Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[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_conn;
42 module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
43                    S_IRUGO | S_IWUSR);
44 MODULE_PARM_DESC(debug_libiscsi_conn,
45                  "Turn on debugging for connections in libiscsi module. "
46                  "Set to 1 to turn on, and zero to turn off. Default is off.");
47
48 static int iscsi_dbg_lib_session;
49 module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
50                    S_IRUGO | S_IWUSR);
51 MODULE_PARM_DESC(debug_libiscsi_session,
52                  "Turn on debugging for sessions in libiscsi module. "
53                  "Set to 1 to turn on, and zero to turn off. Default is off.");
54
55 static int iscsi_dbg_lib_eh;
56 module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
57                    S_IRUGO | S_IWUSR);
58 MODULE_PARM_DESC(debug_libiscsi_eh,
59                  "Turn on debugging for error handling in libiscsi module. "
60                  "Set to 1 to turn on, and zero to turn off. Default is off.");
61
62 #define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)                  \
63         do {                                                    \
64                 if (iscsi_dbg_lib_conn)                         \
65                         iscsi_conn_printk(KERN_INFO, _conn,     \
66                                              "%s " dbg_fmt,     \
67                                              __func__, ##arg);  \
68         } while (0);
69
70 #define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)                    \
71         do {                                                            \
72                 if (iscsi_dbg_lib_session)                              \
73                         iscsi_session_printk(KERN_INFO, _session,       \
74                                              "%s " dbg_fmt,             \
75                                              __func__, ##arg);          \
76         } while (0);
77
78 #define ISCSI_DBG_EH(_session, dbg_fmt, arg...)                         \
79         do {                                                            \
80                 if (iscsi_dbg_lib_eh)                                   \
81                         iscsi_session_printk(KERN_INFO, _session,       \
82                                              "%s " dbg_fmt,             \
83                                              __func__, ##arg);          \
84         } while (0);
85
86 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
87 #define SNA32_CHECK 2147483648UL
88
89 static int iscsi_sna_lt(u32 n1, u32 n2)
90 {
91         return n1 != n2 && ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
92                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
93 }
94
95 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
96 static int iscsi_sna_lte(u32 n1, u32 n2)
97 {
98         return n1 == n2 || ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
99                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
100 }
101
102 inline void iscsi_conn_queue_work(struct iscsi_conn *conn)
103 {
104         struct Scsi_Host *shost = conn->session->host;
105         struct iscsi_host *ihost = shost_priv(shost);
106
107         if (ihost->workq)
108                 queue_work(ihost->workq, &conn->xmitwork);
109 }
110 EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
111
112 void
113 iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
114 {
115         uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
116         uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);
117
118         /*
119          * standard specifies this check for when to update expected and
120          * max sequence numbers
121          */
122         if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
123                 return;
124
125         if (exp_cmdsn != session->exp_cmdsn &&
126             !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
127                 session->exp_cmdsn = exp_cmdsn;
128
129         if (max_cmdsn != session->max_cmdsn &&
130             !iscsi_sna_lt(max_cmdsn, session->max_cmdsn)) {
131                 session->max_cmdsn = max_cmdsn;
132                 /*
133                  * if the window closed with IO queued, then kick the
134                  * xmit thread
135                  */
136                 if (!list_empty(&session->leadconn->cmdqueue) ||
137                     !list_empty(&session->leadconn->mgmtqueue))
138                         iscsi_conn_queue_work(session->leadconn);
139         }
140 }
141 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
142
143 /**
144  * iscsi_prep_data_out_pdu - initialize Data-Out
145  * @task: scsi command task
146  * @r2t: R2T info
147  * @hdr: iscsi data in pdu
148  *
149  * Notes:
150  *      Initialize Data-Out within this R2T sequence and finds
151  *      proper data_offset within this SCSI command.
152  *
153  *      This function is called with connection lock taken.
154  **/
155 void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
156                            struct iscsi_data *hdr)
157 {
158         struct iscsi_conn *conn = task->conn;
159         unsigned int left = r2t->data_length - r2t->sent;
160
161         task->hdr_len = sizeof(struct iscsi_data);
162
163         memset(hdr, 0, sizeof(struct iscsi_data));
164         hdr->ttt = r2t->ttt;
165         hdr->datasn = cpu_to_be32(r2t->datasn);
166         r2t->datasn++;
167         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
168         memcpy(hdr->lun, task->lun, sizeof(hdr->lun));
169         hdr->itt = task->hdr_itt;
170         hdr->exp_statsn = r2t->exp_statsn;
171         hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
172         if (left > conn->max_xmit_dlength) {
173                 hton24(hdr->dlength, conn->max_xmit_dlength);
174                 r2t->data_count = conn->max_xmit_dlength;
175                 hdr->flags = 0;
176         } else {
177                 hton24(hdr->dlength, left);
178                 r2t->data_count = left;
179                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
180         }
181         conn->dataout_pdus_cnt++;
182 }
183 EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
184
185 static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
186 {
187         unsigned exp_len = task->hdr_len + len;
188
189         if (exp_len > task->hdr_max) {
190                 WARN_ON(1);
191                 return -EINVAL;
192         }
193
194         WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
195         task->hdr_len = exp_len;
196         return 0;
197 }
198
199 /*
200  * make an extended cdb AHS
201  */
202 static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
203 {
204         struct scsi_cmnd *cmd = task->sc;
205         unsigned rlen, pad_len;
206         unsigned short ahslength;
207         struct iscsi_ecdb_ahdr *ecdb_ahdr;
208         int rc;
209
210         ecdb_ahdr = iscsi_next_hdr(task);
211         rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
212
213         BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
214         ahslength = rlen + sizeof(ecdb_ahdr->reserved);
215
216         pad_len = iscsi_padding(rlen);
217
218         rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
219                            sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
220         if (rc)
221                 return rc;
222
223         if (pad_len)
224                 memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
225
226         ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
227         ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
228         ecdb_ahdr->reserved = 0;
229         memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
230
231         ISCSI_DBG_SESSION(task->conn->session,
232                           "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
233                           "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
234                           "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
235                           task->hdr_len);
236         return 0;
237 }
238
239 static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
240 {
241         struct scsi_cmnd *sc = task->sc;
242         struct iscsi_rlength_ahdr *rlen_ahdr;
243         int rc;
244
245         rlen_ahdr = iscsi_next_hdr(task);
246         rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
247         if (rc)
248                 return rc;
249
250         rlen_ahdr->ahslength =
251                 cpu_to_be16(sizeof(rlen_ahdr->read_length) +
252                                                   sizeof(rlen_ahdr->reserved));
253         rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
254         rlen_ahdr->reserved = 0;
255         rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
256
257         ISCSI_DBG_SESSION(task->conn->session,
258                           "bidi-in rlen_ahdr->read_length(%d) "
259                           "rlen_ahdr->ahslength(%d)\n",
260                           be32_to_cpu(rlen_ahdr->read_length),
261                           be16_to_cpu(rlen_ahdr->ahslength));
262         return 0;
263 }
264
265 /**
266  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
267  * @task: iscsi task
268  *
269  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
270  * fields like dlength or final based on how much data it sends
271  */
272 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
273 {
274         struct iscsi_conn *conn = task->conn;
275         struct iscsi_session *session = conn->session;
276         struct scsi_cmnd *sc = task->sc;
277         struct iscsi_cmd *hdr;
278         unsigned hdrlength, cmd_len;
279         itt_t itt;
280         int rc;
281
282         if (conn->session->tt->alloc_pdu) {
283                 rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
284                 if (rc)
285                         return rc;
286         }
287         hdr = (struct iscsi_cmd *) task->hdr;
288         itt = hdr->itt;
289         memset(hdr, 0, sizeof(*hdr));
290
291         if (session->tt->parse_pdu_itt)
292                 hdr->itt = task->hdr_itt = itt;
293         else
294                 hdr->itt = task->hdr_itt = build_itt(task->itt,
295                                                      task->conn->session->age);
296         task->hdr_len = 0;
297         rc = iscsi_add_hdr(task, sizeof(*hdr));
298         if (rc)
299                 return rc;
300         hdr->opcode = ISCSI_OP_SCSI_CMD;
301         hdr->flags = ISCSI_ATTR_SIMPLE;
302         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
303         memcpy(task->lun, hdr->lun, sizeof(task->lun));
304         hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
305         session->cmdsn++;
306         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
307         cmd_len = sc->cmd_len;
308         if (cmd_len < ISCSI_CDB_SIZE)
309                 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
310         else if (cmd_len > ISCSI_CDB_SIZE) {
311                 rc = iscsi_prep_ecdb_ahs(task);
312                 if (rc)
313                         return rc;
314                 cmd_len = ISCSI_CDB_SIZE;
315         }
316         memcpy(hdr->cdb, sc->cmnd, cmd_len);
317
318         task->imm_count = 0;
319         if (scsi_bidi_cmnd(sc)) {
320                 hdr->flags |= ISCSI_FLAG_CMD_READ;
321                 rc = iscsi_prep_bidi_ahs(task);
322                 if (rc)
323                         return rc;
324         }
325         if (sc->sc_data_direction == DMA_TO_DEVICE) {
326                 unsigned out_len = scsi_out(sc)->length;
327                 struct iscsi_r2t_info *r2t = &task->unsol_r2t;
328
329                 hdr->data_length = cpu_to_be32(out_len);
330                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
331                 /*
332                  * Write counters:
333                  *
334                  *      imm_count       bytes to be sent right after
335                  *                      SCSI PDU Header
336                  *
337                  *      unsol_count     bytes(as Data-Out) to be sent
338                  *                      without R2T ack right after
339                  *                      immediate data
340                  *
341                  *      r2t data_length bytes to be sent via R2T ack's
342                  *
343                  *      pad_count       bytes to be sent as zero-padding
344                  */
345                 memset(r2t, 0, sizeof(*r2t));
346
347                 if (session->imm_data_en) {
348                         if (out_len >= session->first_burst)
349                                 task->imm_count = min(session->first_burst,
350                                                         conn->max_xmit_dlength);
351                         else
352                                 task->imm_count = min(out_len,
353                                                         conn->max_xmit_dlength);
354                         hton24(hdr->dlength, task->imm_count);
355                 } else
356                         zero_data(hdr->dlength);
357
358                 if (!session->initial_r2t_en) {
359                         r2t->data_length = min(session->first_burst, out_len) -
360                                                task->imm_count;
361                         r2t->data_offset = task->imm_count;
362                         r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
363                         r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
364                 }
365
366                 if (!task->unsol_r2t.data_length)
367                         /* No unsolicit Data-Out's */
368                         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
369         } else {
370                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
371                 zero_data(hdr->dlength);
372                 hdr->data_length = cpu_to_be32(scsi_in(sc)->length);
373
374                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
375                         hdr->flags |= ISCSI_FLAG_CMD_READ;
376         }
377
378         /* calculate size of additional header segments (AHSs) */
379         hdrlength = task->hdr_len - sizeof(*hdr);
380
381         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
382         hdrlength /= ISCSI_PAD_LEN;
383
384         WARN_ON(hdrlength >= 256);
385         hdr->hlength = hdrlength & 0xFF;
386
387         if (session->tt->init_task && session->tt->init_task(task))
388                 return -EIO;
389
390         task->state = ISCSI_TASK_RUNNING;
391
392         conn->scsicmd_pdus_cnt++;
393         ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
394                           "itt 0x%x len %d bidi_len %d cmdsn %d win %d]\n",
395                           scsi_bidi_cmnd(sc) ? "bidirectional" :
396                           sc->sc_data_direction == DMA_TO_DEVICE ?
