[SCSI] libiscsi: don't cap queue depth in iscsi modules
[linux-2.6] / drivers / scsi / libiscsi.c
1 /*
2  * iSCSI lib functions
3  *
4  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
5  * Copyright (C) 2004 - 2006 Mike Christie
6  * Copyright (C) 2004 - 2005 Dmitry Yusupov
7  * Copyright (C) 2004 - 2005 Alex Aizman
8  * maintained by open-iscsi@googlegroups.com
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23  */
24 #include <linux/types.h>
25 #include <linux/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 static int iscsi_dbg_lib;
42 module_param_named(debug_libiscsi, iscsi_dbg_lib, int, S_IRUGO | S_IWUSR);
43 MODULE_PARM_DESC(debug_libiscsi, "Turn on debugging for libiscsi module. "
44                  "Set to 1 to turn on, and zero to turn off. Default "
45                  "is off.");
46
47 #define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)                  \
48         do {                                                    \
49                 if (iscsi_dbg_lib)                              \
50                         iscsi_conn_printk(KERN_INFO, _conn,     \
51                                              "%s " dbg_fmt,     \
52                                              __func__, ##arg);  \
53         } while (0);
54
55 #define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)                    \
56         do {                                                            \
57                 if (iscsi_dbg_lib)                                      \
58                         iscsi_session_printk(KERN_INFO, _session,       \
59                                              "%s " dbg_fmt,             \
60                                              __func__, ##arg);          \
61         } while (0);
62
63 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
64 #define SNA32_CHECK 2147483648UL
65
66 static int iscsi_sna_lt(u32 n1, u32 n2)
67 {
68         return n1 != n2 && ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
69                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
70 }
71
72 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
73 static int iscsi_sna_lte(u32 n1, u32 n2)
74 {
75         return n1 == n2 || ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
76                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
77 }
78
79 void
80 iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
81 {
82         uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
83         uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);
84
85         /*
86          * standard specifies this check for when to update expected and
87          * max sequence numbers
88          */
89         if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
90                 return;
91
92         if (exp_cmdsn != session->exp_cmdsn &&
93             !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
94                 session->exp_cmdsn = exp_cmdsn;
95
96         if (max_cmdsn != session->max_cmdsn &&
97             !iscsi_sna_lt(max_cmdsn, session->max_cmdsn)) {
98                 session->max_cmdsn = max_cmdsn;
99                 /*
100                  * if the window closed with IO queued, then kick the
101                  * xmit thread
102                  */
103                 if (!list_empty(&session->leadconn->xmitqueue) ||
104                     !list_empty(&session->leadconn->mgmtqueue)) {
105                         if (!(session->tt->caps & CAP_DATA_PATH_OFFLOAD))
106                                 scsi_queue_work(session->host,
107                                                 &session->leadconn->xmitwork);
108                 }
109         }
110 }
111 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
112
113 /**
114  * iscsi_prep_data_out_pdu - initialize Data-Out
115  * @task: scsi command task
116  * @r2t: R2T info
117  * @hdr: iscsi data in pdu
118  *
119  * Notes:
120  *      Initialize Data-Out within this R2T sequence and finds
121  *      proper data_offset within this SCSI command.
122  *
123  *      This function is called with connection lock taken.
124  **/
125 void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
126                            struct iscsi_data *hdr)
127 {
128         struct iscsi_conn *conn = task->conn;
129         unsigned int left = r2t->data_length - r2t->sent;
130
131         task->hdr_len = sizeof(struct iscsi_data);
132
133         memset(hdr, 0, sizeof(struct iscsi_data));
134         hdr->ttt = r2t->ttt;
135         hdr->datasn = cpu_to_be32(r2t->datasn);
136         r2t->datasn++;
137         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
138         memcpy(hdr->lun, task->lun, sizeof(hdr->lun));
139         hdr->itt = task->hdr_itt;
140         hdr->exp_statsn = r2t->exp_statsn;
141         hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
142         if (left > conn->max_xmit_dlength) {
143                 hton24(hdr->dlength, conn->max_xmit_dlength);
144                 r2t->data_count = conn->max_xmit_dlength;
145                 hdr->flags = 0;
146         } else {
147                 hton24(hdr->dlength, left);
148                 r2t->data_count = left;
149                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
150         }
151         conn->dataout_pdus_cnt++;
152 }
153 EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
154
155 static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
156 {
157         unsigned exp_len = task->hdr_len + len;
158
159         if (exp_len > task->hdr_max) {
160                 WARN_ON(1);
161                 return -EINVAL;
162         }
163
164         WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
165         task->hdr_len = exp_len;
166         return 0;
167 }
168
169 /*
170  * make an extended cdb AHS
171  */
172 static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
173 {
174         struct scsi_cmnd *cmd = task->sc;
175         unsigned rlen, pad_len;
176         unsigned short ahslength;
177         struct iscsi_ecdb_ahdr *ecdb_ahdr;
178         int rc;
179
180         ecdb_ahdr = iscsi_next_hdr(task);
181         rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
182
183         BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
184         ahslength = rlen + sizeof(ecdb_ahdr->reserved);
185
186         pad_len = iscsi_padding(rlen);
187
188         rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
189                            sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
190         if (rc)
191                 return rc;
192
193         if (pad_len)
194                 memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
195
196         ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
197         ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
198         ecdb_ahdr->reserved = 0;
199         memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
200
201         ISCSI_DBG_SESSION(task->conn->session,
202                           "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
203                           "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
204                           "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
205                           task->hdr_len);
206         return 0;
207 }
208
209 static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
210 {
211         struct scsi_cmnd *sc = task->sc;
212         struct iscsi_rlength_ahdr *rlen_ahdr;
213         int rc;
214
215         rlen_ahdr = iscsi_next_hdr(task);
216         rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
217         if (rc)
218                 return rc;
219
220         rlen_ahdr->ahslength =
221                 cpu_to_be16(sizeof(rlen_ahdr->read_length) +
222                                                   sizeof(rlen_ahdr->reserved));
223         rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
224         rlen_ahdr->reserved = 0;
225         rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
226
227         ISCSI_DBG_SESSION(task->conn->session,
228                           "bidi-in rlen_ahdr->read_length(%d) "
229                           "rlen_ahdr->ahslength(%d)\n",
230                           be32_to_cpu(rlen_ahdr->read_length),
231                           be16_to_cpu(rlen_ahdr->ahslength));
232         return 0;
233 }
234
235 /**
236  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
237  * @task: iscsi task
238  *
239  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
240  * fields like dlength or final based on how much data it sends
241  */
242 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
243 {
244         struct iscsi_conn *conn = task->conn;
245         struct iscsi_session *session = conn->session;
246         struct scsi_cmnd *sc = task->sc;
247         struct iscsi_cmd *hdr;
248         unsigned hdrlength, cmd_len;
249         itt_t itt;
250         int rc;
251
252         rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
253         if (rc)
254                 return rc;
255         hdr = (struct iscsi_cmd *) task->hdr;
256         itt = hdr->itt;
257         memset(hdr, 0, sizeof(*hdr));
258
259         if (session->tt->parse_pdu_itt)
260                 hdr->itt = task->hdr_itt = itt;
261         else
262                 hdr->itt = task->hdr_itt = build_itt(task->itt,
263                                                      task->conn->session->age);
264         task->hdr_len = 0;
265         rc = iscsi_add_hdr(task, sizeof(*hdr));
266         if (rc)
267                 return rc;
268         hdr->opcode = ISCSI_OP_SCSI_CMD;
269         hdr->flags = ISCSI_ATTR_SIMPLE;
270         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
271         memcpy(task->lun, hdr->lun, sizeof(task->lun));
272         hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
273         session->cmdsn++;
274         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
275         cmd_len = sc->cmd_len;
276         if (cmd_len < ISCSI_CDB_SIZE)
277                 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
278         else if (cmd_len > ISCSI_CDB_SIZE) {
279                 rc = iscsi_prep_ecdb_ahs(task);
280                 if (rc)
281                         return rc;
282                 cmd_len = ISCSI_CDB_SIZE;
283         }
284         memcpy(hdr->cdb, sc->cmnd, cmd_len);
285
286         task->imm_count = 0;
287         if (scsi_bidi_cmnd(sc)) {
288                 hdr->flags |= ISCSI_FLAG_CMD_READ;
289                 rc = iscsi_prep_bidi_ahs(task);
290                 if (rc)
291                         return rc;
292         }
293         if (sc->sc_data_direction == DMA_TO_DEVICE) {
294                 unsigned out_len = scsi_out(sc)->length;
295                 struct iscsi_r2t_info *r2t = &task->unsol_r2t;
296
297                 hdr->data_length = cpu_to_be32(out_len);
298                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
299                 /*
300                  * Write counters:
301                  *
302                  *      imm_count       bytes to be sent right after
303                  *                      SCSI PDU Header
304                  *
305                  *      unsol_count     bytes(as Data-Out) to be sent
306                  *                      without R2T ack right after
307                  *                      immediate data
308                  *
309                  *      r2t data_length bytes to be sent via R2T ack's
310                  *
311                  *      pad_count       bytes to be sent as zero-padding
312                  */
313                 memset(r2t, 0, sizeof(*r2t));
314
315                 if (session->imm_data_en) {
316                         if (out_len >= session->first_burst)
317                                 task->imm_count = min(session->first_burst,
318                                                         conn->max_xmit_dlength);
319                         else
320                                 task->imm_count = min(out_len,
321                                                         conn->max_xmit_dlength);
322                         hton24(hdr->dlength, task->imm_count);
323                 } else
324                         zero_data(hdr->dlength);
325
326                 if (!session->initial_r2t_en) {
327                         r2t->data_length = min(session->first_burst, out_len) -
328                                                task->imm_count;
329                         r2t->data_offset = task->imm_count;
330                         r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
331                         r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
332                 }
333
334                 if (!task->unsol_r2t.data_length)
335                         /* No unsolicit Data-Out's */
336                         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
337         } else {
338                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
339                 zero_data(hdr->dlength);
340                 hdr->data_length = cpu_to_be32(scsi_in(sc)->length);
341
342                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
343                         hdr->flags |= ISCSI_FLAG_CMD_READ;
344         }
345
346         /* calculate size of additional header segments (AHSs) */
347         hdrlength = task->hdr_len - sizeof(*hdr);
348
349         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
350         hdrlength /= ISCSI_PAD_LEN;
351
352         WARN_ON(hdrlength >= 256);
353         hdr->hlength = hdrlength & 0xFF;
354
355         if (session->tt->init_task && session->tt->init_task(task))
356                 return -EIO;
357
358         task->state = ISCSI_TASK_RUNNING;
359         list_move_tail(&task->running, &conn->run_list);
360
361         conn->scsicmd_pdus_cnt++;
362         ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
363                           "itt 0x%x len %d bidi_len %d cmdsn %d win %d]\n",
364                           scsi_bidi_cmnd(sc) ? "bidirectional" :
365                           sc->sc_data_direction == DMA_TO_DEVICE ?
366                           "write" : "read", conn->id, sc, sc->cmnd[0],
367                           task->itt, scsi_bufflen(sc),
368                           scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
369                           session->cmdsn,
370                           session->max_cmdsn - session->exp_cmdsn + 1);
371         return 0;
372 }
373
374 /**
375  * iscsi_complete_command - finish a task
376  * @task: iscsi cmd task
377  *
378  * Must be called with session lock.
379  * This function returns the scsi command to scsi-ml or cleans
380  * up mgmt tasks then returns the task to the pool.
