[SCSI] libiscsi: fix oops in connection create failure path
[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         if (!conn) {
782                 reason = FAILURE_SESSION_FREED;
783                 goto fault;
784         }
785
786         if (!__kfifo_get(session->cmdpool.queue, (void*)&ctask,
787                          sizeof(void*))) {
788                 reason = FAILURE_OOM;
789                 goto reject;
790         }
791         sc->SCp.phase = session->age;
792         sc->SCp.ptr = (char *)ctask;
793
794         atomic_set(&ctask->refcount, 1);
795         ctask->state = ISCSI_TASK_PENDING;
796         ctask->mtask = NULL;
797         ctask->conn = conn;
798         ctask->sc = sc;
799         INIT_LIST_HEAD(&ctask->running);
800         ctask->total_length = sc->request_bufflen;
801         iscsi_prep_scsi_cmd_pdu(ctask);
802
803         session->tt->init_cmd_task(ctask);
804
805         list_add_tail(&ctask->running, &conn->xmitqueue);
806         debug_scsi(
807                "ctask enq [%s cid %d sc %p cdb 0x%x itt 0x%x len %d cmdsn %d "
808                 "win %d]\n",
809                 sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
810                 conn->id, sc, sc->cmnd[0], ctask->itt, sc->request_bufflen,
811                 session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
812         spin_unlock(&session->lock);
813
814         scsi_queue_work(host, &conn->xmitwork);
815         return 0;
816
817 reject:
818         spin_unlock(&session->lock);
819         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
820         return SCSI_MLQUEUE_HOST_BUSY;
821
822 fault:
823         spin_unlock(&session->lock);
824         printk(KERN_ERR "iscsi: cmd 0x%x is not queued (%d)\n",
825                sc->cmnd[0], reason);
826         sc->result = (DID_NO_CONNECT << 16);
827         sc->resid = sc->request_bufflen;
828         sc->scsi_done(sc);
829         return 0;
830 }
831 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
832
833 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
834 {
835         if (depth > ISCSI_MAX_CMD_PER_LUN)
836                 depth = ISCSI_MAX_CMD_PER_LUN;
837         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
838         return sdev->queue_depth;
839 }
840 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
841
842 static int
843 iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
844                         char *data, uint32_t data_size)
845 {
846         struct iscsi_session *session = conn->session;
847         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
848         struct iscsi_mgmt_task *mtask;
849
850         spin_lock_bh(&session->lock);
851         if (session->state == ISCSI_STATE_TERMINATE) {
852                 spin_unlock_bh(&session->lock);
853                 return -EPERM;
854         }
855         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
856             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
857                 /*
858                  * Login and Text are sent serially, in
859                  * request-followed-by-response sequence.
860                  * Same mtask can be used. Same ITT must be used.
861                  * Note that login_mtask is preallocated at conn_create().
862                  */
863                 mtask = conn->login_mtask;
864         else {
865                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
866                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
867
868                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
869                 if (!__kfifo_get(session->mgmtpool.queue,
870                                  (void*)&mtask, sizeof(void*))) {
871                         spin_unlock_bh(&session->lock);
872                         return -ENOSPC;
873                 }
874         }
875
876         /*
877          * pre-format CmdSN for outgoing PDU.
878          */
879         if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) {
880                 hdr->itt = mtask->itt | (conn->id << ISCSI_CID_SHIFT) |
881                            (session->age << ISCSI_AGE_SHIFT);
882                 nop->cmdsn = cpu_to_be32(session->cmdsn);
883                 if (conn->c_stage == ISCSI_CONN_STARTED &&
884                     !(hdr->opcode & ISCSI_OP_IMMEDIATE))
885                         session->cmdsn++;
886         } else
887                 /* do not advance CmdSN */
888                 nop->cmdsn = cpu_to_be32(session->cmdsn);
889
890         if (data_size) {
891                 memcpy(mtask->data, data, data_size);
892                 mtask->data_count = data_size;
893         } else
894                 mtask->data_count = 0;
895
896         INIT_LIST_HEAD(&mtask->running);
897         memcpy(mtask->hdr, hdr, sizeof(struct iscsi_hdr));
898         if (session->tt->init_mgmt_task)
899                 session->tt->init_mgmt_task(conn, mtask, data, data_size);
900         spin_unlock_bh(&session->lock);
901
902         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
903                    hdr->opcode, hdr->itt, data_size);
904
905         /*
906          * since send_pdu() could be called at least from two contexts,
907          * we need to serialize __kfifo_put, so we don't have to take
908          * additional lock on fast data-path
909          */
910         if (hdr->opcode & ISCSI_OP_IMMEDIATE)
911                 __kfifo_put(conn->immqueue, (void*)&mtask, sizeof(void*));
912         else
913                 __kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*));
914
915         scsi_queue_work(session->host, &conn->xmitwork);
916         return 0;
917 }
918
919 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
920                         char *data, uint32_t data_size)
921 {
922         struct iscsi_conn *conn = cls_conn->dd_data;
923         int rc;
924
925         mutex_lock(&conn->xmitmutex);