397                           "write" : "read", conn->id, sc, sc->cmnd[0],
398                           task->itt, scsi_bufflen(sc),
399                           scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
400                           session->cmdsn,
401                           session->max_cmdsn - session->exp_cmdsn + 1);
402         return 0;
403 }
404
405 /**
406  * iscsi_free_task - free a task
407  * @task: iscsi cmd task
408  *
409  * Must be called with session lock.
410  * This function returns the scsi command to scsi-ml or cleans
411  * up mgmt tasks then returns the task to the pool.
412  */
413 static void iscsi_free_task(struct iscsi_task *task)
414 {
415         struct iscsi_conn *conn = task->conn;
416         struct iscsi_session *session = conn->session;
417         struct scsi_cmnd *sc = task->sc;
418
419         ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
420                           task->itt, task->state, task->sc);
421
422         session->tt->cleanup_task(task);
423         task->state = ISCSI_TASK_FREE;
424         task->sc = NULL;
425         /*
426          * login task is preallocated so do not free
427          */
428         if (conn->login_task == task)
429                 return;
430
431         __kfifo_put(session->cmdpool.queue, (void*)&task, sizeof(void*));
432
433         if (sc) {
434                 task->sc = NULL;
435                 /* SCSI eh reuses commands to verify us */
436                 sc->SCp.ptr = NULL;
437                 /*
438                  * queue command may call this to free the task, but
439                  * not have setup the sc callback
440                  */
441                 if (sc->scsi_done)
442                         sc->scsi_done(sc);
443         }
444 }
445
446 void __iscsi_get_task(struct iscsi_task *task)
447 {
448         atomic_inc(&task->refcount);
449 }
450 EXPORT_SYMBOL_GPL(__iscsi_get_task);
451
452 static void __iscsi_put_task(struct iscsi_task *task)
453 {
454         if (atomic_dec_and_test(&task->refcount))
455                 iscsi_free_task(task);
456 }
457
458 void iscsi_put_task(struct iscsi_task *task)
459 {
460         struct iscsi_session *session = task->conn->session;
461
462         spin_lock_bh(&session->lock);
463         __iscsi_put_task(task);
464         spin_unlock_bh(&session->lock);
465 }
466 EXPORT_SYMBOL_GPL(iscsi_put_task);
467
468 /**
469  * iscsi_complete_task - finish a task
470  * @task: iscsi cmd task
471  * @state: state to complete task with
472  *
473  * Must be called with session lock.
474  */
475 static void iscsi_complete_task(struct iscsi_task *task, int state)
476 {
477         struct iscsi_conn *conn = task->conn;
478
479         ISCSI_DBG_SESSION(conn->session,
480                           "complete task itt 0x%x state %d sc %p\n",
481                           task->itt, task->state, task->sc);
482         if (task->state == ISCSI_TASK_COMPLETED ||
483             task->state == ISCSI_TASK_ABRT_TMF ||
484             task->state == ISCSI_TASK_ABRT_SESS_RECOV)
485                 return;
486         WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
487         task->state = state;
488
489         if (!list_empty(&task->running))
490                 list_del_init(&task->running);
491
492         if (conn->task == task)
493                 conn->task = NULL;
494
495         if (conn->ping_task == task)
496                 conn->ping_task = NULL;
497
498         /* release get from queueing */
499         __iscsi_put_task(task);
500 }
501
502 /*
503  * session lock must be held and if not called for a task that is
504  * still pending or from the xmit thread, then xmit thread must
505  * be suspended.
506  */
507 static void fail_scsi_task(struct iscsi_task *task, int err)
508 {
509         struct iscsi_conn *conn = task->conn;
510         struct scsi_cmnd *sc;
511         int state;
512
513         /*
514          * if a command completes and we get a successful tmf response
515          * we will hit this because the scsi eh abort code does not take
516          * a ref to the task.
517          */
518         sc = task->sc;
519         if (!sc)
520                 return;
521
522         if (task->state == ISCSI_TASK_PENDING) {
523                 /*
524                  * cmd never made it to the xmit thread, so we should not count
525                  * the cmd in the sequencing
526                  */
527                 conn->session->queued_cmdsn--;
528                 /* it was never sent so just complete like normal */
529                 state = ISCSI_TASK_COMPLETED;
530         } else if (err == DID_TRANSPORT_DISRUPTED)
531                 state = ISCSI_TASK_ABRT_SESS_RECOV;
532         else
533                 state = ISCSI_TASK_ABRT_TMF;
534
535         sc->result = err << 16;
536         if (!scsi_bidi_cmnd(sc))
537                 scsi_set_resid(sc, scsi_bufflen(sc));
538         else {
539                 scsi_out(sc)->resid = scsi_out(sc)->length;
540                 scsi_in(sc)->resid = scsi_in(sc)->length;
541         }
542
543         iscsi_complete_task(task, state);
544 }
545
546 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
547                                 struct iscsi_task *task)
548 {
549         struct iscsi_session *session = conn->session;
550         struct iscsi_hdr *hdr = task->hdr;
551         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
552
553         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
554                 return -ENOTCONN;
555
556         if (hdr->opcode != (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) &&
557             hdr->opcode != (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
558                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
559         /*
560          * pre-format CmdSN for outgoing PDU.
561          */
562         nop->cmdsn = cpu_to_be32(session->cmdsn);
563         if (hdr->itt != RESERVED_ITT) {
564                 /*
565                  * TODO: We always use immediate, so we never hit this.
566                  * If we start to send tmfs or nops as non-immediate then
567                  * we should start checking the cmdsn numbers for mgmt tasks.
568                  */
569                 if (conn->c_stage == ISCSI_CONN_STARTED &&
570                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
571                         session->queued_cmdsn++;
572                         session->cmdsn++;
573                 }
574         }
575
576         if (session->tt->init_task && session->tt->init_task(task))
577                 return -EIO;
578
579         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
580                 session->state = ISCSI_STATE_LOGGING_OUT;
581
582         task->state = ISCSI_TASK_RUNNING;
583         ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
584                           "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
585                           hdr->itt, task->data_count);
586         return 0;
587 }
588
589 static struct iscsi_task *
590 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
591                       char *data, uint32_t data_size)
592 {
593         struct iscsi_session *session = conn->session;
594         struct iscsi_host *ihost = shost_priv(session->host);
595         struct iscsi_task *task;
596         itt_t itt;
597
598         if (session->state == ISCSI_STATE_TERMINATE)
599                 return NULL;
600
601         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
602             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
603                 /*
604                  * Login and Text are sent serially, in
605                  * request-followed-by-response sequence.
606                  * Same task can be used. Same ITT must be used.
607                  * Note that login_task is preallocated at conn_create().
608                  */
609                 task = conn->login_task;
610         else {
611                 if (session->state != ISCSI_STATE_LOGGED_IN)
612                         return NULL;
613
614                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
615                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
616
617                 if (!__kfifo_get(session->cmdpool.queue,
618                                  (void*)&task, sizeof(void*)))
619                         return NULL;
620         }
621         /*
622          * released in complete pdu for task we expect a response for, and
623          * released by the lld when it has transmitted the task for
624          * pdus we do not expect a response for.
625          */
626         atomic_set(&task->refcount, 1);
627         task->conn = conn;
628         task->sc = NULL;
629         INIT_LIST_HEAD(&task->running);
630         task->state = ISCSI_TASK_PENDING;
631
632         if (data_size) {
633                 memcpy(task->data, data, data_size);
634                 task->data_count = data_size;
635         } else
636                 task->data_count = 0;
637
638         if (conn->session->tt->alloc_pdu) {
639                 if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
640                         iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
641                                          "pdu for mgmt task.\n");
642                         goto free_task;
643                 }
644         }
645
646         itt = task->hdr->itt;
647         task->hdr_len = sizeof(struct iscsi_hdr);
648         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
649
650         if (hdr->itt != RESERVED_ITT) {
651                 if (session->tt->parse_pdu_itt)
652                         task->hdr->itt = itt;
653                 else
654                         task->hdr->itt = build_itt(task->itt,
655                                                    task->conn->session->age);
656         }
657
658         if (!ihost->workq) {
659                 if (iscsi_prep_mgmt_task(conn, task))
660                         goto free_task;
661
662                 if (session->tt->xmit_task(task))
663                         goto free_task;
664         } else {
665                 list_add_tail(&task->running, &conn->mgmtqueue);
666                 iscsi_conn_queue_work(conn);
667         }
668
669         return task;
670
671 free_task:
672         __iscsi_put_task(task);
673         return NULL;
674 }
675
676 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
677                         char *data, uint32_t data_size)
678 {
679         struct iscsi_conn *conn = cls_conn->dd_data;
680         struct iscsi_session *session = conn->session;
681         int err = 0;
682
683         spin_lock_bh(&session->lock);
684         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
685                 err = -EPERM;
686         spin_unlock_bh(&session->lock);
687         return err;
688 }
689 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
690
691 /**
692  * iscsi_cmd_rsp - SCSI Command Response processing
693  * @conn: iscsi connection
694  * @hdr: iscsi header
695  * @task: scsi command task
696  * @data: cmd data buffer
697  * @datalen: len of buffer
698  *
699  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
700  * then completes the command and task.
