6c4034b1561c9e87da4cd67cd95c6421fb947b16
[linux-2.6.git] / drivers / scsi / libiscsi.c
1 /*
2  * iSCSI lib functions
3  *
4  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
5  * Copyright (C) 2004 - 2006 Mike Christie
6  * Copyright (C) 2004 - 2005 Dmitry Yusupov
7  * Copyright (C) 2004 - 2005 Alex Aizman
8  * maintained by open-iscsi@googlegroups.com
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23  */
24 #include <linux/types.h>
25 #include <linux/kfifo.h>
26 #include <linux/delay.h>
27 #include <linux/log2.h>
28 #include <asm/unaligned.h>
29 #include <net/tcp.h>
30 #include <scsi/scsi_cmnd.h>
31 #include <scsi/scsi_device.h>
32 #include <scsi/scsi_eh.h>
33 #include <scsi/scsi_tcq.h>
34 #include <scsi/scsi_host.h>
35 #include <scsi/scsi.h>
36 #include <scsi/iscsi_proto.h>
37 #include <scsi/scsi_transport.h>
38 #include <scsi/scsi_transport_iscsi.h>
39 #include <scsi/libiscsi.h>
40
41 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
42 #define SNA32_CHECK 2147483648UL
43
44 static int iscsi_sna_lt(u32 n1, u32 n2)
45 {
46         return n1 != n2 && ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
47                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
48 }
49
50 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
51 static int iscsi_sna_lte(u32 n1, u32 n2)
52 {
53         return n1 == n2 || ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
54                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
55 }
56
57 void
58 iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
59 {
60         uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
61         uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);
62
63         /*
64          * standard specifies this check for when to update expected and
65          * max sequence numbers
66          */
67         if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
68                 return;
69
70         if (exp_cmdsn != session->exp_cmdsn &&
71             !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
72                 session->exp_cmdsn = exp_cmdsn;
73
74         if (max_cmdsn != session->max_cmdsn &&
75             !iscsi_sna_lt(max_cmdsn, session->max_cmdsn)) {
76                 session->max_cmdsn = max_cmdsn;
77                 /*
78                  * if the window closed with IO queued, then kick the
79                  * xmit thread
80                  */
81                 if (!list_empty(&session->leadconn->xmitqueue) ||
82                     !list_empty(&session->leadconn->mgmtqueue)) {
83                         if (!(session->tt->caps & CAP_DATA_PATH_OFFLOAD))
84                                 scsi_queue_work(session->host,
85                                                 &session->leadconn->xmitwork);
86                 }
87         }
88 }
89 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
90
91 /**
92  * iscsi_prep_data_out_pdu - initialize Data-Out
93  * @task: scsi command task
94  * @r2t: R2T info
95  * @hdr: iscsi data in pdu
96  *
97  * Notes:
98  *      Initialize Data-Out within this R2T sequence and finds
99  *      proper data_offset within this SCSI command.
100  *
101  *      This function is called with connection lock taken.
102  **/
103 void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
104                            struct iscsi_data *hdr)
105 {
106         struct iscsi_conn *conn = task->conn;
107         unsigned int left = r2t->data_length - r2t->sent;
108
109         task->hdr_len = sizeof(struct iscsi_data);
110
111         memset(hdr, 0, sizeof(struct iscsi_data));
112         hdr->ttt = r2t->ttt;
113         hdr->datasn = cpu_to_be32(r2t->datasn);
114         r2t->datasn++;
115         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
116         memcpy(hdr->lun, task->lun, sizeof(hdr->lun));
117         hdr->itt = task->hdr_itt;
118         hdr->exp_statsn = r2t->exp_statsn;
119         hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
120         if (left > conn->max_xmit_dlength) {
121                 hton24(hdr->dlength, conn->max_xmit_dlength);
122                 r2t->data_count = conn->max_xmit_dlength;
123                 hdr->flags = 0;
124         } else {
125                 hton24(hdr->dlength, left);
126                 r2t->data_count = left;
127                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
128         }
129         conn->dataout_pdus_cnt++;
130 }
131 EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
132
133 static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
134 {
135         unsigned exp_len = task->hdr_len + len;
136
137         if (exp_len > task->hdr_max) {
138                 WARN_ON(1);
139                 return -EINVAL;
140         }
141
142         WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
143         task->hdr_len = exp_len;
144         return 0;
145 }
146
147 /*
148  * make an extended cdb AHS
149  */
150 static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
151 {
152         struct scsi_cmnd *cmd = task->sc;
153         unsigned rlen, pad_len;
154         unsigned short ahslength;
155         struct iscsi_ecdb_ahdr *ecdb_ahdr;
156         int rc;
157
158         ecdb_ahdr = iscsi_next_hdr(task);
159         rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
160
161         BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
162         ahslength = rlen + sizeof(ecdb_ahdr->reserved);
163
164         pad_len = iscsi_padding(rlen);
165
166         rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
167                            sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
168         if (rc)
169                 return rc;
170
171         if (pad_len)
172                 memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
173
174         ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
175         ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
176         ecdb_ahdr->reserved = 0;
177         memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
178
179         debug_scsi("iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
180                    "rlen %d pad_len %d ahs_length %d iscsi_headers_size %u\n",
181                    cmd->cmd_len, rlen, pad_len, ahslength, task->hdr_len);
182
183         return 0;
184 }
185
186 static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
187 {
188         struct scsi_cmnd *sc = task->sc;
189         struct iscsi_rlength_ahdr *rlen_ahdr;
190         int rc;
191
192         rlen_ahdr = iscsi_next_hdr(task);
193         rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
194         if (rc)
195                 return rc;
196
197         rlen_ahdr->ahslength =
198                 cpu_to_be16(sizeof(rlen_ahdr->read_length) +
199                                                   sizeof(rlen_ahdr->reserved));
200         rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
201         rlen_ahdr->reserved = 0;
202         rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
203
204         debug_scsi("bidi-in rlen_ahdr->read_length(%d) "
205                    "rlen_ahdr->ahslength(%d)\n",
206                    be32_to_cpu(rlen_ahdr->read_length),
207                    be16_to_cpu(rlen_ahdr->ahslength));
208         return 0;
209 }
210
211 /**
212  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
213  * @task: iscsi task
214  *
215  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
216  * fields like dlength or final based on how much data it sends
217  */
218 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
219 {
220         struct iscsi_conn *conn = task->conn;
221         struct iscsi_session *session = conn->session;
222         struct scsi_cmnd *sc = task->sc;
223         struct iscsi_cmd *hdr;
224         unsigned hdrlength, cmd_len;
225         itt_t itt;
226         int rc;
227
228         rc = conn->session->tt->alloc_pdu(task);
229         if (rc)
230                 return rc;
231         hdr = (struct iscsi_cmd *) task->hdr;
232         itt = hdr->itt;
233         memset(hdr, 0, sizeof(*hdr));
234
235         task->hdr_len = 0;
236         rc = iscsi_add_hdr(task, sizeof(*hdr));
237         if (rc)
238                 return rc;
239         hdr->opcode = ISCSI_OP_SCSI_CMD;
240         hdr->flags = ISCSI_ATTR_SIMPLE;
241         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
242         memcpy(task->lun, hdr->lun, sizeof(task->lun));
243         if (session->tt->parse_pdu_itt)
244                 hdr->itt = task->hdr_itt = itt;
245         else
246                 hdr->itt = task->hdr_itt = build_itt(task->itt,
247                                                      task->conn->session->age);
248         hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
249         session->cmdsn++;
250         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
251         cmd_len = sc->cmd_len;
252         if (cmd_len < ISCSI_CDB_SIZE)
253                 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
254         else if (cmd_len > ISCSI_CDB_SIZE) {
255                 rc = iscsi_prep_ecdb_ahs(task);
256                 if (rc)
257                         return rc;
258                 cmd_len = ISCSI_CDB_SIZE;
259         }
260         memcpy(hdr->cdb, sc->cmnd, cmd_len);
261
262         task->imm_count = 0;
263         if (scsi_bidi_cmnd(sc)) {
264                 hdr->flags |= ISCSI_FLAG_CMD_READ;
265                 rc = iscsi_prep_bidi_ahs(task);
266                 if (rc)
267                         return rc;
268         }
269         if (sc->sc_data_direction == DMA_TO_DEVICE) {
270                 unsigned out_len = scsi_out(sc)->length;
271                 struct iscsi_r2t_info *r2t = &task->unsol_r2t;
272
273                 hdr->data_length = cpu_to_be32(out_len);
274                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
275                 /*
276                  * Write counters:
277                  *
278                  *      imm_count       bytes to be sent right after
279                  *                      SCSI PDU Header
280                  *
281                  *      unsol_count     bytes(as Data-Out) to be sent
282                  *                      without R2T ack right after
283                  *                      immediate data
284                  *
285                  *      r2t data_length bytes to be sent via R2T ack's
286                  *
287                  *      pad_count       bytes to be sent as zero-padding
288                  */
289                 memset(r2t, 0, sizeof(*r2t));
290
291                 if (session->imm_data_en) {
292                         if (out_len >= session->first_burst)
293                                 task->imm_count = min(session->first_burst,
294                                                         conn->max_xmit_dlength);
295                         else
296                                 task->imm_count = min(out_len,
297                                                         conn->max_xmit_dlength);
298                         hton24(hdr->dlength, task->imm_count);
299                 } else
300                         zero_data(hdr->dlength);
301
302                 if (!session->initial_r2t_en) {
303                         r2t->data_length = min(session->first_burst, out_len) -
304                                                task->imm_count;
305                         r2t->data_offset = task->imm_count;
306                         r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
307                         r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
308                 }
309
310                 if (!task->unsol_r2t.data_length)
311                         /* No unsolicit Data-Out's */
312                         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
313         } else {
314                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
315                 zero_data(hdr->dlength);
316                 hdr->data_length = cpu_to_be32(scsi_in(sc)->length);
317
318                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
319                         hdr->flags |= ISCSI_FLAG_CMD_READ;
320         }
321
322         /* calculate size of additional header segments (AHSs) */
323         hdrlength = task->hdr_len - sizeof(*hdr);
324
325         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
326         hdrlength /= ISCSI_PAD_LEN;
327
328         WARN_ON(hdrlength >= 256);
329         hdr->hlength = hdrlength & 0xFF;
330
331         if (session->tt->init_task && session->tt->init_task(task))
332                 return -EIO;
333
334         task->state = ISCSI_TASK_RUNNING;
335         list_move_tail(&task->running, &conn->run_list);
336
337         conn->scsicmd_pdus_cnt++;
338         debug_scsi("iscsi prep [%s cid %d sc %p cdb 0x%x itt 0x%x len %d "
339                    "bidi_len %d cmdsn %d win %d]\n", scsi_bidi_cmnd(sc) ?
340                    "bidirectional" : sc->sc_data_direction == DMA_TO_DEVICE ?
341                    "write" : "read", conn->id, sc, sc->cmnd[0], task->itt,
342                    scsi_bufflen(sc),
343                    scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
344                    session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
345         return 0;
346 }
347
348 /**
349  * iscsi_complete_command - finish a task
350  * @task: iscsi cmd task
351  *
352  * Must be called with session lock.
353  * This function returns the scsi command to scsi-ml or cleans
354  * up mgmt tasks then returns the task to the pool.