381  */
382 static void iscsi_complete_command(struct iscsi_task *task)
383 {
384         struct iscsi_conn *conn = task->conn;
385         struct iscsi_session *session = conn->session;
386         struct scsi_cmnd *sc = task->sc;
387
388         session->tt->cleanup_task(task);
389         list_del_init(&task->running);
390         task->state = ISCSI_TASK_COMPLETED;
391         task->sc = NULL;
392
393         if (conn->task == task)
394                 conn->task = NULL;
395         /*
396          * login task is preallocated so do not free
397          */
398         if (conn->login_task == task)
399                 return;
400
401         __kfifo_put(session->cmdpool.queue, (void*)&task, sizeof(void*));
402
403         if (conn->ping_task == task)
404                 conn->ping_task = NULL;
405
406         if (sc) {
407                 task->sc = NULL;
408                 /* SCSI eh reuses commands to verify us */
409                 sc->SCp.ptr = NULL;
410                 /*
411                  * queue command may call this to free the task, but
412                  * not have setup the sc callback
413                  */
414                 if (sc->scsi_done)
415                         sc->scsi_done(sc);
416         }
417 }
418
419 void __iscsi_get_task(struct iscsi_task *task)
420 {
421         atomic_inc(&task->refcount);
422 }
423 EXPORT_SYMBOL_GPL(__iscsi_get_task);
424
425 static void __iscsi_put_task(struct iscsi_task *task)
426 {
427         if (atomic_dec_and_test(&task->refcount))
428                 iscsi_complete_command(task);
429 }
430
431 void iscsi_put_task(struct iscsi_task *task)
432 {
433         struct iscsi_session *session = task->conn->session;
434
435         spin_lock_bh(&session->lock);
436         __iscsi_put_task(task);
437         spin_unlock_bh(&session->lock);
438 }
439 EXPORT_SYMBOL_GPL(iscsi_put_task);
440
441 /*
442  * session lock must be held
443  */
444 static void fail_command(struct iscsi_conn *conn, struct iscsi_task *task,
445                          int err)
446 {
447         struct scsi_cmnd *sc;
448
449         sc = task->sc;
450         if (!sc)
451                 return;
452
453         if (task->state == ISCSI_TASK_PENDING)
454                 /*
455                  * cmd never made it to the xmit thread, so we should not count
456                  * the cmd in the sequencing
457                  */
458                 conn->session->queued_cmdsn--;
459
460         sc->result = err;
461         if (!scsi_bidi_cmnd(sc))
462                 scsi_set_resid(sc, scsi_bufflen(sc));
463         else {
464                 scsi_out(sc)->resid = scsi_out(sc)->length;
465                 scsi_in(sc)->resid = scsi_in(sc)->length;
466         }
467
468         if (conn->task == task)
469                 conn->task = NULL;
470         /* release ref from queuecommand */
471         __iscsi_put_task(task);
472 }
473
474 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
475                                 struct iscsi_task *task)
476 {
477         struct iscsi_session *session = conn->session;
478         struct iscsi_hdr *hdr = task->hdr;
479         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
480
481         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
482                 return -ENOTCONN;
483
484         if (hdr->opcode != (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) &&
485             hdr->opcode != (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
486                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
487         /*
488          * pre-format CmdSN for outgoing PDU.
489          */
490         nop->cmdsn = cpu_to_be32(session->cmdsn);
491         if (hdr->itt != RESERVED_ITT) {
492                 /*
493                  * TODO: We always use immediate, so we never hit this.
494                  * If we start to send tmfs or nops as non-immediate then
495                  * we should start checking the cmdsn numbers for mgmt tasks.
496                  */
497                 if (conn->c_stage == ISCSI_CONN_STARTED &&
498                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
499                         session->queued_cmdsn++;
500                         session->cmdsn++;
501                 }
502         }
503
504         if (session->tt->init_task && session->tt->init_task(task))
505                 return -EIO;
506
507         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
508                 session->state = ISCSI_STATE_LOGGING_OUT;
509
510         task->state = ISCSI_TASK_RUNNING;
511         list_move_tail(&task->running, &conn->mgmt_run_list);
512         ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
513                           "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
514                           hdr->itt, task->data_count);
515         return 0;
516 }
517
518 static struct iscsi_task *
519 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
520                       char *data, uint32_t data_size)
521 {
522         struct iscsi_session *session = conn->session;
523         struct iscsi_task *task;
524         itt_t itt;
525
526         if (session->state == ISCSI_STATE_TERMINATE)
527                 return NULL;
528
529         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
530             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
531                 /*
532                  * Login and Text are sent serially, in
533                  * request-followed-by-response sequence.
534                  * Same task can be used. Same ITT must be used.
535                  * Note that login_task is preallocated at conn_create().
536                  */
537                 task = conn->login_task;
538         else {
539                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
540                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
541
542                 if (!__kfifo_get(session->cmdpool.queue,
543                                  (void*)&task, sizeof(void*)))
544                         return NULL;
545         }
546         /*
547          * released in complete pdu for task we expect a response for, and
548          * released by the lld when it has transmitted the task for
549          * pdus we do not expect a response for.
550          */
551         atomic_set(&task->refcount, 1);
552         task->conn = conn;
553         task->sc = NULL;
554
555         if (data_size) {
556                 memcpy(task->data, data, data_size);
557                 task->data_count = data_size;
558         } else
559                 task->data_count = 0;
560
561         if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
562                 iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
563                                  "pdu for mgmt task.\n");
564                 goto requeue_task;
565         }
566         itt = task->hdr->itt;
567         task->hdr_len = sizeof(struct iscsi_hdr);
568         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
569
570         if (hdr->itt != RESERVED_ITT) {
571                 if (session->tt->parse_pdu_itt)
572                         task->hdr->itt = itt;
573                 else
574                         task->hdr->itt = build_itt(task->itt,
575                                                    task->conn->session->age);
576         }
577
578         INIT_LIST_HEAD(&task->running);
579         list_add_tail(&task->running, &conn->mgmtqueue);
580
581         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
582                 if (iscsi_prep_mgmt_task(conn, task))
583                         goto free_task;
584
585                 if (session->tt->xmit_task(task))
586                         goto free_task;
587
588         } else
589                 scsi_queue_work(conn->session->host, &conn->xmitwork);
590
591         return task;
592
593 free_task:
594         __iscsi_put_task(task);
595         return NULL;
596
597 requeue_task:
598         if (task != conn->login_task)
599                 __kfifo_put(session->cmdpool.queue, (void*)&task,
600                             sizeof(void*));
601         return NULL;
602 }
603
604 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
605                         char *data, uint32_t data_size)
606 {
607         struct iscsi_conn *conn = cls_conn->dd_data;
608         struct iscsi_session *session = conn->session;
609         int err = 0;
610
611         spin_lock_bh(&session->lock);
612         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
613                 err = -EPERM;
614         spin_unlock_bh(&session->lock);
615         return err;
616 }
617 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
618
619 /**
620  * iscsi_cmd_rsp - SCSI Command Response processing
621  * @conn: iscsi connection
622  * @hdr: iscsi header
623  * @task: scsi command task
624  * @data: cmd data buffer
625  * @datalen: len of buffer
626  *
627  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
628  * then completes the command and task.
629  **/
630 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
631                                struct iscsi_task *task, char *data,
632                                int datalen)
633 {
634         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
635         struct iscsi_session *session = conn->session;
636         struct scsi_cmnd *sc = task->sc;
637
638         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
639         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
640
641         sc->result = (DID_OK << 16) | rhdr->cmd_status;
642
643         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
644                 sc->result = DID_ERROR << 16;
645                 goto out;
646         }
647
648         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
649                 uint16_t senselen;
650
651                 if (datalen < 2) {
652 invalid_datalen:
653                         iscsi_conn_printk(KERN_ERR,  conn,
654                                          "Got CHECK_CONDITION but invalid data "
655                                          "buffer size of %d\n", datalen);
656                         sc->result = DID_BAD_TARGET << 16;
657                         goto out;
658                 }
659
660                 senselen = get_unaligned_be16(data);
661                 if (datalen < senselen)
662                         goto invalid_datalen;
663
664                 memcpy(sc->sense_buffer, data + 2,
665                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
666                 ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
667                                   min_t(uint16_t, senselen,
668                                   SCSI_SENSE_BUFFERSIZE));
669         }
670
671         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
672                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
673                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
674
675                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
676                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
677                                  res_count <= scsi_in(sc)->length))
678                         scsi_in(sc)->resid = res_count;
679                 else
680                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
681         }
682
683         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
684                            ISCSI_FLAG_CMD_OVERFLOW)) {
685                 int res_count = be32_to_cpu(rhdr->residual_count);
686
687                 if (res_count > 0 &&
688                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
689                      res_count <= scsi_bufflen(sc)))
690                         /* write side for bidi or uni-io set_resid */
691                         scsi_set_resid(sc, res_count);
692                 else
693                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
694         }
695 out:
696         ISCSI_DBG_SESSION(session, "done [sc %p res %d itt 0x%x]\n",
697                           sc, sc->result, task->itt);
698         conn->scsirsp_pdus_cnt++;
699
700         __iscsi_put_task(task);
701 }
702
703 /**
704  * iscsi_data_in_rsp - SCSI Data-In Response processing
705  * @conn: iscsi connection
706  * @hdr:  iscsi pdu
707  * @task: scsi command task
708  **/
709 static void
710 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
711                   struct iscsi_task *task)
712 {
713         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
714         struct scsi_cmnd *sc = task->sc;
715
716         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
717                 return;
718
719         sc->result = (DID_OK << 16) | rhdr->cmd_status;
720         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
721         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
722                            ISCSI_FLAG_DATA_OVERFLOW)) {
723                 int res_count = be32_to_cpu(rhdr->residual_count);
724
725                 if (res_count > 0 &&
726                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
727                      res_count <= scsi_in(sc)->length))
728                         scsi_in(sc)->resid = res_count;
729                 else
730                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
731         }
732
733         conn->scsirsp_pdus_cnt++;
734         __iscsi_put_task(task);
735 }
736
737 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
738 {
739         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
740
741         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
742         conn->tmfrsp_pdus_cnt++;
743
744         if (conn->tmf_state != TMF_QUEUED)
745                 return;
746
747         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
748                 conn->tmf_state = TMF_SUCCESS;
749         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
750                 conn->tmf_state = TMF_NOT_FOUND;
751         else
752                 conn->tmf_state = TMF_FAILED;
753         wake_up(&conn->ehwait);
754 }
755
756 static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
757 {
758         struct iscsi_nopout hdr;
759         struct iscsi_task *task;
760
761         if (!rhdr && conn->ping_task)
762                 return;
763
764         memset(&hdr, 0, sizeof(struct iscsi_nopout));
765         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
766         hdr.flags = ISCSI_FLAG_CMD_FINAL;
767
768         if (rhdr) {
769                 memcpy(hdr.lun, rhdr->lun, 8);
770                 hdr.ttt = rhdr->ttt;
771                 hdr.itt = RESERVED_ITT;
772         } else
773                 hdr.ttt = RESERVED_ITT;
774
775         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
776         if (!task)
777                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
778         else if (!rhdr) {
779                 /* only track our nops */
780                 conn->ping_task = task;
781                 conn->last_ping = jiffies;
782         }
783 }
784
785 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
786                                char *data, int datalen)
787 {
788         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
789         struct iscsi_hdr rejected_pdu;
790
791         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
792
793         if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
794                 if (ntoh24(reject->dlength) > datalen)
795                         return ISCSI_ERR_PROTO;
796
797                 if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
798                         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
799                         iscsi_conn_printk(KERN_ERR, conn,
800                                           "pdu (op 0x%x) rejected "
801                                           "due to DataDigest error.\n",
802                                           rejected_pdu.opcode);
803                 }
804         }
805         return 0;
806 }
807
808 /**
809  * iscsi_itt_to_task - look up task by itt
810  * @conn: iscsi connection
811  * @itt: itt
812  *
813  * This should be used for mgmt tasks like login and nops, or if
814  * the LDD's itt space does not include the session age.
815  *
816  * The session lock must be held.