701  **/
702 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
703                                struct iscsi_task *task, char *data,
704                                int datalen)
705 {
706         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
707         struct iscsi_session *session = conn->session;
708         struct scsi_cmnd *sc = task->sc;
709
710         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
711         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
712
713         sc->result = (DID_OK << 16) | rhdr->cmd_status;
714
715         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
716                 sc->result = DID_ERROR << 16;
717                 goto out;
718         }
719
720         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
721                 uint16_t senselen;
722
723                 if (datalen < 2) {
724 invalid_datalen:
725                         iscsi_conn_printk(KERN_ERR,  conn,
726                                          "Got CHECK_CONDITION but invalid data "
727                                          "buffer size of %d\n", datalen);
728                         sc->result = DID_BAD_TARGET << 16;
729                         goto out;
730                 }
731
732                 senselen = get_unaligned_be16(data);
733                 if (datalen < senselen)
734                         goto invalid_datalen;
735
736                 memcpy(sc->sense_buffer, data + 2,
737                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
738                 ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
739                                   min_t(uint16_t, senselen,
740                                   SCSI_SENSE_BUFFERSIZE));
741         }
742
743         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
744                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
745                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
746
747                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
748                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
749                                  res_count <= scsi_in(sc)->length))
750                         scsi_in(sc)->resid = res_count;
751                 else
752                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
753         }
754
755         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
756                            ISCSI_FLAG_CMD_OVERFLOW)) {
757                 int res_count = be32_to_cpu(rhdr->residual_count);
758
759                 if (res_count > 0 &&
760                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
761                      res_count <= scsi_bufflen(sc)))
762                         /* write side for bidi or uni-io set_resid */
763                         scsi_set_resid(sc, res_count);
764                 else
765                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
766         }
767 out:
768         ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
769                           sc, sc->result, task->itt);
770         conn->scsirsp_pdus_cnt++;
771         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
772 }
773
774 /**
775  * iscsi_data_in_rsp - SCSI Data-In Response processing
776  * @conn: iscsi connection
777  * @hdr:  iscsi pdu
778  * @task: scsi command task
779  **/
780 static void
781 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
782                   struct iscsi_task *task)
783 {
784         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
785         struct scsi_cmnd *sc = task->sc;
786
787         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
788                 return;
789
790         iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
791         sc->result = (DID_OK << 16) | rhdr->cmd_status;
792         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
793         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
794                            ISCSI_FLAG_DATA_OVERFLOW)) {
795                 int res_count = be32_to_cpu(rhdr->residual_count);
796
797                 if (res_count > 0 &&
798                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
799                      res_count <= scsi_in(sc)->length))
800                         scsi_in(sc)->resid = res_count;
801                 else
802                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
803         }
804
805         ISCSI_DBG_SESSION(conn->session, "data in with status done "
806                           "[sc %p res %d itt 0x%x]\n",
807                           sc, sc->result, task->itt);
808         conn->scsirsp_pdus_cnt++;
809         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
810 }
811
812 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
813 {
814         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
815
816         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
817         conn->tmfrsp_pdus_cnt++;
818
819         if (conn->tmf_state != TMF_QUEUED)
820                 return;
821
822         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
823                 conn->tmf_state = TMF_SUCCESS;
824         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
825                 conn->tmf_state = TMF_NOT_FOUND;
826         else
827                 conn->tmf_state = TMF_FAILED;
828         wake_up(&conn->ehwait);
829 }
830
831 static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
832 {
833         struct iscsi_nopout hdr;
834         struct iscsi_task *task;
835
836         if (!rhdr && conn->ping_task)
837                 return;
838
839         memset(&hdr, 0, sizeof(struct iscsi_nopout));
840         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
841         hdr.flags = ISCSI_FLAG_CMD_FINAL;
842
843         if (rhdr) {
844                 memcpy(hdr.lun, rhdr->lun, 8);
845                 hdr.ttt = rhdr->ttt;
846                 hdr.itt = RESERVED_ITT;
847         } else
848                 hdr.ttt = RESERVED_ITT;
849
850         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
851         if (!task)
852                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
853         else if (!rhdr) {
854                 /* only track our nops */
855                 conn->ping_task = task;
856                 conn->last_ping = jiffies;
857         }
858 }
859
860 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
861                                char *data, int datalen)
862 {
863         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
864         struct iscsi_hdr rejected_pdu;
865
866         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
867
868         if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
869                 if (ntoh24(reject->dlength) > datalen)
870                         return ISCSI_ERR_PROTO;
871
872                 if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
873                         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
874                         iscsi_conn_printk(KERN_ERR, conn,
875                                           "pdu (op 0x%x) rejected "
876                                           "due to DataDigest error.\n",
877                                           rejected_pdu.opcode);
878                 }
879         }
880         return 0;
881 }
882
883 /**
884  * iscsi_itt_to_task - look up task by itt
885  * @conn: iscsi connection
886  * @itt: itt
887  *
888  * This should be used for mgmt tasks like login and nops, or if
889  * the LDD's itt space does not include the session age.
890  *
891  * The session lock must be held.
892  */
893 struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
894 {
895         struct iscsi_session *session = conn->session;
896         int i;
897
898         if (itt == RESERVED_ITT)
899                 return NULL;
900
901         if (session->tt->parse_pdu_itt)
902                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
903         else
904                 i = get_itt(itt);
905         if (i >= session->cmds_max)
906                 return NULL;
907
908         return session->cmds[i];
909 }
910 EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
911
912 /**
913  * __iscsi_complete_pdu - complete pdu
914  * @conn: iscsi conn
915  * @hdr: iscsi header
916  * @data: data buffer
917  * @datalen: len of data buffer
918  *
919  * Completes pdu processing by freeing any resources allocated at
920  * queuecommand or send generic. session lock must be held and verify
921  * itt must have been called.
922  */
923 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
924                          char *data, int datalen)
925 {
926         struct iscsi_session *session = conn->session;
927         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
928         struct iscsi_task *task;
929         uint32_t itt;
930
931         conn->last_recv = jiffies;
932         rc = iscsi_verify_itt(conn, hdr->itt);
933         if (rc)
934                 return rc;
935
936         if (hdr->itt != RESERVED_ITT)
937                 itt = get_itt(hdr->itt);
938         else
939                 itt = ~0U;
940
941         ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
942                           opcode, conn->id, itt, datalen);
943
944         if (itt == ~0U) {
945                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
946
947                 switch(opcode) {
948                 case ISCSI_OP_NOOP_IN:
949                         if (datalen) {
950                                 rc = ISCSI_ERR_PROTO;
951                                 break;
952                         }
953
954                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
955                                 break;
956
957                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
958                         break;
959                 case ISCSI_OP_REJECT:
960                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
961                         break;
962                 case ISCSI_OP_ASYNC_EVENT:
963                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
964                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
965                                 rc = ISCSI_ERR_CONN_FAILED;
966                         break;
967                 default:
968                         rc = ISCSI_ERR_BAD_OPCODE;
969                         break;
970                 }
971                 goto out;
972         }
973
974         switch(opcode) {
975         case ISCSI_OP_SCSI_CMD_RSP:
976         case ISCSI_OP_SCSI_DATA_IN:
977                 task = iscsi_itt_to_ctask(conn, hdr->itt);
978                 if (!task)
979                         return ISCSI_ERR_BAD_ITT;
980                 task->last_xfer = jiffies;
981                 break;
982         case ISCSI_OP_R2T:
983                 /*
984                  * LLD handles R2Ts if they need to.
985                  */
986                 return 0;
987         case ISCSI_OP_LOGOUT_RSP:
988         case ISCSI_OP_LOGIN_RSP:
989         case ISCSI_OP_TEXT_RSP:
990         case ISCSI_OP_SCSI_TMFUNC_RSP:
991         case ISCSI_OP_NOOP_IN:
992                 task = iscsi_itt_to_task(conn, hdr->itt);
993                 if (!task)
994                         return ISCSI_ERR_BAD_ITT;
995                 break;
996         default:
997                 return ISCSI_ERR_BAD_OPCODE;
998         }
999
1000         switch(opcode) {
1001         case ISCSI_OP_SCSI_CMD_RSP:
1002                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1003                 break;
1004         case ISCSI_OP_SCSI_DATA_IN:
1005                 iscsi_data_in_rsp(conn, hdr, task);
1006                 break;
1007         case ISCSI_OP_LOGOUT_RSP:
1008                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1009                 if (datalen) {
1010                         rc = ISCSI_ERR_PROTO;
1011                         break;
1012                 }
1013                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1014                 goto recv_pdu;
1015         case ISCSI_OP_LOGIN_RSP:
1016         case ISCSI_OP_TEXT_RSP:
1017                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1018                 /*
1019                  * login related PDU's exp_statsn is handled in
1020                  * userspace
1021                  */
1022                 goto recv_pdu;
1023         case ISCSI_OP_SCSI_TMFUNC_RSP:
1024                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1025                 if (datalen) {
1026                         rc = ISCSI_ERR_PROTO;
1027                         break;
1028                 }
1029
1030                 iscsi_tmf_rsp(conn, hdr);
1031                 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1032                 break;
1033         case ISCSI_OP_NOOP_IN:
1034                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1035                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1036                         rc = ISCSI_ERR_PROTO;
1037                         break;
1038                 }
1039                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1040
1041                 if (conn->ping_task != task)
1042                         /*
1043                          * If this is not in response to one of our
1044                          * nops then it must be from userspace.
1045                          */
1046                         goto recv_pdu;
1047
1048                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1049                 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1050                 break;
1051         default:
1052                 rc = ISCSI_ERR_BAD_OPCODE;
1053                 break;
1054         }
1055
1056 out:
1057         return rc;
1058 recv_pdu:
1059         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1060                 rc = ISCSI_ERR_CONN_FAILED;
1061         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1062         return rc;
1063 }
1064 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1065
1066 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1067                        char *data, int datalen)
1068 {
1069         int rc;
1070
1071         spin_lock(&conn->session->lock);
1072         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1073         spin_unlock(&conn->session->lock);
1074         return rc;
1075 }
1076 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1077
1078 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1079 {
1080         struct iscsi_session *session = conn->session;
1081         int age = 0, i = 0;
1082
1083         if (itt == RESERVED_ITT)
1084                 return 0;
1085
1086         if (session->tt->parse_pdu_itt)
1087                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
1088         else {
1089                 i = get_itt(itt);
1090                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1091         }
1092
1093         if (age != session->age) {
1094                 iscsi_conn_printk(KERN_ERR, conn,
1095                                   "received itt %x expected session age (%x)\n",
1096                                   (__force u32)itt, session->age);
1097                 return ISCSI_ERR_BAD_ITT;
1098         }
1099
1100         if (i >= session->cmds_max) {
1101                 iscsi_conn_printk(KERN_ERR, conn,
1102                                   "received invalid itt index %u (max cmds "
1103                                    "%u.\n", i, session->cmds_max);
1104                 return ISCSI_ERR_BAD_ITT;
1105         }
1106         return 0;
1107 }
1108 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1109
1110 /**
1111  * iscsi_itt_to_ctask - look up ctask by itt
1112  * @conn: iscsi connection
1113  * @itt: itt
1114  *
1115  * This should be used for cmd tasks.
1116  *
1117  * The session lock must be held.
1118  */
1119 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1120 {
1121         struct iscsi_task *task;
1122
1123         if (iscsi_verify_itt(conn, itt))
1124                 return NULL;
1125
1126         task = iscsi_itt_to_task(conn, itt);
1127         if (!task || !task->sc)
1128                 return NULL;
1129
1130         if (task->sc->SCp.phase != conn->session->age) {
1131                 iscsi_session_printk(KERN_ERR, conn->session,
1132                                   "task's session age %d, expected %d\n",
1133                                   task->sc->SCp.phase, conn->session->age);
1134                 return NULL;
1135         }
1136
1137         return task;
1138 }
1139 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1140
1141 void iscsi_session_failure(struct iscsi_session *session,
1142                            enum iscsi_err err)
1143 {
1144         struct iscsi_conn *conn;
1145         struct device *dev;
1146         unsigned long flags;
1147
1148         spin_lock_irqsave(&session->lock, flags);
1149         conn = session->leadconn;
1150         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1151                 spin_unlock_irqrestore(&session->lock, flags);
1152                 return;
1153         }
1154
1155         dev = get_device(&conn->cls_conn->dev);
1156         spin_unlock_irqrestore(&session->lock, flags);
1157         if (!dev)
1158                 return;
1159         /*
1160          * if the host is being removed bypass the connection
1161          * recovery initialization because we are going to kill
1162          * the session.
1163          */
1164         if (err == ISCSI_ERR_INVALID_HOST)
1165                 iscsi_conn_error_event(conn->cls_conn, err);
1166         else
1167                 iscsi_conn_failure(conn, err);
1168         put_device(dev);
1169 }
1170 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1171
1172 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1173 {
1174         struct iscsi_session *session = conn->session;
1175         unsigned long flags;
1176
1177         spin_lock_irqsave(&session->lock, flags);
1178         if (session->state == ISCSI_STATE_FAILED) {
1179                 spin_unlock_irqrestore(&session->lock, flags);
1180                 return;
1181         }
1182
1183         if (conn->stop_stage == 0)
1184                 session->state = ISCSI_STATE_FAILED;
1185         spin_unlock_irqrestore(&session->lock, flags);
1186
1187         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1188         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1189         iscsi_conn_error_event(conn->cls_conn, err);
1190 }
1191 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1192
1193 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1194 {
1195         struct iscsi_session *session = conn->session;
1196
1197         /*
1198          * Check for iSCSI window and take care of CmdSN wrap-around
1199          */
1200         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1201                 ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1202                                   "%u MaxCmdSN %u CmdSN %u/%u\n",
1203                                   session->exp_cmdsn, session->max_cmdsn,
1204                                   session->cmdsn, session->queued_cmdsn);
1205                 return -ENOSPC;
1206         }
1207         return 0;
1208 }
1209
1210 static int iscsi_xmit_task(struct iscsi_conn *conn)
1211 {
1212         struct iscsi_task *task = conn->task;
1213         int rc;
1214
1215         __iscsi_get_task(task);
1216         spin_unlock_bh(&conn->session->lock);
1217         rc = conn->session->tt->xmit_task(task);
1218         spin_lock_bh(&conn->session->lock);
1219         if (!rc) {
1220                 /* done with this task */
1221                 task->last_xfer = jiffies;
1222                 conn->task = NULL;
1223         }
1224         __iscsi_put_task(task);
1225         return rc;
1226 }
1227
1228 /**
1229  * iscsi_requeue_task - requeue task to run from session workqueue
1230  * @task: task to requeue
1231  *
1232  * LLDs that need to run a task from the session workqueue should call
1233  * this. The session lock must be held. This should only be called
1234  * by software drivers.