355  */
356 static void iscsi_complete_command(struct iscsi_task *task)
357 {
358         struct iscsi_conn *conn = task->conn;
359         struct iscsi_session *session = conn->session;
360         struct scsi_cmnd *sc = task->sc;
361
362         session->tt->cleanup_task(task);
363         list_del_init(&task->running);
364         task->state = ISCSI_TASK_COMPLETED;
365         task->sc = NULL;
366
367         if (conn->task == task)
368                 conn->task = NULL;
369         /*
370          * login task is preallocated so do not free
371          */
372         if (conn->login_task == task)
373                 return;
374
375         __kfifo_put(session->cmdpool.queue, (void*)&task, sizeof(void*));
376
377         if (conn->ping_task == task)
378                 conn->ping_task = NULL;
379
380         if (sc) {
381                 task->sc = NULL;
382                 /* SCSI eh reuses commands to verify us */
383                 sc->SCp.ptr = NULL;
384                 /*
385                  * queue command may call this to free the task, but
386                  * not have setup the sc callback
387                  */
388                 if (sc->scsi_done)
389                         sc->scsi_done(sc);
390         }
391 }
392
393 void __iscsi_get_task(struct iscsi_task *task)
394 {
395         atomic_inc(&task->refcount);
396 }
397 EXPORT_SYMBOL_GPL(__iscsi_get_task);
398
399 static void __iscsi_put_task(struct iscsi_task *task)
400 {
401         if (atomic_dec_and_test(&task->refcount))
402                 iscsi_complete_command(task);
403 }
404
405 void iscsi_put_task(struct iscsi_task *task)
406 {
407         struct iscsi_session *session = task->conn->session;
408
409         spin_lock_bh(&session->lock);
410         __iscsi_put_task(task);
411         spin_unlock_bh(&session->lock);
412 }
413 EXPORT_SYMBOL_GPL(iscsi_put_task);
414
415 /*
416  * session lock must be held
417  */
418 static void fail_command(struct iscsi_conn *conn, struct iscsi_task *task,
419                          int err)
420 {
421         struct scsi_cmnd *sc;
422
423         sc = task->sc;
424         if (!sc)
425                 return;
426
427         if (task->state == ISCSI_TASK_PENDING)
428                 /*
429                  * cmd never made it to the xmit thread, so we should not count
430                  * the cmd in the sequencing
431                  */
432                 conn->session->queued_cmdsn--;
433
434         sc->result = err;
435         if (!scsi_bidi_cmnd(sc))
436                 scsi_set_resid(sc, scsi_bufflen(sc));
437         else {
438                 scsi_out(sc)->resid = scsi_out(sc)->length;
439                 scsi_in(sc)->resid = scsi_in(sc)->length;
440         }
441
442         if (conn->task == task)
443                 conn->task = NULL;
444         /* release ref from queuecommand */
445         __iscsi_put_task(task);
446 }
447
448 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
449                                 struct iscsi_task *task)
450 {
451         struct iscsi_session *session = conn->session;
452         struct iscsi_hdr *hdr = task->hdr;
453         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
454
455         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
456                 return -ENOTCONN;
457
458         if (hdr->opcode != (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) &&
459             hdr->opcode != (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
460                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
461         /*
462          * pre-format CmdSN for outgoing PDU.
463          */
464         nop->cmdsn = cpu_to_be32(session->cmdsn);
465         if (hdr->itt != RESERVED_ITT) {
466                 /*
467                  * TODO: We always use immediate, so we never hit this.
468                  * If we start to send tmfs or nops as non-immediate then
469                  * we should start checking the cmdsn numbers for mgmt tasks.
470                  */
471                 if (conn->c_stage == ISCSI_CONN_STARTED &&
472                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
473                         session->queued_cmdsn++;
474                         session->cmdsn++;
475                 }
476         }
477
478         if (session->tt->init_task)
479                 session->tt->init_task(task);
480
481         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
482                 session->state = ISCSI_STATE_LOGGING_OUT;
483
484         task->state = ISCSI_TASK_RUNNING;
485         list_move_tail(&task->running, &conn->mgmt_run_list);
486         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
487                    hdr->opcode & ISCSI_OPCODE_MASK, hdr->itt,
488                    task->data_count);
489         return 0;
490 }
491
492 static struct iscsi_task *
493 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
494                       char *data, uint32_t data_size)
495 {
496         struct iscsi_session *session = conn->session;
497         struct iscsi_task *task;
498         itt_t itt;
499
500         if (session->state == ISCSI_STATE_TERMINATE)
501                 return NULL;
502
503         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
504             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
505                 /*
506                  * Login and Text are sent serially, in
507                  * request-followed-by-response sequence.
508                  * Same task can be used. Same ITT must be used.
509                  * Note that login_task is preallocated at conn_create().
510                  */
511                 task = conn->login_task;
512         else {
513                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
514                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
515
516                 if (!__kfifo_get(session->cmdpool.queue,
517                                  (void*)&task, sizeof(void*)))
518                         return NULL;
519         }
520         /*
521          * released in complete pdu for task we expect a response for, and
522          * released by the lld when it has transmitted the task for
523          * pdus we do not expect a response for.
524          */
525         atomic_set(&task->refcount, 1);
526         task->conn = conn;
527         task->sc = NULL;
528
529         if (data_size) {
530                 memcpy(task->data, data, data_size);
531                 task->data_count = data_size;
532         } else
533                 task->data_count = 0;
534
535         if (conn->session->tt->alloc_pdu(task)) {
536                 iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
537                                  "pdu for mgmt task.\n");
538                 goto requeue_task;
539         }
540         itt = task->hdr->itt;
541         task->hdr_len = sizeof(struct iscsi_hdr);
542         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
543
544         if (hdr->itt != RESERVED_ITT) {
545                 if (session->tt->parse_pdu_itt)
546                         task->hdr->itt = itt;
547                 else
548                         task->hdr->itt = build_itt(task->itt,
549                                                    task->conn->session->age);
550         }
551
552         INIT_LIST_HEAD(&task->running);
553         list_add_tail(&task->running, &conn->mgmtqueue);
554
555         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
556                 if (iscsi_prep_mgmt_task(conn, task))
557                         goto free_task;
558
559                 if (session->tt->xmit_task(task))
560                         goto free_task;
561
562         } else
563                 scsi_queue_work(conn->session->host, &conn->xmitwork);
564
565         return task;
566
567 free_task:
568         __iscsi_put_task(task);
569         return NULL;
570
571 requeue_task:
572         if (task != conn->login_task)
573                 __kfifo_put(session->cmdpool.queue, (void*)&task,
574                             sizeof(void*));
575         return NULL;
576 }
577
578 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
579                         char *data, uint32_t data_size)
580 {
581         struct iscsi_conn *conn = cls_conn->dd_data;
582         struct iscsi_session *session = conn->session;
583         int err = 0;
584
585         spin_lock_bh(&session->lock);
586         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
587                 err = -EPERM;
588         spin_unlock_bh(&session->lock);
589         return err;
590 }
591 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
592
593 /**
594  * iscsi_cmd_rsp - SCSI Command Response processing
595  * @conn: iscsi connection
596  * @hdr: iscsi header
597  * @task: scsi command task
598  * @data: cmd data buffer
599  * @datalen: len of buffer
600  *
601  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
602  * then completes the command and task.
603  **/
604 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
605                                struct iscsi_task *task, char *data,
606                                int datalen)
607 {
608         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
609         struct iscsi_session *session = conn->session;
610         struct scsi_cmnd *sc = task->sc;
611
612         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
613         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
614
615         sc->result = (DID_OK << 16) | rhdr->cmd_status;
616
617         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
618                 sc->result = DID_ERROR << 16;
619                 goto out;
620         }
621
622         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
623                 uint16_t senselen;
624
625                 if (datalen < 2) {
626 invalid_datalen:
627                         iscsi_conn_printk(KERN_ERR,  conn,
628                                          "Got CHECK_CONDITION but invalid data "
629                                          "buffer size of %d\n", datalen);
630                         sc->result = DID_BAD_TARGET << 16;
631                         goto out;
632                 }
633
634                 senselen = get_unaligned_be16(data);
635                 if (datalen < senselen)
636                         goto invalid_datalen;
637
638                 memcpy(sc->sense_buffer, data + 2,
639                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
640                 debug_scsi("copied %d bytes of sense\n",
641                            min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
642         }
643
644         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
645                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
646                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
647
648                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
649                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
650                                  res_count <= scsi_in(sc)->length))
651                         scsi_in(sc)->resid = res_count;
652                 else
653                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
654         }
655
656         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
657                            ISCSI_FLAG_CMD_OVERFLOW)) {
658                 int res_count = be32_to_cpu(rhdr->residual_count);
659
660                 if (res_count > 0 &&
661                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
662                      res_count <= scsi_bufflen(sc)))
663                         /* write side for bidi or uni-io set_resid */
664                         scsi_set_resid(sc, res_count);
665                 else
666                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
667         }
668 out:
669         debug_scsi("done [sc %lx res %d itt 0x%x]\n",
670                    (long)sc, sc->result, task->itt);
671         conn->scsirsp_pdus_cnt++;
672
673         __iscsi_put_task(task);
674 }
675
676 /**
677  * iscsi_data_in_rsp - SCSI Data-In Response processing
678  * @conn: iscsi connection
679  * @hdr:  iscsi pdu
680  * @task: scsi command task
681  **/
682 static void
683 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
684                   struct iscsi_task *task)
685 {
686         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
687         struct scsi_cmnd *sc = task->sc;
688
689         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
690                 return;
691
692         sc->result = (DID_OK << 16) | rhdr->cmd_status;
693         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
694         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
695                            ISCSI_FLAG_DATA_OVERFLOW)) {
696                 int res_count = be32_to_cpu(rhdr->residual_count);
697
698                 if (res_count > 0 &&
699                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
700                      res_count <= scsi_in(sc)->length))
701                         scsi_in(sc)->resid = res_count;
702                 else
703                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
704         }
705
706         conn->scsirsp_pdus_cnt++;
707         __iscsi_put_task(task);
708 }
709
710 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
711 {
712         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
713
714         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
715         conn->tmfrsp_pdus_cnt++;
716
717         if (conn->tmf_state != TMF_QUEUED)
718                 return;
719
720         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
721                 conn->tmf_state = TMF_SUCCESS;
722         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
723                 conn->tmf_state = TMF_NOT_FOUND;
724         else
725                 conn->tmf_state = TMF_FAILED;
726         wake_up(&conn->ehwait);
727 }
728
729 static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
730 {
731         struct iscsi_nopout hdr;
732         struct iscsi_task *task;
733
734         if (!rhdr && conn->ping_task)
735                 return;
736
737         memset(&hdr, 0, sizeof(struct iscsi_nopout));
738         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
739         hdr.flags = ISCSI_FLAG_CMD_FINAL;
740
741         if (rhdr) {
742                 memcpy(hdr.lun, rhdr->lun, 8);
743                 hdr.ttt = rhdr->ttt;
744                 hdr.itt = RESERVED_ITT;
745         } else
746                 hdr.ttt = RESERVED_ITT;
747
748         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
749         if (!task)
750                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
751         else if (!rhdr) {
752                 /* only track our nops */
753                 conn->ping_task = task;
754                 conn->last_ping = jiffies;
755         }
756 }
757
758 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
759                                char *data, int datalen)
760 {
761         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
762         struct iscsi_hdr rejected_pdu;
763
764         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
765
766         if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
767                 if (ntoh24(reject->dlength) > datalen)
768                         return ISCSI_ERR_PROTO;
769
770                 if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
771                         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
772                         iscsi_conn_printk(KERN_ERR, conn,
773                                           "pdu (op 0x%x) rejected "
774                                           "due to DataDigest error.\n",
775                                           rejected_pdu.opcode);
776                 }
777         }
778         return 0;
779 }
780
781 /**
782  * iscsi_itt_to_task - look up task by itt
783  * @conn: iscsi connection
784  * @itt: itt
785  *
786  * This should be used for mgmt tasks like login and nops, or if
787  * the LDD's itt space does not include the session age.
788  *
789  * The session lock must be held.