926         rc = iscsi_conn_send_generic(conn, hdr, data, data_size);
927         mutex_unlock(&conn->xmitmutex);
928
929         return rc;
930 }
931 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
932
933 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
934 {
935         struct iscsi_session *session = class_to_transport_session(cls_session);
936         struct iscsi_conn *conn = session->leadconn;
937
938         spin_lock_bh(&session->lock);
939         if (session->state != ISCSI_STATE_LOGGED_IN) {
940                 session->state = ISCSI_STATE_RECOVERY_FAILED;
941                 if (conn)
942                         wake_up(&conn->ehwait);
943         }
944         spin_unlock_bh(&session->lock);
945 }
946 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
947
948 int iscsi_eh_host_reset(struct scsi_cmnd *sc)
949 {
950         struct Scsi_Host *host = sc->device->host;
951         struct iscsi_session *session = iscsi_hostdata(host->hostdata);
952         struct iscsi_conn *conn = session->leadconn;
953         int fail_session = 0;
954
955         spin_lock_bh(&session->lock);
956         if (session->state == ISCSI_STATE_TERMINATE) {
957 failed:
958                 debug_scsi("failing host reset: session terminated "
959                            "[CID %d age %d]", conn->id, session->age);
960                 spin_unlock_bh(&session->lock);
961                 return FAILED;
962         }
963
964         if (sc->SCp.phase == session->age) {
965                 debug_scsi("failing connection CID %d due to SCSI host reset",
966                            conn->id);
967                 fail_session = 1;
968         }
969         spin_unlock_bh(&session->lock);
970
971         /*
972          * we drop the lock here but the leadconn cannot be destoyed while
973          * we are in the scsi eh
974          */
975         if (fail_session)
976                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
977
978         debug_scsi("iscsi_eh_host_reset wait for relogin\n");
979         wait_event_interruptible(conn->ehwait,
980                                  session->state == ISCSI_STATE_TERMINATE ||
981                                  session->state == ISCSI_STATE_LOGGED_IN ||
982                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
983         if (signal_pending(current))
984                 flush_signals(current);
985
986         spin_lock_bh(&session->lock);
987         if (session->state == ISCSI_STATE_LOGGED_IN)
988                 printk(KERN_INFO "iscsi: host reset succeeded\n");
989         else
990                 goto failed;
991         spin_unlock_bh(&session->lock);
992
993         return SUCCESS;
994 }
995 EXPORT_SYMBOL_GPL(iscsi_eh_host_reset);
996
997 static void iscsi_tmabort_timedout(unsigned long data)
998 {
999         struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)data;
1000         struct iscsi_conn *conn = ctask->conn;
1001         struct iscsi_session *session = conn->session;
1002
1003         spin_lock(&session->lock);
1004         if (conn->tmabort_state == TMABORT_INITIAL) {
1005                 conn->tmabort_state = TMABORT_TIMEDOUT;
1006                 debug_scsi("tmabort timedout [sc %p itt 0x%x]\n",
1007                         ctask->sc, ctask->itt);
1008                 /* unblock eh_abort() */
1009                 wake_up(&conn->ehwait);
1010         }
1011         spin_unlock(&session->lock);
1012 }
1013
1014 /* must be called with the mutex lock */
1015 static int iscsi_exec_abort_task(struct scsi_cmnd *sc,
1016                                  struct iscsi_cmd_task *ctask)
1017 {
1018         struct iscsi_conn *conn = ctask->conn;
1019         struct iscsi_session *session = conn->session;
1020         struct iscsi_tm *hdr = &conn->tmhdr;
1021         int rc;
1022
1023         /*
1024          * ctask timed out but session is OK requests must be serialized.
1025          */
1026         memset(hdr, 0, sizeof(struct iscsi_tm));
1027         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1028         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK;
1029         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1030         memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
1031         hdr->rtt = ctask->hdr->itt;
1032         hdr->refcmdsn = ctask->hdr->cmdsn;
1033
1034         rc = iscsi_conn_send_generic(conn, (struct iscsi_hdr *)hdr,
1035                                      NULL, 0);
1036         if (rc) {
1037                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1038                 debug_scsi("abort sent failure [itt 0x%x] %d", ctask->itt, rc);
1039                 return rc;
1040         }
1041
1042         debug_scsi("abort sent [itt 0x%x]\n", ctask->itt);
1043
1044         spin_lock_bh(&session->lock);
1045         ctask->mtask = (struct iscsi_mgmt_task *)
1046                         session->mgmt_cmds[(hdr->itt & ISCSI_ITT_MASK) -
1047                                         ISCSI_MGMT_ITT_OFFSET];
1048
1049         if (conn->tmabort_state == TMABORT_INITIAL) {
1050                 conn->tmfcmd_pdus_cnt++;
1051                 conn->tmabort_timer.expires = 10*HZ + jiffies;
1052                 conn->tmabort_timer.function = iscsi_tmabort_timedout;
1053                 conn->tmabort_timer.data = (unsigned long)ctask;
1054                 add_timer(&conn->tmabort_timer);
1055                 debug_scsi("abort set timeout [itt 0x%x]", ctask->itt);
1056         }
1057         spin_unlock_bh(&session->lock);
1058         mutex_unlock(&conn->xmitmutex);
1059
1060         /*
1061          * block eh thread until:
1062          *
1063          * 1) abort response
1064          * 2) abort timeout
1065          * 3) session is terminated or restarted or userspace has
1066          * given up on recovery
1067          */
1068         wait_event_interruptible(conn->ehwait,
1069                                  sc->SCp.phase != session->age ||
