The function can return -EAGAIN in which case the caller must
587  *      re-schedule it again later or recover. '0' return code means
588  *      successful xmit.
589  **/
590 static int iscsi_data_xmit(struct iscsi_conn *conn)
591 {
592         struct iscsi_transport *tt;
593         int rc = 0;
594
595         if (unlikely(conn->suspend_tx)) {
596                 debug_scsi("conn %d Tx suspended!\n", conn->id);
597                 return -ENODATA;
598         }
599         tt = conn->session->tt;
600
601         /*
602          * Transmit in the following order:
603          *
604          * 1) un-finished xmit (ctask or mtask)
605          * 2) immediate control PDUs
606          * 3) write data
607          * 4) SCSI commands
608          * 5) non-immediate control PDUs
609          *
610          * No need to lock around __kfifo_get as long as
611          * there's one producer and one consumer.
612          */
613
614         BUG_ON(conn->ctask && conn->mtask);
615
616         if (conn->ctask) {
617                 iscsi_get_ctask(conn->ctask);
618                 rc = tt->xmit_cmd_task(conn, conn->ctask);
619                 iscsi_put_ctask(conn->ctask);
620                 if (rc)
621                         goto again;
622                 /* done with this in-progress ctask */
623                 conn->ctask = NULL;
624         }
625         if (conn->mtask) {
626                 rc = tt->xmit_mgmt_task(conn, conn->mtask);
627                 if (rc)
628                         goto again;
629                 /* done with this in-progress mtask */
630                 conn->mtask = NULL;
631         }
632
633         /* process immediate first */
634         if (unlikely(__kfifo_len(conn->immqueue))) {
635                 while (__kfifo_get(conn->immqueue, (void*)&conn->mtask,
636                                    sizeof(void*))) {
637                         spin_lock_bh(&conn->session->lock);
638                         list_add_tail(&conn->mtask->running,
639                                       &conn->mgmt_run_list);
640                         spin_unlock_bh(&conn->session->lock);
641                         rc = tt->xmit_mgmt_task(conn, conn->mtask);
642                         if (rc)
643                                 goto again;
644                 }
645                 /* done with this mtask */
646                 conn->mtask = NULL;
647         }
648
649         /* process command queue */
650         spin_lock_bh(&conn->session->lock);
651         while (!list_empty(&conn->xmitqueue)) {
652                 /*
653                  * iscsi tcp may readd the task to the xmitqueue to send
654                  * write data
655                  */
656                 conn->ctask = list_entry(conn->xmitqueue.next,
657                                          struct iscsi_cmd_task, running);
658                 conn->ctask->state = ISCSI_TASK_RUNNING;
659                 list_move_tail(conn->xmitqueue.next, &conn->run_list);
660                 __iscsi_get_ctask(conn->ctask);
661                 spin_unlock_bh(&conn->session->lock);
662
663                 rc = tt->xmit_cmd_task(conn, conn->ctask);
664                 if (rc)
665                         goto again;
666
667                 spin_lock_bh(&conn->session->lock);
668                 __iscsi_put_ctask(conn->ctask);
669                 if (rc) {
670                         spin_unlock_bh(&conn->session->lock);
671                         goto again;
672                 }
673         }
674         spin_unlock_bh(&conn->session->lock);
675         /* done with this ctask */
676         conn->ctask = NULL;
677
678         /* process the rest control plane PDUs, if any */
679         if (unlikely(__kfifo_len(conn->mgmtqueue))) {
680                 while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask,
681                                    sizeof(void*))) {
682                         spin_lock_bh(&conn->session->lock);
683                         list_add_tail(&conn->mtask->running,
684                                       &conn->mgmt_run_list);
685                         spin_unlock_bh(&conn->session->lock);
686                         rc = tt->xmit_mgmt_task(conn, conn->mtask);
687                         if (rc)
688                                 goto again;
689                 }
690                 /* done with this mtask */
691                 conn->mtask = NULL;
692         }
693
694         return -ENODATA;
695
696 again:
697         if (unlikely(conn->suspend_tx))
698                 return -ENODATA;
699
700         return rc;
701 }
702
703 static void iscsi_xmitworker(void *data)
704 {
705         struct iscsi_conn *conn = data;
706         int rc;
707         /*
708          * serialize Xmit worker on a per-connection basis.
709          */
710         mutex_lock(&conn->xmitmutex);
711         do {
712                 rc = iscsi_data_xmit(conn);
713         } while (rc >= 0 || rc == -EAGAIN);
714         mutex_unlock(&conn->xmitmutex);
715 }
716
717 enum {
718         FAILURE_BAD_HOST = 1,
719         FAILURE_SESSION_FAILED,
720         FAILURE_SESSION_FREED,
721         FAILURE_WINDOW_CLOSED,
722         FAILURE_OOM,
723         FAILURE_SESSION_TERMINATE,
724         FAILURE_SESSION_IN_RECOVERY,
725         FAILURE_SESSION_RECOVERY_TIMEOUT,
726 };
727
728 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
729 {
730         struct Scsi_Host *host;
731         int reason = 0;
732         struct iscsi_session *session;
733         struct iscsi_conn *conn;
734         struct iscsi_cmd_task *ctask = NULL;
735
736         sc->scsi_done = done;
737         sc->result = 0;
738         sc->SCp.ptr = NULL;
739
740         host = sc->device->host;
741         session = iscsi_hostdata(host->hostdata);
742
743         spin_lock(&session->lock);
744
745         /*
746          * ISCSI_STATE_FAILED is a temp. state. The recovery
747          * code will decide what is best to do with command queued
748          * during this time
749          */
750         if (session->state != ISCSI_STATE_LOGGED_IN &&
751             session->state != ISCSI_STATE_FAILED) {
752                 /*
753                  * to handle the race between when we set the recovery state
754                  * and block the session we requeue here (commands could
755                  * be entering our queuecommand while a block is starting
756                  * up because the block code is not locked)
757                  */
758                 if (session->state == ISCSI_STATE_IN_RECOVERY) {
759                         reason = FAILURE_SESSION_IN_RECOVERY;
760                         goto reject;
761                 }
762
763                 if (session->state == ISCSI_STATE_RECOVERY_FAILED)
764                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
765                 else if (session->state == ISCSI_STATE_TERMINATE)
766                         reason = FAILURE_SESSION_TERMINATE;
767                 else
768                         reason = FAILURE_SESSION_FREED;
769                 goto fault;
770         }
771
772         /*
773          * Check for iSCSI window and take care of CmdSN wrap-around
774          */
775         if ((int)(session->max_cmdsn - session->cmdsn) < 0) {