817  */
818 static struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
819 {
820         struct iscsi_session *session = conn->session;
821         int i;
822
823         if (itt == RESERVED_ITT)
824                 return NULL;
825
826         if (session->tt->parse_pdu_itt)
827                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
828         else
829                 i = get_itt(itt);
830         if (i >= session->cmds_max)
831                 return NULL;
832
833         return session->cmds[i];
834 }
835
836 /**
837  * __iscsi_complete_pdu - complete pdu
838  * @conn: iscsi conn
839  * @hdr: iscsi header
840  * @data: data buffer
841  * @datalen: len of data buffer
842  *
843  * Completes pdu processing by freeing any resources allocated at
844  * queuecommand or send generic. session lock must be held and verify
845  * itt must have been called.
846  */
847 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
848                          char *data, int datalen)
849 {
850         struct iscsi_session *session = conn->session;
851         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
852         struct iscsi_task *task;
853         uint32_t itt;
854
855         conn->last_recv = jiffies;
856         rc = iscsi_verify_itt(conn, hdr->itt);
857         if (rc)
858                 return rc;
859
860         if (hdr->itt != RESERVED_ITT)
861                 itt = get_itt(hdr->itt);
862         else
863                 itt = ~0U;
864
865         ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
866                           opcode, conn->id, itt, datalen);
867
868         if (itt == ~0U) {
869                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
870
871                 switch(opcode) {
872                 case ISCSI_OP_NOOP_IN:
873                         if (datalen) {
874                                 rc = ISCSI_ERR_PROTO;
875                                 break;
876                         }
877
878                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
879                                 break;
880
881                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
882                         break;
883                 case ISCSI_OP_REJECT:
884                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
885                         break;
886                 case ISCSI_OP_ASYNC_EVENT:
887                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
888                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
889                                 rc = ISCSI_ERR_CONN_FAILED;
890                         break;
891                 default:
892                         rc = ISCSI_ERR_BAD_OPCODE;
893                         break;
894                 }
895                 goto out;
896         }
897
898         switch(opcode) {
899         case ISCSI_OP_SCSI_CMD_RSP:
900         case ISCSI_OP_SCSI_DATA_IN:
901                 task = iscsi_itt_to_ctask(conn, hdr->itt);
902                 if (!task)
903                         return ISCSI_ERR_BAD_ITT;
904                 break;
905         case ISCSI_OP_R2T:
906                 /*
907                  * LLD handles R2Ts if they need to.
908                  */
909                 return 0;
910         case ISCSI_OP_LOGOUT_RSP:
911         case ISCSI_OP_LOGIN_RSP:
912         case ISCSI_OP_TEXT_RSP:
913         case ISCSI_OP_SCSI_TMFUNC_RSP:
914         case ISCSI_OP_NOOP_IN:
915                 task = iscsi_itt_to_task(conn, hdr->itt);
916                 if (!task)
917                         return ISCSI_ERR_BAD_ITT;
918                 break;
919         default:
920                 return ISCSI_ERR_BAD_OPCODE;
921         }
922
923         switch(opcode) {
924         case ISCSI_OP_SCSI_CMD_RSP:
925                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
926                 break;
927         case ISCSI_OP_SCSI_DATA_IN:
928                 iscsi_data_in_rsp(conn, hdr, task);
929                 break;
930         case ISCSI_OP_LOGOUT_RSP:
931                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
932                 if (datalen) {
933                         rc = ISCSI_ERR_PROTO;
934                         break;
935                 }
936                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
937                 goto recv_pdu;
938         case ISCSI_OP_LOGIN_RSP:
939         case ISCSI_OP_TEXT_RSP:
940                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
941                 /*
942                  * login related PDU's exp_statsn is handled in
943                  * userspace
944                  */
945                 goto recv_pdu;
946         case ISCSI_OP_SCSI_TMFUNC_RSP:
947                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
948                 if (datalen) {
949                         rc = ISCSI_ERR_PROTO;
950                         break;
951                 }
952
953                 iscsi_tmf_rsp(conn, hdr);
954                 __iscsi_put_task(task);
955                 break;
956         case ISCSI_OP_NOOP_IN:
957                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
958                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
959                         rc = ISCSI_ERR_PROTO;
960                         break;
961                 }
962                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
963
964                 if (conn->ping_task != task)
965                         /*
966                          * If this is not in response to one of our
967                          * nops then it must be from userspace.
968                          */
969                         goto recv_pdu;
970
971                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
972                 __iscsi_put_task(task);
973                 break;
974         default:
975                 rc = ISCSI_ERR_BAD_OPCODE;
976                 break;
977         }
978
979 out:
980         return rc;
981 recv_pdu:
982         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
983                 rc = ISCSI_ERR_CONN_FAILED;
984         __iscsi_put_task(task);
985         return rc;
986 }
987 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
988
989 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
990                        char *data, int datalen)
991 {
992         int rc;
993
994         spin_lock(&conn->session->lock);
995         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
996         spin_unlock(&conn->session->lock);
997         return rc;
998 }
999 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1000
1001 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1002 {
1003         struct iscsi_session *session = conn->session;
1004         int age = 0, i = 0;
1005
1006         if (itt == RESERVED_ITT)
1007                 return 0;
1008
1009         if (session->tt->parse_pdu_itt)
1010                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
1011         else {
1012                 i = get_itt(itt);
1013                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1014         }
1015
1016         if (age != session->age) {
1017                 iscsi_conn_printk(KERN_ERR, conn,
1018                                   "received itt %x expected session age (%x)\n",
1019                                   (__force u32)itt, session->age);
1020                 return ISCSI_ERR_BAD_ITT;
1021         }
1022
1023         if (i >= session->cmds_max) {
1024                 iscsi_conn_printk(KERN_ERR, conn,
1025                                   "received invalid itt index %u (max cmds "
1026                                    "%u.\n", i, session->cmds_max);
1027                 return ISCSI_ERR_BAD_ITT;
1028         }
1029         return 0;
1030 }
1031 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1032
1033 /**
1034  * iscsi_itt_to_ctask - look up ctask by itt
1035  * @conn: iscsi connection
1036  * @itt: itt
1037  *
1038  * This should be used for cmd tasks.
1039  *
1040  * The session lock must be held.
1041  */
1042 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1043 {
1044         struct iscsi_task *task;
1045
1046         if (iscsi_verify_itt(conn, itt))
1047                 return NULL;
1048
1049         task = iscsi_itt_to_task(conn, itt);
1050         if (!task || !task->sc)
1051                 return NULL;
1052
1053         if (task->sc->SCp.phase != conn->session->age) {
1054                 iscsi_session_printk(KERN_ERR, conn->session,
1055                                   "task's session age %d, expected %d\n",
1056                                   task->sc->SCp.phase, conn->session->age);
1057                 return NULL;
1058         }
1059
1060         return task;
1061 }
1062 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1063
1064 void iscsi_session_failure(struct iscsi_cls_session *cls_session,
1065                            enum iscsi_err err)
1066 {
1067         struct iscsi_session *session = cls_session->dd_data;
1068         struct iscsi_conn *conn;
1069         struct device *dev;
1070         unsigned long flags;
1071
1072         spin_lock_irqsave(&session->lock, flags);
1073         conn = session->leadconn;
1074         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1075                 spin_unlock_irqrestore(&session->lock, flags);
1076                 return;
1077         }
1078
1079         dev = get_device(&conn->cls_conn->dev);
1080         spin_unlock_irqrestore(&session->lock, flags);
1081         if (!dev)
1082                 return;
1083         /*
1084          * if the host is being removed bypass the connection
1085          * recovery initialization because we are going to kill
1086          * the session.
1087          */
1088         if (err == ISCSI_ERR_INVALID_HOST)
1089                 iscsi_conn_error_event(conn->cls_conn, err);
1090         else
1091                 iscsi_conn_failure(conn, err);
1092         put_device(dev);
1093 }
1094 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1095
1096 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1097 {
1098         struct iscsi_session *session = conn->session;
1099         unsigned long flags;
1100
1101         spin_lock_irqsave(&session->lock, flags);
1102         if (session->state == ISCSI_STATE_FAILED) {
1103                 spin_unlock_irqrestore(&session->lock, flags);
1104                 return;
1105         }
1106
1107         if (conn->stop_stage == 0)
1108                 session->state = ISCSI_STATE_FAILED;
1109         spin_unlock_irqrestore(&session->lock, flags);
1110
1111         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1112         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1113         iscsi_conn_error_event(conn->cls_conn, err);
1114 }
1115 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1116
1117 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1118 {
1119         struct iscsi_session *session = conn->session;
1120
1121         /*
1122          * Check for iSCSI window and take care of CmdSN wrap-around
1123          */
1124         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1125                 ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1126                                   "%u MaxCmdSN %u CmdSN %u/%u\n",
1127                                   session->exp_cmdsn, session->max_cmdsn,
1128                                   session->cmdsn, session->queued_cmdsn);
1129                 return -ENOSPC;
1130         }
1131         return 0;
1132 }
1133
1134 static int iscsi_xmit_task(struct iscsi_conn *conn)
1135 {
1136         struct iscsi_task *task = conn->task;
1137         int rc;
1138
1139         __iscsi_get_task(task);
1140         spin_unlock_bh(&conn->session->lock);
1141         rc = conn->session->tt->xmit_task(task);
1142         spin_lock_bh(&conn->session->lock);
1143         __iscsi_put_task(task);
1144         if (!rc)
1145                 /* done with this task */
1146                 conn->task = NULL;
1147         return rc;
1148 }
1149
1150 /**
1151  * iscsi_requeue_task - requeue task to run from session workqueue
1152  * @task: task to requeue
1153  *
1154  * LLDs that need to run a task from the session workqueue should call
1155  * this. The session lock must be held. This should only be called
1156  * by software drivers.
1157  */
1158 void iscsi_requeue_task(struct iscsi_task *task)
1159 {
1160         struct iscsi_conn *conn = task->conn;
1161
1162         list_move_tail(&task->running, &conn->requeue);
1163         scsi_queue_work(conn->session->host, &conn->xmitwork);
1164 }
1165 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1166
1167 /**
1168  * iscsi_data_xmit - xmit any command into the scheduled connection
1169  * @conn: iscsi connection
1170  *
1171  * Notes:
1172  *      The function can return -EAGAIN in which case the caller must
1173  *      re-schedule it again later or recover. '0' return code means
1174  *      successful xmit.
1175  **/
1176 static int iscsi_data_xmit(struct iscsi_conn *conn)
1177 {
1178         int rc = 0;
1179
1180         spin_lock_bh(&conn->session->lock);
1181         if (unlikely(conn->suspend_tx)) {
1182                 ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1183                 spin_unlock_bh(&conn->session->lock);
1184                 return -ENODATA;
1185         }
1186
1187         if (conn->task) {
1188                 rc = iscsi_xmit_task(conn);
1189                 if (rc)
1190                         goto again;
1191         }
1192
1193         /*
1194          * process mgmt pdus like nops before commands since we should
1195          * only have one nop-out as a ping from us and targets should not
1196          * overflow us with nop-ins
1197          */
1198 check_mgmt:
1199         while (!list_empty(&conn->mgmtqueue)) {
1200                 conn->task = list_entry(conn->mgmtqueue.next,
1201                                          struct iscsi_task, running);
1202                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1203                         __iscsi_put_task(conn->task);
1204                         conn->task = NULL;
1205                         continue;
1206                 }
1207                 rc = iscsi_xmit_task(conn);
1208                 if (rc)
1209                         goto again;
1210         }
1211
1212         /* process pending command queue */
1213         while (!list_empty(&conn->xmitqueue)) {
1214                 if (conn->tmf_state == TMF_QUEUED)
1215                         break;
1216
1217                 conn->task = list_entry(conn->xmitqueue.next,
1218                                          struct iscsi_task, running);
1219                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1220                         fail_command(conn, conn->task, DID_IMM_RETRY << 16);
1221                         continue;
1222                 }
1223                 rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1224                 if (rc) {
1225                         if (rc == -ENOMEM) {
1226                                 conn->task = NULL;
1227                                 goto again;
1228                         } else
1229                                 fail_command(conn, conn->task, DID_ABORT << 16);
1230                         continue;
1231                 }
1232                 rc = iscsi_xmit_task(conn);
1233                 if (rc)
1234                         goto again;
1235                 /*
1236                  * we could continuously get new task requests so
1237                  * we need to check the mgmt queue for nops that need to
1238                  * be sent to aviod starvation
1239                  */
1240                 if (!list_empty(&conn->mgmtqueue))
1241                         goto check_mgmt;
1242         }
1243
1244         while (!list_empty(&conn->requeue)) {
1245                 if (conn->session->fast_abort && conn->tmf_state != TMF_INITIAL)
1246                         break;
1247
1248                 /*
1249                  * we always do fastlogout - conn stop code will clean up.