790  */
791 static struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
792 {
793         struct iscsi_session *session = conn->session;
794         int i;
795
796         if (itt == RESERVED_ITT)
797                 return NULL;
798
799         if (session->tt->parse_pdu_itt)
800                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
801         else
802                 i = get_itt(itt);
803         if (i >= session->cmds_max)
804                 return NULL;
805
806         return session->cmds[i];
807 }
808
809 /**
810  * __iscsi_complete_pdu - complete pdu
811  * @conn: iscsi conn
812  * @hdr: iscsi header
813  * @data: data buffer
814  * @datalen: len of data buffer
815  *
816  * Completes pdu processing by freeing any resources allocated at
817  * queuecommand or send generic. session lock must be held and verify
818  * itt must have been called.
819  */
820 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
821                          char *data, int datalen)
822 {
823         struct iscsi_session *session = conn->session;
824         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
825         struct iscsi_task *task;
826         uint32_t itt;
827
828         conn->last_recv = jiffies;
829         rc = iscsi_verify_itt(conn, hdr->itt);
830         if (rc)
831                 return rc;
832
833         if (hdr->itt != RESERVED_ITT)
834                 itt = get_itt(hdr->itt);
835         else
836                 itt = ~0U;
837
838         debug_scsi("[op 0x%x cid %d itt 0x%x len %d]\n",
839                    opcode, conn->id, itt, datalen);
840
841         if (itt == ~0U) {
842                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
843
844                 switch(opcode) {
845                 case ISCSI_OP_NOOP_IN:
846                         if (datalen) {
847                                 rc = ISCSI_ERR_PROTO;
848                                 break;
849                         }
850
851                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
852                                 break;
853
854                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
855                         break;
856                 case ISCSI_OP_REJECT:
857                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
858                         break;
859                 case ISCSI_OP_ASYNC_EVENT:
860                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
861                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
862                                 rc = ISCSI_ERR_CONN_FAILED;
863                         break;
864                 default:
865                         rc = ISCSI_ERR_BAD_OPCODE;
866                         break;
867                 }
868                 goto out;
869         }
870
871         switch(opcode) {
872         case ISCSI_OP_SCSI_CMD_RSP:
873         case ISCSI_OP_SCSI_DATA_IN:
874                 task = iscsi_itt_to_ctask(conn, hdr->itt);
875                 if (!task)
876                         return ISCSI_ERR_BAD_ITT;
877                 break;
878         case ISCSI_OP_R2T:
879                 /*
880                  * LLD handles R2Ts if they need to.
881                  */
882                 return 0;
883         case ISCSI_OP_LOGOUT_RSP:
884         case ISCSI_OP_LOGIN_RSP:
885         case ISCSI_OP_TEXT_RSP:
886         case ISCSI_OP_SCSI_TMFUNC_RSP:
887         case ISCSI_OP_NOOP_IN:
888                 task = iscsi_itt_to_task(conn, hdr->itt);
889                 if (!task)
890                         return ISCSI_ERR_BAD_ITT;
891                 break;
892         default:
893                 return ISCSI_ERR_BAD_OPCODE;
894         }
895
896         switch(opcode) {
897         case ISCSI_OP_SCSI_CMD_RSP:
898                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
899                 break;
900         case ISCSI_OP_SCSI_DATA_IN:
901                 iscsi_data_in_rsp(conn, hdr, task);
902                 break;
903         case ISCSI_OP_LOGOUT_RSP:
904                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
905                 if (datalen) {
906                         rc = ISCSI_ERR_PROTO;
907                         break;
908                 }
909                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
910                 goto recv_pdu;
911         case ISCSI_OP_LOGIN_RSP:
912         case ISCSI_OP_TEXT_RSP:
913                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
914                 /*
915                  * login related PDU's exp_statsn is handled in
916                  * userspace
917                  */
918                 goto recv_pdu;
919         case ISCSI_OP_SCSI_TMFUNC_RSP:
920                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
921                 if (datalen) {
922                         rc = ISCSI_ERR_PROTO;
923                         break;
924                 }
925
926                 iscsi_tmf_rsp(conn, hdr);
927                 __iscsi_put_task(task);
928                 break;
929         case ISCSI_OP_NOOP_IN:
930                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
931                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
932                         rc = ISCSI_ERR_PROTO;
933                         break;
934                 }
935                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
936
937                 if (conn->ping_task != task)
938                         /*
939                          * If this is not in response to one of our
940                          * nops then it must be from userspace.
941                          */
942                         goto recv_pdu;
943
944                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
945                 __iscsi_put_task(task);
946                 break;
947         default:
948                 rc = ISCSI_ERR_BAD_OPCODE;
949                 break;
950         }
951
952 out:
953         return rc;
954 recv_pdu:
955         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
956                 rc = ISCSI_ERR_CONN_FAILED;
957         __iscsi_put_task(task);
958         return rc;
959 }
960 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
961
962 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
963                        char *data, int datalen)
964 {
965         int rc;
966
967         spin_lock(&conn->session->lock);
968         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
969         spin_unlock(&conn->session->lock);
970         return rc;
971 }
972 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
973
974 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
975 {
976         struct iscsi_session *session = conn->session;
977         int age = 0, i = 0;
978
979         if (itt == RESERVED_ITT)
980                 return 0;
981
982         if (session->tt->parse_pdu_itt)
983                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
984         else {
985                 i = get_itt(itt);
986                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
987         }
988
989         if (age != session->age) {
990                 iscsi_conn_printk(KERN_ERR, conn,
991                                   "received itt %x expected session age (%x)\n",
992                                   (__force u32)itt, session->age);
993                 return ISCSI_ERR_BAD_ITT;
994         }
995
996         if (i >= session->cmds_max) {
997                 iscsi_conn_printk(KERN_ERR, conn,
998                                   "received invalid itt index %u (max cmds "
999                                    "%u.\n", i, session->cmds_max);
1000                 return ISCSI_ERR_BAD_ITT;
1001         }
1002         return 0;
1003 }
1004 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1005
1006 /**
1007  * iscsi_itt_to_ctask - look up ctask by itt
1008  * @conn: iscsi connection
1009  * @itt: itt
1010  *
1011  * This should be used for cmd tasks.
1012  *
1013  * The session lock must be held.
1014  */
1015 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1016 {
1017         struct iscsi_task *task;
1018
1019         if (iscsi_verify_itt(conn, itt))
1020                 return NULL;
1021
1022         task = iscsi_itt_to_task(conn, itt);
1023         if (!task || !task->sc)
1024                 return NULL;
1025
1026         if (task->sc->SCp.phase != conn->session->age) {
1027                 iscsi_session_printk(KERN_ERR, conn->session,
1028                                   "task's session age %d, expected %d\n",
1029                                   task->sc->SCp.phase, conn->session->age);
1030                 return NULL;
1031         }
1032
1033         return task;
1034 }
1035 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1036
1037 void iscsi_session_failure(struct iscsi_cls_session *cls_session,
1038                            enum iscsi_err err)
1039 {
1040         struct iscsi_session *session = cls_session->dd_data;
1041         struct iscsi_conn *conn;
1042         struct device *dev;
1043         unsigned long flags;
1044
1045         spin_lock_irqsave(&session->lock, flags);
1046         conn = session->leadconn;
1047         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1048                 spin_unlock_irqrestore(&session->lock, flags);
1049                 return;
1050         }
1051
1052         dev = get_device(&conn->cls_conn->dev);
1053         spin_unlock_irqrestore(&session->lock, flags);
1054         if (!dev)
1055                 return;
1056         /*
1057          * if the host is being removed bypass the connection
1058          * recovery initialization because we are going to kill
1059          * the session.
1060          */
1061         if (err == ISCSI_ERR_INVALID_HOST)
1062                 iscsi_conn_error_event(conn->cls_conn, err);
1063         else
1064                 iscsi_conn_failure(conn, err);
1065         put_device(dev);
1066 }
1067 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1068
1069 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1070 {
1071         struct iscsi_session *session = conn->session;
1072         unsigned long flags;
1073
1074         spin_lock_irqsave(&session->lock, flags);
1075         if (session->state == ISCSI_STATE_FAILED) {
1076                 spin_unlock_irqrestore(&session->lock, flags);
1077                 return;
1078         }
1079
1080         if (conn->stop_stage == 0)
1081                 session->state = ISCSI_STATE_FAILED;
1082         spin_unlock_irqrestore(&session->lock, flags);
1083
1084         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1085         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1086         iscsi_conn_error_event(conn->cls_conn, err);
1087 }
1088 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1089
1090 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1091 {
1092         struct iscsi_session *session = conn->session;
1093
1094         /*
1095          * Check for iSCSI window and take care of CmdSN wrap-around
1096          */
1097         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1098                 debug_scsi("iSCSI CmdSN closed. ExpCmdSn %u MaxCmdSN %u "
1099                            "CmdSN %u/%u\n", session->exp_cmdsn,
1100                            session->max_cmdsn, session->cmdsn,
1101                            session->queued_cmdsn);
1102                 return -ENOSPC;
1103         }
1104         return 0;
1105 }
1106
1107 static int iscsi_xmit_task(struct iscsi_conn *conn)
1108 {
1109         struct iscsi_task *task = conn->task;
1110         int rc;
1111
1112         __iscsi_get_task(task);
1113         spin_unlock_bh(&conn->session->lock);
1114         rc = conn->session->tt->xmit_task(task);
1115         spin_lock_bh(&conn->session->lock);
1116         __iscsi_put_task(task);
1117         if (!rc)
1118                 /* done with this task */
1119                 conn->task = NULL;
1120         return rc;
1121 }
1122
1123 /**
1124  * iscsi_requeue_task - requeue task to run from session workqueue
1125  * @task: task to requeue
1126  *
1127  * LLDs that need to run a task from the session workqueue should call
1128  * this. The session lock must be held. This should only be called
1129  * by software drivers.
1130  */
1131 void iscsi_requeue_task(struct iscsi_task *task)
1132 {
1133         struct iscsi_conn *conn = task->conn;
1134
1135         list_move_tail(&task->running, &conn->requeue);
1136         scsi_queue_work(conn->session->host, &conn->xmitwork);
1137 }
1138 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1139
1140 /**
1141  * iscsi_data_xmit - xmit any command into the scheduled connection
1142  * @conn: iscsi connection
1143  *
1144  * Notes:
1145  *      The function can return -EAGAIN in which case the caller must
1146  *      re-schedule it again later or recover. '0' return code means
1147  *      successful xmit.
1148  **/
1149 static int iscsi_data_xmit(struct iscsi_conn *conn)
1150 {
1151         int rc = 0;
1152
1153         spin_lock_bh(&conn->session->lock);
1154         if (unlikely(conn->suspend_tx)) {
1155                 debug_scsi("conn %d Tx suspended!\n", conn->id);
1156                 spin_unlock_bh(&conn->session->lock);
1157                 return -ENODATA;
1158         }
1159
1160         if (conn->task) {
1161                 rc = iscsi_xmit_task(conn);
1162                 if (rc)
1163                         goto again;
1164         }
1165
1166         /*
1167          * process mgmt pdus like nops before commands since we should
1168          * only have one nop-out as a ping from us and targets should not
1169          * overflow us with nop-ins
1170          */
1171 check_mgmt:
1172         while (!list_empty(&conn->mgmtqueue)) {
1173                 conn->task = list_entry(conn->mgmtqueue.next,
1174                                          struct iscsi_task, running);
1175                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1176                         __iscsi_put_task(conn->task);
1177                         conn->task = NULL;
1178                         continue;
1179                 }
1180                 rc = iscsi_xmit_task(conn);
1181                 if (rc)
1182                         goto again;
1183         }
1184
1185         /* process pending command queue */
1186         while (!list_empty(&conn->xmitqueue)) {
1187                 if (conn->tmf_state == TMF_QUEUED)
1188                         break;
1189
1190                 conn->task = list_entry(conn->xmitqueue.next,
1191                                          struct iscsi_task, running);
1192                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1193                         fail_command(conn, conn->task, DID_IMM_RETRY << 16);
1194                         continue;
1195                 }
1196                 rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1197                 if (rc) {
1198                         if (rc == -ENOMEM) {
1199                                 conn->task = NULL;
1200                                 goto again;
1201                         } else
1202                                 fail_command(conn, conn->task, DID_ABORT << 16);
1203                         continue;
1204                 }
1205                 rc = iscsi_xmit_task(conn);
1206                 if (rc)
1207                         goto again;
1208                 /*
1209                  * we could continuously get new task requests so
1210                  * we need to check the mgmt queue for nops that need to
1211                  * be sent to aviod starvation
1212                  */
1213                 if (!list_empty(&conn->mgmtqueue))
1214                         goto check_mgmt;
1215         }
1216
1217         while (!list_empty(&conn->requeue)) {
1218                 if (conn->session->fast_abort && conn->tmf_state != TMF_INITIAL)
1219                         break;
1220
1221                 /*
1222                  * we always do fastlogout - conn stop code will clean up.