776                 reason = FAILURE_WINDOW_CLOSED;
777                 goto reject;
778         }
779
780         conn = session->leadconn;
781
782         if (!__kfifo_get(session->cmdpool.queue, (void*)&ctask,
783                          sizeof(void*))) {
784                 reason = FAILURE_OOM;
785                 goto reject;
786         }
787         sc->SCp.phase = session->age;
788         sc->SCp.ptr = (char *)ctask;
789
790         atomic_set(&ctask->refcount, 1);
791         ctask->state = ISCSI_TASK_PENDING;
792         ctask->mtask = NULL;
793         ctask->conn = conn;
794         ctask->sc = sc;
795         INIT_LIST_HEAD(&ctask->running);
796         ctask->total_length = sc->request_bufflen;
797         iscsi_prep_scsi_cmd_pdu(ctask);
798
799         session->tt->init_cmd_task(ctask);
800
801         list_add_tail(&ctask->running, &conn->xmitqueue);
802         debug_scsi(
803                "ctask enq [%s cid %d sc %p cdb 0x%x itt 0x%x len %d cmdsn %d "
804                 "win %d]\n",
805                 sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
806                 conn->id, sc, sc->cmnd[0], ctask->itt, sc->request_bufflen,
807                 session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
808         spin_unlock(&session->lock);
809
810         scsi_queue_work(host, &conn->xmitwork);
811         return 0;
812
813 reject:
814         spin_unlock(&session->lock);
815         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
816         return SCSI_MLQUEUE_HOST_BUSY;
817
818 fault:
819         spin_unlock(&session->lock);
820         printk(KERN_ERR "iscsi: cmd 0x%x is not queued (%d)\n",
821                sc->cmnd[0], reason);
822         sc->result = (DID_NO_CONNECT << 16);
823         sc->resid = sc->request_bufflen;
824         sc->scsi_done(sc);
825         return 0;
826 }
827 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
828
829 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
830 {
831         if (depth > ISCSI_MAX_CMD_PER_LUN)
832                 depth = ISCSI_MAX_CMD_PER_LUN;
833         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
834         return sdev->queue_depth;
835 }
836 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
837
838 static int
839 iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
840                         char *data, uint32_t data_size)
841 {
842         struct iscsi_session *session = conn->session;
843         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
844         struct iscsi_mgmt_task *mtask;
845
846         spin_lock_bh(&session->lock);
847         if (session->state == ISCSI_STATE_TERMINATE) {
848                 spin_unlock_bh(&session->lock);
849                 return -EPERM;
850         }
851         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
852             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
853                 /*
854                  * Login and Text are sent serially, in
855                  * request-followed-by-response sequence.
856                  * Same mtask can be used. Same ITT must be used.
857                  * Note that login_mtask is preallocated at conn_create().
858                  */
859                 mtask = conn->login_mtask;
860         else {
861                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
862                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
863
864                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
865                 if (!__kfifo_get(session->mgmtpool.queue,
866                                  (void*)&mtask, sizeof(void*))) {
867                         spin_unlock_bh(&session->lock);
868                         return -ENOSPC;
869                 }
870         }
871
872         /*
873          * pre-format CmdSN for outgoing PDU.
874          */
875         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
876                 hdr->itt = mtask->itt | (conn->id << ISCSI_CID_SHIFT) |
877                            (session->age << ISCSI_AGE_SHIFT);
878                 nop->cmdsn = cpu_to_be32(session->cmdsn);
879                 if (conn->c_stage == ISCSI_CONN_STARTED &&
880                     !(hdr->opcode & ISCSI_OP_IMMEDIATE))
881                         session->cmdsn++;
882         } else
883                 /* do not advance CmdSN */
884                 nop->cmdsn = cpu_to_be32(session->cmdsn);
885
886         if (data_size) {
887                 memcpy(mtask->data, data, data_size);
888                 mtask->data_count = data_size;
889         } else
890                 mtask->data_count = 0;
891
892         INIT_LIST_HEAD(&mtask->running);
893         memcpy(mtask->hdr, hdr, sizeof(struct iscsi_hdr));
894         if (session->tt->init_mgmt_task)
895                 session->tt->init_mgmt_task(conn, mtask, data, data_size);
896         spin_unlock_bh(&session->lock);
897
898         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
899                    hdr->opcode, hdr->itt, data_size);
900
901         /*
902          * since send_pdu() could be called at least from two contexts,
903          * we need to serialize __kfifo_put, so we don't have to take
904          * additional lock on fast data-path
905          */
906         if (hdr->opcode & ISCSI_OP_IMMEDIATE)
907                 __kfifo_put(conn->immqueue, (void*)&mtask, sizeof(void*));
908         else
909                 __kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*));
910
911         scsi_queue_work(session->host, &conn->xmitwork);
912         return 0;
913 }
914
915 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
916                         char *data, uint32_t data_size)
917 {
918         struct iscsi_conn *conn = cls_conn->dd_data;
919         int rc;
920
921         mutex_lock(&conn->xmitmutex);
922         rc = iscsi_conn_send_generic(conn, hdr, data, data_size);
923         mutex_unlock(&conn->xmitmutex);
924
925         return rc;
926 }
927 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
928
929 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
930 {
931         struct iscsi_session *session = class_to_transport_session(cls_session);
932         struct iscsi_conn *conn = session->leadconn;
933
934         spin_lock_bh(&session->lock);
935         if (session->state != ISCSI_STATE_LOGGED_IN) {
936                 session->state = ISCSI_STATE_RECOVERY_FAILED;
937                 if (conn)
938                         wake_up(&conn->ehwait);
939         }
940         spin_unlock_bh(&session->lock);
941 }
942 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
943
944 int iscsi_eh_host_reset(struct scsi_cmnd *sc)
945 {
946         struct Scsi_Host *host = sc->device->host;
947         struct iscsi_session *session = iscsi_hostdata(host->hostdata);
948         struct iscsi_conn *conn = session->leadconn;
949         int fail_session = 0;
950
951         spin_lock_bh(&session->lock);
952         if (session->state == ISCSI_STATE_TERMINATE) {
953 failed:
954                 debug_scsi("failing host reset: session terminated "
955                            "[CID %d age %d]", conn->id, session->age);
956                 spin_unlock_bh(&session->lock);