1250                  */
1251                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1252                         break;
1253
1254                 conn->task = list_entry(conn->requeue.next,
1255                                          struct iscsi_task, running);
1256                 conn->task->state = ISCSI_TASK_RUNNING;
1257                 list_move_tail(conn->requeue.next, &conn->run_list);
1258                 rc = iscsi_xmit_task(conn);
1259                 if (rc)
1260                         goto again;
1261                 if (!list_empty(&conn->mgmtqueue))
1262                         goto check_mgmt;
1263         }
1264         spin_unlock_bh(&conn->session->lock);
1265         return -ENODATA;
1266
1267 again:
1268         if (unlikely(conn->suspend_tx))
1269                 rc = -ENODATA;
1270         spin_unlock_bh(&conn->session->lock);
1271         return rc;
1272 }
1273
1274 static void iscsi_xmitworker(struct work_struct *work)
1275 {
1276         struct iscsi_conn *conn =
1277                 container_of(work, struct iscsi_conn, xmitwork);
1278         int rc;
1279         /*
1280          * serialize Xmit worker on a per-connection basis.
1281          */
1282         do {
1283                 rc = iscsi_data_xmit(conn);
1284         } while (rc >= 0 || rc == -EAGAIN);
1285 }
1286
1287 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1288                                                   struct scsi_cmnd *sc)
1289 {
1290         struct iscsi_task *task;
1291
1292         if (!__kfifo_get(conn->session->cmdpool.queue,
1293                          (void *) &task, sizeof(void *)))
1294                 return NULL;
1295
1296         sc->SCp.phase = conn->session->age;
1297         sc->SCp.ptr = (char *) task;
1298
1299         atomic_set(&task->refcount, 1);
1300         task->state = ISCSI_TASK_PENDING;
1301         task->conn = conn;
1302         task->sc = sc;
1303         INIT_LIST_HEAD(&task->running);
1304         return task;
1305 }
1306
1307 enum {
1308         FAILURE_BAD_HOST = 1,
1309         FAILURE_SESSION_FAILED,
1310         FAILURE_SESSION_FREED,
1311         FAILURE_WINDOW_CLOSED,
1312         FAILURE_OOM,
1313         FAILURE_SESSION_TERMINATE,
1314         FAILURE_SESSION_IN_RECOVERY,
1315         FAILURE_SESSION_RECOVERY_TIMEOUT,
1316         FAILURE_SESSION_LOGGING_OUT,
1317         FAILURE_SESSION_NOT_READY,
1318 };
1319
1320 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
1321 {
1322         struct iscsi_cls_session *cls_session;
1323         struct Scsi_Host *host;
1324         int reason = 0;
1325         struct iscsi_session *session;
1326         struct iscsi_conn *conn;
1327         struct iscsi_task *task = NULL;
1328
1329         sc->scsi_done = done;
1330         sc->result = 0;
1331         sc->SCp.ptr = NULL;
1332
1333         host = sc->device->host;
1334         spin_unlock(host->host_lock);
1335
1336         cls_session = starget_to_session(scsi_target(sc->device));
1337         session = cls_session->dd_data;
1338         spin_lock(&session->lock);
1339
1340         reason = iscsi_session_chkready(cls_session);
1341         if (reason) {
1342                 sc->result = reason;
1343                 goto fault;
1344         }
1345
1346         /*
1347          * ISCSI_STATE_FAILED is a temp. state. The recovery
1348          * code will decide what is best to do with command queued
1349          * during this time
1350          */
1351         if (session->state != ISCSI_STATE_LOGGED_IN &&
1352             session->state != ISCSI_STATE_FAILED) {
1353                 /*
1354                  * to handle the race between when we set the recovery state
1355                  * and block the session we requeue here (commands could
1356                  * be entering our queuecommand while a block is starting
1357                  * up because the block code is not locked)
1358                  */
1359                 switch (session->state) {
1360                 case ISCSI_STATE_IN_RECOVERY:
1361                         reason = FAILURE_SESSION_IN_RECOVERY;
1362                         goto reject;
1363                 case ISCSI_STATE_LOGGING_OUT:
1364                         reason = FAILURE_SESSION_LOGGING_OUT;
1365                         goto reject;
1366                 case ISCSI_STATE_RECOVERY_FAILED:
1367                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1368                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1369                         break;
1370                 case ISCSI_STATE_TERMINATE:
1371                         reason = FAILURE_SESSION_TERMINATE;
1372                         sc->result = DID_NO_CONNECT << 16;
1373                         break;
1374                 default:
1375                         reason = FAILURE_SESSION_FREED;
1376                         sc->result = DID_NO_CONNECT << 16;
1377                 }
1378                 goto fault;
1379         }
1380
1381         conn = session->leadconn;
1382         if (!conn) {
1383                 reason = FAILURE_SESSION_FREED;
1384                 sc->result = DID_NO_CONNECT << 16;
1385                 goto fault;
1386         }
1387
1388         if (iscsi_check_cmdsn_window_closed(conn)) {
1389                 reason = FAILURE_WINDOW_CLOSED;
1390                 goto reject;
1391         }
1392
1393         task = iscsi_alloc_task(conn, sc);
1394         if (!task) {
1395                 reason = FAILURE_OOM;
1396                 goto reject;
1397         }
1398         list_add_tail(&task->running, &conn->xmitqueue);
1399
1400         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
1401                 reason = iscsi_prep_scsi_cmd_pdu(task);
1402                 if (reason) {
1403                         if (reason == -ENOMEM) {
1404                                 reason = FAILURE_OOM;
1405                                 goto prepd_reject;
1406                         } else {
1407                                 sc->result = DID_ABORT << 16;
1408                                 goto prepd_fault;
1409                         }
1410                 }
1411                 if (session->tt->xmit_task(task)) {
1412                         reason = FAILURE_SESSION_NOT_READY;
1413                         goto prepd_reject;
1414                 }
1415         } else
1416                 scsi_queue_work(session->host, &conn->xmitwork);
1417
1418         session->queued_cmdsn++;
1419         spin_unlock(&session->lock);
1420         spin_lock(host->host_lock);
1421         return 0;
1422
1423 prepd_reject:
1424         sc->scsi_done = NULL;
1425         iscsi_complete_command(task);
1426 reject:
1427         spin_unlock(&session->lock);
1428         ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1429                           sc->cmnd[0], reason);
1430         spin_lock(host->host_lock);
1431         return SCSI_MLQUEUE_TARGET_BUSY;
1432
1433 prepd_fault:
1434         sc->scsi_done = NULL;
1435         iscsi_complete_command(task);
1436 fault:
1437         spin_unlock(&session->lock);
1438         ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1439                           sc->cmnd[0], reason);
1440         if (!scsi_bidi_cmnd(sc))
1441                 scsi_set_resid(sc, scsi_bufflen(sc));
1442         else {
1443                 scsi_out(sc)->resid = scsi_out(sc)->length;
1444                 scsi_in(sc)->resid = scsi_in(sc)->length;
1445         }
1446         done(sc);
1447         spin_lock(host->host_lock);
1448         return 0;
1449 }
1450 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1451
1452 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
1453 {
1454         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1455         return sdev->queue_depth;
1456 }
1457 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1458
1459 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
1460 {
1461         struct iscsi_session *session = cls_session->dd_data;
1462
1463         spin_lock_bh(&session->lock);
1464         if (session->state != ISCSI_STATE_LOGGED_IN) {
1465                 session->state = ISCSI_STATE_RECOVERY_FAILED;
1466                 if (session->leadconn)
1467                         wake_up(&session->leadconn->ehwait);
1468         }
1469         spin_unlock_bh(&session->lock);
1470 }
1471 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
1472
1473 int iscsi_eh_target_reset(struct scsi_cmnd *sc)
1474 {
1475         struct iscsi_cls_session *cls_session;
1476         struct iscsi_session *session;
1477         struct iscsi_conn *conn;
1478
1479         cls_session = starget_to_session(scsi_target(sc->device));
1480         session = cls_session->dd_data;
1481         conn = session->leadconn;
1482
1483         mutex_lock(&session->eh_mutex);
1484         spin_lock_bh(&session->lock);
1485         if (session->state == ISCSI_STATE_TERMINATE) {
1486 failed:
1487                 iscsi_session_printk(KERN_INFO, session,
1488                                      "failing target reset: Could not log "
1489                                      "back into target [age %d]\n",
1490                                      session->age);
1491                 spin_unlock_bh(&session->lock);
1492                 mutex_unlock(&session->eh_mutex);
1493                 return FAILED;
1494         }
1495
1496         spin_unlock_bh(&session->lock);
1497         mutex_unlock(&session->eh_mutex);
1498         /*
1499          * we drop the lock here but the leadconn cannot be destoyed while
1500          * we are in the scsi eh
1501          */
1502         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1503
1504         ISCSI_DBG_SESSION(session, "wait for relogin\n");
1505         wait_event_interruptible(conn->ehwait,
1506                                  session->state == ISCSI_STATE_TERMINATE ||
1507                                  session->state == ISCSI_STATE_LOGGED_IN ||
1508                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
1509         if (signal_pending(current))
1510                 flush_signals(current);
1511
1512         mutex_lock(&session->eh_mutex);
1513         spin_lock_bh(&session->lock);
1514         if (session->state == ISCSI_STATE_LOGGED_IN)
1515                 iscsi_session_printk(KERN_INFO, session,
1516                                      "target reset succeeded\n");
1517         else
1518                 goto failed;
1519         spin_unlock_bh(&session->lock);
1520         mutex_unlock(&session->eh_mutex);
1521         return SUCCESS;
1522 }
1523 EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
1524
1525 static void iscsi_tmf_timedout(unsigned long data)
1526 {
1527         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1528         struct iscsi_session *session = conn->session;
1529
1530         spin_lock(&session->lock);
1531         if (conn->tmf_state == TMF_QUEUED) {
1532                 conn->tmf_state = TMF_TIMEDOUT;
1533                 ISCSI_DBG_SESSION(session, "tmf timedout\n");
1534                 /* unblock eh_abort() */
1535                 wake_up(&conn->ehwait);
1536         }
1537         spin_unlock(&session->lock);
1538 }
1539
1540 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1541                                    struct iscsi_tm *hdr, int age,
1542                                    int timeout)
1543 {
1544         struct iscsi_session *session = conn->session;
1545         struct iscsi_task *task;
1546
1547         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1548                                       NULL, 0);
1549         if (!task) {
1550                 spin_unlock_bh(&session->lock);
1551                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1552                 spin_lock_bh(&session->lock);
1553                 ISCSI_DBG_SESSION(session, "tmf exec failure\n");
1554                 return -EPERM;
1555         }
1556         conn->tmfcmd_pdus_cnt++;
1557         conn->tmf_timer.expires = timeout * HZ + jiffies;
1558         conn->tmf_timer.function = iscsi_tmf_timedout;
1559         conn->tmf_timer.data = (unsigned long)conn;
1560         add_timer(&conn->tmf_timer);
1561         ISCSI_DBG_SESSION(session, "tmf set timeout\n");
1562
1563         spin_unlock_bh(&session->lock);
1564         mutex_unlock(&session->eh_mutex);
1565
1566         /*
1567          * block eh thread until:
1568          *
1569          * 1) tmf response
1570          * 2) tmf timeout
1571          * 3) session is terminated or restarted or userspace has
1572          * given up on recovery
1573          */
1574         wait_event_interruptible(conn->ehwait, age != session->age ||
1575                                  session->state != ISCSI_STATE_LOGGED_IN ||
1576                                  conn->tmf_state != TMF_QUEUED);
1577         if (signal_pending(current))
1578                 flush_signals(current);
1579         del_timer_sync(&conn->tmf_timer);
1580
1581         mutex_lock(&session->eh_mutex);
1582         spin_lock_bh(&session->lock);
1583         /* if the session drops it will clean up the task */
1584         if (age != session->age ||
1585             session->state != ISCSI_STATE_LOGGED_IN)
1586                 return -ENOTCONN;