1070                                  session->state != ISCSI_STATE_LOGGED_IN ||
1071                                  conn->tmabort_state != TMABORT_INITIAL);
1072         if (signal_pending(current))
1073                 flush_signals(current);
1074         del_timer_sync(&conn->tmabort_timer);
1075
1076         mutex_lock(&conn->xmitmutex);
1077         return 0;
1078 }
1079
1080 /*
1081  * xmit mutex and session lock must be held
1082  */
1083 static struct iscsi_mgmt_task *
1084 iscsi_remove_mgmt_task(struct kfifo *fifo, uint32_t itt)
1085 {
1086         int i, nr_tasks = __kfifo_len(fifo) / sizeof(void*);
1087         struct iscsi_mgmt_task *task;
1088
1089         debug_scsi("searching %d tasks\n", nr_tasks);
1090
1091         for (i = 0; i < nr_tasks; i++) {
1092                 __kfifo_get(fifo, (void*)&task, sizeof(void*));
1093                 debug_scsi("check task %u\n", task->itt);
1094
1095                 if (task->itt == itt) {
1096                         debug_scsi("matched task\n");
1097                         return task;
1098                 }
1099
1100                 __kfifo_put(fifo, (void*)&task, sizeof(void*));
1101         }
1102         return NULL;
1103 }
1104
1105 static int iscsi_ctask_mtask_cleanup(struct iscsi_cmd_task *ctask)
1106 {
1107         struct iscsi_conn *conn = ctask->conn;
1108         struct iscsi_session *session = conn->session;
1109
1110         if (!ctask->mtask)
1111                 return -EINVAL;
1112
1113         if (!iscsi_remove_mgmt_task(conn->immqueue, ctask->mtask->itt))
1114                 list_del(&ctask->mtask->running);
1115         __kfifo_put(session->mgmtpool.queue, (void*)&ctask->mtask,
1116                     sizeof(void*));
1117         ctask->mtask = NULL;
1118         return 0;
1119 }
1120
1121 /*
1122  * session lock and xmitmutex must be held
1123  */
1124 static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
1125                          int err)
1126 {
1127         struct scsi_cmnd *sc;
1128
1129         sc = ctask->sc;
1130         if (!sc)
1131                 return;
1132
1133         conn->session->tt->cleanup_cmd_task(conn, ctask);
1134         iscsi_ctask_mtask_cleanup(ctask);
1135
1136         sc->result = err;
1137         sc->resid = sc->request_bufflen;
1138         /* release ref from queuecommand */
1139         __iscsi_put_ctask(ctask);
1140 }
1141
1142 int iscsi_eh_abort(struct scsi_cmnd *sc)
1143 {
1144         struct iscsi_cmd_task *ctask;
1145         struct iscsi_conn *conn;
1146         struct iscsi_session *session;
1147         int rc;
1148
1149         /*
1150          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1151          * got the command.
1152          */
1153         if (!sc->SCp.ptr) {
1154                 debug_scsi("sc never reached iscsi layer or it completed.\n");
1155                 return SUCCESS;
1156         }
1157
1158         ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
1159         conn = ctask->conn;
1160         session = conn->session;
1161
1162         conn->eh_abort_cnt++;
1163         debug_scsi("aborting [sc %p itt 0x%x]\n", sc, ctask->itt);
1164
1165         mutex_lock(&conn->xmitmutex);
1166         spin_lock_bh(&session->lock);
1167
1168         /*
1169          * If we are not logged in or we have started a new session
1170          * then let the host reset code handle this
1171          */
1172         if (session->state != ISCSI_STATE_LOGGED_IN ||
1173             sc->SCp.phase != session->age)
1174                 goto failed;
1175
1176         /* ctask completed before time out */
1177         if (!ctask->sc) {
1178                 spin_unlock_bh(&session->lock);
1179                 debug_scsi("sc completed while abort in progress\n");
1180                 goto success_rel_mutex;
1181         }
1182
1183         /* what should we do here ? */
1184         if (conn->ctask == ctask) {
1185                 printk(KERN_INFO "iscsi: sc %p itt 0x%x partially sent. "
1186                        "Failing abort\n", sc, ctask->itt);
1187                 goto failed;
1188         }
1189
1190         if (ctask->state == ISCSI_TASK_PENDING)
1191                 goto success_cleanup;
1192
1193         conn->tmabort_state = TMABORT_INITIAL;
1194
1195         spin_unlock_bh(&session->lock);
1196         rc = iscsi_exec_abort_task(sc, ctask);
1197         spin_lock_bh(&session->lock);
1198
1199         if (rc || sc->SCp.phase != session->age ||
1200             session->state != ISCSI_STATE_LOGGED_IN)
1201                 goto failed;
1202         iscsi_ctask_mtask_cleanup(ctask);
1203
1204         switch (conn->tmabort_state) {
1205         case TMABORT_SUCCESS:
1206                 goto success_cleanup;
1207         case TMABORT_NOT_FOUND:
1208                 if (!ctask->sc) {
1209                         /* ctask completed before tmf abort response */
1210                         spin_unlock_bh(&session->lock);
1211                         debug_scsi("sc completed while abort in progress\n");
1212                         goto success_rel_mutex;
1213                 }
1214                 /* fall through */
1215         default:
1216                 /* timedout or failed */
1217                 spin_unlock_bh(&session->lock);
1218                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1219                 spin_lock_bh(&session->lock);
1220                 goto failed;
1221         }
1222
1223 success_cleanup:
1224         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1225         spin_unlock_bh(&session->lock);
1226
1227         /*
1228          * clean up task if aborted. we have the xmitmutex so grab
1229          * the recv lock as a writer
1230          */
1231         write_lock_bh(conn->recv_lock);
1232         spin_lock(&session->lock);
1233         fail_command(conn, ctask, DID_ABORT << 16);
1234         spin_unlock(&session->lock);