957                 return FAILED;
958         }
959
960         if (sc->SCp.phase == session->age) {
961                 debug_scsi("failing connection CID %d due to SCSI host reset",
962                            conn->id);
963                 fail_session = 1;
964         }
965         spin_unlock_bh(&session->lock);
966
967         /*
968          * we drop the lock here but the leadconn cannot be destoyed while
969          * we are in the scsi eh
970          */
971         if (fail_session)
972                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
973
974         debug_scsi("iscsi_eh_host_reset wait for relogin\n");
975         wait_event_interruptible(conn->ehwait,
976                                  session->state == ISCSI_STATE_TERMINATE ||
977                                  session->state == ISCSI_STATE_LOGGED_IN ||
978                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
979         if (signal_pending(current))
980                 flush_signals(current);
981
982         spin_lock_bh(&session->lock);
983         if (session->state == ISCSI_STATE_LOGGED_IN)
984                 printk(KERN_INFO "iscsi: host reset succeeded\n");
985         else
986                 goto failed;
987         spin_unlock_bh(&session->lock);
988
989         return SUCCESS;
990 }
991 EXPORT_SYMBOL_GPL(iscsi_eh_host_reset);
992
993 static void iscsi_tmabort_timedout(unsigned long data)
994 {
995         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)data;
996         struct iscsi_conn *conn = ctask->conn;
997         struct iscsi_session *session = conn->session;
998
999         spin_lock(&session->lock);
1000         if (conn->tmabort_state == TMABORT_INITIAL) {
1001                 conn->tmabort_state = TMABORT_TIMEDOUT;
1002                 debug_scsi("tmabort timedout [sc %p itt 0x%x]\n",
1003                         ctask->sc, ctask->itt);
1004                 /* unblock eh_abort() */
1005                 wake_up(&conn->ehwait);
1006         }
1007         spin_unlock(&session->lock);
1008 }
1009
1010 /* must be called with the mutex lock */
1011 static int iscsi_exec_abort_task(struct scsi_cmnd *sc,
1012                                  struct iscsi_cmd_task *ctask)
1013 {
1014         struct iscsi_conn *conn = ctask->conn;
1015         struct iscsi_session *session = conn->session;
1016         struct iscsi_tm *hdr = &conn->tmhdr;
1017         int rc;
1018
1019         /*
1020          * ctask timed out but session is OK requests must be serialized.
1021          */
1022         memset(hdr, 0, sizeof(struct iscsi_tm));
1023         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1024         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK;
1025         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1026         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1027         hdr->rtt = ctask->hdr->itt;
1028         hdr->refcmdsn = ctask->hdr->cmdsn;
1029
1030         rc = iscsi_conn_send_generic(conn, (struct iscsi_hdr *)hdr,
1031                                      NULL, 0);
1032         if (rc) {
1033                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1034                 debug_scsi("abort sent failure [itt 0x%x] %d", ctask->itt, rc);
1035                 return rc;
1036         }
1037
1038         debug_scsi("abort sent [itt 0x%x]\n", ctask->itt);
1039
1040         spin_lock_bh(&session->lock);
1041         ctask->mtask = (struct iscsi_mgmt_task *)
1042                         session->mgmt_cmds[(hdr->itt & ISCSI_ITT_MASK) -
1043                                         ISCSI_MGMT_ITT_OFFSET];
1044
1045         if (conn->tmabort_state == TMABORT_INITIAL) {
1046                 conn->tmfcmd_pdus_cnt++;
1047                 conn->tmabort_timer.expires = 10*HZ + jiffies;
1048                 conn->tmabort_timer.function = iscsi_tmabort_timedout;
1049                 conn->tmabort_timer.data = (unsigned long)ctask;
1050                 add_timer(&conn->tmabort_timer);
1051                 debug_scsi("abort set timeout [itt 0x%x]", ctask->itt);
1052         }
1053         spin_unlock_bh(&session->lock);
1054         mutex_unlock(&conn->xmitmutex);
1055
1056         /*
1057          * block eh thread until:
1058          *
1059          * 1) abort response
1060          * 2) abort timeout
1061          * 3) session is terminated or restarted or userspace has
1062          * given up on recovery
1063          */
1064         wait_event_interruptible(conn->ehwait,
1065                                  sc->SCp.phase != session->age ||
1066                                  session->state != ISCSI_STATE_LOGGED_IN ||
1067                                  conn->tmabort_state != TMABORT_INITIAL);
1068         if (signal_pending(current))
1069                 flush_signals(current);
1070         del_timer_sync(&conn->tmabort_timer);
1071
1072         mutex_lock(&conn->xmitmutex);
1073         return 0;
1074 }
1075
1076 /*
1077  * xmit mutex and session lock must be held
1078  */
1079 static struct iscsi_mgmt_task *
1080 iscsi_remove_mgmt_task(struct kfifo *fifo, uint32_t itt)
1081 {
1082         int i, nr_tasks = __kfifo_len(fifo) / sizeof(void*);
1083         struct iscsi_mgmt_task *task;
1084
1085         debug_scsi("searching %d tasks\n", nr_tasks);
1086
1087         for (i = 0; i < nr_tasks; i++) {
1088                 __kfifo_get(fifo, (void*)&task, sizeof(void*));
1089                 debug_scsi("check task %u\n", task->itt);
1090
1091                 if (task->itt == itt) {
1092                         debug_scsi("matched task\n");
1093                         return task;
1094                 }
1095
1096                 __kfifo_put(fifo, (void*)&task, sizeof(void*));
1097         }
1098         return NULL;
1099 }
1100
1101 static int iscsi_ctask_mtask_cleanup(struct iscsi_cmd_task *ctask)
1102 {
1103         struct iscsi_conn *conn = ctask->conn;
1104         struct iscsi_session *session = conn->session;
1105
1106         if (!ctask->mtask)
1107                 return -EINVAL;
1108
1109         if (!iscsi_remove_mgmt_task(conn->immqueue, ctask->mtask->itt))
1110                 list_del(&ctask->mtask->running);
1111         __kfifo_put(session->mgmtpool.queue, (void*)&ctask->mtask,
1112                     sizeof(void*));
1113         ctask->mtask = NULL;
1114         return 0;
1115 }
1116
1117 /*
1118  * session lock and xmitmutex must be held
1119  */
1120 static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1121                          int err)
1122 {
1123         struct scsi_cmnd *sc;
1124
1125         sc = ctask->sc;
1126         if (!sc)
1127                 return;
1128
1129         conn->session->tt->cleanup_cmd_task(conn, ctask);
1130         iscsi_ctask_mtask_cleanup(ctask);
1131
1132         sc->result = err;
1133         sc->resid = sc->request_bufflen;
1134         /* release ref from queuecommand */
1135         __iscsi_put_ctask(ctask);
1136 }
1137
1138 int iscsi_eh_abort(struct scsi_cmnd *sc)
1139 {
1140         struct iscsi_cmd_task *ctask;
1141         struct iscsi_conn *conn;
1142         struct iscsi_session *session;
1143         int rc;
1144
1145         /*
1146          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1147          * got the command.