1587         return 0;
1588 }
1589
1590 /*
1591  * Fail commands. session lock held and recv side suspended and xmit
1592  * thread flushed
1593  */
1594 static void fail_all_commands(struct iscsi_conn *conn, unsigned lun,
1595                               int error)
1596 {
1597         struct iscsi_task *task, *tmp;
1598
1599         if (conn->task && (conn->task->sc->device->lun == lun || lun == -1))
1600                 conn->task = NULL;
1601
1602         /* flush pending */
1603         list_for_each_entry_safe(task, tmp, &conn->xmitqueue, running) {
1604                 if (lun == task->sc->device->lun || lun == -1) {
1605                         ISCSI_DBG_SESSION(conn->session,
1606                                           "failing pending sc %p itt 0x%x\n",
1607                                           task->sc, task->itt);
1608                         fail_command(conn, task, error << 16);
1609                 }
1610         }
1611
1612         list_for_each_entry_safe(task, tmp, &conn->requeue, running) {
1613                 if (lun == task->sc->device->lun || lun == -1) {
1614                         ISCSI_DBG_SESSION(conn->session,
1615                                           "failing requeued sc %p itt 0x%x\n",
1616                                           task->sc, task->itt);
1617                         fail_command(conn, task, error << 16);
1618                 }
1619         }
1620
1621         /* fail all other running */
1622         list_for_each_entry_safe(task, tmp, &conn->run_list, running) {
1623                 if (lun == task->sc->device->lun || lun == -1) {
1624                         ISCSI_DBG_SESSION(conn->session,
1625                                          "failing in progress sc %p itt 0x%x\n",
1626                                          task->sc, task->itt);
1627                         fail_command(conn, task, error << 16);
1628                 }
1629         }
1630 }
1631
1632 void iscsi_suspend_tx(struct iscsi_conn *conn)
1633 {
1634         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1635         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1636                 scsi_flush_work(conn->session->host);
1637 }
1638 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1639
1640 static void iscsi_start_tx(struct iscsi_conn *conn)
1641 {
1642         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1643         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1644                 scsi_queue_work(conn->session->host, &conn->xmitwork);
1645 }
1646
1647 static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *scmd)
1648 {
1649         struct iscsi_cls_session *cls_session;
1650         struct iscsi_session *session;
1651         struct iscsi_conn *conn;
1652         enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1653
1654         cls_session = starget_to_session(scsi_target(scmd->device));
1655         session = cls_session->dd_data;
1656
1657         ISCSI_DBG_SESSION(session, "scsi cmd %p timedout\n", scmd);
1658
1659         spin_lock(&session->lock);
1660         if (session->state != ISCSI_STATE_LOGGED_IN) {
1661                 /*
1662                  * We are probably in the middle of iscsi recovery so let
1663                  * that complete and handle the error.
1664                  */
1665                 rc = BLK_EH_RESET_TIMER;
1666                 goto done;
1667         }
1668
1669         conn = session->leadconn;
1670         if (!conn) {
1671                 /* In the middle of shuting down */
1672                 rc = BLK_EH_RESET_TIMER;
1673                 goto done;
1674         }
1675
1676         if (!conn->recv_timeout && !conn->ping_timeout)
1677                 goto done;
1678         /*
1679          * if the ping timedout then we are in the middle of cleaning up
1680          * and can let the iscsi eh handle it
1681          */
1682         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1683                             (conn->ping_timeout * HZ), jiffies))
1684                 rc = BLK_EH_RESET_TIMER;
1685         /*
1686          * if we are about to check the transport then give the command
1687          * more time
1688          */
1689         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ),
1690                            jiffies))
1691                 rc = BLK_EH_RESET_TIMER;
1692         /* if in the middle of checking the transport then give us more time */
1693         if (conn->ping_task)
1694                 rc = BLK_EH_RESET_TIMER;
1695 done:
1696         spin_unlock(&session->lock);
1697         ISCSI_DBG_SESSION(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
1698                           "timer reset" : "nh");
1699         return rc;
1700 }
1701
1702 static void iscsi_check_transport_timeouts(unsigned long data)
1703 {
1704         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1705         struct iscsi_session *session = conn->session;
1706         unsigned long recv_timeout, next_timeout = 0, last_recv;
1707
1708         spin_lock(&session->lock);
1709         if (session->state != ISCSI_STATE_LOGGED_IN)
1710                 goto done;
1711
1712         recv_timeout = conn->recv_timeout;
1713         if (!recv_timeout)
1714                 goto done;
1715
1716         recv_timeout *= HZ;
1717         last_recv = conn->last_recv;
1718         if (conn->ping_task &&
1719             time_before_eq(conn->last_ping + (conn->ping_timeout * HZ),
1720                            jiffies)) {
1721                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
1722                                   "expired, last rx %lu, last ping %lu, "
1723                                   "now %lu\n", conn->ping_timeout, last_recv,
1724                                   conn->last_ping, jiffies);
1725                 spin_unlock(&session->lock);
1726                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1727                 return;
1728         }
1729
1730         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
1731                 /* send a ping to try to provoke some traffic */
1732                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
1733                 iscsi_send_nopout(conn, NULL);
1734                 next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
1735         } else
1736                 next_timeout = last_recv + recv_timeout;
1737
1738         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
1739         mod_timer(&conn->transport_timer, next_timeout);
1740 done:
1741         spin_unlock(&session->lock);
1742 }
1743
1744 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
1745                                       struct iscsi_tm *hdr)
1746 {
1747         memset(hdr, 0, sizeof(*hdr));
1748         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1749         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
1750         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1751         memcpy(hdr->lun, task->lun, sizeof(hdr->lun));
1752         hdr->rtt = task->hdr_itt;
1753         hdr->refcmdsn = task->cmdsn;
1754 }
1755
1756 int iscsi_eh_abort(struct scsi_cmnd *sc)
1757 {
1758         struct iscsi_cls_session *cls_session;
1759         struct iscsi_session *session;
1760         struct iscsi_conn *conn;
1761         struct iscsi_task *task;
1762         struct iscsi_tm *hdr;
1763         int rc, age;
1764
1765         cls_session = starget_to_session(scsi_target(sc->device));
1766         session = cls_session->dd_data;
1767
1768         mutex_lock(&session->eh_mutex);
1769         spin_lock_bh(&session->lock);
1770         /*
1771          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1772          * got the command.
1773          */
1774         if (!sc->SCp.ptr) {
1775                 ISCSI_DBG_SESSION(session, "sc never reached iscsi layer or "
1776                                   "it completed.\n");
1777                 spin_unlock_bh(&session->lock);
1778                 mutex_unlock(&session->eh_mutex);
1779                 return SUCCESS;
1780         }
1781
1782         /*
1783          * If we are not logged in or we have started a new session
1784          * then let the host reset code handle this
1785          */
1786         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
1787             sc->SCp.phase != session->age) {
1788                 spin_unlock_bh(&session->lock);
1789                 mutex_unlock(&session->eh_mutex);
1790                 return FAILED;
1791         }
1792
1793         conn = session->leadconn;
1794         conn->eh_abort_cnt++;
1795         age = session->age;
1796
1797         task = (struct iscsi_task *)sc->SCp.ptr;
1798         ISCSI_DBG_SESSION(session, "aborting [sc %p itt 0x%x]\n",
1799                           sc, task->itt);
1800
1801         /* task completed before time out */
1802         if (!task->sc) {
1803                 ISCSI_DBG_SESSION(session, "sc completed while abort in "
1804                                   "progress\n");
1805                 goto success;
1806         }
1807
1808         if (task->state == ISCSI_TASK_PENDING) {
1809                 fail_command(conn, task, DID_ABORT << 16);
1810                 goto success;
1811         }
1812
1813         /* only have one tmf outstanding at a time */
1814         if (conn->tmf_state != TMF_INITIAL)
1815                 goto failed;
1816         conn->tmf_state = TMF_QUEUED;
1817
1818         hdr = &conn->tmhdr;
1819         iscsi_prep_abort_task_pdu(task, hdr);
1820
1821         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
1822                 rc = FAILED;
1823                 goto failed;
1824         }
1825
1826         switch (conn->tmf_state) {
1827         case TMF_SUCCESS:
1828                 spin_unlock_bh(&session->lock);
1829                 /*
1830                  * stop tx side incase the target had sent a abort rsp but
1831                  * the initiator was still writing out data.
1832                  */
1833                 iscsi_suspend_tx(conn);
1834                 /*
1835                  * we do not stop the recv side because targets have been
1836                  * good and have never sent us a successful tmf response
1837                  * then sent more data for the cmd.
1838                  */
1839                 spin_lock(&session->lock);
1840                 fail_command(conn, task, DID_ABORT << 16);
1841                 conn->tmf_state = TMF_INITIAL;
1842                 spin_unlock(&session->lock);
1843                 iscsi_start_tx(conn);
1844                 goto success_unlocked;
1845         case TMF_TIMEDOUT:
1846                 spin_unlock_bh(&session->lock);
1847                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1848                 goto failed_unlocked;
1849         case TMF_NOT_FOUND:
1850                 if (!sc->SCp.ptr) {
1851                         conn->tmf_state = TMF_INITIAL;
1852                         /* task completed before tmf abort response */
1853                         ISCSI_DBG_SESSION(session, "sc completed while abort "
1854                                           "in progress\n");
1855                         goto success;
1856                 }
1857                 /* fall through */
1858         default:
1859                 conn->tmf_state = TMF_INITIAL;
1860                 goto failed;
1861         }
1862
1863 success:
1864         spin_unlock_bh(&session->lock);
1865 success_unlocked:
1866         ISCSI_DBG_SESSION(session, "abort success [sc %p itt 0x%x]\n",
1867                           sc, task->itt);
1868         mutex_unlock(&session->eh_mutex);
1869         return SUCCESS;
1870
1871 failed:
1872         spin_unlock_bh(&session->lock);
1873 failed_unlocked:
1874         ISCSI_DBG_SESSION(session, "abort failed [sc %p itt 0x%x]\n", sc,
1875                           task ? task->itt : 0);
1876         mutex_unlock(&session->eh_mutex);
1877         return FAILED;
1878 }
1879 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1880
1881 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
1882 {
1883         memset(hdr, 0, sizeof(*hdr));
1884         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1885         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
1886         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1887         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
1888         hdr->rtt = RESERVED_ITT;
1889 }
1890
1891 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
1892 {
1893         struct iscsi_cls_session *cls_session;
1894         struct iscsi_session *session;
1895         struct iscsi_conn *conn;
1896         struct iscsi_tm *hdr;
1897         int rc = FAILED;
1898
1899         cls_session = starget_to_session(scsi_target(sc->device));
1900         session = cls_session->dd_data;
1901
1902         ISCSI_DBG_SESSION(session, "LU Reset [sc %p lun %u]\n",
1903                           sc, sc->device->lun);
1904
1905         mutex_lock(&session->eh_mutex);
1906         spin_lock_bh(&session->lock);
1907         /*
1908          * Just check if we are not logged in. We cannot check for
1909          * the phase because the reset could come from a ioctl.