1235         write_unlock_bh(conn->recv_lock);
1236
1237 success_rel_mutex:
1238         mutex_unlock(&conn->xmitmutex);
1239         return SUCCESS;
1240
1241 failed:
1242         spin_unlock_bh(&session->lock);
1243         mutex_unlock(&conn->xmitmutex);
1244
1245         debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
1246         return FAILED;
1247 }
1248 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1249
1250 int
1251 iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
1252 {
1253         int i;
1254
1255         *items = kmalloc(max * sizeof(void*), GFP_KERNEL);
1256         if (*items == NULL)
1257                 return -ENOMEM;
1258
1259         q->max = max;
1260         q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL);
1261         if (q->pool == NULL) {
1262                 kfree(*items);
1263                 return -ENOMEM;
1264         }
1265
1266         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1267                               GFP_KERNEL, NULL);
1268         if (q->queue == ERR_PTR(-ENOMEM)) {
1269                 kfree(q->pool);
1270                 kfree(*items);
1271                 return -ENOMEM;
1272         }
1273
1274         for (i = 0; i < max; i++) {
1275                 q->pool[i] = kmalloc(item_size, GFP_KERNEL);
1276                 if (q->pool[i] == NULL) {
1277                         int j;
1278
1279                         for (j = 0; j < i; j++)
1280                                 kfree(q->pool[j]);
1281
1282                         kfifo_free(q->queue);
1283                         kfree(q->pool);
1284                         kfree(*items);
1285                         return -ENOMEM;
1286                 }
1287                 memset(q->pool[i], 0, item_size);
1288                 (*items)[i] = q->pool[i];
1289                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1290         }
1291         return 0;
1292 }
1293 EXPORT_SYMBOL_GPL(iscsi_pool_init);
1294
1295 void iscsi_pool_free(struct iscsi_queue *q, void **items)
1296 {
1297         int i;
1298
1299         for (i = 0; i < q->max; i++)
1300                 kfree(items[i]);
1301         kfree(q->pool);
1302         kfree(items);
1303 }
1304 EXPORT_SYMBOL_GPL(iscsi_pool_free);
1305
1306 /*
1307  * iSCSI Session's hostdata organization:
1308  *
1309  *    *------------------* <== hostdata_session(host->hostdata)
1310  *    | ptr to class sess|
1311  *    |------------------| <== iscsi_hostdata(host->hostdata)
1312  *    | iscsi_session    |
1313  *    *------------------*
1314  */
1315
1316 #define hostdata_privsize(_sz)  (sizeof(unsigned long) + _sz + \
1317                                  _sz % sizeof(unsigned long))
1318
1319 #define hostdata_session(_hostdata) (iscsi_ptr(*(unsigned long *)_hostdata))
1320
1321 /**
1322  * iscsi_session_setup - create iscsi cls session and host and session
1323  * @scsit: scsi transport template
1324  * @iscsit: iscsi transport template
1325  * @initial_cmdsn: initial CmdSN
1326  * @hostno: host no allocated
1327  *
1328  * This can be used by software iscsi_transports that allocate
1329  * a session per scsi host.
1330  **/
1331 struct iscsi_cls_session *
1332 iscsi_session_setup(struct iscsi_transport *iscsit,
1333                     struct scsi_transport_template *scsit,
1334                     int cmd_task_size, int mgmt_task_size,
1335                     uint32_t initial_cmdsn, uint32_t *hostno)
1336 {
1337         struct Scsi_Host *shost;
1338         struct iscsi_session *session;
1339         struct iscsi_cls_session *cls_session;
1340         int cmd_i;
1341
1342         shost = scsi_host_alloc(iscsit->host_template,
1343                                 hostdata_privsize(sizeof(*session)));
1344         if (!shost)
1345                 return NULL;
1346
1347         shost->max_id = 1;
1348         shost->max_channel = 0;
1349         shost->max_lun = iscsit->max_lun;
1350         shost->max_cmd_len = iscsit->max_cmd_len;
1351         shost->transportt = scsit;
1352         shost->transportt->create_work_queue = 1;
1353         *hostno = shost->host_no;
1354
1355         session = iscsi_hostdata(shost->hostdata);
1356         memset(session, 0, sizeof(struct iscsi_session));
1357         session->host = shost;
1358         session->state = ISCSI_STATE_FREE;
1359         session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
1360         session->cmds_max = ISCSI_XMIT_CMDS_MAX;
1361         session->cmdsn = initial_cmdsn;
1362         session->exp_cmdsn = initial_cmdsn + 1;
1363         session->max_cmdsn = initial_cmdsn + 1;
1364         session->max_r2t = 1;
1365         session->tt = iscsit;
1366
1367         /* initialize SCSI PDU commands pool */
1368         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
1369                             (void***)&session->cmds,
1370                             cmd_task_size + sizeof(struct iscsi_cmd_task)))
1371                 goto cmdpool_alloc_fail;
1372
1373         /* pre-format cmds pool with ITT */
1374         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1375                 struct iscsi_cmd_task *ctask = session->cmds[cmd_i];
1376
1377                 if (cmd_task_size)
1378                         ctask->dd_data = &ctask[1];
1379                 ctask->itt = cmd_i;
1380                 INIT_LIST_HEAD(&ctask->running);
1381         }
1382
1383         spin_lock_init(&session->lock);
1384
1385         /* initialize immediate command pool */
1386         if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max,
1387                            (void***)&session->mgmt_cmds,
1388                            mgmt_task_size + sizeof(struct iscsi_mgmt_task)))
1389                 goto mgmtpool_alloc_fail;
1390
1391
1392         /* pre-format immediate cmds pool with ITT */
1393         for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) {
1394                 struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i];