1148          */
1149         if (!sc->SCp.ptr) {
1150                 debug_scsi("sc never reached iscsi layer or it completed.\n");
1151                 return SUCCESS;
1152         }
1153
1154         ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
1155         conn = ctask->conn;
1156         session = conn->session;
1157
1158         conn->eh_abort_cnt++;
1159         debug_scsi("aborting [sc %p itt 0x%x]\n", sc, ctask->itt);
1160
1161         mutex_lock(&conn->xmitmutex);
1162         spin_lock_bh(&session->lock);
1163
1164         /*
1165          * If we are not logged in or we have started a new session
1166          * then let the host reset code handle this
1167          */
1168         if (session->state != ISCSI_STATE_LOGGED_IN ||
1169             sc->SCp.phase != session->age)
1170                 goto failed;
1171
1172         /* ctask completed before time out */
1173         if (!ctask->sc) {
1174                 spin_unlock_bh(&session->lock);
1175                 debug_scsi("sc completed while abort in progress\n");
1176                 goto success_rel_mutex;
1177         }
1178
1179         /* what should we do here ? */
1180         if (conn->ctask == ctask) {
1181                 printk(KERN_INFO "iscsi: sc %p itt 0x%x partially sent. "
1182                        "Failing abort\n", sc, ctask->itt);
1183                 goto failed;
1184         }
1185
1186         if (ctask->state == ISCSI_TASK_PENDING)
1187                 goto success_cleanup;
1188
1189         conn->tmabort_state = TMABORT_INITIAL;
1190
1191         spin_unlock_bh(&session->lock);
1192         rc = iscsi_exec_abort_task(sc, ctask);
1193         spin_lock_bh(&session->lock);
1194
1195         if (rc || sc->SCp.phase != session->age ||
1196             session->state != ISCSI_STATE_LOGGED_IN)
1197                 goto failed;
1198         iscsi_ctask_mtask_cleanup(ctask);
1199
1200         switch (conn->tmabort_state) {
1201         case TMABORT_SUCCESS:
1202                 goto success_cleanup;
1203         case TMABORT_NOT_FOUND:
1204                 if (!ctask->sc) {
1205                         /* ctask completed before tmf abort response */
1206                         spin_unlock_bh(&session->lock);
1207                         debug_scsi("sc completed while abort in progress\n");
1208                         goto success_rel_mutex;
1209                 }
1210                 /* fall through */
1211         default:
1212                 /* timedout or failed */
1213                 spin_unlock_bh(&session->lock);
1214                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1215                 spin_lock_bh(&session->lock);
1216                 goto failed;
1217         }
1218
1219 success_cleanup:
1220         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1221         spin_unlock_bh(&session->lock);
1222
1223         /*
1224          * clean up task if aborted. we have the xmitmutex so grab
1225          * the recv lock as a writer
1226          */
1227         write_lock_bh(conn->recv_lock);
1228         spin_lock(&session->lock);
1229         fail_command(conn, ctask, DID_ABORT << 16);
1230         spin_unlock(&session->lock);
1231         write_unlock_bh(conn->recv_lock);
1232
1233 success_rel_mutex:
1234         mutex_unlock(&conn->xmitmutex);
1235         return SUCCESS;
1236
1237 failed:
1238         spin_unlock_bh(&session->lock);
1239         mutex_unlock(&conn->xmitmutex);
1240
1241         debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1242         return FAILED;
1243 }
1244 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1245
1246 int
1247 iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
1248 {
1249         int i;
1250
1251         *items = kmalloc(max * sizeof(void*), GFP_KERNEL);
1252         if (*items == NULL)
1253                 return -ENOMEM;
1254
1255         q->max = max;
1256         q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL);
1257         if (q->pool == NULL) {
1258                 kfree(*items);
1259                 return -ENOMEM;
1260         }
1261
1262         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1263                               GFP_KERNEL, NULL);
1264         if (q->queue == ERR_PTR(-ENOMEM)) {
1265                 kfree(q->pool);
1266                 kfree(*items);
1267                 return -ENOMEM;
1268         }
1269
1270         for (i = 0; i < max; i++) {
1271                 q->pool[i] = kmalloc(item_size, GFP_KERNEL);
1272                 if (q->pool[i] == NULL) {
1273                         int j;
1274
1275                         for (j = 0; j < i; j++)
1276                                 kfree(q->pool[j]);
1277
1278                         kfifo_free(q->queue);
1279                         kfree(q->pool);
1280                         kfree(*items);
1281                         return -ENOMEM;
1282                 }
1283                 memset(q->pool[i], 0, item_size);
1284                 (*items)[i] = q->pool[i];
1285                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1286         }
1287         return 0;
1288 }
1289 EXPORT_SYMBOL_GPL(iscsi_pool_init);
1290
1291 void iscsi_pool_free(struct iscsi_queue *q, void **items)
1292 {
1293         int i;
1294
1295         for (i = 0; i < q->max; i++)
1296                 kfree(items[i]);
1297         kfree(q->pool);
1298         kfree(items);
1299 }
1300 EXPORT_SYMBOL_GPL(iscsi_pool_free);
1301
1302 /*
1303  * iSCSI Session's hostdata organization:
1304  *
1305  *    *------------------* <== hostdata_session(host->hostdata)
1306  *    | ptr to class sess|
1307  *    |------------------| <== iscsi_hostdata(host->hostdata)
1308  *    | iscsi_session    |
1309  *    *------------------*
1310  */
1311
1312 #define hostdata_privsize(_sz)  (sizeof(unsigned long) + _sz + \
1313                                  _sz % sizeof(unsigned long))
1314
1315 #define hostdata_session(_hostdata) (iscsi_ptr(*(unsigned long *)_hostdata))
1316
1317 /**
1318  * iscsi_session_setup - create iscsi cls session and host and session
1319  * @scsit: scsi transport template
1320  * @iscsit: iscsi transport template
1321  * @initial_cmdsn: initial CmdSN
1322  * @hostno: host no allocated
1323  *
1324  * This can be used by software iscsi_transports that allocate
1325  * a session per scsi host.