1223                  */
1224                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1225                         break;
1226
1227                 conn->task = list_entry(conn->requeue.next,
1228                                          struct iscsi_task, running);
1229                 conn->task->state = ISCSI_TASK_RUNNING;
1230                 list_move_tail(conn->requeue.next, &conn->run_list);
1231                 rc = iscsi_xmit_task(conn);
1232                 if (rc)
1233                         goto again;
1234                 if (!list_empty(&conn->mgmtqueue))
1235                         goto check_mgmt;
1236         }
1237         spin_unlock_bh(&conn->session->lock);
1238         return -ENODATA;
1239
1240 again:
1241         if (unlikely(conn->suspend_tx))
1242                 rc = -ENODATA;
1243         spin_unlock_bh(&conn->session->lock);
1244         return rc;
1245 }
1246
1247 static void iscsi_xmitworker(struct work_struct *work)
1248 {
1249         struct iscsi_conn *conn =
1250                 container_of(work, struct iscsi_conn, xmitwork);
1251         int rc;
1252         /*
1253          * serialize Xmit worker on a per-connection basis.
1254          */
1255         do {
1256                 rc = iscsi_data_xmit(conn);
1257         } while (rc >= 0 || rc == -EAGAIN);
1258 }
1259
1260 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1261                                                   struct scsi_cmnd *sc)
1262 {
1263         struct iscsi_task *task;
1264
1265         if (!__kfifo_get(conn->session->cmdpool.queue,
1266                          (void *) &task, sizeof(void *)))
1267                 return NULL;
1268
1269         sc->SCp.phase = conn->session->age;
1270         sc->SCp.ptr = (char *) task;
1271
1272         atomic_set(&task->refcount, 1);
1273         task->state = ISCSI_TASK_PENDING;
1274         task->conn = conn;
1275         task->sc = sc;
1276         INIT_LIST_HEAD(&task->running);
1277         return task;
1278 }
1279
1280 enum {
1281         FAILURE_BAD_HOST = 1,
1282         FAILURE_SESSION_FAILED,
1283         FAILURE_SESSION_FREED,
1284         FAILURE_WINDOW_CLOSED,
1285         FAILURE_OOM,
1286         FAILURE_SESSION_TERMINATE,
1287         FAILURE_SESSION_IN_RECOVERY,
1288         FAILURE_SESSION_RECOVERY_TIMEOUT,
1289         FAILURE_SESSION_LOGGING_OUT,
1290         FAILURE_SESSION_NOT_READY,
1291 };
1292
1293 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
1294 {
1295         struct iscsi_cls_session *cls_session;
1296         struct Scsi_Host *host;
1297         int reason = 0;
1298         struct iscsi_session *session;
1299         struct iscsi_conn *conn;
1300         struct iscsi_task *task = NULL;
1301
1302         sc->scsi_done = done;
1303         sc->result = 0;
1304         sc->SCp.ptr = NULL;
1305
1306         host = sc->device->host;
1307         spin_unlock(host->host_lock);
1308
1309         cls_session = starget_to_session(scsi_target(sc->device));
1310         session = cls_session->dd_data;
1311         spin_lock(&session->lock);
1312
1313         reason = iscsi_session_chkready(cls_session);
1314         if (reason) {
1315                 sc->result = reason;
1316                 goto fault;
1317         }
1318
1319         /*
1320          * ISCSI_STATE_FAILED is a temp. state. The recovery
1321          * code will decide what is best to do with command queued
1322          * during this time
1323          */
1324         if (session->state != ISCSI_STATE_LOGGED_IN &&
1325             session->state != ISCSI_STATE_FAILED) {
1326                 /*
1327                  * to handle the race between when we set the recovery state
1328                  * and block the session we requeue here (commands could
1329                  * be entering our queuecommand while a block is starting
1330                  * up because the block code is not locked)
1331                  */
1332                 switch (session->state) {
1333                 case ISCSI_STATE_IN_RECOVERY:
1334                         reason = FAILURE_SESSION_IN_RECOVERY;
1335                         goto reject;
1336                 case ISCSI_STATE_LOGGING_OUT:
1337                         reason = FAILURE_SESSION_LOGGING_OUT;
1338                         goto reject;
1339                 case ISCSI_STATE_RECOVERY_FAILED:
1340                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1341                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1342                         break;
1343                 case ISCSI_STATE_TERMINATE:
1344                         reason = FAILURE_SESSION_TERMINATE;
1345                         sc->result = DID_NO_CONNECT << 16;
1346                         break;
1347                 default:
1348                         reason = FAILURE_SESSION_FREED;
1349                         sc->result = DID_NO_CONNECT << 16;
1350                 }
1351                 goto fault;
1352         }
1353
1354         conn = session->leadconn;
1355         if (!conn) {
1356                 reason = FAILURE_SESSION_FREED;
1357                 sc->result = DID_NO_CONNECT << 16;
1358                 goto fault;
1359         }
1360
1361         if (iscsi_check_cmdsn_window_closed(conn)) {
1362                 reason = FAILURE_WINDOW_CLOSED;
1363                 goto reject;
1364         }
1365
1366         task = iscsi_alloc_task(conn, sc);
1367         if (!task) {
1368                 reason = FAILURE_OOM;
1369                 goto reject;
1370         }
1371         list_add_tail(&task->running, &conn->xmitqueue);
1372
1373         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
1374                 reason = iscsi_prep_scsi_cmd_pdu(task);
1375                 if (reason) {
1376                         if (reason == -ENOMEM) {
1377                                 reason = FAILURE_OOM;
1378                                 goto prepd_reject;
1379                         } else {
1380                                 sc->result = DID_ABORT << 16;
1381                                 goto prepd_fault;
1382                         }
1383                 }
1384                 if (session->tt->xmit_task(task)) {
1385                         reason = FAILURE_SESSION_NOT_READY;
1386                         goto prepd_reject;
1387                 }
1388         } else
1389                 scsi_queue_work(session->host, &conn->xmitwork);
1390
1391         session->queued_cmdsn++;
1392         spin_unlock(&session->lock);
1393         spin_lock(host->host_lock);
1394         return 0;
1395
1396 prepd_reject:
1397         sc->scsi_done = NULL;
1398         iscsi_complete_command(task);
1399 reject:
1400         spin_unlock(&session->lock);
1401         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
1402         spin_lock(host->host_lock);
1403         return SCSI_MLQUEUE_TARGET_BUSY;
1404
1405 prepd_fault:
1406         sc->scsi_done = NULL;
1407         iscsi_complete_command(task);
1408 fault:
1409         spin_unlock(&session->lock);
1410         debug_scsi("iscsi: cmd 0x%x is not queued (%d)\n", sc->cmnd[0], reason);
1411         if (!scsi_bidi_cmnd(sc))
1412                 scsi_set_resid(sc, scsi_bufflen(sc));
1413         else {
1414                 scsi_out(sc)->resid = scsi_out(sc)->length;
1415                 scsi_in(sc)->resid = scsi_in(sc)->length;
1416         }
1417         done(sc);
1418         spin_lock(host->host_lock);
1419         return 0;
1420 }
1421 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1422
1423 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
1424 {
1425         if (depth > ISCSI_MAX_CMD_PER_LUN)
1426                 depth = ISCSI_MAX_CMD_PER_LUN;
1427         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1428         return sdev->queue_depth;
1429 }
1430 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1431
1432 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
1433 {
1434         struct iscsi_session *session = cls_session->dd_data;
1435
1436         spin_lock_bh(&session->lock);
1437         if (session->state != ISCSI_STATE_LOGGED_IN) {
1438                 session->state = ISCSI_STATE_RECOVERY_FAILED;
1439                 if (session->leadconn)
1440                         wake_up(&session->leadconn->ehwait);
1441         }
1442         spin_unlock_bh(&session->lock);
1443 }
1444 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
1445
1446 int iscsi_eh_target_reset(struct scsi_cmnd *sc)
1447 {
1448         struct iscsi_cls_session *cls_session;
1449         struct iscsi_session *session;
1450         struct iscsi_conn *conn;
1451
1452         cls_session = starget_to_session(scsi_target(sc->device));
1453         session = cls_session->dd_data;
1454         conn = session->leadconn;
1455
1456         mutex_lock(&session->eh_mutex);
1457         spin_lock_bh(&session->lock);
1458         if (session->state == ISCSI_STATE_TERMINATE) {
1459 failed:
1460                 debug_scsi("failing target reset: session terminated "
1461                            "[CID %d age %d]\n", conn->id, session->age);
1462                 spin_unlock_bh(&session->lock);
1463                 mutex_unlock(&session->eh_mutex);
1464                 return FAILED;
1465         }
1466
1467         spin_unlock_bh(&session->lock);
1468         mutex_unlock(&session->eh_mutex);
1469         /*
1470          * we drop the lock here but the leadconn cannot be destoyed while
1471          * we are in the scsi eh
1472          */
1473         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1474
1475         debug_scsi("iscsi_eh_target_reset wait for relogin\n");
1476         wait_event_interruptible(conn->ehwait,
1477                                  session->state == ISCSI_STATE_TERMINATE ||
1478                                  session->state == ISCSI_STATE_LOGGED_IN ||
1479                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
1480         if (signal_pending(current))
1481                 flush_signals(current);
1482
1483         mutex_lock(&session->eh_mutex);
1484         spin_lock_bh(&session->lock);
1485         if (session->state == ISCSI_STATE_LOGGED_IN)
1486                 iscsi_session_printk(KERN_INFO, session,
1487                                      "target reset succeeded\n");
1488         else
1489                 goto failed;
1490         spin_unlock_bh(&session->lock);
1491         mutex_unlock(&session->eh_mutex);
1492         return SUCCESS;
1493 }
1494 EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
1495
1496 static void iscsi_tmf_timedout(unsigned long data)
1497 {
1498         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1499         struct iscsi_session *session = conn->session;
1500
1501         spin_lock(&session->lock);
1502         if (conn->tmf_state == TMF_QUEUED) {
1503                 conn->tmf_state = TMF_TIMEDOUT;
1504                 debug_scsi("tmf timedout\n");
1505                 /* unblock eh_abort() */
1506                 wake_up(&conn->ehwait);
1507         }
1508         spin_unlock(&session->lock);
1509 }
1510
1511 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1512                                    struct iscsi_tm *hdr, int age,
1513                                    int timeout)
1514 {
1515         struct iscsi_session *session = conn->session;
1516         struct iscsi_task *task;
1517
1518         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1519                                       NULL, 0);
1520         if (!task) {
1521                 spin_unlock_bh(&session->lock);
1522                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1523                 spin_lock_bh(&session->lock);
1524                 debug_scsi("tmf exec failure\n");
1525                 return -EPERM;
1526         }
1527         conn->tmfcmd_pdus_cnt++;
1528         conn->tmf_timer.expires = timeout * HZ + jiffies;
1529         conn->tmf_timer.function = iscsi_tmf_timedout;
1530         conn->tmf_timer.data = (unsigned long)conn;
1531         add_timer(&conn->tmf_timer);
1532         debug_scsi("tmf set timeout\n");
1533
1534         spin_unlock_bh(&session->lock);
1535         mutex_unlock(&session->eh_mutex);
1536
1537         /*
1538          * block eh thread until:
1539          *
1540          * 1) tmf response
1541          * 2) tmf timeout
1542          * 3) session is terminated or restarted or userspace has
1543          * given up on recovery
1544          */
1545         wait_event_interruptible(conn->ehwait, age != session->age ||
1546                                  session->state != ISCSI_STATE_LOGGED_IN ||
1547                                  conn->tmf_state != TMF_QUEUED);
1548         if (signal_pending(current))
1549                 flush_signals(current);
1550         del_timer_sync(&conn->tmf_timer);
1551
1552         mutex_lock(&session->eh_mutex);
1553         spin_lock_bh(&session->lock);
1554         /* if the session drops it will clean up the task */
1555         if (age != session->age ||
1556             session->state != ISCSI_STATE_LOGGED_IN)
1557                 return -ENOTCONN;
1558         return 0;
1559 }
1560
1561 /*
1562  * Fail commands. session lock held and recv side suspended and xmit
1563  * thread flushed
1564  */
1565 static void fail_all_commands(struct iscsi_conn *conn, unsigned lun,
1566                               int error)
1567 {
1568         struct iscsi_task *task, *tmp;
1569
1570         if (conn->task && (conn->task->sc->device->lun == lun || lun == -1))
1571                 conn->task = NULL;
1572
1573         /* flush pending */
1574         list_for_each_entry_safe(task, tmp, &conn->xmitqueue, running) {
1575                 if (lun == task->sc->device->lun || lun == -1) {
1576                         debug_scsi("failing pending sc %p itt 0x%x\n",
1577                                    task->sc, task->itt);
1578                         fail_command(conn, task, error << 16);
1579                 }
1580         }
1581
1582         list_for_each_entry_safe(task, tmp, &conn->requeue, running) {
1583                 if (lun == task->sc->device->lun || lun == -1) {
1584                         debug_scsi("failing requeued sc %p itt 0x%x\n",
1585                                    task->sc, task->itt);
1586                         fail_command(conn, task, error << 16);
1587                 }
1588         }
1589
1590         /* fail all other running */
1591         list_for_each_entry_safe(task, tmp, &conn->run_list, running) {
1592                 if (lun == task->sc->device->lun || lun == -1) {
1593                         debug_scsi("failing in progress sc %p itt 0x%x\n",
1594                                    task->sc, task->itt);
1595                         fail_command(conn, task, error << 16);
1596                 }
1597         }
1598 }
1599
1600 void iscsi_suspend_tx(struct iscsi_conn *conn)
1601 {
1602         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1603         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1604                 scsi_flush_work(conn->session->host);
1605 }
1606 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1607
1608 static void iscsi_start_tx(struct iscsi_conn *conn)
1609 {
1610         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1611         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1612                 scsi_queue_work(conn->session->host, &conn->xmitwork);
1613 }
1614
1615 static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *scmd)
1616 {
1617         struct iscsi_cls_session *cls_session;
1618         struct iscsi_session *session;
1619         struct iscsi_conn *conn;
1620         enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1621
1622         cls_session = starget_to_session(scsi_target(scmd->device));
1623         session = cls_session->dd_data;
1624
1625         debug_scsi("scsi cmd %p timedout\n", scmd);
1626
1627         spin_lock(&session->lock);
1628         if (session->state != ISCSI_STATE_LOGGED_IN) {
1629                 /*
1630                  * We are probably in the middle of iscsi recovery so let
1631                  * that complete and handle the error.