1235  */
1236 void iscsi_requeue_task(struct iscsi_task *task)
1237 {
1238         struct iscsi_conn *conn = task->conn;
1239
1240         /*
1241          * this may be on the requeue list already if the xmit_task callout
1242          * is handling the r2ts while we are adding new ones
1243          */
1244         if (list_empty(&task->running))
1245                 list_add_tail(&task->running, &conn->requeue);
1246         iscsi_conn_queue_work(conn);
1247 }
1248 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1249
1250 /**
1251  * iscsi_data_xmit - xmit any command into the scheduled connection
1252  * @conn: iscsi connection
1253  *
1254  * Notes:
1255  *      The function can return -EAGAIN in which case the caller must
1256  *      re-schedule it again later or recover. '0' return code means
1257  *      successful xmit.
1258  **/
1259 static int iscsi_data_xmit(struct iscsi_conn *conn)
1260 {
1261         int rc = 0;
1262
1263         spin_lock_bh(&conn->session->lock);
1264         if (unlikely(conn->suspend_tx)) {
1265                 ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1266                 spin_unlock_bh(&conn->session->lock);
1267                 return -ENODATA;
1268         }
1269
1270         if (conn->task) {
1271                 rc = iscsi_xmit_task(conn);
1272                 if (rc)
1273                         goto again;
1274         }
1275
1276         /*
1277          * process mgmt pdus like nops before commands since we should
1278          * only have one nop-out as a ping from us and targets should not
1279          * overflow us with nop-ins
1280          */
1281 check_mgmt:
1282         while (!list_empty(&conn->mgmtqueue)) {
1283                 conn->task = list_entry(conn->mgmtqueue.next,
1284                                          struct iscsi_task, running);
1285                 list_del_init(&conn->task->running);
1286                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1287                         __iscsi_put_task(conn->task);
1288                         conn->task = NULL;
1289                         continue;
1290                 }
1291                 rc = iscsi_xmit_task(conn);
1292                 if (rc)
1293                         goto again;
1294         }
1295
1296         /* process pending command queue */
1297         while (!list_empty(&conn->cmdqueue)) {
1298                 if (conn->tmf_state == TMF_QUEUED)
1299                         break;
1300
1301                 conn->task = list_entry(conn->cmdqueue.next,
1302                                          struct iscsi_task, running);
1303                 list_del_init(&conn->task->running);
1304                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1305                         fail_scsi_task(conn->task, DID_IMM_RETRY);
1306                         continue;
1307                 }
1308                 rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1309                 if (rc) {
1310                         if (rc == -ENOMEM) {
1311                                 list_add_tail(&conn->task->running,
1312                                               &conn->cmdqueue);
1313                                 conn->task = NULL;
1314                                 goto again;
1315                         } else
1316                                 fail_scsi_task(conn->task, DID_ABORT);
1317                         continue;
1318                 }
1319                 rc = iscsi_xmit_task(conn);
1320                 if (rc)
1321                         goto again;
1322                 /*
1323                  * we could continuously get new task requests so
1324                  * we need to check the mgmt queue for nops that need to
1325                  * be sent to aviod starvation
1326                  */
1327                 if (!list_empty(&conn->mgmtqueue))
1328                         goto check_mgmt;
1329         }
1330
1331         while (!list_empty(&conn->requeue)) {
1332                 if (conn->session->fast_abort && conn->tmf_state != TMF_INITIAL)
1333                         break;
1334
1335                 /*
1336                  * we always do fastlogout - conn stop code will clean up.
1337                  */
1338                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1339                         break;
1340
1341                 conn->task = list_entry(conn->requeue.next,
1342                                          struct iscsi_task, running);
1343                 list_del_init(&conn->task->running);
1344                 conn->task->state = ISCSI_TASK_RUNNING;
1345                 rc = iscsi_xmit_task(conn);
1346                 if (rc)
1347                         goto again;
1348                 if (!list_empty(&conn->mgmtqueue))
1349                         goto check_mgmt;
1350         }
1351         spin_unlock_bh(&conn->session->lock);
1352         return -ENODATA;
1353
1354 again:
1355         if (unlikely(conn->suspend_tx))
1356                 rc = -ENODATA;
1357         spin_unlock_bh(&conn->session->lock);
1358         return rc;
1359 }
1360
1361 static void iscsi_xmitworker(struct work_struct *work)
1362 {
1363         struct iscsi_conn *conn =
1364                 container_of(work, struct iscsi_conn, xmitwork);
1365         int rc;
1366         /*
1367          * serialize Xmit worker on a per-connection basis.
1368          */
1369         do {
1370                 rc = iscsi_data_xmit(conn);
1371         } while (rc >= 0 || rc == -EAGAIN);
1372 }
1373
1374 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1375                                                   struct scsi_cmnd *sc)
1376 {
1377         struct iscsi_task *task;
1378
1379         if (!__kfifo_get(conn->session->cmdpool.queue,
1380                          (void *) &task, sizeof(void *)))
1381                 return NULL;
1382
1383         sc->SCp.phase = conn->session->age;
1384         sc->SCp.ptr = (char *) task;
1385
1386         atomic_set(&task->refcount, 1);
1387         task->state = ISCSI_TASK_PENDING;
1388         task->conn = conn;
1389         task->sc = sc;
1390         task->have_checked_conn = false;
1391         task->last_timeout = jiffies;
1392         task->last_xfer = jiffies;
1393         INIT_LIST_HEAD(&task->running);
1394         return task;
1395 }
1396
1397 enum {
1398         FAILURE_BAD_HOST = 1,
1399         FAILURE_SESSION_FAILED,
1400         FAILURE_SESSION_FREED,
1401         FAILURE_WINDOW_CLOSED,
1402         FAILURE_OOM,
1403         FAILURE_SESSION_TERMINATE,
1404         FAILURE_SESSION_IN_RECOVERY,
1405         FAILURE_SESSION_RECOVERY_TIMEOUT,
1406         FAILURE_SESSION_LOGGING_OUT,
1407         FAILURE_SESSION_NOT_READY,
1408 };
1409
1410 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
1411 {
1412         struct iscsi_cls_session *cls_session;
1413         struct Scsi_Host *host;
1414         struct iscsi_host *ihost;
1415         int reason = 0;
1416         struct iscsi_session *session;
1417         struct iscsi_conn *conn;
1418         struct iscsi_task *task = NULL;
1419
1420         sc->scsi_done = done;
1421         sc->result = 0;
1422         sc->SCp.ptr = NULL;
1423
1424         host = sc->device->host;
1425         ihost = shost_priv(host);
1426         spin_unlock(host->host_lock);
1427
1428         cls_session = starget_to_session(scsi_target(sc->device));
1429         session = cls_session->dd_data;
1430         spin_lock(&session->lock);
1431
1432         reason = iscsi_session_chkready(cls_session);
1433         if (reason) {
1434                 sc->result = reason;
1435                 goto fault;
1436         }
1437
1438         if (session->state != ISCSI_STATE_LOGGED_IN) {
1439                 /*
1440                  * to handle the race between when we set the recovery state
1441                  * and block the session we requeue here (commands could
1442                  * be entering our queuecommand while a block is starting
1443                  * up because the block code is not locked)
1444                  */
1445                 switch (session->state) {
1446                 case ISCSI_STATE_FAILED:
1447                 case ISCSI_STATE_IN_RECOVERY:
1448                         reason = FAILURE_SESSION_IN_RECOVERY;
1449                         sc->result = DID_IMM_RETRY << 16;
1450                         break;
1451                 case ISCSI_STATE_LOGGING_OUT:
1452                         reason = FAILURE_SESSION_LOGGING_OUT;
1453                         sc->result = DID_IMM_RETRY << 16;
1454                         break;
1455                 case ISCSI_STATE_RECOVERY_FAILED:
1456                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1457                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1458                         break;
1459                 case ISCSI_STATE_TERMINATE:
1460                         reason = FAILURE_SESSION_TERMINATE;
1461                         sc->result = DID_NO_CONNECT << 16;
1462                         break;
1463                 default:
1464                         reason = FAILURE_SESSION_FREED;
1465                         sc->result = DID_NO_CONNECT << 16;
1466                 }
1467                 goto fault;
1468         }
1469
1470         conn = session->leadconn;
1471         if (!conn) {
1472                 reason = FAILURE_SESSION_FREED;
1473                 sc->result = DID_NO_CONNECT << 16;
1474                 goto fault;
1475         }
1476
1477         if (iscsi_check_cmdsn_window_closed(conn)) {
1478                 reason = FAILURE_WINDOW_CLOSED;
1479                 goto reject;
1480         }
1481
1482         task = iscsi_alloc_task(conn, sc);
1483         if (!task) {
1484                 reason = FAILURE_OOM;
1485                 goto reject;
1486         }
1487
1488         if (!ihost->workq) {
1489                 reason = iscsi_prep_scsi_cmd_pdu(task);
1490                 if (reason) {
1491                         if (reason == -ENOMEM) {
1492                                 reason = FAILURE_OOM;
1493                                 goto prepd_reject;
1494                         } else {
1495                                 sc->result = DID_ABORT << 16;
1496                                 goto prepd_fault;
1497                         }
1498                 }
1499                 if (session->tt->xmit_task(task)) {
1500                         reason = FAILURE_SESSION_NOT_READY;
1501                         goto prepd_reject;
1502                 }
1503         } else {
1504                 list_add_tail(&task->running, &conn->cmdqueue);
1505                 iscsi_conn_queue_work(conn);
1506         }
1507
1508         session->queued_cmdsn++;
1509         spin_unlock(&session->lock);
1510         spin_lock(host->host_lock);
1511         return 0;
1512
1513 prepd_reject:
1514         sc->scsi_done = NULL;
1515         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1516 reject:
1517         spin_unlock(&session->lock);
1518         ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1519                           sc->cmnd[0], reason);
1520         spin_lock(host->host_lock);
1521         return SCSI_MLQUEUE_TARGET_BUSY;
1522
1523 prepd_fault:
1524         sc->scsi_done = NULL;
1525         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1526 fault:
1527         spin_unlock(&session->lock);
1528         ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1529                           sc->cmnd[0], reason);
1530         if (!scsi_bidi_cmnd(sc))
1531                 scsi_set_resid(sc, scsi_bufflen(sc));
1532         else {
1533                 scsi_out(sc)->resid = scsi_out(sc)->length;
1534                 scsi_in(sc)->resid = scsi_in(sc)->length;
1535         }
1536         done(sc);
1537         spin_lock(host->host_lock);
1538         return 0;
1539 }
1540 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1541
1542 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
1543 {
1544         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1545         return sdev->queue_depth;
1546 }
1547 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1548
1549 int iscsi_target_alloc(struct scsi_target *starget)
1550 {
1551         struct iscsi_cls_session *cls_session = starget_to_session(starget);
1552         struct iscsi_session *session = cls_session->dd_data;
1553
1554         starget->can_queue = session->scsi_cmds_max;
1555         return 0;
1556 }
1557 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1558
1559 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
1560 {
1561         struct iscsi_session *session = cls_session->dd_data;
1562
1563         spin_lock_bh(&session->lock);
1564         if (session->state != ISCSI_STATE_LOGGED_IN) {
1565                 session->state = ISCSI_STATE_RECOVERY_FAILED;
1566                 if (session->leadconn)
1567                         wake_up(&session->leadconn->ehwait);
1568         }
1569         spin_unlock_bh(&session->lock);
1570 }
1571 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
1572
1573 int iscsi_eh_target_reset(struct scsi_cmnd *sc)
1574 {
1575         struct iscsi_cls_session *cls_session;