1395
1396                 if (mgmt_task_size)
1397                         mtask->dd_data = &mtask[1];
1398                 mtask->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i;
1399                 INIT_LIST_HEAD(&mtask->running);
1400         }
1401
1402         if (scsi_add_host(shost, NULL))
1403                 goto add_host_fail;
1404
1405         if (!try_module_get(iscsit->owner))
1406                 goto cls_session_fail;
1407
1408         cls_session = iscsi_create_session(shost, iscsit, 0);
1409         if (!cls_session)
1410                 goto module_put;
1411         *(unsigned long*)shost->hostdata = (unsigned long)cls_session;
1412
1413         return cls_session;
1414
1415 module_put:
1416         module_put(iscsit->owner);
1417 cls_session_fail:
1418         scsi_remove_host(shost);
1419 add_host_fail:
1420         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1421 mgmtpool_alloc_fail:
1422         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1423 cmdpool_alloc_fail:
1424         scsi_host_put(shost);
1425         return NULL;
1426 }
1427 EXPORT_SYMBOL_GPL(iscsi_session_setup);
1428
1429 /**
1430  * iscsi_session_teardown - destroy session, host, and cls_session
1431  * shost: scsi host
1432  *
1433  * This can be used by software iscsi_transports that allocate
1434  * a session per scsi host.
1435  **/
1436 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
1437 {
1438         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1439         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1440         struct module *owner = cls_session->transport->owner;
1441
1442         scsi_remove_host(shost);
1443
1444         iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds);
1445         iscsi_pool_free(&session->cmdpool, (void**)session->cmds);
1446
1447         kfree(session->targetname);
1448
1449         iscsi_destroy_session(cls_session);
1450         scsi_host_put(shost);
1451         module_put(owner);
1452 }
1453 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
1454
1455 /**
1456  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
1457  * @cls_session: iscsi_cls_session
1458  * @conn_idx: cid
1459  **/
1460 struct iscsi_cls_conn *
1461 iscsi_conn_setup(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
1462 {
1463         struct iscsi_session *session = class_to_transport_session(cls_session);
1464         struct iscsi_conn *conn;
1465         struct iscsi_cls_conn *cls_conn;
1466         char *data;
1467
1468         cls_conn = iscsi_create_conn(cls_session, conn_idx);
1469         if (!cls_conn)
1470                 return NULL;
1471         conn = cls_conn->dd_data;
1472         memset(conn, 0, sizeof(*conn));
1473
1474         conn->session = session;
1475         conn->cls_conn = cls_conn;
1476         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
1477         conn->id = conn_idx;
1478         conn->exp_statsn = 0;
1479         conn->tmabort_state = TMABORT_INITIAL;
1480         INIT_LIST_HEAD(&conn->run_list);
1481         INIT_LIST_HEAD(&conn->mgmt_run_list);
1482         INIT_LIST_HEAD(&conn->xmitqueue);
1483
1484         /* initialize general immediate & non-immediate PDU commands queue */
1485         conn->immqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
1486                                         GFP_KERNEL, NULL);
1487         if (conn->immqueue == ERR_PTR(-ENOMEM))
1488                 goto immqueue_alloc_fail;
1489
1490         conn->mgmtqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
1491                                         GFP_KERNEL, NULL);
1492         if (conn->mgmtqueue == ERR_PTR(-ENOMEM))
1493                 goto mgmtqueue_alloc_fail;
1494
1495         INIT_WORK(&conn->xmitwork, iscsi_xmitworker, conn);
1496
1497         /* allocate login_mtask used for the login/text sequences */
1498         spin_lock_bh(&session->lock);
1499         if (!__kfifo_get(session->mgmtpool.queue,
1500                          (void*)&conn->login_mtask,
1501                          sizeof(void*))) {
1502                 spin_unlock_bh(&session->lock);
1503                 goto login_mtask_alloc_fail;
1504         }
1505         spin_unlock_bh(&session->lock);
1506
1507         data = kmalloc(DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH, GFP_KERNEL);
1508         if (!data)
1509                 goto login_mtask_data_alloc_fail;
1510         conn->login_mtask->data = conn->data = data;
1511
1512         init_timer(&conn->tmabort_timer);
1513         mutex_init(&conn->xmitmutex);
1514         init_waitqueue_head(&conn->ehwait);
1515
1516         return cls_conn;
1517
1518 login_mtask_data_alloc_fail:
1519         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1520                     sizeof(void*));
1521 login_mtask_alloc_fail:
1522         kfifo_free(conn->mgmtqueue);
1523 mgmtqueue_alloc_fail:
1524         kfifo_free(conn->immqueue);
1525 immqueue_alloc_fail:
1526         iscsi_destroy_conn(cls_conn);
1527         return NULL;
1528 }
1529 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
1530
1531 /**
1532  * iscsi_conn_teardown - teardown iscsi connection
1533  * cls_conn: iscsi class connection
1534  *
1535  * TODO: we may need to make this into a two step process
1536  * like scsi-mls remove + put host
1537  */
1538 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
1539 {
1540         struct iscsi_conn *conn = cls_conn->dd_data;
1541         struct iscsi_session *session = conn->session;
1542         unsigned long flags;
1543
1544         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1545         mutex_lock(&conn->xmitmutex);
1546
1547         spin_lock_bh(&session->lock);
1548         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
1549         if (session->leadconn == conn) {
1550                 /*
1551                  * leading connection? then give up on recovery.