1910          */
1911         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
1912                 goto unlock;
1913         conn = session->leadconn;
1914
1915         /* only have one tmf outstanding at a time */
1916         if (conn->tmf_state != TMF_INITIAL)
1917                 goto unlock;
1918         conn->tmf_state = TMF_QUEUED;
1919
1920         hdr = &conn->tmhdr;
1921         iscsi_prep_lun_reset_pdu(sc, hdr);
1922
1923         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
1924                                     session->lu_reset_timeout)) {
1925                 rc = FAILED;
1926                 goto unlock;
1927         }
1928
1929         switch (conn->tmf_state) {
1930         case TMF_SUCCESS:
1931                 break;
1932         case TMF_TIMEDOUT:
1933                 spin_unlock_bh(&session->lock);
1934                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1935                 goto done;
1936         default:
1937                 conn->tmf_state = TMF_INITIAL;
1938                 goto unlock;
1939         }
1940
1941         rc = SUCCESS;
1942         spin_unlock_bh(&session->lock);
1943
1944         iscsi_suspend_tx(conn);
1945
1946         spin_lock_bh(&session->lock);
1947         fail_all_commands(conn, sc->device->lun, DID_ERROR);
1948         conn->tmf_state = TMF_INITIAL;
1949         spin_unlock_bh(&session->lock);
1950
1951         iscsi_start_tx(conn);
1952         goto done;
1953
1954 unlock:
1955         spin_unlock_bh(&session->lock);
1956 done:
1957         ISCSI_DBG_SESSION(session, "dev reset result = %s\n",
1958                          rc == SUCCESS ? "SUCCESS" : "FAILED");
1959         mutex_unlock(&session->eh_mutex);
1960         return rc;
1961 }
1962 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
1963
1964 /*
1965  * Pre-allocate a pool of @max items of @item_size. By default, the pool
1966  * should be accessed via kfifo_{get,put} on q->queue.
1967  * Optionally, the caller can obtain the array of object pointers
1968  * by passing in a non-NULL @items pointer
1969  */
1970 int
1971 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
1972 {
1973         int i, num_arrays = 1;
1974
1975         memset(q, 0, sizeof(*q));
1976
1977         q->max = max;
1978
1979         /* If the user passed an items pointer, he wants a copy of
1980          * the array. */
1981         if (items)
1982                 num_arrays++;
1983         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
1984         if (q->pool == NULL)
1985                 return -ENOMEM;
1986
1987         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1988                               GFP_KERNEL, NULL);
1989         if (q->queue == ERR_PTR(-ENOMEM))
1990                 goto enomem;
1991
1992         for (i = 0; i < max; i++) {
1993                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
1994                 if (q->pool[i] == NULL) {
1995                         q->max = i;
1996                         goto enomem;
1997                 }
1998                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1999         }
2000
2001         if (items) {
2002                 *items = q->pool + max;
2003                 memcpy(*items, q->pool, max * sizeof(void *));
2004         }
2005
2006         return 0;
2007
2008 enomem:
2009         iscsi_pool_free(q);
2010         return -ENOMEM;
2011 }
2012 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2013
2014 void iscsi_pool_free(struct iscsi_pool *q)
2015 {
2016         int i;
2017
2018         for (i = 0; i < q->max; i++)
2019                 kfree(q->pool[i]);
2020         kfree(q->pool);
2021         kfree(q->queue);
2022 }
2023 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2024
2025 /**
2026  * iscsi_host_add - add host to system
2027  * @shost: scsi host
2028  * @pdev: parent device
2029  *
2030  * This should be called by partial offload and software iscsi drivers
2031  * to add a host to the system.
2032  */
2033 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2034 {
2035         if (!shost->can_queue)
2036                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2037
2038         if (!shost->transportt->eh_timed_out)
2039                 shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
2040         return scsi_add_host(shost, pdev);
2041 }
2042 EXPORT_SYMBOL_GPL(iscsi_host_add);
2043
2044 /**
2045  * iscsi_host_alloc - allocate a host and driver data
2046  * @sht: scsi host template
2047  * @dd_data_size: driver host data size
2048  * @qdepth: default device queue depth
2049  *
2050  * This should be called by partial offload and software iscsi drivers.
2051  * To access the driver specific memory use the iscsi_host_priv() macro.
2052  */
2053 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2054                                    int dd_data_size, uint16_t qdepth)
2055 {
2056         struct Scsi_Host *shost;
2057         struct iscsi_host *ihost;
2058
2059         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2060         if (!shost)
2061                 return NULL;
2062
2063         if (qdepth == 0)
2064                 qdepth = ISCSI_DEF_CMD_PER_LUN;
2065         shost->cmd_per_lun = qdepth;
2066
2067         ihost = shost_priv(shost);
2068         spin_lock_init(&ihost->lock);
2069         ihost->state = ISCSI_HOST_SETUP;
2070         ihost->num_sessions = 0;
2071         init_waitqueue_head(&ihost->session_removal_wq);
2072         return shost;
2073 }
2074 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2075
2076 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2077 {
2078         iscsi_session_failure(cls_session, ISCSI_ERR_INVALID_HOST);
2079 }
2080
2081 /**
2082  * iscsi_host_remove - remove host and sessions
2083  * @shost: scsi host
2084  *
2085  * If there are any sessions left, this will initiate the removal and wait
2086  * for the completion.
2087  */
2088 void iscsi_host_remove(struct Scsi_Host *shost)
2089 {
2090         struct iscsi_host *ihost = shost_priv(shost);
2091         unsigned long flags;
2092
2093         spin_lock_irqsave(&ihost->lock, flags);
2094         ihost->state = ISCSI_HOST_REMOVED;
2095         spin_unlock_irqrestore(&ihost->lock, flags);
2096
2097         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2098         wait_event_interruptible(ihost->session_removal_wq,
2099                                  ihost->num_sessions == 0);
2100         if (signal_pending(current))
2101                 flush_signals(current);
2102
2103         scsi_remove_host(shost);
2104 }
2105 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2106
2107 void iscsi_host_free(struct Scsi_Host *shost)
2108 {
2109         struct iscsi_host *ihost = shost_priv(shost);
2110
2111         kfree(ihost->netdev);
2112         kfree(ihost->hwaddress);
2113         kfree(ihost->initiatorname);
2114         scsi_host_put(shost);
2115 }
2116 EXPORT_SYMBOL_GPL(iscsi_host_free);
2117
2118 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2119 {
2120         struct iscsi_host *ihost = shost_priv(shost);
2121         unsigned long flags;
2122
2123         shost = scsi_host_get(shost);
2124         if (!shost) {
2125                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2126                       "of session teardown event because host already "
2127                       "removed.\n");
2128                 return;
2129         }
2130
2131         spin_lock_irqsave(&ihost->lock, flags);
2132         ihost->num_sessions--;
2133         if (ihost->num_sessions == 0)
2134                 wake_up(&ihost->session_removal_wq);
2135         spin_unlock_irqrestore(&ihost->lock, flags);
2136         scsi_host_put(shost);
2137 }
2138
2139 /**
2140  * iscsi_session_setup - create iscsi cls session and host and session
2141  * @iscsit: iscsi transport template
2142  * @shost: scsi host
2143  * @cmds_max: session can queue
2144  * @cmd_task_size: LLD task private data size
2145  * @initial_cmdsn: initial CmdSN
2146  *
2147  * This can be used by software iscsi_transports that allocate
2148  * a session per scsi host.
2149  *
2150  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2151  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2152  * for nop handling and login/logout requests.
2153  */
2154 struct iscsi_cls_session *
2155 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2156                     uint16_t cmds_max, int cmd_task_size,
2157                     uint32_t initial_cmdsn, unsigned int id)
2158 {
2159         struct iscsi_host *ihost = shost_priv(shost);
2160         struct iscsi_session *session;
2161         struct iscsi_cls_session *cls_session;
2162         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2163         unsigned long flags;
2164
2165         spin_lock_irqsave(&ihost->lock, flags);
2166         if (ihost->state == ISCSI_HOST_REMOVED) {
2167                 spin_unlock_irqrestore(&ihost->lock, flags);
2168                 return NULL;
2169         }
2170         ihost->num_sessions++;
2171         spin_unlock_irqrestore(&ihost->lock, flags);
2172
2173         if (!total_cmds)
2174                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2175         /*
2176          * The iscsi layer needs some tasks for nop handling and tmfs,
2177          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2178          * + 1 command for scsi IO.
2179          */
2180         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2181                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2182                        "must be a power of two that is at least %d.\n",
2183                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2184                 goto dec_session_count;
2185         }
2186
2187         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2188                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2189                        "must be a power of 2 less than or equal to %d.\n",
2190                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2191                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2192         }
2193
2194         if (!is_power_of_2(total_cmds)) {
2195                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2196                        "must be a power of 2.\n", total_cmds);
2197                 total_cmds = rounddown_pow_of_two(total_cmds);
2198                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2199                         return NULL;
2200                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2201                        total_cmds);
2202         }
2203         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2204
2205         cls_session = iscsi_alloc_session(shost, iscsit,
2206                                           sizeof(struct iscsi_session));
2207         if (!cls_session)
2208                 goto dec_session_count;
2209         session = cls_session->dd_data;
2210         session->cls_session = cls_session;
2211         session->host = shost;
2212         session->state = ISCSI_STATE_FREE;
2213         session->fast_abort = 1;
2214         session->lu_reset_timeout = 15;
2215         session->abort_timeout = 10;
2216         session->scsi_cmds_max = scsi_cmds;
2217         session->cmds_max = total_cmds;
2218         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2219         session->exp_cmdsn = initial_cmdsn + 1;
2220         session->max_cmdsn = initial_cmdsn + 1;
2221         session->max_r2t = 1;
2222         session->tt = iscsit;
2223         mutex_init(&session->eh_mutex);
2224         spin_lock_init(&session->lock);
2225
2226         /* initialize SCSI PDU commands pool */
2227         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2228                             (void***)&session->cmds,
2229                             cmd_task_size + sizeof(struct iscsi_task)))
2230                 goto cmdpool_alloc_fail;
2231
2232         /* pre-format cmds pool with ITT */
2233         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2234                 struct iscsi_task *task = session->cmds[cmd_i];
2235
2236                 if (cmd_task_size)
2237                         task->dd_data = &task[1];
2238                 task->itt = cmd_i;
2239                 INIT_LIST_HEAD(&task->running);
2240         }
2241
2242         if (!try_module_get(iscsit->owner))
2243                 goto module_get_fail;
2244
2245         if (iscsi_add_session(cls_session, id))
2246                 goto cls_session_fail;
2247
2248         return cls_session;
2249
2250 cls_session_fail:
2251         module_put(iscsit->owner);
2252 module_get_fail:
2253         iscsi_pool_free(&session->cmdpool);
2254 cmdpool_alloc_fail:
2255         iscsi_free_session(cls_session);
2256 dec_session_count:
2257         iscsi_host_dec_session_cnt(shost);
2258         return NULL;
2259 }
2260 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2261
2262 /**
2263  * iscsi_session_teardown - destroy session, host, and cls_session
2264  * @cls_session: iscsi session
2265  *
2266  * The driver must have called iscsi_remove_session before
2267  * calling this.