1576         struct iscsi_session *session;
1577         struct iscsi_conn *conn;
1578
1579         cls_session = starget_to_session(scsi_target(sc->device));
1580         session = cls_session->dd_data;
1581         conn = session->leadconn;
1582
1583         mutex_lock(&session->eh_mutex);
1584         spin_lock_bh(&session->lock);
1585         if (session->state == ISCSI_STATE_TERMINATE) {
1586 failed:
1587                 ISCSI_DBG_EH(session,
1588                              "failing target reset: Could not log back into "
1589                              "target [age %d]\n",
1590                              session->age);
1591                 spin_unlock_bh(&session->lock);
1592                 mutex_unlock(&session->eh_mutex);
1593                 return FAILED;
1594         }
1595
1596         spin_unlock_bh(&session->lock);
1597         mutex_unlock(&session->eh_mutex);
1598         /*
1599          * we drop the lock here but the leadconn cannot be destoyed while
1600          * we are in the scsi eh
1601          */
1602         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1603
1604         ISCSI_DBG_EH(session, "wait for relogin\n");
1605         wait_event_interruptible(conn->ehwait,
1606                                  session->state == ISCSI_STATE_TERMINATE ||
1607                                  session->state == ISCSI_STATE_LOGGED_IN ||
1608                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
1609         if (signal_pending(current))
1610                 flush_signals(current);
1611
1612         mutex_lock(&session->eh_mutex);
1613         spin_lock_bh(&session->lock);
1614         if (session->state == ISCSI_STATE_LOGGED_IN) {
1615                 ISCSI_DBG_EH(session,
1616                              "target reset succeeded\n");
1617         } else
1618                 goto failed;
1619         spin_unlock_bh(&session->lock);
1620         mutex_unlock(&session->eh_mutex);
1621         return SUCCESS;
1622 }
1623 EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
1624
1625 static void iscsi_tmf_timedout(unsigned long data)
1626 {
1627         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1628         struct iscsi_session *session = conn->session;
1629
1630         spin_lock(&session->lock);
1631         if (conn->tmf_state == TMF_QUEUED) {
1632                 conn->tmf_state = TMF_TIMEDOUT;
1633                 ISCSI_DBG_EH(session, "tmf timedout\n");
1634                 /* unblock eh_abort() */
1635                 wake_up(&conn->ehwait);
1636         }
1637         spin_unlock(&session->lock);
1638 }
1639
1640 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1641                                    struct iscsi_tm *hdr, int age,
1642                                    int timeout)
1643 {
1644         struct iscsi_session *session = conn->session;
1645         struct iscsi_task *task;
1646
1647         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1648                                       NULL, 0);
1649         if (!task) {
1650                 spin_unlock_bh(&session->lock);
1651                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1652                 spin_lock_bh(&session->lock);
1653                 ISCSI_DBG_EH(session, "tmf exec failure\n");
1654                 return -EPERM;
1655         }
1656         conn->tmfcmd_pdus_cnt++;
1657         conn->tmf_timer.expires = timeout * HZ + jiffies;
1658         conn->tmf_timer.function = iscsi_tmf_timedout;
1659         conn->tmf_timer.data = (unsigned long)conn;
1660         add_timer(&conn->tmf_timer);
1661         ISCSI_DBG_EH(session, "tmf set timeout\n");
1662
1663         spin_unlock_bh(&session->lock);
1664         mutex_unlock(&session->eh_mutex);
1665
1666         /*
1667          * block eh thread until:
1668          *
1669          * 1) tmf response
1670          * 2) tmf timeout
1671          * 3) session is terminated or restarted or userspace has
1672          * given up on recovery
1673          */
1674         wait_event_interruptible(conn->ehwait, age != session->age ||
1675                                  session->state != ISCSI_STATE_LOGGED_IN ||
1676                                  conn->tmf_state != TMF_QUEUED);
1677         if (signal_pending(current))
1678                 flush_signals(current);
1679         del_timer_sync(&conn->tmf_timer);
1680
1681         mutex_lock(&session->eh_mutex);
1682         spin_lock_bh(&session->lock);
1683         /* if the session drops it will clean up the task */
1684         if (age != session->age ||
1685             session->state != ISCSI_STATE_LOGGED_IN)
1686                 return -ENOTCONN;
1687         return 0;
1688 }
1689
1690 /*
1691  * Fail commands. session lock held and recv side suspended and xmit
1692  * thread flushed
1693  */
1694 static void fail_scsi_tasks(struct iscsi_conn *conn, unsigned lun,
1695                             int error)
1696 {
1697         struct iscsi_task *task;
1698         int i;
1699
1700         for (i = 0; i < conn->session->cmds_max; i++) {
1701                 task = conn->session->cmds[i];
1702                 if (!task->sc || task->state == ISCSI_TASK_FREE)
1703                         continue;
1704
1705                 if (lun != -1 && lun != task->sc->device->lun)
1706                         continue;
1707
1708                 ISCSI_DBG_SESSION(conn->session,
1709                                   "failing sc %p itt 0x%x state %d\n",
1710                                   task->sc, task->itt, task->state);
1711                 fail_scsi_task(task, error);
1712         }
1713 }
1714
1715 void iscsi_suspend_tx(struct iscsi_conn *conn)
1716 {
1717         struct Scsi_Host *shost = conn->session->host;
1718         struct iscsi_host *ihost = shost_priv(shost);
1719
1720         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1721         if (ihost->workq)
1722                 flush_workqueue(ihost->workq);
1723 }
1724 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1725
1726 static void iscsi_start_tx(struct iscsi_conn *conn)
1727 {
1728         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1729         iscsi_conn_queue_work(conn);
1730 }
1731
1732 /*
1733  * We want to make sure a ping is in flight. It has timed out.
1734  * And we are not busy processing a pdu that is making
1735  * progress but got started before the ping and is taking a while
1736  * to complete so the ping is just stuck behind it in a queue.
1737  */
1738 static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1739 {
1740         if (conn->ping_task &&
1741             time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1742                            (conn->ping_timeout * HZ), jiffies))
1743                 return 1;
1744         else
1745                 return 0;
1746 }
1747
1748 static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1749 {
1750         enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1751         struct iscsi_task *task = NULL;
1752         struct iscsi_cls_session *cls_session;
1753         struct iscsi_session *session;
1754         struct iscsi_conn *conn;
1755
1756         cls_session = starget_to_session(scsi_target(sc->device));
1757         session = cls_session->dd_data;
1758
1759         ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1760
1761         spin_lock(&session->lock);
1762         if (session->state != ISCSI_STATE_LOGGED_IN) {
1763                 /*
1764                  * We are probably in the middle of iscsi recovery so let
1765                  * that complete and handle the error.
1766                  */
1767                 rc = BLK_EH_RESET_TIMER;
1768                 goto done;
1769         }
1770
1771         conn = session->leadconn;
1772         if (!conn) {
1773                 /* In the middle of shuting down */
1774                 rc = BLK_EH_RESET_TIMER;
1775                 goto done;
1776         }
1777
1778         task = (struct iscsi_task *)sc->SCp.ptr;
1779         if (!task)
1780                 goto done;
1781         /*
1782          * If we have sent (at least queued to the network layer) a pdu or
1783          * recvd one for the task since the last timeout ask for
1784          * more time. If on the next timeout we have not made progress
1785          * we can check if it is the task or connection when we send the
1786          * nop as a ping.
1787          */
1788         if (time_after_eq(task->last_xfer, task->last_timeout)) {
1789                 ISCSI_DBG_EH(session, "Command making progress. Asking "
1790                              "scsi-ml for more time to complete. "
1791                              "Last data recv at %lu. Last timeout was at "
1792                              "%lu\n.", task->last_xfer, task->last_timeout);
1793                 task->have_checked_conn = false;
1794                 rc = BLK_EH_RESET_TIMER;
1795                 goto done;
1796         }
1797
1798         if (!conn->recv_timeout && !conn->ping_timeout)
1799                 goto done;
1800         /*
1801          * if the ping timedout then we are in the middle of cleaning up
1802          * and can let the iscsi eh handle it
1803          */
1804         if (iscsi_has_ping_timed_out(conn)) {
1805                 rc = BLK_EH_RESET_TIMER;
1806                 goto done;
1807         }
1808
1809         /* Assumes nop timeout is shorter than scsi cmd timeout */
1810         if (task->have_checked_conn)
1811                 goto done;
1812
1813         /*
1814          * Checking the transport already or nop from a cmd timeout still
1815          * running
1816          */
1817         if (conn->ping_task) {
1818                 task->have_checked_conn = true;
1819                 rc = BLK_EH_RESET_TIMER;
1820                 goto done;
1821         }
1822
1823         /* Make sure there is a transport check done */
1824         iscsi_send_nopout(conn, NULL);
1825         task->have_checked_conn = true;
1826         rc = BLK_EH_RESET_TIMER;
1827
1828 done:
1829         if (task)
1830                 task->last_timeout = jiffies;
1831         spin_unlock(&session->lock);
1832         ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
1833                      "timer reset" : "nh");
1834         return rc;
1835 }
1836
1837 static void iscsi_check_transport_timeouts(unsigned long data)
1838 {
1839         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1840         struct iscsi_session *session = conn->session;
1841         unsigned long recv_timeout, next_timeout = 0, last_recv;
1842
1843         spin_lock(&session->lock);
1844         if (session->state != ISCSI_STATE_LOGGED_IN)
1845                 goto done;
1846
1847         recv_timeout = conn->recv_timeout;
1848         if (!recv_timeout)
1849                 goto done;
1850
1851         recv_timeout *= HZ;
1852         last_recv = conn->last_recv;
1853
1854         if (iscsi_has_ping_timed_out(conn)) {
1855                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
1856                                   "expired, recv timeout %d, last rx %lu, "
1857                                   "last ping %lu, now %lu\n",
1858                                   conn->ping_timeout, conn->recv_timeout,
1859                                   last_recv, conn->last_ping, jiffies);
1860                 spin_unlock(&session->lock);
1861                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1862                 return;
1863         }
1864
1865         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
1866                 /* send a ping to try to provoke some traffic */
1867                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
1868                 iscsi_send_nopout(conn, NULL);
1869                 next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
1870         } else
1871                 next_timeout = last_recv + recv_timeout;
1872
1873         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
1874         mod_timer(&conn->transport_timer, next_timeout);
1875 done:
1876         spin_unlock(&session->lock);
1877 }
1878
1879 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
1880                                       struct iscsi_tm *hdr)
1881 {
1882         memset(hdr, 0, sizeof(*hdr));
1883         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1884         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
1885         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1886         memcpy(hdr->lun, task->lun, sizeof(hdr->lun));
1887         hdr->rtt = task->hdr_itt;
1888         hdr->refcmdsn = task->cmdsn;
1889 }
1890
1891 int iscsi_eh_abort(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_task *task;
1897         struct iscsi_tm *hdr;
1898         int rc, age;
1899
1900         cls_session = starget_to_session(scsi_target(sc->device));
1901         session = cls_session->dd_data;
1902
1903         ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
1904
1905         mutex_lock(&session->eh_mutex);
1906         spin_lock_bh(&session->lock);
1907         /*
1908          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1909          * got the command.