1632                  */
1633                 rc = BLK_EH_RESET_TIMER;
1634                 goto done;
1635         }
1636
1637         conn = session->leadconn;
1638         if (!conn) {
1639                 /* In the middle of shuting down */
1640                 rc = BLK_EH_RESET_TIMER;
1641                 goto done;
1642         }
1643
1644         if (!conn->recv_timeout && !conn->ping_timeout)
1645                 goto done;
1646         /*
1647          * if the ping timedout then we are in the middle of cleaning up
1648          * and can let the iscsi eh handle it
1649          */
1650         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1651                             (conn->ping_timeout * HZ), jiffies))
1652                 rc = BLK_EH_RESET_TIMER;
1653         /*
1654          * if we are about to check the transport then give the command
1655          * more time
1656          */
1657         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ),
1658                            jiffies))
1659                 rc = BLK_EH_RESET_TIMER;
1660         /* if in the middle of checking the transport then give us more time */
1661         if (conn->ping_task)
1662                 rc = BLK_EH_RESET_TIMER;
1663 done:
1664         spin_unlock(&session->lock);
1665         debug_scsi("return %s\n", rc == BLK_EH_RESET_TIMER ?
1666                                         "timer reset" : "nh");
1667         return rc;
1668 }
1669
1670 static void iscsi_check_transport_timeouts(unsigned long data)
1671 {
1672         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1673         struct iscsi_session *session = conn->session;
1674         unsigned long recv_timeout, next_timeout = 0, last_recv;
1675
1676         spin_lock(&session->lock);
1677         if (session->state != ISCSI_STATE_LOGGED_IN)
1678                 goto done;
1679
1680         recv_timeout = conn->recv_timeout;
1681         if (!recv_timeout)
1682                 goto done;
1683
1684         recv_timeout *= HZ;
1685         last_recv = conn->last_recv;
1686         if (conn->ping_task &&
1687             time_before_eq(conn->last_ping + (conn->ping_timeout * HZ),
1688                            jiffies)) {
1689                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
1690                                   "expired, last rx %lu, last ping %lu, "
1691                                   "now %lu\n", conn->ping_timeout, last_recv,
1692                                   conn->last_ping, jiffies);
1693                 spin_unlock(&session->lock);
1694                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1695                 return;
1696         }
1697
1698         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
1699                 /* send a ping to try to provoke some traffic */
1700                 debug_scsi("Sending nopout as ping on conn %p\n", conn);
1701                 iscsi_send_nopout(conn, NULL);
1702                 next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
1703         } else
1704                 next_timeout = last_recv + recv_timeout;
1705
1706         debug_scsi("Setting next tmo %lu\n", next_timeout);
1707         mod_timer(&conn->transport_timer, next_timeout);
1708 done:
1709         spin_unlock(&session->lock);
1710 }
1711
1712 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
1713                                       struct iscsi_tm *hdr)
1714 {
1715         memset(hdr, 0, sizeof(*hdr));
1716         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1717         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
1718         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1719         memcpy(hdr->lun, task->lun, sizeof(hdr->lun));
1720         hdr->rtt = task->hdr_itt;
1721         hdr->refcmdsn = task->cmdsn;
1722 }
1723
1724 int iscsi_eh_abort(struct scsi_cmnd *sc)
1725 {
1726         struct iscsi_cls_session *cls_session;
1727         struct iscsi_session *session;
1728         struct iscsi_conn *conn;
1729         struct iscsi_task *task;
1730         struct iscsi_tm *hdr;
1731         int rc, age;
1732
1733         cls_session = starget_to_session(scsi_target(sc->device));
1734         session = cls_session->dd_data;
1735
1736         mutex_lock(&session->eh_mutex);
1737         spin_lock_bh(&session->lock);
1738         /*
1739          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1740          * got the command.
1741          */
1742         if (!sc->SCp.ptr) {
1743                 debug_scsi("sc never reached iscsi layer or it completed.\n");
1744                 spin_unlock_bh(&session->lock);
1745                 mutex_unlock(&session->eh_mutex);
1746                 return SUCCESS;
1747         }
1748
1749         /*
1750          * If we are not logged in or we have started a new session
1751          * then let the host reset code handle this
1752          */
1753         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
1754             sc->SCp.phase != session->age) {
1755                 spin_unlock_bh(&session->lock);
1756                 mutex_unlock(&session->eh_mutex);
1757                 return FAILED;
1758         }
1759
1760         conn = session->leadconn;
1761         conn->eh_abort_cnt++;
1762         age = session->age;
1763
1764         task = (struct iscsi_task *)sc->SCp.ptr;
1765         debug_scsi("aborting [sc %p itt 0x%x]\n", sc, task->itt);
1766
1767         /* task completed before time out */
1768         if (!task->sc) {
1769                 debug_scsi("sc completed while abort in progress\n");
1770                 goto success;
1771         }
1772
1773         if (task->state == ISCSI_TASK_PENDING) {
1774                 fail_command(conn, task, DID_ABORT << 16);
1775                 goto success;
1776         }
1777
1778         /* only have one tmf outstanding at a time */
1779         if (conn->tmf_state != TMF_INITIAL)
1780                 goto failed;
1781         conn->tmf_state = TMF_QUEUED;
1782
1783         hdr = &conn->tmhdr;
1784         iscsi_prep_abort_task_pdu(task, hdr);
1785
1786         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
1787                 rc = FAILED;
1788                 goto failed;
1789         }
1790
1791         switch (conn->tmf_state) {
1792         case TMF_SUCCESS:
1793                 spin_unlock_bh(&session->lock);
1794                 /*
1795                  * stop tx side incase the target had sent a abort rsp but
1796                  * the initiator was still writing out data.
1797                  */
1798                 iscsi_suspend_tx(conn);
1799                 /*
1800                  * we do not stop the recv side because targets have been
1801                  * good and have never sent us a successful tmf response
1802                  * then sent more data for the cmd.
1803                  */
1804                 spin_lock(&session->lock);
1805                 fail_command(conn, task, DID_ABORT << 16);
1806                 conn->tmf_state = TMF_INITIAL;
1807                 spin_unlock(&session->lock);
1808                 iscsi_start_tx(conn);
1809                 goto success_unlocked;
1810         case TMF_TIMEDOUT:
1811                 spin_unlock_bh(&session->lock);
1812                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1813                 goto failed_unlocked;
1814         case TMF_NOT_FOUND:
1815                 if (!sc->SCp.ptr) {
1816                         conn->tmf_state = TMF_INITIAL;
1817                         /* task completed before tmf abort response */
1818                         debug_scsi("sc completed while abort in progress\n");
1819                         goto success;
1820                 }
1821                 /* fall through */
1822         default:
1823                 conn->tmf_state = TMF_INITIAL;
1824                 goto failed;
1825         }
1826
1827 success:
1828         spin_unlock_bh(&session->lock);
1829 success_unlocked:
1830         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, task->itt);
1831         mutex_unlock(&session->eh_mutex);
1832         return SUCCESS;
1833
1834 failed:
1835         spin_unlock_bh(&session->lock);
1836 failed_unlocked:
1837         debug_scsi("abort failed [sc %p itt 0x%x]\n", sc,
1838                     task ? task->itt : 0);
1839         mutex_unlock(&session->eh_mutex);
1840         return FAILED;
1841 }
1842 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1843
1844 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
1845 {
1846         memset(hdr, 0, sizeof(*hdr));
1847         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1848         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
1849         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1850         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
1851         hdr->rtt = RESERVED_ITT;
1852 }
1853
1854 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
1855 {
1856         struct iscsi_cls_session *cls_session;
1857         struct iscsi_session *session;
1858         struct iscsi_conn *conn;
1859         struct iscsi_tm *hdr;
1860         int rc = FAILED;
1861
1862         cls_session = starget_to_session(scsi_target(sc->device));
1863         session = cls_session->dd_data;
1864
1865         debug_scsi("LU Reset [sc %p lun %u]\n", sc, sc->device->lun);
1866
1867         mutex_lock(&session->eh_mutex);
1868         spin_lock_bh(&session->lock);
1869         /*
1870          * Just check if we are not logged in. We cannot check for
1871          * the phase because the reset could come from a ioctl.