1326  **/
1327 struct iscsi_cls_session *
1328 iscsi_session_setup(struct iscsi_transport *iscsit,
1329                     struct scsi_transport_template *scsit,
1330                     int cmd_task_size, int mgmt_task_size,
1331                     uint32_t initial_cmdsn, uint32_t *hostno)
1332 {
1333         struct Scsi_Host *shost;
1334         struct iscsi_session *session;
1335         struct iscsi_cls_session *cls_session;
1336         int cmd_i;
1337
1338         shost = scsi_host_alloc(iscsit->host_template,
1339                                 hostdata_privsize(sizeof(*session)));
1340         if (!shost)
1341                 return NULL;
1342
1343         shost->max_id = 1;
1344         shost->max_channel = 0;
1345         shost->max_lun = iscsit->max_lun;
1346         shost->max_cmd_len = iscsit->max_cmd_len;
1347         shost->transportt = scsit;
1348         shost->transportt->create_work_queue = 1;
1349         *hostno = shost->host_no;
1350
1351         session = iscsi_hostdata(shost->hostdata);
1352         memset(session, 0, sizeof(struct iscsi_session));
1353         session->host = shost;
1354         session->state = ISCSI_STATE_FREE;
1355         session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
1356         session->cmds_max = ISCSI_XMIT_CMDS_MAX;
1357         session->cmdsn = initial_cmdsn;
1358         session->exp_cmdsn = initial_cmdsn + 1;
1359         session->max_cmdsn = initial_cmdsn + 1;
1360         session->max_r2t = 1;
1361         session->tt = iscsit;
1362
1363         /* initialize SCSI PDU commands pool */
1364         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
1365                             (void***)&session->cmds,
1366                             cmd_task_size + sizeof(struct iscsi_cmd_task)))
1367                 goto cmdpool_alloc_fail;
1368
1369         /* pre-format cmds pool with ITT */
1370         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1371                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1372
1373                 if (cmd_task_size)
1374                         ctask->dd_data = &ctask[1];
1375                 ctask->itt = cmd_i;
1376                 INIT_LIST_HEAD(&ctask->running);
1377         }
1378
1379         spin_lock_init(&session->lock);
1380         INIT_LIST_HEAD(&session->connections);
1381
1382         /* initialize immediate command pool */
1383         if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max,
1384                            (void***)&session->mgmt_cmds,
1385                            mgmt_task_size + sizeof(struct iscsi_mgmt_task)))
1386                 goto mgmtpool_alloc_fail;
1387
1388
1389         /* pre-format immediate cmds pool with ITT */
1390         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
1391                 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
1392
1393                 if (mgmt_task_size)
1394                         mtask->dd_data = &mtask[1];
1395                 mtask->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i;
1396                 INIT_LIST_HEAD(&mtask->running);
1397         }
1398
1399         if (scsi_add_host(shost, NULL))
1400                 goto add_host_fail;
1401
1402         if (!try_module_get(iscsit->owner))
1403                 goto cls_session_fail;
1404
1405         cls_session = iscsi_create_session(shost, iscsit, 0);
1406         if (!cls_session)
1407                 goto module_put;
1408         *(unsigned long*)shost->hostdata = (unsigned long)cls_session;
1409
1410         return cls_session;
1411
1412 module_put:
1413         module_put(iscsit->owner);
1414 cls_session_fail:
1415         scsi_remove_host(shost);
1416 add_host_fail:
1417         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1418 mgmtpool_alloc_fail:
1419         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1420 cmdpool_alloc_fail:
1421         scsi_host_put(shost);
1422         return NULL;
1423 }
1424 EXPORT_SYMBOL_GPL(iscsi_session_setup);
1425
1426 /**
1427  * iscsi_session_teardown - destroy session, host, and cls_session
1428  * shost: scsi host
1429  *
1430  * This can be used by software iscsi_transports that allocate
1431  * a session per scsi host.