1552                  */
1553                 session->state = ISCSI_STATE_TERMINATE;
1554                 wake_up(&conn->ehwait);
1555         }
1556         spin_unlock_bh(&session->lock);
1557
1558         mutex_unlock(&conn->xmitmutex);
1559
1560         /*
1561          * Block until all in-progress commands for this connection
1562          * time out or fail.
1563          */
1564         for (;;) {
1565                 spin_lock_irqsave(session->host->host_lock, flags);
1566                 if (!session->host->host_busy) { /* OK for ERL == 0 */
1567                         spin_unlock_irqrestore(session->host->host_lock, flags);
1568                         break;
1569                 }
1570                 spin_unlock_irqrestore(session->host->host_lock, flags);
1571                 msleep_interruptible(500);
1572                 printk(KERN_INFO "iscsi: scsi conn_destroy(): host_busy %d "
1573                        "host_failed %d\n", session->host->host_busy,
1574                        session->host->host_failed);
1575                 /*
1576                  * force eh_abort() to unblock
1577                  */
1578                 wake_up(&conn->ehwait);
1579         }
1580
1581         spin_lock_bh(&session->lock);
1582         kfree(conn->data);
1583         kfree(conn->persistent_address);
1584         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
1585                     sizeof(void*));
1586         if (session->leadconn == conn) {
1587                 session->leadconn = NULL;
1588                 /* no connections exits.. reset sequencing */
1589                 session->cmdsn = session->max_cmdsn = session->exp_cmdsn = 1;
1590         }
1591         spin_unlock_bh(&session->lock);
1592
1593         kfifo_free(conn->immqueue);
1594         kfifo_free(conn->mgmtqueue);
1595
1596         iscsi_destroy_conn(cls_conn);
1597 }
1598 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
1599
1600 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
1601 {
1602         struct iscsi_conn *conn = cls_conn->dd_data;
1603         struct iscsi_session *session = conn->session;
1604
1605         if (!session) {
1606                 printk(KERN_ERR "iscsi: can't start unbound connection\n");
1607                 return -EPERM;
1608         }
1609
1610         if ((session->imm_data_en || !session->initial_r2t_en) &&
1611              session->first_burst > session->max_burst) {
1612                 printk("iscsi: invalid burst lengths: "
1613                        "first_burst %d max_burst %d\n",
1614                        session->first_burst, session->max_burst);
1615                 return -EINVAL;
1616         }
1617
1618         spin_lock_bh(&session->lock);
1619         conn->c_stage = ISCSI_CONN_STARTED;
1620         session->state = ISCSI_STATE_LOGGED_IN;
1621
1622         switch(conn->stop_stage) {
1623         case STOP_CONN_RECOVER:
1624                 /*
1625                  * unblock eh_abort() if it is blocked. re-try all
1626                  * commands after successful recovery
1627                  */
1628                 conn->stop_stage = 0;
1629                 conn->tmabort_state = TMABORT_INITIAL;
1630                 session->age++;
1631                 spin_unlock_bh(&session->lock);
1632
1633                 iscsi_unblock_session(session_to_cls(session));
1634                 wake_up(&conn->ehwait);
1635                 return 0;
1636         case STOP_CONN_TERM:
1637                 conn->stop_stage = 0;
1638                 break;
1639         default:
1640                 break;
1641         }
1642         spin_unlock_bh(&session->lock);
1643
1644         return 0;
1645 }
1646 EXPORT_SYMBOL_GPL(iscsi_conn_start);
1647
1648 static void
1649 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
1650 {
1651         struct iscsi_mgmt_task *mtask, *tmp;
1652
1653         /* handle pending */
1654         while (__kfifo_get(conn->immqueue, (void*)&mtask, sizeof(void*)) ||
1655                __kfifo_get(conn->mgmtqueue, (void*)&mtask, sizeof(void*))) {
1656                 if (mtask == conn->login_mtask)
1657                         continue;
1658                 debug_scsi("flushing pending mgmt task itt 0x%x\n", mtask->itt);
1659                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1660                             sizeof(void*));
1661         }
1662
1663         /* handle running */
1664         list_for_each_entry_safe(mtask, tmp, &conn->mgmt_run_list, running) {
1665                 debug_scsi("flushing running mgmt task itt 0x%x\n", mtask->itt);
1666                 list_del(&mtask->running);
1667
1668                 if (mtask == conn->login_mtask)
1669                         continue;
1670                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
1671                            sizeof(void*));
1672         }
1673
1674         conn->mtask = NULL;
1675 }
1676
1677 /* Fail commands. Mutex and session lock held and recv side suspended */
1678 static void fail_all_commands(struct iscsi_conn *conn)
1679 {
1680         struct iscsi_cmd_task *ctask, *tmp;
1681
1682         /* flush pending */
1683         list_for_each_entry_safe(ctask, tmp, &conn->xmitqueue, running) {
1684                 debug_scsi("failing pending sc %p itt 0x%x\n", ctask->sc,
1685                            ctask->itt);
1686                 fail_command(conn, ctask, DID_BUS_BUSY << 16);
1687         }
1688
1689         /* fail all other running */
1690         list_for_each_entry_safe(ctask, tmp, &conn->run_list, running) {
1691                 debug_scsi("failing in progress sc %p itt 0x%x\n",
1692                            ctask->sc, ctask->itt);