1872          */
1873         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
1874                 goto unlock;
1875         conn = session->leadconn;
1876
1877         /* only have one tmf outstanding at a time */
1878         if (conn->tmf_state != TMF_INITIAL)
1879                 goto unlock;
1880         conn->tmf_state = TMF_QUEUED;
1881
1882         hdr = &conn->tmhdr;
1883         iscsi_prep_lun_reset_pdu(sc, hdr);
1884
1885         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
1886                                     session->lu_reset_timeout)) {
1887                 rc = FAILED;
1888                 goto unlock;
1889         }
1890
1891         switch (conn->tmf_state) {
1892         case TMF_SUCCESS:
1893                 break;
1894         case TMF_TIMEDOUT:
1895                 spin_unlock_bh(&session->lock);
1896                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1897                 goto done;
1898         default:
1899                 conn->tmf_state = TMF_INITIAL;
1900                 goto unlock;
1901         }
1902
1903         rc = SUCCESS;
1904         spin_unlock_bh(&session->lock);
1905
1906         iscsi_suspend_tx(conn);
1907
1908         spin_lock_bh(&session->lock);
1909         fail_all_commands(conn, sc->device->lun, DID_ERROR);
1910         conn->tmf_state = TMF_INITIAL;
1911         spin_unlock_bh(&session->lock);
1912
1913         iscsi_start_tx(conn);
1914         goto done;
1915
1916 unlock:
1917         spin_unlock_bh(&session->lock);
1918 done:
1919         debug_scsi("iscsi_eh_device_reset %s\n",
1920                   rc == SUCCESS ? "SUCCESS" : "FAILED");
1921         mutex_unlock(&session->eh_mutex);
1922         return rc;
1923 }
1924 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
1925
1926 /*
1927  * Pre-allocate a pool of @max items of @item_size. By default, the pool
1928  * should be accessed via kfifo_{get,put} on q->queue.
1929  * Optionally, the caller can obtain the array of object pointers
1930  * by passing in a non-NULL @items pointer
1931  */
1932 int
1933 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
1934 {
1935         int i, num_arrays = 1;
1936
1937         memset(q, 0, sizeof(*q));
1938
1939         q->max = max;
1940
1941         /* If the user passed an items pointer, he wants a copy of
1942          * the array. */
1943         if (items)
1944                 num_arrays++;
1945         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
1946         if (q->pool == NULL)
1947                 goto enomem;
1948
1949         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1950                               GFP_KERNEL, NULL);
1951         if (q->queue == ERR_PTR(-ENOMEM))
1952                 goto enomem;
1953
1954         for (i = 0; i < max; i++) {
1955                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
1956                 if (q->pool[i] == NULL) {
1957                         q->max = i;
1958                         goto enomem;
1959                 }
1960                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1961         }
1962
1963         if (items) {
1964                 *items = q->pool + max;
1965                 memcpy(*items, q->pool, max * sizeof(void *));
1966         }
1967
1968         return 0;
1969
1970 enomem:
1971         iscsi_pool_free(q);
1972         return -ENOMEM;
1973 }
1974 EXPORT_SYMBOL_GPL(iscsi_pool_init);
1975
1976 void iscsi_pool_free(struct iscsi_pool *q)
1977 {
1978         int i;
1979
1980         for (i = 0; i < q->max; i++)
1981                 kfree(q->pool[i]);
1982         if (q->pool)
1983                 kfree(q->pool);
1984 }
1985 EXPORT_SYMBOL_GPL(iscsi_pool_free);
1986
1987 /**
1988  * iscsi_host_add - add host to system
1989  * @shost: scsi host
1990  * @pdev: parent device
1991  *
1992  * This should be called by partial offload and software iscsi drivers
1993  * to add a host to the system.
1994  */
1995 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
1996 {
1997         if (!shost->can_queue)
1998                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
1999
2000         return scsi_add_host(shost, pdev);
2001 }
2002 EXPORT_SYMBOL_GPL(iscsi_host_add);
2003
2004 /**
2005  * iscsi_host_alloc - allocate a host and driver data
2006  * @sht: scsi host template
2007  * @dd_data_size: driver host data size
2008  * @qdepth: default device queue depth
2009  *
2010  * This should be called by partial offload and software iscsi drivers.
2011  * To access the driver specific memory use the iscsi_host_priv() macro.
2012  */
2013 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2014                                    int dd_data_size, uint16_t qdepth)
2015 {
2016         struct Scsi_Host *shost;
2017         struct iscsi_host *ihost;
2018
2019         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2020         if (!shost)
2021                 return NULL;
2022         shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
2023
2024         if (qdepth > ISCSI_MAX_CMD_PER_LUN || qdepth < 1) {
2025                 if (qdepth != 0)
2026                         printk(KERN_ERR "iscsi: invalid queue depth of %d. "
2027                                "Queue depth must be between 1 and %d.\n",
2028                                qdepth, ISCSI_MAX_CMD_PER_LUN);
2029                 qdepth = ISCSI_DEF_CMD_PER_LUN;
2030         }
2031         shost->cmd_per_lun = qdepth;
2032
2033         ihost = shost_priv(shost);
2034         spin_lock_init(&ihost->lock);
2035         ihost->state = ISCSI_HOST_SETUP;
2036         ihost->num_sessions = 0;
2037         init_waitqueue_head(&ihost->session_removal_wq);
2038         return shost;
2039 }
2040 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2041
2042 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2043 {
2044         iscsi_session_failure(cls_session, ISCSI_ERR_INVALID_HOST);
2045 }
2046
2047 /**
2048  * iscsi_host_remove - remove host and sessions
2049  * @shost: scsi host
2050  *
2051  * If there are any sessions left, this will initiate the removal and wait
2052  * for the completion.
2053  */
2054 void iscsi_host_remove(struct Scsi_Host *shost)
2055 {
2056         struct iscsi_host *ihost = shost_priv(shost);
2057         unsigned long flags;
2058
2059         spin_lock_irqsave(&ihost->lock, flags);
2060         ihost->state = ISCSI_HOST_REMOVED;
2061         spin_unlock_irqrestore(&ihost->lock, flags);
2062
2063         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2064         wait_event_interruptible(ihost->session_removal_wq,
2065                                  ihost->num_sessions == 0);
2066         if (signal_pending(current))
2067                 flush_signals(current);
2068
2069         scsi_remove_host(shost);
2070 }
2071 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2072
2073 void iscsi_host_free(struct Scsi_Host *shost)
2074 {
2075         struct iscsi_host *ihost = shost_priv(shost);
2076
2077         kfree(ihost->netdev);
2078         kfree(ihost->hwaddress);
2079         kfree(ihost->initiatorname);
2080         scsi_host_put(shost);
2081 }
2082 EXPORT_SYMBOL_GPL(iscsi_host_free);
2083
2084 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2085 {
2086         struct iscsi_host *ihost = shost_priv(shost);
2087         unsigned long flags;
2088
2089         shost = scsi_host_get(shost);
2090         if (!shost) {
2091                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2092                       "of session teardown event because host already "
2093                       "removed.\n");
2094                 return;
2095         }
2096
2097         spin_lock_irqsave(&ihost->lock, flags);
2098         ihost->num_sessions--;
2099         if (ihost->num_sessions == 0)
2100                 wake_up(&ihost->session_removal_wq);
2101         spin_unlock_irqrestore(&ihost->lock, flags);
2102         scsi_host_put(shost);
2103 }
2104
2105 /**
2106  * iscsi_session_setup - create iscsi cls session and host and session
2107  * @iscsit: iscsi transport template
2108  * @shost: scsi host
2109  * @cmds_max: session can queue
2110  * @cmd_task_size: LLD task private data size
2111  * @initial_cmdsn: initial CmdSN
2112  *
2113  * This can be used by software iscsi_transports that allocate
2114  * a session per scsi host.
2115  *
2116  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2117  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2118  * for nop handling and login/logout requests.
2119  */
2120 struct iscsi_cls_session *
2121 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2122                     uint16_t cmds_max, int cmd_task_size,
2123                     uint32_t initial_cmdsn, unsigned int id)
2124 {
2125         struct iscsi_host *ihost = shost_priv(shost);
2126         struct iscsi_session *session;
2127         struct iscsi_cls_session *cls_session;
2128         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2129         unsigned long flags;
2130
2131         spin_lock_irqsave(&ihost->lock, flags);
2132         if (ihost->state == ISCSI_HOST_REMOVED) {
2133                 spin_unlock_irqrestore(&ihost->lock, flags);
2134                 return NULL;
2135         }
2136         ihost->num_sessions++;
2137         spin_unlock_irqrestore(&ihost->lock, flags);
2138
2139         if (!total_cmds)
2140                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2141         /*
2142          * The iscsi layer needs some tasks for nop handling and tmfs,
2143          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2144          * + 1 command for scsi IO.
2145          */
2146         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2147                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2148                        "must be a power of two that is at least %d.\n",
2149                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2150                 goto dec_session_count;
2151         }
2152
2153         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2154                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2155                        "must be a power of 2 less than or equal to %d.\n",
2156                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2157                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2158         }
2159
2160         if (!is_power_of_2(total_cmds)) {
2161                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2162                        "must be a power of 2.\n", total_cmds);
2163                 total_cmds = rounddown_pow_of_two(total_cmds);
2164                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2165                         return NULL;
2166                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2167                        total_cmds);
2168         }
2169         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2170
2171         cls_session = iscsi_alloc_session(shost, iscsit,
2172                                           sizeof(struct iscsi_session));
2173         if (!cls_session)
2174                 goto dec_session_count;
2175         session = cls_session->dd_data;
2176         session->cls_session = cls_session;
2177         session->host = shost;
2178         session->state = ISCSI_STATE_FREE;
2179         session->fast_abort = 1;
2180         session->lu_reset_timeout = 15;
2181         session->abort_timeout = 10;
2182         session->scsi_cmds_max = scsi_cmds;
2183         session->cmds_max = total_cmds;
2184         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2185         session->exp_cmdsn = initial_cmdsn + 1;
2186         session->max_cmdsn = initial_cmdsn + 1;
2187         session->max_r2t = 1;
2188         session->tt = iscsit;
2189         mutex_init(&session->eh_mutex);
2190         spin_lock_init(&session->lock);
2191
2192         /* initialize SCSI PDU commands pool */
2193         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2194                             (void***)&session->cmds,
2195                             cmd_task_size + sizeof(struct iscsi_task)))
2196                 goto cmdpool_alloc_fail;
2197
2198         /* pre-format cmds pool with ITT */
2199         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2200                 struct iscsi_task *task = session->cmds[cmd_i];
2201
2202                 if (cmd_task_size)
2203                         task->dd_data = &task[1];
2204                 task->itt = cmd_i;
2205                 INIT_LIST_HEAD(&task->running);
2206         }
2207
2208         if (!try_module_get(iscsit->owner))
2209                 goto module_get_fail;
2210
2211         if (iscsi_add_session(cls_session, id))
2212                 goto cls_session_fail;
2213
2214         return cls_session;
2215
2216 cls_session_fail:
2217         module_put(iscsit->owner);
2218 module_get_fail:
2219         iscsi_pool_free(&session->cmdpool);
2220 cmdpool_alloc_fail:
2221         iscsi_free_session(cls_session);
2222 dec_session_count:
2223         iscsi_host_dec_session_cnt(shost);
2224         return NULL;
2225 }
2226 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2227
2228 /**
2229  * iscsi_session_teardown - destroy session, host, and cls_session
2230  * @cls_session: iscsi session
2231  *
2232  * The driver must have called iscsi_remove_session before
2233  * calling this.