1910          */
1911         if (!sc->SCp.ptr) {
1912                 ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
1913                                       "it completed.\n");
1914                 spin_unlock_bh(&session->lock);
1915                 mutex_unlock(&session->eh_mutex);
1916                 return SUCCESS;
1917         }
1918
1919         /*
1920          * If we are not logged in or we have started a new session
1921          * then let the host reset code handle this
1922          */
1923         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
1924             sc->SCp.phase != session->age) {
1925                 spin_unlock_bh(&session->lock);
1926                 mutex_unlock(&session->eh_mutex);
1927                 ISCSI_DBG_EH(session, "failing abort due to dropped "
1928                                   "session.\n");
1929                 return FAILED;
1930         }
1931
1932         conn = session->leadconn;
1933         conn->eh_abort_cnt++;
1934         age = session->age;
1935
1936         task = (struct iscsi_task *)sc->SCp.ptr;
1937         ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
1938                      sc, task->itt);
1939
1940         /* task completed before time out */
1941         if (!task->sc) {
1942                 ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
1943                 goto success;
1944         }
1945
1946         if (task->state == ISCSI_TASK_PENDING) {
1947                 fail_scsi_task(task, DID_ABORT);
1948                 goto success;
1949         }
1950
1951         /* only have one tmf outstanding at a time */
1952         if (conn->tmf_state != TMF_INITIAL)
1953                 goto failed;
1954         conn->tmf_state = TMF_QUEUED;
1955
1956         hdr = &conn->tmhdr;
1957         iscsi_prep_abort_task_pdu(task, hdr);
1958
1959         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
1960                 rc = FAILED;
1961                 goto failed;
1962         }
1963
1964         switch (conn->tmf_state) {
1965         case TMF_SUCCESS:
1966                 spin_unlock_bh(&session->lock);
1967                 /*
1968                  * stop tx side incase the target had sent a abort rsp but
1969                  * the initiator was still writing out data.
1970                  */
1971                 iscsi_suspend_tx(conn);
1972                 /*
1973                  * we do not stop the recv side because targets have been
1974                  * good and have never sent us a successful tmf response
1975                  * then sent more data for the cmd.
1976                  */
1977                 spin_lock(&session->lock);
1978                 fail_scsi_task(task, DID_ABORT);
1979                 conn->tmf_state = TMF_INITIAL;
1980                 spin_unlock(&session->lock);
1981                 iscsi_start_tx(conn);
1982                 goto success_unlocked;
1983         case TMF_TIMEDOUT:
1984                 spin_unlock_bh(&session->lock);
1985                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1986                 goto failed_unlocked;
1987         case TMF_NOT_FOUND:
1988                 if (!sc->SCp.ptr) {
1989                         conn->tmf_state = TMF_INITIAL;
1990                         /* task completed before tmf abort response */
1991                         ISCSI_DBG_EH(session, "sc completed while abort in "
1992                                               "progress\n");
1993                         goto success;
1994                 }
1995                 /* fall through */
1996         default:
1997                 conn->tmf_state = TMF_INITIAL;
1998                 goto failed;
1999         }
2000
2001 success:
2002         spin_unlock_bh(&session->lock);
2003 success_unlocked:
2004         ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2005                      sc, task->itt);
2006         mutex_unlock(&session->eh_mutex);
2007         return SUCCESS;
2008
2009 failed:
2010         spin_unlock_bh(&session->lock);
2011 failed_unlocked:
2012         ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2013                      task ? task->itt : 0);
2014         mutex_unlock(&session->eh_mutex);
2015         return FAILED;
2016 }
2017 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2018
2019 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2020 {
2021         memset(hdr, 0, sizeof(*hdr));
2022         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2023         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2024         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2025         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
2026         hdr->rtt = RESERVED_ITT;
2027 }
2028
2029 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2030 {
2031         struct iscsi_cls_session *cls_session;
2032         struct iscsi_session *session;
2033         struct iscsi_conn *conn;
2034         struct iscsi_tm *hdr;
2035         int rc = FAILED;
2036
2037         cls_session = starget_to_session(scsi_target(sc->device));
2038         session = cls_session->dd_data;
2039
2040         ISCSI_DBG_EH(session, "LU Reset [sc %p lun %u]\n", sc, sc->device->lun);
2041
2042         mutex_lock(&session->eh_mutex);
2043         spin_lock_bh(&session->lock);
2044         /*
2045          * Just check if we are not logged in. We cannot check for
2046          * the phase because the reset could come from a ioctl.
2047          */
2048         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2049                 goto unlock;
2050         conn = session->leadconn;
2051
2052         /* only have one tmf outstanding at a time */
2053         if (conn->tmf_state != TMF_INITIAL)
2054                 goto unlock;
2055         conn->tmf_state = TMF_QUEUED;
2056
2057         hdr = &conn->tmhdr;
2058         iscsi_prep_lun_reset_pdu(sc, hdr);
2059
2060         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2061                                     session->lu_reset_timeout)) {
2062                 rc = FAILED;
2063                 goto unlock;
2064         }
2065
2066         switch (conn->tmf_state) {
2067         case TMF_SUCCESS:
2068                 break;
2069         case TMF_TIMEDOUT:
2070                 spin_unlock_bh(&session->lock);
2071                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
2072                 goto done;
2073         default:
2074                 conn->tmf_state = TMF_INITIAL;
2075                 goto unlock;
2076         }
2077
2078         rc = SUCCESS;
2079         spin_unlock_bh(&session->lock);
2080
2081         iscsi_suspend_tx(conn);
2082
2083         spin_lock_bh(&session->lock);
2084         fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2085         conn->tmf_state = TMF_INITIAL;
2086         spin_unlock_bh(&session->lock);
2087
2088         iscsi_start_tx(conn);
2089         goto done;
2090
2091 unlock:
2092         spin_unlock_bh(&session->lock);
2093 done:
2094         ISCSI_DBG_EH(session, "dev reset result = %s\n",
2095                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2096         mutex_unlock(&session->eh_mutex);
2097         return rc;
2098 }
2099 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2100
2101 /*
2102  * Pre-allocate a pool of @max items of @item_size. By default, the pool
2103  * should be accessed via kfifo_{get,put} on q->queue.
2104  * Optionally, the caller can obtain the array of object pointers
2105  * by passing in a non-NULL @items pointer
2106  */
2107 int
2108 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2109 {
2110         int i, num_arrays = 1;
2111
2112         memset(q, 0, sizeof(*q));
2113
2114         q->max = max;
2115
2116         /* If the user passed an items pointer, he wants a copy of
2117          * the array. */
2118         if (items)
2119                 num_arrays++;
2120         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
2121         if (q->pool == NULL)
2122                 return -ENOMEM;
2123
2124         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
2125                               GFP_KERNEL, NULL);
2126         if (IS_ERR(q->queue)) {
2127                 q->queue = NULL;
2128                 goto enomem;
2129         }
2130
2131         for (i = 0; i < max; i++) {
2132                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2133                 if (q->pool[i] == NULL) {
2134                         q->max = i;
2135                         goto enomem;
2136                 }
2137                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
2138         }
2139
2140         if (items) {
2141                 *items = q->pool + max;
2142                 memcpy(*items, q->pool, max * sizeof(void *));
2143         }
2144
2145         return 0;
2146
2147 enomem:
2148         iscsi_pool_free(q);
2149         return -ENOMEM;
2150 }
2151 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2152
2153 void iscsi_pool_free(struct iscsi_pool *q)
2154 {
2155         int i;
2156
2157         for (i = 0; i < q->max; i++)
2158                 kfree(q->pool[i]);
2159         kfree(q->pool);
2160         kfree(q->queue);
2161 }
2162 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2163
2164 /**
2165  * iscsi_host_add - add host to system
2166  * @shost: scsi host
2167  * @pdev: parent device
2168  *
2169  * This should be called by partial offload and software iscsi drivers
2170  * to add a host to the system.
2171  */
2172 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2173 {
2174         if (!shost->can_queue)
2175                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2176
2177         if (!shost->cmd_per_lun)
2178                 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2179
2180         if (!shost->transportt->eh_timed_out)
2181                 shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
2182         return scsi_add_host(shost, pdev);
2183 }
2184 EXPORT_SYMBOL_GPL(iscsi_host_add);
2185
2186 /**
2187  * iscsi_host_alloc - allocate a host and driver data
2188  * @sht: scsi host template
2189  * @dd_data_size: driver host data size
2190  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2191  *
2192  * This should be called by partial offload and software iscsi drivers.
2193  * To access the driver specific memory use the iscsi_host_priv() macro.
2194  */
2195 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2196                                    int dd_data_size, bool xmit_can_sleep)
2197 {
2198         struct Scsi_Host *shost;
2199         struct iscsi_host *ihost;
2200
2201         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2202         if (!shost)
2203                 return NULL;
2204         ihost = shost_priv(shost);
2205
2206         if (xmit_can_sleep) {
2207                 snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2208                         "iscsi_q_%d", shost->host_no);
2209                 ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2210                 if (!ihost->workq)
2211                         goto free_host;
2212         }
2213
2214         spin_lock_init(&ihost->lock);
2215         ihost->state = ISCSI_HOST_SETUP;
2216         ihost->num_sessions = 0;
2217         init_waitqueue_head(&ihost->session_removal_wq);
2218         return shost;
2219
2220 free_host:
2221         scsi_host_put(shost);
2222         return NULL;
2223 }
2224 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2225
2226 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2227 {
2228         iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2229 }
2230
2231 /**
2232  * iscsi_host_remove - remove host and sessions
2233  * @shost: scsi host
2234  *
2235  * If there are any sessions left, this will initiate the removal and wait
2236  * for the completion.
2237  */
2238 void iscsi_host_remove(struct Scsi_Host *shost)
2239 {
2240         struct iscsi_host *ihost = shost_priv(shost);
2241         unsigned long flags;
2242
2243         spin_lock_irqsave(&ihost->lock, flags);
2244         ihost->state = ISCSI_HOST_REMOVED;
2245         spin_unlock_irqrestore(&ihost->lock, flags);
2246
2247         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2248         wait_event_interruptible(ihost->session_removal_wq,
2249                                  ihost->num_sessions == 0);
2250         if (signal_pending(current))
2251                 flush_signals(current);
2252
2253         scsi_remove_host(shost);
2254         if (ihost->workq)
2255                 destroy_workqueue(ihost->workq);
2256 }
2257 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2258
2259 void iscsi_host_free(struct Scsi_Host *shost)
2260 {
2261         struct iscsi_host *ihost = shost_priv(shost);
2262
2263         kfree(ihost->netdev);
2264         kfree(ihost->hwaddress);
2265         kfree(ihost->initiatorname);
2266         scsi_host_put(shost);
2267 }
2268 EXPORT_SYMBOL_GPL(iscsi_host_free);
2269
2270 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2271 {
2272         struct iscsi_host *ihost = shost_priv(shost);
2273         unsigned long flags;
2274
2275         shost = scsi_host_get(shost);
2276         if (!shost) {
2277                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2278                       "of session teardown event because host already "
2279                       "removed.\n");
2280                 return;
2281         }
2282
2283         spin_lock_irqsave(&ihost->lock, flags);
2284         ihost->num_sessions--;
2285         if (ihost->num_sessions == 0)
2286                 wake_up(&ihost->session_removal_wq);
2287         spin_unlock_irqrestore(&ihost->lock, flags);
2288         scsi_host_put(shost);
2289 }
2290
2291 /**
2292  * iscsi_session_setup - create iscsi cls session and host and session
2293  * @iscsit: iscsi transport template
2294  * @shost: scsi host
2295  * @cmds_max: session can queue
2296  * @cmd_task_size: LLD task private data size
2297  * @initial_cmdsn: initial CmdSN
2298  *
2299  * This can be used by software iscsi_transports that allocate
2300  * a session per scsi host.