1693                 fail_command(conn, ctask, DID_BUS_BUSY << 16);
1694         }
1695
1696         conn->ctask = NULL;
1697 }
1698
1699 static void iscsi_start_session_recovery(struct iscsi_session *session,
1700                                          struct iscsi_conn *conn, int flag)
1701 {
1702         int old_stop_stage;
1703
1704         spin_lock_bh(&session->lock);
1705         if (conn->stop_stage == STOP_CONN_TERM) {
1706                 spin_unlock_bh(&session->lock);
1707                 return;
1708         }
1709
1710         /*
1711          * When this is called for the in_login state, we only want to clean
1712          * up the login task and connection. We do not need to block and set
1713          * the recovery state again
1714          */
1715         if (flag == STOP_CONN_TERM)
1716                 session->state = ISCSI_STATE_TERMINATE;
1717         else if (conn->stop_stage != STOP_CONN_RECOVER)
1718                 session->state = ISCSI_STATE_IN_RECOVERY;
1719
1720         old_stop_stage = conn->stop_stage;
1721         conn->stop_stage = flag;
1722         conn->c_stage = ISCSI_CONN_STOPPED;
1723         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1724         spin_unlock_bh(&session->lock);
1725
1726         write_lock_bh(conn->recv_lock);
1727         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1728         write_unlock_bh(conn->recv_lock);
1729
1730         mutex_lock(&conn->xmitmutex);
1731         /*
1732          * for connection level recovery we should not calculate
1733          * header digest. conn->hdr_size used for optimization
1734          * in hdr_extract() and will be re-negotiated at
1735          * set_param() time.
1736          */
1737         if (flag == STOP_CONN_RECOVER) {
1738                 conn->hdrdgst_en = 0;
1739                 conn->datadgst_en = 0;
1740                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
1741                     old_stop_stage != STOP_CONN_RECOVER) {
1742                         debug_scsi("blocking session\n");
1743                         iscsi_block_session(session_to_cls(session));
1744                 }
1745         }
1746
1747         /*
1748          * flush queues.
1749          */
1750         spin_lock_bh(&session->lock);
1751         fail_all_commands(conn);
1752         flush_control_queues(session, conn);
1753         spin_unlock_bh(&session->lock);
1754
1755         mutex_unlock(&conn->xmitmutex);
1756 }
1757
1758 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
1759 {
1760         struct iscsi_conn *conn = cls_conn->dd_data;
1761         struct iscsi_session *session = conn->session;
1762
1763         switch (flag) {
1764         case STOP_CONN_RECOVER:
1765         case STOP_CONN_TERM:
1766                 iscsi_start_session_recovery(session, conn, flag);
1767                 break;
1768         default:
1769                 printk(KERN_ERR "iscsi: invalid stop flag %d\n", flag);
1770         }
1771 }
1772 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
1773
1774 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
1775                     struct iscsi_cls_conn *cls_conn, int is_leading)
1776 {
1777         struct iscsi_session *session = class_to_transport_session(cls_session);
1778         struct iscsi_conn *conn = cls_conn->dd_data;
1779
1780         spin_lock_bh(&session->lock);
1781         if (is_leading)
1782                 session->leadconn = conn;
1783         spin_unlock_bh(&session->lock);
1784
1785         /*
1786          * Unblock xmitworker(), Login Phase will pass through.
1787          */
1788         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1789         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1790         return 0;
1791 }
1792 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
1793
1794
1795 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
1796                     enum iscsi_param param, char *buf, int buflen)
1797 {
1798         struct iscsi_conn *conn = cls_conn->dd_data;
1799         struct iscsi_session *session = conn->session;
1800         uint32_t value;
1801
1802         switch(param) {
1803         case ISCSI_PARAM_MAX_RECV_DLENGTH:
1804                 sscanf(buf, "%d", &conn->max_recv_dlength);
1805                 break;
1806         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
1807                 sscanf(buf, "%d", &conn->max_xmit_dlength);
1808                 break;
1809         case ISCSI_PARAM_HDRDGST_EN:
1810                 sscanf(buf, "%d", &conn->hdrdgst_en);
1811                 break;
1812         case ISCSI_PARAM_DATADGST_EN:
1813                 sscanf(buf, "%d", &conn->datadgst_en);
1814                 break;
1815         case ISCSI_PARAM_INITIAL_R2T_EN:
1816                 sscanf(buf, "%d", &session->initial_r2t_en);
1817                 break;
1818         case ISCSI_PARAM_MAX_R2T:
1819                 sscanf(buf, "%d", &session->max_r2t);
1820                 break;
1821         case ISCSI_PARAM_IMM_DATA_EN:
1822                 sscanf(buf, "%d", &session->imm_data_en);
1823                 break;
1824         case ISCSI_PARAM_FIRST_BURST:
1825                 sscanf(buf, "%d", &session->first_burst);
1826                 break;
1827         case ISCSI_PARAM_MAX_BURST:
1828                 sscanf(buf, "%d", &session->max_burst);
1829                 break;
1830         case ISCSI_PARAM_PDU_INORDER_EN:
1831                 sscanf(buf, "%d", &session->pdu_inorder_en);
1832                 break;
1833         case ISCSI_PARAM_DATASEQ_INORDER_EN:
1834                 sscanf(buf, "%d", &session->dataseq_inorder_en);