1432  **/
1433 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
1434 {
1435         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1436         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1437         struct module *owner = cls_session->transport->owner;
1438
1439         scsi_remove_host(shost);
1440
1441         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1442         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1443
1444         kfree(session->targetname);
1445
1446         iscsi_destroy_session(cls_session);
1447         scsi_host_put(shost);
1448         module_put(owner);
1449 }
1450 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
1451
1452 /**
1453  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
1454  * @cls_session: iscsi_cls_session
1455  * @conn_idx: cid
1456  **/
1457 struct iscsi_cls_conn *
1458 iscsi_conn_setup(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1459 {
1460         struct iscsi_session *session = class_to_transport_session(cls_session);
1461         struct iscsi_conn *conn;
1462         struct iscsi_cls_conn *cls_conn;
1463         char *data;
1464
1465         cls_conn = iscsi_create_conn(cls_session, conn_idx);
1466         if (!cls_conn)
1467                 return NULL;
1468         conn = cls_conn->dd_data;
1469         memset(conn, 0, sizeof(*conn));
1470
1471         conn->session = session;
1472         conn->cls_conn = cls_conn;
1473         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
1474         conn->id = conn_idx;
1475         conn->exp_statsn = 0;
1476         conn->tmabort_state = TMABORT_INITIAL;
1477         INIT_LIST_HEAD(&conn->run_list);
1478         INIT_LIST_HEAD(&conn->mgmt_run_list);
1479         INIT_LIST_HEAD(&conn->xmitqueue);
1480
1481         /* initialize general immediate & non-immediate PDU commands queue */
1482         conn->immqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
1483                                         GFP_KERNEL, NULL);
1484         if (conn->immqueue == ERR_PTR(-ENOMEM))
1485                 goto immqueue_alloc_fail;
1486
1487         conn->mgmtqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
1488                                         GFP_KERNEL, NULL);
1489         if (conn->mgmtqueue == ERR_PTR(-ENOMEM))
1490                 goto mgmtqueue_alloc_fail;
1491
1492         INIT_WORK(&conn->xmitwork, iscsi_xmitworker, conn);
1493
1494         /* allocate login_mtask used for the login/text sequences */
1495         spin_lock_bh(&session->lock);
1496         if (!__kfifo_get(session->mgmtpool.queue,
1497                          (void*)&conn->login_mtask,
1498                          sizeof(void*))) {
1499                 spin_unlock_bh(&session->lock);
1500                 goto login_mtask_alloc_fail;
1501         }
1502         spin_unlock_bh(&session->lock);
1503
1504         data = kmalloc(DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH, GFP_KERNEL);
1505         if (!data)
1506                 goto login_mtask_data_alloc_fail;
1507         conn->login_mtask->data = conn->data = data;
1508
1509         init_timer(&conn->tmabort_timer);
1510         mutex_init(&conn->xmitmutex);
1511         init_waitqueue_head(&conn->ehwait);
1512
1513         return cls_conn;
1514
1515 login_mtask_data_alloc_fail:
1516         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1517                     sizeof(void*));
1518 login_mtask_alloc_fail:
1519         kfifo_free(conn->mgmtqueue);
1520 mgmtqueue_alloc_fail:
1521         kfifo_free(conn->immqueue);
1522 immqueue_alloc_fail:
1523         iscsi_destroy_conn(cls_conn);
1524         return NULL;
1525 }
1526 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
1527
1528 /**
1529  * iscsi_conn_teardown - teardown iscsi connection
1530  * cls_conn: iscsi class connection
1531  *
1532  * TODO: we may need to make this into a two step process
1533  * like scsi-mls remove + put host
1534  */
1535 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
1536 {
1537         struct iscsi_conn *conn = cls_conn->dd_data;
1538         struct iscsi_session *session = conn->session;
1539         unsigned long flags;
1540
1541         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1542         mutex_lock(&conn->xmitmutex);
1543
1544         spin_lock_bh(&session->lock);
1545         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
1546         if (session->leadconn == conn) {
1547                 /*
1548                  * leading connection? then give up on recovery.
1549                  */
1550                 session->state = ISCSI_STATE_TERMINATE;
1551                 wake_up(&conn->ehwait);
1552         }
1553         spin_unlock_bh(&session->lock);
1554
1555         mutex_unlock(&conn->xmitmutex);
1556
1557         /*
1558          * Block until all in-progress commands for this connection
1559          * time out or fail.
1560          */
1561         for (;;) {
1562                 spin_lock_irqsave(session->host->host_lock, flags);
1563                 if (!session->host->host_busy) { /* OK for ERL == 0 */
1564                         spin_unlock_irqrestore(session->host->host_lock, flags);
1565                         break;
1566                 }
1567                 spin_unlock_irqrestore(session->host->host_lock, flags);
1568                 msleep_interruptible(500);
1569                 printk(KERN_INFO "iscsi: scsi conn_destroy(): host_busy %d "
1570                        "host_failed %d\n", session->host->host_busy,
1571                        session->host->host_failed);
1572                 /*
1573                  * force eh_abort() to unblock
1574                  */
1575                 wake_up(&conn->ehwait);
1576         }
1577
1578         spin_lock_bh(&session->lock);
1579         kfree(conn->data);
1580         kfree(conn->persistent_address);
1581         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1582                     sizeof(void*));
1583         list_del(&conn->item);
1584         if (list_empty(&session->connections))
1585                 session->leadconn = NULL;
1586         if (session->leadconn && session->leadconn == conn)
1587                 session->leadconn = container_of(session->connections.next,
1588                         struct iscsi_conn, item);
1589
1590         if (session->leadconn == NULL)
1591                 /* no connections exits.. reset sequencing */
1592                 session->cmdsn = session->max_cmdsn = session->exp_cmdsn = 1;
1593         spin_unlock_bh(&session->lock);
1594
1595         kfifo_free(conn->immqueue);
1596         kfifo_free(conn->mgmtqueue);
1597
1598         iscsi_destroy_conn(cls_conn);
1599 }
1600 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
1601
1602 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
1603 {
1604         struct iscsi_conn *conn = cls_conn->dd_data;
1605         struct iscsi_session *session = conn->session;
1606
1607         if (!session) {
1608                 printk(KERN_ERR "iscsi: can't start unbound connection\n");
1609                 return -EPERM;
1610         }
1611
1612         if ((session->imm_data_en || !session->initial_r2t_en) &&
1613              session->first_burst > session->max_burst) {
1614                 printk("iscsi: invalid burst lengths: "
1615                        "first_burst %d max_burst %d\n",
1616                        session->first_burst, session->max_burst);
1617                 return -EINVAL;
1618         }
1619
1620         spin_lock_bh(&session->lock);