2234  */
2235 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2236 {
2237         struct iscsi_session *session = cls_session->dd_data;
2238         struct module *owner = cls_session->transport->owner;
2239         struct Scsi_Host *shost = session->host;
2240
2241         iscsi_pool_free(&session->cmdpool);
2242
2243         kfree(session->password);
2244         kfree(session->password_in);
2245         kfree(session->username);
2246         kfree(session->username_in);
2247         kfree(session->targetname);
2248         kfree(session->initiatorname);
2249         kfree(session->ifacename);
2250
2251         iscsi_destroy_session(cls_session);
2252         iscsi_host_dec_session_cnt(shost);
2253         module_put(owner);
2254 }
2255 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2256
2257 /**
2258  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2259  * @cls_session: iscsi_cls_session
2260  * @dd_size: private driver data size
2261  * @conn_idx: cid
2262  */
2263 struct iscsi_cls_conn *
2264 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2265                  uint32_t conn_idx)
2266 {
2267         struct iscsi_session *session = cls_session->dd_data;
2268         struct iscsi_conn *conn;
2269         struct iscsi_cls_conn *cls_conn;
2270         char *data;
2271
2272         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2273                                      conn_idx);
2274         if (!cls_conn)
2275                 return NULL;
2276         conn = cls_conn->dd_data;
2277         memset(conn, 0, sizeof(*conn) + dd_size);
2278
2279         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2280         conn->session = session;
2281         conn->cls_conn = cls_conn;
2282         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2283         conn->id = conn_idx;
2284         conn->exp_statsn = 0;
2285         conn->tmf_state = TMF_INITIAL;
2286
2287         init_timer(&conn->transport_timer);
2288         conn->transport_timer.data = (unsigned long)conn;
2289         conn->transport_timer.function = iscsi_check_transport_timeouts;
2290
2291         INIT_LIST_HEAD(&conn->run_list);
2292         INIT_LIST_HEAD(&conn->mgmt_run_list);
2293         INIT_LIST_HEAD(&conn->mgmtqueue);
2294         INIT_LIST_HEAD(&conn->xmitqueue);
2295         INIT_LIST_HEAD(&conn->requeue);
2296         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2297
2298         /* allocate login_task used for the login/text sequences */
2299         spin_lock_bh(&session->lock);
2300         if (!__kfifo_get(session->cmdpool.queue,
2301                          (void*)&conn->login_task,
2302                          sizeof(void*))) {
2303                 spin_unlock_bh(&session->lock);
2304                 goto login_task_alloc_fail;
2305         }
2306         spin_unlock_bh(&session->lock);
2307
2308         data = (char *) __get_free_pages(GFP_KERNEL,
2309                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2310         if (!data)
2311                 goto login_task_data_alloc_fail;
2312         conn->login_task->data = conn->data = data;
2313
2314         init_timer(&conn->tmf_timer);
2315         init_waitqueue_head(&conn->ehwait);
2316
2317         return cls_conn;
2318
2319 login_task_data_alloc_fail:
2320         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2321                     sizeof(void*));
2322 login_task_alloc_fail:
2323         iscsi_destroy_conn(cls_conn);
2324         return NULL;
2325 }
2326 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2327
2328 /**
2329  * iscsi_conn_teardown - teardown iscsi connection
2330  * cls_conn: iscsi class connection
2331  *
2332  * TODO: we may need to make this into a two step process
2333  * like scsi-mls remove + put host
2334  */
2335 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2336 {
2337         struct iscsi_conn *conn = cls_conn->dd_data;
2338         struct iscsi_session *session = conn->session;
2339         unsigned long flags;
2340
2341         del_timer_sync(&conn->transport_timer);
2342
2343         spin_lock_bh(&session->lock);
2344         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2345         if (session->leadconn == conn) {
2346                 /*
2347                  * leading connection? then give up on recovery.
2348                  */
2349                 session->state = ISCSI_STATE_TERMINATE;
2350                 wake_up(&conn->ehwait);
2351         }
2352         spin_unlock_bh(&session->lock);
2353
2354         /*
2355          * Block until all in-progress commands for this connection
2356          * time out or fail.
2357          */
2358         for (;;) {
2359                 spin_lock_irqsave(session->host->host_lock, flags);
2360                 if (!session->host->host_busy) { /* OK for ERL == 0 */
2361                         spin_unlock_irqrestore(session->host->host_lock, flags);
2362                         break;
2363                 }
2364                 spin_unlock_irqrestore(session->host->host_lock, flags);
2365                 msleep_interruptible(500);
2366                 iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2367                                   "host_busy %d host_failed %d\n",
2368                                   session->host->host_busy,
2369                                   session->host->host_failed);
2370                 /*
2371                  * force eh_abort() to unblock
2372                  */
2373                 wake_up(&conn->ehwait);
2374         }
2375
2376         /* flush queued up work because we free the connection below */
2377         iscsi_suspend_tx(conn);
2378
2379         spin_lock_bh(&session->lock);
2380         free_pages((unsigned long) conn->data,
2381                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2382         kfree(conn->persistent_address);
2383         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2384                     sizeof(void*));
2385         if (session->leadconn == conn)
2386                 session->leadconn = NULL;
2387         spin_unlock_bh(&session->lock);
2388
2389         iscsi_destroy_conn(cls_conn);
2390 }
2391 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2392
2393 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2394 {
2395         struct iscsi_conn *conn = cls_conn->dd_data;
2396         struct iscsi_session *session = conn->session;
2397
2398         if (!session) {
2399                 iscsi_conn_printk(KERN_ERR, conn,
2400                                   "can't start unbound connection\n");
2401                 return -EPERM;
2402         }
2403
2404         if ((session->imm_data_en || !session->initial_r2t_en) &&
2405              session->first_burst > session->max_burst) {
2406                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2407                                   "first_burst %d max_burst %d\n",
2408                                   session->first_burst, session->max_burst);
2409                 return -EINVAL;
2410         }
2411
2412         if (conn->ping_timeout && !conn->recv_timeout) {
2413                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
2414                                   "zero. Using 5 seconds\n.");
2415                 conn->recv_timeout = 5;
2416         }
2417
2418         if (conn->recv_timeout && !conn->ping_timeout) {
2419                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
2420                                   "zero. Using 5 seconds.\n");
2421                 conn->ping_timeout = 5;
2422         }
2423
2424         spin_lock_bh(&session->lock);
2425         conn->c_stage = ISCSI_CONN_STARTED;
2426         session->state = ISCSI_STATE_LOGGED_IN;
2427         session->queued_cmdsn = session->cmdsn;
2428
2429         conn->last_recv = jiffies;
2430         conn->last_ping = jiffies;
2431         if (conn->recv_timeout && conn->ping_timeout)
2432                 mod_timer(&conn->transport_timer,
2433                           jiffies + (conn->recv_timeout * HZ));
2434
2435         switch(conn->stop_stage) {
2436         case STOP_CONN_RECOVER:
2437                 /*
2438                  * unblock eh_abort() if it is blocked. re-try all
2439                  * commands after successful recovery
2440                  */
2441                 conn->stop_stage = 0;
2442                 conn->tmf_state = TMF_INITIAL;
2443                 session->age++;
2444                 if (session->age == 16)
2445                         session->age = 0;
2446                 break;
2447         case STOP_CONN_TERM:
2448                 conn->stop_stage = 0;
2449                 break;
2450         default:
2451                 break;
2452         }
2453         spin_unlock_bh(&session->lock);
2454
2455         iscsi_unblock_session(session->cls_session);
2456         wake_up(&conn->ehwait);
2457         return 0;
2458 }
2459 EXPORT_SYMBOL_GPL(iscsi_conn_start);
2460
2461 static void
2462 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
2463 {
2464         struct iscsi_task *task, *tmp;
2465
2466         /* handle pending */
2467         list_for_each_entry_safe(task, tmp, &conn->mgmtqueue, running) {
2468                 debug_scsi("flushing pending mgmt task itt 0x%x\n", task->itt);
2469                 /* release ref from prep task */
2470                 __iscsi_put_task(task);
2471         }
2472
2473         /* handle running */
2474         list_for_each_entry_safe(task, tmp, &conn->mgmt_run_list, running) {
2475                 debug_scsi("flushing running mgmt task itt 0x%x\n", task->itt);
2476                 /* release ref from prep task */
2477                 __iscsi_put_task(task);
2478         }
2479
2480         conn->task = NULL;
2481 }
2482
2483 static void iscsi_start_session_recovery(struct iscsi_session *session,
2484                                          struct iscsi_conn *conn, int flag)
2485 {
2486         int old_stop_stage;
2487
2488         del_timer_sync(&conn->transport_timer);
2489
2490         mutex_lock(&session->eh_mutex);
2491         spin_lock_bh(&session->lock);
2492         if (conn->stop_stage == STOP_CONN_TERM) {
2493                 spin_unlock_bh(&session->lock);
2494                 mutex_unlock(&session->eh_mutex);
2495                 return;
2496         }
2497
2498         /*
2499          * When this is called for the in_login state, we only want to clean
2500          * up the login task and connection. We do not need to block and set
2501          * the recovery state again
2502          */
2503         if (flag == STOP_CONN_TERM)
2504                 session->state = ISCSI_STATE_TERMINATE;
2505         else if (conn->stop_stage != STOP_CONN_RECOVER)
2506                 session->state = ISCSI_STATE_IN_RECOVERY;
2507
2508         old_stop_stage = conn->stop_stage;
2509         conn->stop_stage = flag;
2510         conn->c_stage = ISCSI_CONN_STOPPED;
2511         spin_unlock_bh(&session->lock);
2512
2513         iscsi_suspend_tx(conn);
2514         /*
2515          * for connection level recovery we should not calculate
2516          * header digest. conn->hdr_size used for optimization
2517          * in hdr_extract() and will be re-negotiated at
2518          * set_param() time.
2519          */
2520         if (flag == STOP_CONN_RECOVER) {
2521                 conn->hdrdgst_en = 0;
2522                 conn->datadgst_en = 0;
2523                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
2524                     old_stop_stage != STOP_CONN_RECOVER) {
2525                         debug_scsi("blocking session\n");
2526                         iscsi_block_session(session->cls_session);
2527                 }
2528         }
2529
2530         /*
2531          * flush queues.
2532          */
2533         spin_lock_bh(&session->lock);
2534         if (flag == STOP_CONN_RECOVER)
2535                 fail_all_commands(conn, -1, DID_TRANSPORT_DISRUPTED);
2536         else
2537                 fail_all_commands(conn, -1, DID_ERROR);
2538         flush_control_queues(session, conn);
2539         spin_unlock_bh(&session->lock);
2540         mutex_unlock(&session->eh_mutex);
2541 }
2542
2543 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
2544 {
2545         struct iscsi_conn *conn = cls_conn->dd_data;
2546         struct iscsi_session *session = conn->session;
2547
2548         switch (flag) {
2549         case STOP_CONN_RECOVER:
2550         case STOP_CONN_TERM:
2551                 iscsi_start_session_recovery(session, conn, flag);
2552                 break;
2553         default:
2554                 iscsi_conn_printk(KERN_ERR, conn,
2555                                   "invalid stop flag %d\n", flag);
2556         }
2557 }
2558 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
2559
2560 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
2561                     struct iscsi_cls_conn *cls_conn, int is_leading)
2562 {
2563         struct iscsi_session *session = cls_session->dd_data;
2564         struct iscsi_conn *conn = cls_conn->dd_data;
2565
2566         spin_lock_bh(&session->lock);
2567         if (is_leading)
2568                 session->leadconn = conn;
2569         spin_unlock_bh(&session->lock);
2570
2571         /*
2572          * Unblock xmitworker(), Login Phase will pass through.