2268  */
2269 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2270 {
2271         struct iscsi_session *session = cls_session->dd_data;
2272         struct module *owner = cls_session->transport->owner;
2273         struct Scsi_Host *shost = session->host;
2274
2275         iscsi_pool_free(&session->cmdpool);
2276
2277         kfree(session->password);
2278         kfree(session->password_in);
2279         kfree(session->username);
2280         kfree(session->username_in);
2281         kfree(session->targetname);
2282         kfree(session->initiatorname);
2283         kfree(session->ifacename);
2284
2285         iscsi_destroy_session(cls_session);
2286         iscsi_host_dec_session_cnt(shost);
2287         module_put(owner);
2288 }
2289 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2290
2291 /**
2292  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2293  * @cls_session: iscsi_cls_session
2294  * @dd_size: private driver data size
2295  * @conn_idx: cid
2296  */
2297 struct iscsi_cls_conn *
2298 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2299                  uint32_t conn_idx)
2300 {
2301         struct iscsi_session *session = cls_session->dd_data;
2302         struct iscsi_conn *conn;
2303         struct iscsi_cls_conn *cls_conn;
2304         char *data;
2305
2306         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2307                                      conn_idx);
2308         if (!cls_conn)
2309                 return NULL;
2310         conn = cls_conn->dd_data;
2311         memset(conn, 0, sizeof(*conn) + dd_size);
2312
2313         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2314         conn->session = session;
2315         conn->cls_conn = cls_conn;
2316         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2317         conn->id = conn_idx;
2318         conn->exp_statsn = 0;
2319         conn->tmf_state = TMF_INITIAL;
2320
2321         init_timer(&conn->transport_timer);
2322         conn->transport_timer.data = (unsigned long)conn;
2323         conn->transport_timer.function = iscsi_check_transport_timeouts;
2324
2325         INIT_LIST_HEAD(&conn->run_list);
2326         INIT_LIST_HEAD(&conn->mgmt_run_list);
2327         INIT_LIST_HEAD(&conn->mgmtqueue);
2328         INIT_LIST_HEAD(&conn->xmitqueue);
2329         INIT_LIST_HEAD(&conn->requeue);
2330         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2331
2332         /* allocate login_task used for the login/text sequences */
2333         spin_lock_bh(&session->lock);
2334         if (!__kfifo_get(session->cmdpool.queue,
2335                          (void*)&conn->login_task,
2336                          sizeof(void*))) {
2337                 spin_unlock_bh(&session->lock);
2338                 goto login_task_alloc_fail;
2339         }
2340         spin_unlock_bh(&session->lock);
2341
2342         data = (char *) __get_free_pages(GFP_KERNEL,
2343                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2344         if (!data)
2345                 goto login_task_data_alloc_fail;
2346         conn->login_task->data = conn->data = data;
2347
2348         init_timer(&conn->tmf_timer);
2349         init_waitqueue_head(&conn->ehwait);
2350
2351         return cls_conn;
2352
2353 login_task_data_alloc_fail:
2354         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2355                     sizeof(void*));
2356 login_task_alloc_fail:
2357         iscsi_destroy_conn(cls_conn);
2358         return NULL;
2359 }
2360 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2361
2362 /**
2363  * iscsi_conn_teardown - teardown iscsi connection
2364  * cls_conn: iscsi class connection
2365  *
2366  * TODO: we may need to make this into a two step process
2367  * like scsi-mls remove + put host
2368  */
2369 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2370 {
2371         struct iscsi_conn *conn = cls_conn->dd_data;
2372         struct iscsi_session *session = conn->session;
2373         unsigned long flags;
2374
2375         del_timer_sync(&conn->transport_timer);
2376
2377         spin_lock_bh(&session->lock);
2378         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2379         if (session->leadconn == conn) {
2380                 /*
2381                  * leading connection? then give up on recovery.
2382                  */
2383                 session->state = ISCSI_STATE_TERMINATE;
2384                 wake_up(&conn->ehwait);
2385         }
2386         spin_unlock_bh(&session->lock);
2387
2388         /*
2389          * Block until all in-progress commands for this connection
2390          * time out or fail.
2391          */
2392         for (;;) {
2393                 spin_lock_irqsave(session->host->host_lock, flags);
2394                 if (!session->host->host_busy) { /* OK for ERL == 0 */
2395                         spin_unlock_irqrestore(session->host->host_lock, flags);
2396                         break;
2397                 }
2398                 spin_unlock_irqrestore(session->host->host_lock, flags);
2399                 msleep_interruptible(500);
2400                 iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2401                                   "host_busy %d host_failed %d\n",
2402                                   session->host->host_busy,
2403                                   session->host->host_failed);
2404                 /*
2405                  * force eh_abort() to unblock
2406                  */
2407                 wake_up(&conn->ehwait);
2408         }
2409
2410         /* flush queued up work because we free the connection below */
2411         iscsi_suspend_tx(conn);
2412
2413         spin_lock_bh(&session->lock);
2414         free_pages((unsigned long) conn->data,
2415                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2416         kfree(conn->persistent_address);
2417         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2418                     sizeof(void*));
2419         if (session->leadconn == conn)
2420                 session->leadconn = NULL;
2421         spin_unlock_bh(&session->lock);
2422
2423         iscsi_destroy_conn(cls_conn);
2424 }
2425 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2426
2427 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2428 {
2429         struct iscsi_conn *conn = cls_conn->dd_data;
2430         struct iscsi_session *session = conn->session;
2431
2432         if (!session) {
2433                 iscsi_conn_printk(KERN_ERR, conn,
2434                                   "can't start unbound connection\n");
2435                 return -EPERM;
2436         }
2437
2438         if ((session->imm_data_en || !session->initial_r2t_en) &&
2439              session->first_burst > session->max_burst) {
2440                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2441                                   "first_burst %d max_burst %d\n",
2442                                   session->first_burst, session->max_burst);
2443                 return -EINVAL;
2444         }
2445
2446         if (conn->ping_timeout && !conn->recv_timeout) {
2447                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
2448                                   "zero. Using 5 seconds\n.");
2449                 conn->recv_timeout = 5;
2450         }
2451
2452         if (conn->recv_timeout && !conn->ping_timeout) {
2453                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
2454                                   "zero. Using 5 seconds.\n");
2455                 conn->ping_timeout = 5;
2456         }
2457
2458         spin_lock_bh(&session->lock);
2459         conn->c_stage = ISCSI_CONN_STARTED;
2460         session->state = ISCSI_STATE_LOGGED_IN;
2461         session->queued_cmdsn = session->cmdsn;
2462
2463         conn->last_recv = jiffies;
2464         conn->last_ping = jiffies;
2465         if (conn->recv_timeout && conn->ping_timeout)
2466                 mod_timer(&conn->transport_timer,
2467                           jiffies + (conn->recv_timeout * HZ));
2468
2469         switch(conn->stop_stage) {
2470         case STOP_CONN_RECOVER:
2471                 /*
2472                  * unblock eh_abort() if it is blocked. re-try all
2473                  * commands after successful recovery
2474                  */
2475                 conn->stop_stage = 0;
2476                 conn->tmf_state = TMF_INITIAL;
2477                 session->age++;
2478                 if (session->age == 16)
2479                         session->age = 0;
2480                 break;
2481         case STOP_CONN_TERM:
2482                 conn->stop_stage = 0;
2483                 break;
2484         default:
2485                 break;
2486         }
2487         spin_unlock_bh(&session->lock);
2488
2489         iscsi_unblock_session(session->cls_session);
2490         wake_up(&conn->ehwait);
2491         return 0;
2492 }
2493 EXPORT_SYMBOL_GPL(iscsi_conn_start);
2494
2495 static void
2496 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
2497 {
2498         struct iscsi_task *task, *tmp;
2499
2500         /* handle pending */
2501         list_for_each_entry_safe(task, tmp, &conn->mgmtqueue, running) {
2502                 ISCSI_DBG_SESSION(session, "flushing pending mgmt task "
2503                                   "itt 0x%x\n", task->itt);
2504                 /* release ref from prep task */
2505                 __iscsi_put_task(task);
2506         }
2507
2508         /* handle running */
2509         list_for_each_entry_safe(task, tmp, &conn->mgmt_run_list, running) {
2510                 ISCSI_DBG_SESSION(session, "flushing running mgmt task "
2511                                   "itt 0x%x\n", task->itt);
2512                 /* release ref from prep task */
2513                 __iscsi_put_task(task);
2514         }
2515
2516         conn->task = NULL;
2517 }
2518
2519 static void iscsi_start_session_recovery(struct iscsi_session *session,
2520                                          struct iscsi_conn *conn, int flag)
2521 {
2522         int old_stop_stage;
2523
2524         del_timer_sync(&conn->transport_timer);
2525
2526         mutex_lock(&session->eh_mutex);
2527         spin_lock_bh(&session->lock);
2528         if (conn->stop_stage == STOP_CONN_TERM) {
2529                 spin_unlock_bh(&session->lock);
2530                 mutex_unlock(&session->eh_mutex);
2531                 return;
2532         }
2533
2534         /*
2535          * When this is called for the in_login state, we only want to clean
2536          * up the login task and connection. We do not need to block and set
2537          * the recovery state again
2538          */
2539         if (flag == STOP_CONN_TERM)
2540                 session->state = ISCSI_STATE_TERMINATE;
2541         else if (conn->stop_stage != STOP_CONN_RECOVER)
2542                 session->state = ISCSI_STATE_IN_RECOVERY;
2543
2544         old_stop_stage = conn->stop_stage;
2545         conn->stop_stage = flag;
2546         conn->c_stage = ISCSI_CONN_STOPPED;
2547         spin_unlock_bh(&session->lock);
2548
2549         iscsi_suspend_tx(conn);
2550         /*
2551          * for connection level recovery we should not calculate
2552          * header digest. conn->hdr_size used for optimization
2553          * in hdr_extract() and will be re-negotiated at
2554          * set_param() time.
2555          */
2556         if (flag == STOP_CONN_RECOVER) {
2557                 conn->hdrdgst_en = 0;
2558                 conn->datadgst_en = 0;
2559                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
2560                     old_stop_stage != STOP_CONN_RECOVER) {
2561                         ISCSI_DBG_SESSION(session, "blocking session\n");
2562                         iscsi_block_session(session->cls_session);
2563                 }
2564         }
2565
2566         /*
2567          * flush queues.
2568          */
2569         spin_lock_bh(&session->lock);
2570         if (flag == STOP_CONN_RECOVER)
2571                 fail_all_commands(conn, -1, DID_TRANSPORT_DISRUPTED);
2572         else
2573                 fail_all_commands(conn, -1, DID_ERROR);
2574         flush_control_queues(session, conn);
2575         spin_unlock_bh(&session->lock);
2576         mutex_unlock(&session->eh_mutex);
2577 }
2578
2579 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
2580 {
2581         struct iscsi_conn *conn = cls_conn->dd_data;
2582         struct iscsi_session *session = conn->session;
2583
2584         switch (flag) {
2585         case STOP_CONN_RECOVER:
2586         case STOP_CONN_TERM:
2587                 iscsi_start_session_recovery(session, conn, flag);
2588                 break;
2589         default:
2590                 iscsi_conn_printk(KERN_ERR, conn,
2591                                   "invalid stop flag %d\n", flag);
2592         }
2593 }
2594 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
2595
2596 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
2597                     struct iscsi_cls_conn *cls_conn, int is_leading)
2598 {
2599         struct iscsi_session *session = cls_session->dd_data;
2600         struct iscsi_conn *conn = cls_conn->dd_data;
2601
2602         spin_lock_bh(&session->lock);
2603         if (is_leading)
2604                 session->leadconn = conn;
2605         spin_unlock_bh(&session->lock);
2606
2607         /*
2608          * Unblock xmitworker(), Login Phase will pass through.