1621         conn->c_stage = ISCSI_CONN_STARTED;
1622         session->state = ISCSI_STATE_LOGGED_IN;
1623
1624         switch(conn->stop_stage) {
1625         case STOP_CONN_RECOVER:
1626                 /*
1627                  * unblock eh_abort() if it is blocked. re-try all
1628                  * commands after successful recovery
1629                  */
1630                 conn->stop_stage = 0;
1631                 conn->tmabort_state = TMABORT_INITIAL;
1632                 session->age++;
1633                 spin_unlock_bh(&session->lock);
1634
1635                 iscsi_unblock_session(session_to_cls(session));
1636                 wake_up(&conn->ehwait);
1637                 return 0;
1638         case STOP_CONN_TERM:
1639                 conn->stop_stage = 0;
1640                 break;
1641         default:
1642                 break;
1643         }
1644         spin_unlock_bh(&session->lock);
1645
1646         return 0;
1647 }
1648 EXPORT_SYMBOL_GPL(iscsi_conn_start);
1649
1650 static void
1651 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
1652 {
1653         struct iscsi_mgmt_task *mtask, *tmp;
1654
1655         /* handle pending */
1656         while (__kfifo_get(conn->immqueue, (void*)&mtask, sizeof(void*)) ||
1657                __kfifo_get(conn->mgmtqueue, (void*)&mtask, sizeof(void*))) {
1658                 if (mtask == conn->login_mtask)
1659                         continue;
1660                 debug_scsi("flushing pending mgmt task itt 0x%x\n", mtask->itt);
1661                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1662                             sizeof(void*));
1663         }
1664
1665         /* handle running */
1666         list_for_each_entry_safe(mtask, tmp, &conn->mgmt_run_list, running) {
1667                 debug_scsi("flushing running mgmt task itt 0x%x\n", mtask->itt);
1668                 list_del(&mtask->running);
1669
1670                 if (mtask == conn->login_mtask)
1671                         continue;
1672                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1673                            sizeof(void*));
1674         }
1675
1676         conn->mtask = NULL;
1677 }
1678
1679 /* Fail commands. Mutex and session lock held and recv side suspended */
1680 static void fail_all_commands(struct iscsi_conn *conn)
1681 {
1682         struct iscsi_cmd_task *ctask, *tmp;
1683
1684         /* flush pending */
1685         list_for_each_entry_safe(ctask, tmp, &conn->xmitqueue, running) {
1686                 debug_scsi("failing pending sc %p itt 0x%x\n", ctask->sc,
1687                            ctask->itt);
1688                 fail_command(conn, ctask, DID_BUS_BUSY << 16);
1689         }
1690
1691         /* fail all other running */
1692         list_for_each_entry_safe(ctask, tmp, &conn->run_list, running) {
1693                 debug_scsi("failing in progress sc %p itt 0x%x\n",
1694                            ctask->sc, ctask->itt);
1695                 fail_command(conn, ctask, DID_BUS_BUSY << 16);
1696         }
1697
1698         conn->ctask = NULL;
1699 }
1700
1701 static void iscsi_start_session_recovery(struct iscsi_session *session,
1702                                          struct iscsi_conn *conn, int flag)
1703 {
1704         int old_stop_stage;
1705
1706         spin_lock_bh(&session->lock);
1707         if (conn->stop_stage == STOP_CONN_TERM) {
1708                 spin_unlock_bh(&session->lock);
1709                 return;
1710         }
1711
1712         /*
1713          * When this is called for the in_login state, we only want to clean
1714          * up the login task and connection. We do not need to block and set
1715          * the recovery state again
1716          */
1717         if (flag == STOP_CONN_TERM)
1718                 session->state = ISCSI_STATE_TERMINATE;
1719         else if (conn->stop_stage != STOP_CONN_RECOVER)
1720                 session->state = ISCSI_STATE_IN_RECOVERY;
1721
1722         old_stop_stage = conn->stop_stage;
1723         conn->stop_stage = flag;
1724         conn->c_stage = ISCSI_CONN_STOPPED;
1725         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1726         spin_unlock_bh(&session->lock);
1727
1728         write_lock_bh(conn->recv_lock);
1729         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1730         write_unlock_bh(conn->recv_lock);
1731
1732         mutex_lock(&conn->xmitmutex);
1733         /*
1734          * for connection level recovery we should not calculate
1735          * header digest. conn->hdr_size used for optimization
1736          * in hdr_extract() and will be re-negotiated at
1737          * set_param() time.
1738          */
1739         if (flag == STOP_CONN_RECOVER) {
1740                 conn->hdrdgst_en = 0;
1741                 conn->datadgst_en = 0;
1742                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
1743                     old_stop_stage != STOP_CONN_RECOVER) {
1744                         debug_scsi("blocking session\n");
1745                         iscsi_block_session(session_to_cls(session));
1746                 }
1747         }
1748
1749         /*
1750          * flush queues.
1751          */
1752         spin_lock_bh(&session->lock);
1753         fail_all_commands(conn);
1754         flush_control_queues(session, conn);
1755         spin_unlock_bh(&session->lock);
1756
1757         mutex_unlock(&conn->xmitmutex);
1758 }
1759
1760 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1761 {
1762         struct iscsi_conn *conn = cls_conn->dd_data;
1763         struct iscsi_session *session = conn->session;
1764
1765         switch (flag) {
1766         case STOP_CONN_RECOVER:
1767         case STOP_CONN_TERM:
1768                 iscsi_start_session_recovery(session, conn, flag);
1769                 break;
1770         default:
1771                 printk(KERN_ERR "iscsi: invalid stop flag %d\n", flag);
1772         }
1773 }
1774 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
1775
1776 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
1777                     struct iscsi_cls_conn *cls_conn, int is_leading)
1778 {
1779         struct iscsi_session *session = class_to_transport_session(cls_session);
1780         struct iscsi_conn *tmp = ERR_PTR(-EEXIST), *conn = cls_conn->dd_data;
1781
1782         /* lookup for existing connection */
1783         spin_lock_bh(&session->lock);
1784         list_for_each_entry(tmp, &session->connections, item) {
1785                 if (tmp == conn) {
1786                         if (conn->c_stage != ISCSI_CONN_STOPPED ||
1787                             conn->stop_stage == STOP_CONN_TERM) {
1788                                 printk(KERN_ERR "iscsi: can't bind "
1789                                        "non-stopped connection (%d:%d)\n",
1790                                        conn->c_stage, conn->stop_stage);
1791                                 spin_unlock_bh(&session->lock);
1792                                 return -EIO;
1793                         }
1794                         break;
1795                 }
1796         }
1797         if (tmp != conn) {
1798                 /* bind new iSCSI connection to session */
1799                 conn->session = session;
1800                 list_add(&conn->item, &session->connections);
1801         }
1802         spin_unlock_bh(&session->lock);
1803
1804         if (is_leading)
1805                 session->leadconn = conn;
1806
1807         /*
1808          * Unblock xmitworker(), Login Phase will pass through.