2573          */
2574         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
2575         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
2576         return 0;
2577 }
2578 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
2579
2580
2581 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
2582                     enum iscsi_param param, char *buf, int buflen)
2583 {
2584         struct iscsi_conn *conn = cls_conn->dd_data;
2585         struct iscsi_session *session = conn->session;
2586         uint32_t value;
2587
2588         switch(param) {
2589         case ISCSI_PARAM_FAST_ABORT:
2590                 sscanf(buf, "%d", &session->fast_abort);
2591                 break;
2592         case ISCSI_PARAM_ABORT_TMO:
2593                 sscanf(buf, "%d", &session->abort_timeout);
2594                 break;
2595         case ISCSI_PARAM_LU_RESET_TMO:
2596                 sscanf(buf, "%d", &session->lu_reset_timeout);
2597                 break;
2598         case ISCSI_PARAM_PING_TMO:
2599                 sscanf(buf, "%d", &conn->ping_timeout);
2600                 break;
2601         case ISCSI_PARAM_RECV_TMO:
2602                 sscanf(buf, "%d", &conn->recv_timeout);
2603                 break;
2604         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2605                 sscanf(buf, "%d", &conn->max_recv_dlength);
2606                 break;
2607         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2608                 sscanf(buf, "%d", &conn->max_xmit_dlength);
2609                 break;
2610         case ISCSI_PARAM_HDRDGST_EN:
2611                 sscanf(buf, "%d", &conn->hdrdgst_en);
2612                 break;
2613         case ISCSI_PARAM_DATADGST_EN:
2614                 sscanf(buf, "%d", &conn->datadgst_en);
2615                 break;
2616         case ISCSI_PARAM_INITIAL_R2T_EN:
2617                 sscanf(buf, "%d", &session->initial_r2t_en);
2618                 break;
2619         case ISCSI_PARAM_MAX_R2T:
2620                 sscanf(buf, "%d", &session->max_r2t);
2621                 break;
2622         case ISCSI_PARAM_IMM_DATA_EN:
2623                 sscanf(buf, "%d", &session->imm_data_en);
2624                 break;
2625         case ISCSI_PARAM_FIRST_BURST:
2626                 sscanf(buf, "%d", &session->first_burst);
2627                 break;
2628         case ISCSI_PARAM_MAX_BURST:
2629                 sscanf(buf, "%d", &session->max_burst);
2630                 break;
2631         case ISCSI_PARAM_PDU_INORDER_EN:
2632                 sscanf(buf, "%d", &session->pdu_inorder_en);
2633                 break;
2634         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2635                 sscanf(buf, "%d", &session->dataseq_inorder_en);
2636                 break;
2637         case ISCSI_PARAM_ERL:
2638                 sscanf(buf, "%d", &session->erl);
2639                 break;
2640         case ISCSI_PARAM_IFMARKER_EN:
2641                 sscanf(buf, "%d", &value);
2642                 BUG_ON(value);
2643                 break;
2644         case ISCSI_PARAM_OFMARKER_EN:
2645                 sscanf(buf, "%d", &value);
2646                 BUG_ON(value);
2647                 break;
2648         case ISCSI_PARAM_EXP_STATSN:
2649                 sscanf(buf, "%u", &conn->exp_statsn);
2650                 break;
2651         case ISCSI_PARAM_USERNAME:
2652                 kfree(session->username);
2653                 session->username = kstrdup(buf, GFP_KERNEL);
2654                 if (!session->username)
2655                         return -ENOMEM;
2656                 break;
2657         case ISCSI_PARAM_USERNAME_IN:
2658                 kfree(session->username_in);
2659                 session->username_in = kstrdup(buf, GFP_KERNEL);
2660                 if (!session->username_in)
2661                         return -ENOMEM;
2662                 break;
2663         case ISCSI_PARAM_PASSWORD:
2664                 kfree(session->password);
2665                 session->password = kstrdup(buf, GFP_KERNEL);
2666                 if (!session->password)
2667                         return -ENOMEM;
2668                 break;
2669         case ISCSI_PARAM_PASSWORD_IN:
2670                 kfree(session->password_in);
2671                 session->password_in = kstrdup(buf, GFP_KERNEL);
2672                 if (!session->password_in)
2673                         return -ENOMEM;
2674                 break;
2675         case ISCSI_PARAM_TARGET_NAME:
2676                 /* this should not change between logins */
2677                 if (session->targetname)
2678                         break;
2679
2680                 session->targetname = kstrdup(buf, GFP_KERNEL);
2681                 if (!session->targetname)
2682                         return -ENOMEM;
2683                 break;
2684         case ISCSI_PARAM_TPGT:
2685                 sscanf(buf, "%d", &session->tpgt);
2686                 break;
2687         case ISCSI_PARAM_PERSISTENT_PORT:
2688                 sscanf(buf, "%d", &conn->persistent_port);
2689                 break;
2690         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2691                 /*
2692                  * this is the address returned in discovery so it should
2693                  * not change between logins.
2694                  */
2695                 if (conn->persistent_address)
2696                         break;
2697
2698                 conn->persistent_address = kstrdup(buf, GFP_KERNEL);
2699                 if (!conn->persistent_address)
2700                         return -ENOMEM;
2701                 break;
2702         case ISCSI_PARAM_IFACE_NAME:
2703                 if (!session->ifacename)
2704                         session->ifacename = kstrdup(buf, GFP_KERNEL);
2705                 break;
2706         case ISCSI_PARAM_INITIATOR_NAME:
2707                 if (!session->initiatorname)
2708                         session->initiatorname = kstrdup(buf, GFP_KERNEL);
2709                 break;
2710         default:
2711                 return -ENOSYS;
2712         }
2713
2714         return 0;
2715 }
2716 EXPORT_SYMBOL_GPL(iscsi_set_param);
2717
2718 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
2719                             enum iscsi_param param, char *buf)
2720 {
2721         struct iscsi_session *session = cls_session->dd_data;
2722         int len;
2723
2724         switch(param) {
2725         case ISCSI_PARAM_FAST_ABORT:
2726                 len = sprintf(buf, "%d\n", session->fast_abort);
2727                 break;
2728         case ISCSI_PARAM_ABORT_TMO:
2729                 len = sprintf(buf, "%d\n", session->abort_timeout);
2730                 break;
2731         case ISCSI_PARAM_LU_RESET_TMO:
2732                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
2733                 break;
2734         case ISCSI_PARAM_INITIAL_R2T_EN:
2735                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
2736                 break;
2737         case ISCSI_PARAM_MAX_R2T:
2738                 len = sprintf(buf, "%hu\n", session->max_r2t);
2739                 break;
2740         case ISCSI_PARAM_IMM_DATA_EN:
2741                 len = sprintf(buf, "%d\n", session->imm_data_en);
2742                 break;
2743         case ISCSI_PARAM_FIRST_BURST:
2744                 len = sprintf(buf, "%u\n", session->first_burst);
2745                 break;
2746         case ISCSI_PARAM_MAX_BURST:
2747                 len = sprintf(buf, "%u\n", session->max_burst);
2748                 break;
2749         case ISCSI_PARAM_PDU_INORDER_EN:
2750                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
2751                 break;
2752         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2753                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
2754                 break;
2755         case ISCSI_PARAM_ERL:
2756                 len = sprintf(buf, "%d\n", session->erl);
2757                 break;
2758         case ISCSI_PARAM_TARGET_NAME:
2759                 len = sprintf(buf, "%s\n", session->targetname);
2760                 break;
2761         case ISCSI_PARAM_TPGT:
2762                 len = sprintf(buf, "%d\n", session->tpgt);
2763                 break;
2764         case ISCSI_PARAM_USERNAME:
2765                 len = sprintf(buf, "%s\n", session->username);
2766                 break;
2767         case ISCSI_PARAM_USERNAME_IN:
2768                 len = sprintf(buf, "%s\n", session->username_in);
2769                 break;
2770         case ISCSI_PARAM_PASSWORD:
2771                 len = sprintf(buf, "%s\n", session->password);
2772                 break;
2773         case ISCSI_PARAM_PASSWORD_IN:
2774                 len = sprintf(buf, "%s\n", session->password_in);
2775                 break;
2776         case ISCSI_PARAM_IFACE_NAME:
2777                 len = sprintf(buf, "%s\n", session->ifacename);
2778                 break;
2779         case ISCSI_PARAM_INITIATOR_NAME:
2780                 if (!session->initiatorname)
2781                         len = sprintf(buf, "%s\n", "unknown");
2782                 else
2783                         len = sprintf(buf, "%s\n", session->initiatorname);
2784                 break;
2785         default:
2786                 return -ENOSYS;
2787         }
2788
2789         return len;
2790 }
2791 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
2792
2793 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2794                          enum iscsi_param param, char *buf)
2795 {
2796         struct iscsi_conn *conn = cls_conn->dd_data;
2797         int len;
2798
2799         switch(param) {
2800         case ISCSI_PARAM_PING_TMO:
2801                 len = sprintf(buf, "%u\n", conn->ping_timeout);
2802                 break;
2803         case ISCSI_PARAM_RECV_TMO:
2804                 len = sprintf(buf, "%u\n", conn->recv_timeout);
2805                 break;
2806         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2807                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
2808                 break;
2809         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2810                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
2811                 break;
2812         case ISCSI_PARAM_HDRDGST_EN:
2813                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
2814                 break;
2815         case ISCSI_PARAM_DATADGST_EN:
2816                 len = sprintf(buf, "%d\n", conn->datadgst_en);
2817                 break;
2818         case ISCSI_PARAM_IFMARKER_EN:
2819                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
2820                 break;
2821         case ISCSI_PARAM_OFMARKER_EN:
2822                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
2823                 break;
2824         case ISCSI_PARAM_EXP_STATSN:
2825                 len = sprintf(buf, "%u\n", conn->exp_statsn);
2826                 break;
2827         case ISCSI_PARAM_PERSISTENT_PORT:
2828                 len = sprintf(buf, "%d\n", conn->persistent_port);
2829                 break;
2830         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2831                 len = sprintf(buf, "%s\n", conn->persistent_address);
2832                 break;
2833         default:
2834                 return -ENOSYS;
2835         }
2836
2837         return len;
2838 }
2839 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
2840
2841 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2842                          char *buf)
2843 {
2844         struct iscsi_host *ihost = shost_priv(shost);
2845         int len;
2846
2847         switch (param) {
2848         case ISCSI_HOST_PARAM_NETDEV_NAME:
2849                 if (!ihost->netdev)
2850                         len = sprintf(buf, "%s\n", "default");
2851                 else
2852                         len = sprintf(buf, "%s\n", ihost->netdev);
2853                 break;
2854         case ISCSI_HOST_PARAM_HWADDRESS:
2855                 if (!ihost->hwaddress)
2856                         len = sprintf(buf, "%s\n", "default");
2857                 else
2858                         len = sprintf(buf, "%s\n", ihost->hwaddress);
2859                 break;
2860         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2861                 if (!ihost->initiatorname)
2862                         len = sprintf(buf, "%s\n", "unknown");
2863                 else
2864                         len = sprintf(buf, "%s\n", ihost->initiatorname);
2865                 break;
2866         case ISCSI_HOST_PARAM_IPADDRESS:
2867                 if (!strlen(ihost->local_address))
2868                         len = sprintf(buf, "%s\n", "unknown");
2869                 else
2870                         len = sprintf(buf, "%s\n",
2871                                       ihost->local_address);
2872                 break;
2873         default:
2874                 return -ENOSYS;
2875         }
2876
2877         return len;
2878 }
2879 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
2880
2881 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2882                          char *buf, int buflen)
2883 {
2884         struct iscsi_host *ihost = shost_priv(shost);
2885
2886         switch (param) {
2887         case ISCSI_HOST_PARAM_NETDEV_NAME:
2888                 if (!ihost->netdev)
2889                         ihost->netdev = kstrdup(buf, GFP_KERNEL);
2890                 break;
2891         case ISCSI_HOST_PARAM_HWADDRESS:
2892                 if (!ihost->hwaddress)
2893                         ihost->hwaddress = kstrdup(buf, GFP_KERNEL);
2894                 break;
2895         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2896                 if (!ihost->initiatorname)
2897                         ihost->initiatorname = kstrdup(buf, GFP_KERNEL);
2898                 break;
2899         default:
2900                 return -ENOSYS;
2901         }
2902
2903         return 0;
2904 }
2905 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
2906
2907 MODULE_AUTHOR("Mike Christie");
2908 MODULE_DESCRIPTION("iSCSI library functions");
2909 MODULE_LICENSE("GPL");