1835                 break;
1836         case ISCSI_PARAM_ERL:
1837                 sscanf(buf, "%d", &session->erl);
1838                 break;
1839         case ISCSI_PARAM_IFMARKER_EN:
1840                 sscanf(buf, "%d", &value);
1841                 BUG_ON(value);
1842                 break;
1843         case ISCSI_PARAM_OFMARKER_EN:
1844                 sscanf(buf, "%d", &value);
1845                 BUG_ON(value);
1846                 break;
1847         case ISCSI_PARAM_EXP_STATSN:
1848                 sscanf(buf, "%u", &conn->exp_statsn);
1849                 break;
1850         case ISCSI_PARAM_TARGET_NAME:
1851                 /* this should not change between logins */
1852                 if (session->targetname)
1853                         break;
1854
1855                 session->targetname = kstrdup(buf, GFP_KERNEL);
1856                 if (!session->targetname)
1857                         return -ENOMEM;
1858                 break;
1859         case ISCSI_PARAM_TPGT:
1860                 sscanf(buf, "%d", &session->tpgt);
1861                 break;
1862         case ISCSI_PARAM_PERSISTENT_PORT:
1863                 sscanf(buf, "%d", &conn->persistent_port);
1864                 break;
1865         case ISCSI_PARAM_PERSISTENT_ADDRESS:
1866                 /*
1867                  * this is the address returned in discovery so it should
1868                  * not change between logins.
1869                  */
1870                 if (conn->persistent_address)
1871                         break;
1872
1873                 conn->persistent_address = kstrdup(buf, GFP_KERNEL);
1874                 if (!conn->persistent_address)
1875                         return -ENOMEM;
1876                 break;
1877         default:
1878                 return -ENOSYS;
1879         }
1880
1881         return 0;
1882 }
1883 EXPORT_SYMBOL_GPL(iscsi_set_param);
1884
1885 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
1886                             enum iscsi_param param, char *buf)
1887 {
1888         struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
1889         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
1890         int len;
1891
1892         switch(param) {
1893         case ISCSI_PARAM_INITIAL_R2T_EN:
1894                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
1895                 break;
1896         case ISCSI_PARAM_MAX_R2T:
1897                 len = sprintf(buf, "%hu\n", session->max_r2t);
1898                 break;
1899         case ISCSI_PARAM_IMM_DATA_EN:
1900                 len = sprintf(buf, "%d\n", session->imm_data_en);
1901                 break;
1902         case ISCSI_PARAM_FIRST_BURST:
1903                 len = sprintf(buf, "%u\n", session->first_burst);
1904                 break;
1905         case ISCSI_PARAM_MAX_BURST:
1906                 len = sprintf(buf, "%u\n", session->max_burst);
1907                 break;
1908         case ISCSI_PARAM_PDU_INORDER_EN:
1909                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
1910                 break;
1911         case ISCSI_PARAM_DATASEQ_INORDER_EN:
1912                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
1913                 break;
1914         case ISCSI_PARAM_ERL:
1915                 len = sprintf(buf, "%d\n", session->erl);
1916                 break;
1917         case ISCSI_PARAM_TARGET_NAME:
1918                 len = sprintf(buf, "%s\n", session->targetname);
1919                 break;
1920         case ISCSI_PARAM_TPGT:
1921                 len = sprintf(buf, "%d\n", session->tpgt);
1922                 break;
1923         default:
1924                 return -ENOSYS;
1925         }
1926
1927         return len;
1928 }
1929 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
1930
1931 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
1932                          enum iscsi_param param, char *buf)
1933 {
1934         struct iscsi_conn *conn = cls_conn->dd_data;
1935         int len;
1936
1937         switch(param) {
1938         case ISCSI_PARAM_MAX_RECV_DLENGTH:
1939                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
1940                 break;
1941         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
1942                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
1943                 break;
1944         case ISCSI_PARAM_HDRDGST_EN:
1945                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
1946                 break;
1947         case ISCSI_PARAM_DATADGST_EN:
1948                 len = sprintf(buf, "%d\n", conn->datadgst_en);
1949                 break;
1950         case ISCSI_PARAM_IFMARKER_EN:
1951                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
1952                 break;
1953         case ISCSI_PARAM_OFMARKER_EN:
1954                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
1955                 break;
1956         case ISCSI_PARAM_EXP_STATSN:
1957                 len = sprintf(buf, "%u\n", conn->exp_statsn);
1958                 break;
1959         case ISCSI_PARAM_PERSISTENT_PORT:
1960                 len = sprintf(buf, "%d\n", conn->persistent_port);
1961                 break;
1962         case ISCSI_PARAM_PERSISTENT_ADDRESS:
1963                 len = sprintf(buf, "%s\n", conn->persistent_address);
1964                 break;
1965         default:
1966                 return -ENOSYS;
1967         }
1968
1969         return len;
1970 }
1971 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
1972
1973 MODULE_AUTHOR("Mike Christie");
1974 MODULE_DESCRIPTION("iSCSI library functions");
1975 MODULE_LICENSE("GPL");