1809          */
1810         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1811         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1812         return 0;
1813 }
1814 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
1815
1816
1817 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
1818                     enum iscsi_param param, char *buf, int buflen)
1819 {
1820         struct iscsi_conn *conn = cls_conn->dd_data;
1821         struct iscsi_session *session = conn->session;
1822         uint32_t value;
1823
1824         switch(param) {
1825         case ISCSI_PARAM_MAX_RECV_DLENGTH:
1826                 sscanf(buf, "%d", &conn->max_recv_dlength);
1827                 break;
1828         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
1829                 sscanf(buf, "%d", &conn->max_xmit_dlength);
1830                 break;
1831         case ISCSI_PARAM_HDRDGST_EN:
1832                 sscanf(buf, "%d", &conn->hdrdgst_en);
1833                 break;
1834         case ISCSI_PARAM_DATADGST_EN:
1835                 sscanf(buf, "%d", &conn->datadgst_en);
1836                 break;
1837         case ISCSI_PARAM_INITIAL_R2T_EN:
1838                 sscanf(buf, "%d", &session->initial_r2t_en);
1839                 break;
1840         case ISCSI_PARAM_MAX_R2T:
1841                 sscanf(buf, "%d", &session->max_r2t);
1842                 break;
1843         case ISCSI_PARAM_IMM_DATA_EN:
1844                 sscanf(buf, "%d", &session->imm_data_en);
1845                 break;
1846         case ISCSI_PARAM_FIRST_BURST:
1847                 sscanf(buf, "%d", &session->first_burst);
1848                 break;
1849         case ISCSI_PARAM_MAX_BURST:
1850                 sscanf(buf, "%d", &session->max_burst);
1851                 break;
1852         case ISCSI_PARAM_PDU_INORDER_EN:
1853                 sscanf(buf, "%d", &session->pdu_inorder_en);
1854                 break;
1855         case ISCSI_PARAM_DATASEQ_INORDER_EN:
1856                 sscanf(buf, "%d", &session->dataseq_inorder_en);
1857                 break;
1858         case ISCSI_PARAM_ERL:
1859                 sscanf(buf, "%d", &session->erl);
1860                 break;
1861         case ISCSI_PARAM_IFMARKER_EN:
1862                 sscanf(buf, "%d", &value);
1863                 BUG_ON(value);
1864                 break;
1865         case ISCSI_PARAM_OFMARKER_EN:
1866                 sscanf(buf, "%d", &value);
1867                 BUG_ON(value);
1868                 break;
1869         case ISCSI_PARAM_EXP_STATSN:
1870                 sscanf(buf, "%u", &conn->exp_statsn);
1871                 break;
1872         case ISCSI_PARAM_TARGET_NAME:
1873                 /* this should not change between logins */
1874                 if (session->targetname)
1875                         break;
1876
1877                 session->targetname = kstrdup(buf, GFP_KERNEL);
1878                 if (!session->targetname)
1879                         return -ENOMEM;
1880                 break;
1881         case ISCSI_PARAM_TPGT:
1882                 sscanf(buf, "%d", &session->tpgt);
1883                 break;
1884         case ISCSI_PARAM_PERSISTENT_PORT:
1885                 sscanf(buf, "%d", &conn->persistent_port);
1886                 break;
1887         case ISCSI_PARAM_PERSISTENT_ADDRESS:
1888                 /*
1889                  * this is the address returned in discovery so it should
1890                  * not change between logins.
1891                  */
1892                 if (conn->persistent_address)
1893                         break;
1894
1895                 conn->persistent_address = kstrdup(buf, GFP_KERNEL);
1896                 if (!conn->persistent_address)
1897                         return -ENOMEM;
1898                 break;
1899         default:
1900                 return -ENOSYS;
1901         }
1902
1903         return 0;
1904 }
1905 EXPORT_SYMBOL_GPL(iscsi_set_param);
1906
1907 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
1908                             enum iscsi_param param, char *buf)
1909 {
1910         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1911         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1912         int len;
1913
1914         switch(param) {
1915         case ISCSI_PARAM_INITIAL_R2T_EN:
1916                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
1917                 break;
1918         case ISCSI_PARAM_MAX_R2T:
1919                 len = sprintf(buf, "%hu\n", session->max_r2t);
1920                 break;
1921         case ISCSI_PARAM_IMM_DATA_EN:
1922                 len = sprintf(buf, "%d\n", session->imm_data_en);
1923                 break;
1924         case ISCSI_PARAM_FIRST_BURST:
1925                 len = sprintf(buf, "%u\n", session->first_burst);
1926                 break;
1927         case ISCSI_PARAM_MAX_BURST:
1928                 len = sprintf(buf, "%u\n", session->max_burst);
1929                 break;
1930         case ISCSI_PARAM_PDU_INORDER_EN:
1931                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
1932                 break;
1933         case ISCSI_PARAM_DATASEQ_INORDER_EN:
1934                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
1935                 break;
1936         case ISCSI_PARAM_ERL:
1937                 len = sprintf(buf, "%d\n", session->erl);
1938                 break;
1939         case ISCSI_PARAM_TARGET_NAME:
1940                 len = sprintf(buf, "%s\n", session->targetname);
1941                 break;
1942         case ISCSI_PARAM_TPGT:
1943                 len = sprintf(buf, "%d\n", session->tpgt);
1944                 break;
1945         default:
1946                 return -ENOSYS;
1947         }
1948
1949         return len;
1950 }
1951 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
1952
1953 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
1954                          enum iscsi_param param, char *buf)
1955 {
1956         struct iscsi_conn *conn = cls_conn->dd_data;
1957         int len;
1958
1959         switch(param) {
1960         case ISCSI_PARAM_MAX_RECV_DLENGTH:
1961                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
1962                 break;
1963         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
1964                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
1965                 break;
1966         case ISCSI_PARAM_HDRDGST_EN:
1967                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
1968                 break;
1969         case ISCSI_PARAM_DATADGST_EN:
1970                 len = sprintf(buf, "%d\n", conn->datadgst_en);
1971                 break;
1972         case ISCSI_PARAM_IFMARKER_EN:
1973                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
1974                 break;
1975         case ISCSI_PARAM_OFMARKER_EN:
1976                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
1977                 break;
1978         case ISCSI_PARAM_EXP_STATSN:
1979                 len = sprintf(buf, "%u\n", conn->exp_statsn);
1980                 break;
1981         case ISCSI_PARAM_PERSISTENT_PORT:
1982                 len = sprintf(buf, "%d\n", conn->persistent_port);
1983                 break;
1984         case ISCSI_PARAM_PERSISTENT_ADDRESS:
1985                 len = sprintf(buf, "%s\n", conn->persistent_address);
1986                 break;
1987         default:
1988                 return -ENOSYS;
1989         }
1990
1991         return len;
1992 }
1993 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
1994
1995 MODULE_AUTHOR("Mike Christie");
1996 MODULE_DESCRIPTION("iSCSI library functions");
1997 MODULE_LICENSE("GPL");