2301  *
2302  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2303  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2304  * for nop handling and login/logout requests.
2305  */
2306 struct iscsi_cls_session *
2307 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2308                     uint16_t cmds_max, int cmd_task_size,
2309                     uint32_t initial_cmdsn, unsigned int id)
2310 {
2311         struct iscsi_host *ihost = shost_priv(shost);
2312         struct iscsi_session *session;
2313         struct iscsi_cls_session *cls_session;
2314         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2315         unsigned long flags;
2316
2317         spin_lock_irqsave(&ihost->lock, flags);
2318         if (ihost->state == ISCSI_HOST_REMOVED) {
2319                 spin_unlock_irqrestore(&ihost->lock, flags);
2320                 return NULL;
2321         }
2322         ihost->num_sessions++;
2323         spin_unlock_irqrestore(&ihost->lock, flags);
2324
2325         if (!total_cmds)
2326                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2327         /*
2328          * The iscsi layer needs some tasks for nop handling and tmfs,
2329          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2330          * + 1 command for scsi IO.
2331          */
2332         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2333                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2334                        "must be a power of two that is at least %d.\n",
2335                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2336                 goto dec_session_count;
2337         }
2338
2339         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2340                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2341                        "must be a power of 2 less than or equal to %d.\n",
2342                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2343                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2344         }
2345
2346         if (!is_power_of_2(total_cmds)) {
2347                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2348                        "must be a power of 2.\n", total_cmds);
2349                 total_cmds = rounddown_pow_of_two(total_cmds);
2350                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2351                         return NULL;
2352                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2353                        total_cmds);
2354         }
2355         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2356
2357         cls_session = iscsi_alloc_session(shost, iscsit,
2358                                           sizeof(struct iscsi_session));
2359         if (!cls_session)
2360                 goto dec_session_count;
2361         session = cls_session->dd_data;
2362         session->cls_session = cls_session;
2363         session->host = shost;
2364         session->state = ISCSI_STATE_FREE;
2365         session->fast_abort = 1;
2366         session->lu_reset_timeout = 15;
2367         session->abort_timeout = 10;
2368         session->scsi_cmds_max = scsi_cmds;
2369         session->cmds_max = total_cmds;
2370         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2371         session->exp_cmdsn = initial_cmdsn + 1;
2372         session->max_cmdsn = initial_cmdsn + 1;
2373         session->max_r2t = 1;
2374         session->tt = iscsit;
2375         mutex_init(&session->eh_mutex);
2376         spin_lock_init(&session->lock);
2377
2378         /* initialize SCSI PDU commands pool */
2379         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2380                             (void***)&session->cmds,
2381                             cmd_task_size + sizeof(struct iscsi_task)))
2382                 goto cmdpool_alloc_fail;
2383
2384         /* pre-format cmds pool with ITT */
2385         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2386                 struct iscsi_task *task = session->cmds[cmd_i];
2387
2388                 if (cmd_task_size)
2389                         task->dd_data = &task[1];
2390                 task->itt = cmd_i;
2391                 task->state = ISCSI_TASK_FREE;
2392                 INIT_LIST_HEAD(&task->running);
2393         }
2394
2395         if (!try_module_get(iscsit->owner))
2396                 goto module_get_fail;
2397
2398         if (iscsi_add_session(cls_session, id))
2399                 goto cls_session_fail;
2400
2401         return cls_session;
2402
2403 cls_session_fail:
2404         module_put(iscsit->owner);
2405 module_get_fail:
2406         iscsi_pool_free(&session->cmdpool);
2407 cmdpool_alloc_fail:
2408         iscsi_free_session(cls_session);
2409 dec_session_count:
2410         iscsi_host_dec_session_cnt(shost);
2411         return NULL;
2412 }
2413 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2414
2415 /**
2416  * iscsi_session_teardown - destroy session, host, and cls_session
2417  * @cls_session: iscsi session
2418  *
2419  * The driver must have called iscsi_remove_session before
2420  * calling this.
2421  */
2422 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2423 {
2424         struct iscsi_session *session = cls_session->dd_data;
2425         struct module *owner = cls_session->transport->owner;
2426         struct Scsi_Host *shost = session->host;
2427
2428         iscsi_pool_free(&session->cmdpool);
2429
2430         kfree(session->password);
2431         kfree(session->password_in);
2432         kfree(session->username);
2433         kfree(session->username_in);
2434         kfree(session->targetname);
2435         kfree(session->initiatorname);
2436         kfree(session->ifacename);
2437
2438         iscsi_destroy_session(cls_session);
2439         iscsi_host_dec_session_cnt(shost);
2440         module_put(owner);
2441 }
2442 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2443
2444 /**
2445  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2446  * @cls_session: iscsi_cls_session
2447  * @dd_size: private driver data size
2448  * @conn_idx: cid
2449  */
2450 struct iscsi_cls_conn *
2451 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2452                  uint32_t conn_idx)
2453 {
2454         struct iscsi_session *session = cls_session->dd_data;
2455         struct iscsi_conn *conn;
2456         struct iscsi_cls_conn *cls_conn;
2457         char *data;
2458
2459         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2460                                      conn_idx);
2461         if (!cls_conn)
2462                 return NULL;
2463         conn = cls_conn->dd_data;
2464         memset(conn, 0, sizeof(*conn) + dd_size);
2465
2466         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2467         conn->session = session;
2468         conn->cls_conn = cls_conn;
2469         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2470         conn->id = conn_idx;
2471         conn->exp_statsn = 0;
2472         conn->tmf_state = TMF_INITIAL;
2473
2474         init_timer(&conn->transport_timer);
2475         conn->transport_timer.data = (unsigned long)conn;
2476         conn->transport_timer.function = iscsi_check_transport_timeouts;
2477
2478         INIT_LIST_HEAD(&conn->mgmtqueue);
2479         INIT_LIST_HEAD(&conn->cmdqueue);
2480         INIT_LIST_HEAD(&conn->requeue);
2481         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2482
2483         /* allocate login_task used for the login/text sequences */
2484         spin_lock_bh(&session->lock);
2485         if (!__kfifo_get(session->cmdpool.queue,
2486                          (void*)&conn->login_task,
2487                          sizeof(void*))) {
2488                 spin_unlock_bh(&session->lock);
2489                 goto login_task_alloc_fail;
2490         }
2491         spin_unlock_bh(&session->lock);
2492
2493         data = (char *) __get_free_pages(GFP_KERNEL,
2494                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2495         if (!data)
2496                 goto login_task_data_alloc_fail;
2497         conn->login_task->data = conn->data = data;
2498
2499         init_timer(&conn->tmf_timer);
2500         init_waitqueue_head(&conn->ehwait);
2501
2502         return cls_conn;
2503
2504 login_task_data_alloc_fail:
2505         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2506                     sizeof(void*));
2507 login_task_alloc_fail:
2508         iscsi_destroy_conn(cls_conn);
2509         return NULL;
2510 }
2511 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2512
2513 /**
2514  * iscsi_conn_teardown - teardown iscsi connection
2515  * cls_conn: iscsi class connection
2516  *
2517  * TODO: we may need to make this into a two step process
2518  * like scsi-mls remove + put host
2519  */
2520 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2521 {
2522         struct iscsi_conn *conn = cls_conn->dd_data;
2523         struct iscsi_session *session = conn->session;
2524         unsigned long flags;
2525
2526         del_timer_sync(&conn->transport_timer);
2527
2528         spin_lock_bh(&session->lock);
2529         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2530         if (session->leadconn == conn) {
2531                 /*
2532                  * leading connection? then give up on recovery.
2533                  */
2534                 session->state = ISCSI_STATE_TERMINATE;
2535                 wake_up(&conn->ehwait);
2536         }
2537         spin_unlock_bh(&session->lock);
2538
2539         /*
2540          * Block until all in-progress commands for this connection
2541          * time out or fail.