2609          */
2610         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
2611         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
2612         return 0;
2613 }
2614 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
2615
2616
2617 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
2618                     enum iscsi_param param, char *buf, int buflen)
2619 {
2620         struct iscsi_conn *conn = cls_conn->dd_data;
2621         struct iscsi_session *session = conn->session;
2622         uint32_t value;
2623
2624         switch(param) {
2625         case ISCSI_PARAM_FAST_ABORT:
2626                 sscanf(buf, "%d", &session->fast_abort);
2627                 break;
2628         case ISCSI_PARAM_ABORT_TMO:
2629                 sscanf(buf, "%d", &session->abort_timeout);
2630                 break;
2631         case ISCSI_PARAM_LU_RESET_TMO:
2632                 sscanf(buf, "%d", &session->lu_reset_timeout);
2633                 break;
2634         case ISCSI_PARAM_PING_TMO:
2635                 sscanf(buf, "%d", &conn->ping_timeout);
2636                 break;
2637         case ISCSI_PARAM_RECV_TMO:
2638                 sscanf(buf, "%d", &conn->recv_timeout);
2639                 break;
2640         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2641                 sscanf(buf, "%d", &conn->max_recv_dlength);
2642                 break;
2643         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2644                 sscanf(buf, "%d", &conn->max_xmit_dlength);
2645                 break;
2646         case ISCSI_PARAM_HDRDGST_EN:
2647                 sscanf(buf, "%d", &conn->hdrdgst_en);
2648                 break;
2649         case ISCSI_PARAM_DATADGST_EN:
2650                 sscanf(buf, "%d", &conn->datadgst_en);
2651                 break;
2652         case ISCSI_PARAM_INITIAL_R2T_EN:
2653                 sscanf(buf, "%d", &session->initial_r2t_en);
2654                 break;
2655         case ISCSI_PARAM_MAX_R2T:
2656                 sscanf(buf, "%d", &session->max_r2t);
2657                 break;
2658         case ISCSI_PARAM_IMM_DATA_EN:
2659                 sscanf(buf, "%d", &session->imm_data_en);
2660                 break;
2661         case ISCSI_PARAM_FIRST_BURST:
2662                 sscanf(buf, "%d", &session->first_burst);
2663                 break;
2664         case ISCSI_PARAM_MAX_BURST:
2665                 sscanf(buf, "%d", &session->max_burst);
2666                 break;
2667         case ISCSI_PARAM_PDU_INORDER_EN:
2668                 sscanf(buf, "%d", &session->pdu_inorder_en);
2669                 break;
2670         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2671                 sscanf(buf, "%d", &session->dataseq_inorder_en);
2672                 break;
2673         case ISCSI_PARAM_ERL:
2674                 sscanf(buf, "%d", &session->erl);
2675                 break;
2676         case ISCSI_PARAM_IFMARKER_EN:
2677                 sscanf(buf, "%d", &value);
2678                 BUG_ON(value);
2679                 break;
2680         case ISCSI_PARAM_OFMARKER_EN:
2681                 sscanf(buf, "%d", &value);
2682                 BUG_ON(value);
2683                 break;
2684         case ISCSI_PARAM_EXP_STATSN:
2685                 sscanf(buf, "%u", &conn->exp_statsn);
2686                 break;
2687         case ISCSI_PARAM_USERNAME:
2688                 kfree(session->username);
2689                 session->username = kstrdup(buf, GFP_KERNEL);
2690                 if (!session->username)
2691                         return -ENOMEM;
2692                 break;
2693         case ISCSI_PARAM_USERNAME_IN:
2694                 kfree(session->username_in);
2695                 session->username_in = kstrdup(buf, GFP_KERNEL);
2696                 if (!session->username_in)
2697                         return -ENOMEM;
2698                 break;
2699         case ISCSI_PARAM_PASSWORD:
2700                 kfree(session->password);
2701                 session->password = kstrdup(buf, GFP_KERNEL);
2702                 if (!session->password)
2703                         return -ENOMEM;
2704                 break;
2705         case ISCSI_PARAM_PASSWORD_IN:
2706                 kfree(session->password_in);
2707                 session->password_in = kstrdup(buf, GFP_KERNEL);
2708                 if (!session->password_in)
2709                         return -ENOMEM;
2710                 break;
2711         case ISCSI_PARAM_TARGET_NAME:
2712                 /* this should not change between logins */
2713                 if (session->targetname)
2714                         break;
2715
2716                 session->targetname = kstrdup(buf, GFP_KERNEL);
2717                 if (!session->targetname)
2718                         return -ENOMEM;
2719                 break;
2720         case ISCSI_PARAM_TPGT:
2721                 sscanf(buf, "%d", &session->tpgt);
2722                 break;
2723         case ISCSI_PARAM_PERSISTENT_PORT:
2724                 sscanf(buf, "%d", &conn->persistent_port);
2725                 break;
2726         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2727                 /*
2728                  * this is the address returned in discovery so it should
2729                  * not change between logins.
2730                  */
2731                 if (conn->persistent_address)
2732                         break;
2733
2734                 conn->persistent_address = kstrdup(buf, GFP_KERNEL);
2735                 if (!conn->persistent_address)
2736                         return -ENOMEM;
2737                 break;
2738         case ISCSI_PARAM_IFACE_NAME:
2739                 if (!session->ifacename)
2740                         session->ifacename = kstrdup(buf, GFP_KERNEL);
2741                 break;
2742         case ISCSI_PARAM_INITIATOR_NAME:
2743                 if (!session->initiatorname)
2744                         session->initiatorname = kstrdup(buf, GFP_KERNEL);
2745                 break;
2746         default:
2747                 return -ENOSYS;
2748         }
2749
2750         return 0;
2751 }
2752 EXPORT_SYMBOL_GPL(iscsi_set_param);
2753
2754 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
2755                             enum iscsi_param param, char *buf)
2756 {
2757         struct iscsi_session *session = cls_session->dd_data;
2758         int len;
2759
2760         switch(param) {
2761         case ISCSI_PARAM_FAST_ABORT:
2762                 len = sprintf(buf, "%d\n", session->fast_abort);
2763                 break;
2764         case ISCSI_PARAM_ABORT_TMO:
2765                 len = sprintf(buf, "%d\n", session->abort_timeout);
2766                 break;
2767         case ISCSI_PARAM_LU_RESET_TMO:
2768                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
2769                 break;
2770         case ISCSI_PARAM_INITIAL_R2T_EN:
2771                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
2772                 break;
2773         case ISCSI_PARAM_MAX_R2T:
2774                 len = sprintf(buf, "%hu\n", session->max_r2t);
2775                 break;
2776         case ISCSI_PARAM_IMM_DATA_EN:
2777                 len = sprintf(buf, "%d\n", session->imm_data_en);
2778                 break;
2779         case ISCSI_PARAM_FIRST_BURST:
2780                 len = sprintf(buf, "%u\n", session->first_burst);
2781                 break;
2782         case ISCSI_PARAM_MAX_BURST:
2783                 len = sprintf(buf, "%u\n", session->max_burst);
2784                 break;
2785         case ISCSI_PARAM_PDU_INORDER_EN:
2786                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
2787                 break;
2788         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2789                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
2790                 break;
2791         case ISCSI_PARAM_ERL:
2792                 len = sprintf(buf, "%d\n", session->erl);
2793                 break;
2794         case ISCSI_PARAM_TARGET_NAME:
2795                 len = sprintf(buf, "%s\n", session->targetname);
2796                 break;
2797         case ISCSI_PARAM_TPGT:
2798                 len = sprintf(buf, "%d\n", session->tpgt);
2799                 break;
2800         case ISCSI_PARAM_USERNAME:
2801                 len = sprintf(buf, "%s\n", session->username);
2802                 break;
2803         case ISCSI_PARAM_USERNAME_IN:
2804                 len = sprintf(buf, "%s\n", session->username_in);
2805                 break;
2806         case ISCSI_PARAM_PASSWORD:
2807                 len = sprintf(buf, "%s\n", session->password);
2808                 break;
2809         case ISCSI_PARAM_PASSWORD_IN:
2810                 len = sprintf(buf, "%s\n", session->password_in);
2811                 break;
2812         case ISCSI_PARAM_IFACE_NAME:
2813                 len = sprintf(buf, "%s\n", session->ifacename);
2814                 break;
2815         case ISCSI_PARAM_INITIATOR_NAME:
2816                 if (!session->initiatorname)
2817                         len = sprintf(buf, "%s\n", "unknown");
2818                 else
2819                         len = sprintf(buf, "%s\n", session->initiatorname);
2820                 break;
2821         default:
2822                 return -ENOSYS;
2823         }
2824
2825         return len;
2826 }
2827 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
2828
2829 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2830                          enum iscsi_param param, char *buf)
2831 {
2832         struct iscsi_conn *conn = cls_conn->dd_data;
2833         int len;
2834
2835         switch(param) {
2836         case ISCSI_PARAM_PING_TMO:
2837                 len = sprintf(buf, "%u\n", conn->ping_timeout);
2838                 break;
2839         case ISCSI_PARAM_RECV_TMO:
2840                 len = sprintf(buf, "%u\n", conn->recv_timeout);
2841                 break;
2842         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2843                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
2844                 break;
2845         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2846                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
2847                 break;
2848         case ISCSI_PARAM_HDRDGST_EN:
2849                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
2850                 break;
2851         case ISCSI_PARAM_DATADGST_EN:
2852                 len = sprintf(buf, "%d\n", conn->datadgst_en);
2853                 break;
2854         case ISCSI_PARAM_IFMARKER_EN:
2855                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
2856                 break;
2857         case ISCSI_PARAM_OFMARKER_EN:
2858                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
2859                 break;
2860         case ISCSI_PARAM_EXP_STATSN:
2861                 len = sprintf(buf, "%u\n", conn->exp_statsn);
2862                 break;
2863         case ISCSI_PARAM_PERSISTENT_PORT:
2864                 len = sprintf(buf, "%d\n", conn->persistent_port);
2865                 break;
2866         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2867                 len = sprintf(buf, "%s\n", conn->persistent_address);
2868                 break;
2869         default:
2870                 return -ENOSYS;
2871         }
2872
2873         return len;
2874 }
2875 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
2876
2877 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2878                          char *buf)
2879 {
2880         struct iscsi_host *ihost = shost_priv(shost);
2881         int len;
2882
2883         switch (param) {
2884         case ISCSI_HOST_PARAM_NETDEV_NAME:
2885                 if (!ihost->netdev)
2886                         len = sprintf(buf, "%s\n", "default");
2887                 else
2888                         len = sprintf(buf, "%s\n", ihost->netdev);
2889                 break;
2890         case ISCSI_HOST_PARAM_HWADDRESS:
2891                 if (!ihost->hwaddress)
2892                         len = sprintf(buf, "%s\n", "default");
2893                 else
2894                         len = sprintf(buf, "%s\n", ihost->hwaddress);
2895                 break;
2896         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2897                 if (!ihost->initiatorname)
2898                         len = sprintf(buf, "%s\n", "unknown");
2899                 else
2900                         len = sprintf(buf, "%s\n", ihost->initiatorname);
2901                 break;
2902         case ISCSI_HOST_PARAM_IPADDRESS:
2903                 if (!strlen(ihost->local_address))
2904                         len = sprintf(buf, "%s\n", "unknown");
2905                 else
2906                         len = sprintf(buf, "%s\n",
2907                                       ihost->local_address);
2908                 break;
2909         default:
2910                 return -ENOSYS;
2911         }
2912
2913         return len;
2914 }
2915 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
2916
2917 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2918                          char *buf, int buflen)
2919 {
2920         struct iscsi_host *ihost = shost_priv(shost);
2921
2922         switch (param) {
2923         case ISCSI_HOST_PARAM_NETDEV_NAME:
2924                 if (!ihost->netdev)
2925                         ihost->netdev = kstrdup(buf, GFP_KERNEL);
2926                 break;
2927         case ISCSI_HOST_PARAM_HWADDRESS:
2928                 if (!ihost->hwaddress)
2929                         ihost->hwaddress = kstrdup(buf, GFP_KERNEL);
2930                 break;
2931         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2932                 if (!ihost->initiatorname)
2933                         ihost->initiatorname = kstrdup(buf, GFP_KERNEL);
2934                 break;
2935         default:
2936                 return -ENOSYS;
2937         }
2938
2939         return 0;
2940 }
2941 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
2942
2943 MODULE_AUTHOR("Mike Christie");
2944 MODULE_DESCRIPTION("iSCSI library functions");
2945 MODULE_LICENSE("GPL");