2542          */
2543         for (;;) {
2544                 spin_lock_irqsave(session->host->host_lock, flags);
2545                 if (!session->host->host_busy) { /* OK for ERL == 0 */
2546                         spin_unlock_irqrestore(session->host->host_lock, flags);
2547                         break;
2548                 }
2549                 spin_unlock_irqrestore(session->host->host_lock, flags);
2550                 msleep_interruptible(500);
2551                 iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2552                                   "host_busy %d host_failed %d\n",
2553                                   session->host->host_busy,
2554                                   session->host->host_failed);
2555                 /*
2556                  * force eh_abort() to unblock
2557                  */
2558                 wake_up(&conn->ehwait);
2559         }
2560
2561         /* flush queued up work because we free the connection below */
2562         iscsi_suspend_tx(conn);
2563
2564         spin_lock_bh(&session->lock);
2565         free_pages((unsigned long) conn->data,
2566                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2567         kfree(conn->persistent_address);
2568         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2569                     sizeof(void*));
2570         if (session->leadconn == conn)
2571                 session->leadconn = NULL;
2572         spin_unlock_bh(&session->lock);
2573
2574         iscsi_destroy_conn(cls_conn);
2575 }
2576 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2577
2578 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2579 {
2580         struct iscsi_conn *conn = cls_conn->dd_data;
2581         struct iscsi_session *session = conn->session;
2582
2583         if (!session) {
2584                 iscsi_conn_printk(KERN_ERR, conn,
2585                                   "can't start unbound connection\n");
2586                 return -EPERM;
2587         }
2588
2589         if ((session->imm_data_en || !session->initial_r2t_en) &&
2590              session->first_burst > session->max_burst) {
2591                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2592                                   "first_burst %d max_burst %d\n",
2593                                   session->first_burst, session->max_burst);
2594                 return -EINVAL;
2595         }
2596
2597         if (conn->ping_timeout && !conn->recv_timeout) {
2598                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
2599                                   "zero. Using 5 seconds\n.");
2600                 conn->recv_timeout = 5;
2601         }
2602
2603         if (conn->recv_timeout && !conn->ping_timeout) {
2604                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
2605                                   "zero. Using 5 seconds.\n");
2606                 conn->ping_timeout = 5;
2607         }
2608
2609         spin_lock_bh(&session->lock);
2610         conn->c_stage = ISCSI_CONN_STARTED;
2611         session->state = ISCSI_STATE_LOGGED_IN;
2612         session->queued_cmdsn = session->cmdsn;
2613
2614         conn->last_recv = jiffies;
2615         conn->last_ping = jiffies;
2616         if (conn->recv_timeout && conn->ping_timeout)
2617                 mod_timer(&conn->transport_timer,
2618                           jiffies + (conn->recv_timeout * HZ));
2619
2620         switch(conn->stop_stage) {
2621         case STOP_CONN_RECOVER:
2622                 /*
2623                  * unblock eh_abort() if it is blocked. re-try all
2624                  * commands after successful recovery
2625                  */
2626                 conn->stop_stage = 0;
2627                 conn->tmf_state = TMF_INITIAL;
2628                 session->age++;
2629                 if (session->age == 16)
2630                         session->age = 0;
2631                 break;
2632         case STOP_CONN_TERM:
2633                 conn->stop_stage = 0;
2634                 break;
2635         default:
2636                 break;
2637         }
2638         spin_unlock_bh(&session->lock);
2639
2640         iscsi_unblock_session(session->cls_session);
2641         wake_up(&conn->ehwait);
2642         return 0;
2643 }
2644 EXPORT_SYMBOL_GPL(iscsi_conn_start);
2645
2646 static void
2647 fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
2648 {
2649         struct iscsi_task *task;
2650         int i, state;
2651
2652         for (i = 0; i < conn->session->cmds_max; i++) {
2653                 task = conn->session->cmds[i];
2654                 if (task->sc)
2655                         continue;
2656
2657                 if (task->state == ISCSI_TASK_FREE)
2658                         continue;
2659
2660                 ISCSI_DBG_SESSION(conn->session,
2661                                   "failing mgmt itt 0x%x state %d\n",
2662                                   task->itt, task->state);
2663                 state = ISCSI_TASK_ABRT_SESS_RECOV;
2664                 if (task->state == ISCSI_TASK_PENDING)
2665                         state = ISCSI_TASK_COMPLETED;
2666                 iscsi_complete_task(task, state);
2667
2668         }
2669 }
2670
2671 static void iscsi_start_session_recovery(struct iscsi_session *session,
2672                                          struct iscsi_conn *conn, int flag)
2673 {
2674         int old_stop_stage;
2675
2676         mutex_lock(&session->eh_mutex);
2677         spin_lock_bh(&session->lock);
2678         if (conn->stop_stage == STOP_CONN_TERM) {
2679                 spin_unlock_bh(&session->lock);
2680                 mutex_unlock(&session->eh_mutex);
2681                 return;
2682         }
2683
2684         /*
2685          * When this is called for the in_login state, we only want to clean
2686          * up the login task and connection. We do not need to block and set
2687          * the recovery state again
2688          */
2689         if (flag == STOP_CONN_TERM)
2690                 session->state = ISCSI_STATE_TERMINATE;
2691         else if (conn->stop_stage != STOP_CONN_RECOVER)
2692                 session->state = ISCSI_STATE_IN_RECOVERY;
2693         spin_unlock_bh(&session->lock);
2694
2695         del_timer_sync(&conn->transport_timer);
2696         iscsi_suspend_tx(conn);
2697
2698         spin_lock_bh(&session->lock);
2699         old_stop_stage = conn->stop_stage;
2700         conn->stop_stage = flag;
2701         conn->c_stage = ISCSI_CONN_STOPPED;
2702         spin_unlock_bh(&session->lock);
2703
2704         /*
2705          * for connection level recovery we should not calculate
2706          * header digest. conn->hdr_size used for optimization
2707          * in hdr_extract() and will be re-negotiated at
2708          * set_param() time.
2709          */
2710         if (flag == STOP_CONN_RECOVER) {
2711                 conn->hdrdgst_en = 0;
2712                 conn->datadgst_en = 0;
2713                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
2714                     old_stop_stage != STOP_CONN_RECOVER) {
2715                         ISCSI_DBG_SESSION(session, "blocking session\n");
2716                         iscsi_block_session(session->cls_session);
2717                 }
2718         }
2719
2720         /*
2721          * flush queues.
2722          */
2723         spin_lock_bh(&session->lock);
2724         fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
2725         fail_mgmt_tasks(session, conn);
2726         spin_unlock_bh(&session->lock);
2727         mutex_unlock(&session->eh_mutex);
2728 }
2729
2730 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
2731 {
2732         struct iscsi_conn *conn = cls_conn->dd_data;
2733         struct iscsi_session *session = conn->session;
2734
2735         switch (flag) {
2736         case STOP_CONN_RECOVER:
2737         case STOP_CONN_TERM:
2738                 iscsi_start_session_recovery(session, conn, flag);
2739                 break;
2740         default:
2741                 iscsi_conn_printk(KERN_ERR, conn,
2742                                   "invalid stop flag %d\n", flag);
2743         }
2744 }
2745 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
2746
2747 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
2748                     struct iscsi_cls_conn *cls_conn, int is_leading)
2749 {
2750         struct iscsi_session *session = cls_session->dd_data;
2751         struct iscsi_conn *conn = cls_conn->dd_data;
2752
2753         spin_lock_bh(&session->lock);
2754         if (is_leading)
2755                 session->leadconn = conn;
2756         spin_unlock_bh(&session->lock);
2757
2758         /*
2759          * Unblock xmitworker(), Login Phase will pass through.
2760          */
2761         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
2762         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
2763         return 0;
2764 }
2765 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
2766
2767 static int iscsi_switch_str_param(char **param, char *new_val_buf)
2768 {
2769         char *new_val;
2770
2771         if (*param) {
2772                 if (!strcmp(*param, new_val_buf))
2773                         return 0;
2774         }
2775
2776         new_val = kstrdup(new_val_buf, GFP_NOIO);
2777         if (!new_val)
2778                 return -ENOMEM;
2779
2780         kfree(*param);
2781         *param = new_val;
2782         return 0;
2783 }
2784
2785 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
2786                     enum iscsi_param param, char *buf, int buflen)
2787 {
2788         struct iscsi_conn *conn = cls_conn->dd_data;
2789         struct iscsi_session *session = conn->session;
2790         uint32_t value;
2791
2792         switch(param) {
2793         case ISCSI_PARAM_FAST_ABORT:
2794                 sscanf(buf, "%d", &session->fast_abort);
2795                 break;
2796         case ISCSI_PARAM_ABORT_TMO:
2797                 sscanf(buf, "%d", &session->abort_timeout);
2798                 break;
2799         case ISCSI_PARAM_LU_RESET_TMO:
2800                 sscanf(buf, "%d", &session->lu_reset_timeout);
2801                 break;
2802         case ISCSI_PARAM_PING_TMO:
2803                 sscanf(buf, "%d", &conn->ping_timeout);
2804                 break;
2805         case ISCSI_PARAM_RECV_TMO:
2806                 sscanf(buf, "%d", &conn->recv_timeout);
2807                 break;
2808         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2809                 sscanf(buf, "%d", &conn->max_recv_dlength);
2810                 break;
2811         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2812                 sscanf(buf, "%d", &conn->max_xmit_dlength);
2813                 break;
2814         case ISCSI_PARAM_HDRDGST_EN:
2815                 sscanf(buf, "%d", &conn->hdrdgst_en);
2816                 break;
2817         case ISCSI_PARAM_DATADGST_EN:
2818                 sscanf(buf, "%d", &conn->datadgst_en);
2819                 break;
2820         case ISCSI_PARAM_INITIAL_R2T_EN:
2821                 sscanf(buf, "%d", &session->initial_r2t_en);
2822                 break;
2823         case ISCSI_PARAM_MAX_R2T:
2824                 sscanf(buf, "%d", &session->max_r2t);
2825                 break;
2826         case ISCSI_PARAM_IMM_DATA_EN:
2827                 sscanf(buf, "%d", &session->imm_data_en);
2828                 break;
2829         case ISCSI_PARAM_FIRST_BURST:
2830                 sscanf(buf, "%d", &session->first_burst);
2831                 break;
2832         case ISCSI_PARAM_MAX_BURST:
2833                 sscanf(buf, "%d", &session->max_burst);
2834                 break;
2835         case ISCSI_PARAM_PDU_INORDER_EN:
2836                 sscanf(buf, "%d", &session->pdu_inorder_en);
2837                 break;
2838         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2839                 sscanf(buf, "%d", &session->dataseq_inorder_en);
2840                 break;
2841         case ISCSI_PARAM_ERL:
2842                 sscanf(buf, "%d", &session->erl);
2843                 break;
2844         case ISCSI_PARAM_IFMARKER_EN:
2845                 sscanf(buf, "%d", &value);
2846                 BUG_ON(value);
2847                 break;
2848         case ISCSI_PARAM_OFMARKER_EN:
2849                 sscanf(buf, "%d", &value);
2850                 BUG_ON(value);
2851                 break;
2852         case ISCSI_PARAM_EXP_STATSN:
2853                 sscanf(buf, "%u", &conn->exp_statsn);
2854                 break;
2855         case ISCSI_PARAM_USERNAME:
2856                 return iscsi_switch_str_param(&session->username, buf);
2857         case ISCSI_PARAM_USERNAME_IN:
2858                 return iscsi_switch_str_param(&session->username_in, buf);
2859         case ISCSI_PARAM_PASSWORD:
2860                 return iscsi_switch_str_param(&session->password, buf);
2861         case ISCSI_PARAM_PASSWORD_IN:
2862                 return iscsi_switch_str_param(&session->password_in, buf);
2863         case ISCSI_PARAM_TARGET_NAME:
2864                 return iscsi_switch_str_param(&session->targetname, buf);
2865         case ISCSI_PARAM_TPGT:
2866                 sscanf(buf, "%d", &session->tpgt);
2867                 break;
2868         case ISCSI_PARAM_PERSISTENT_PORT:
2869                 sscanf(buf, "%d", &conn->persistent_port);
2870                 break;
2871         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2872                 return iscsi_switch_str_param(&conn->persistent_address, buf);
2873         case ISCSI_PARAM_IFACE_NAME:
2874                 return iscsi_switch_str_param(&session->ifacename, buf);
2875         case ISCSI_PARAM_INITIATOR_NAME:
2876                 return iscsi_switch_str_param(&session->initiatorname, buf);
2877         default:
2878                 return -ENOSYS;
2879         }
2880
2881         return 0;
2882 }
2883 EXPORT_SYMBOL_GPL(iscsi_set_param);
2884
2885 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
2886                             enum iscsi_param param, char *buf)
2887 {
2888         struct iscsi_session *session = cls_session->dd_data;
2889         int len;
2890
2891         switch(param) {
2892         case ISCSI_PARAM_FAST_ABORT:
2893                 len = sprintf(buf, "%d\n", session->fast_abort);
2894                 break;
2895         case ISCSI_PARAM_ABORT_TMO:
2896                 len = sprintf(buf, "%d\n", session->abort_timeout);
2897                 break;
2898         case ISCSI_PARAM_LU_RESET_TMO:
2899                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
2900                 break;
2901         case ISCSI_PARAM_INITIAL_R2T_EN:
2902                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
2903                 break;
2904         case ISCSI_PARAM_MAX_R2T:
2905                 len = sprintf(buf, "%hu\n", session->max_r2t);
2906                 break;
2907         case ISCSI_PARAM_IMM_DATA_EN:
2908                 len = sprintf(buf, "%d\n", session->imm_data_en);
2909                 break;
2910         case ISCSI_PARAM_FIRST_BURST:
2911                 len = sprintf(buf, "%u\n", session->first_burst);
2912                 break;
2913         case ISCSI_PARAM_MAX_BURST:
2914                 len = sprintf(buf, "%u\n", session->max_burst);
2915                 break;
2916         case ISCSI_PARAM_PDU_INORDER_EN:
2917                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
2918                 break;
2919         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2920                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
2921                 break;
2922         case ISCSI_PARAM_ERL:
2923                 len = sprintf(buf, "%d\n", session->erl);
2924                 break;
2925         case ISCSI_PARAM_TARGET_NAME:
2926                 len = sprintf(buf, "%s\n", session->targetname);
2927                 break;
2928         case ISCSI_PARAM_TPGT:
2929                 len = sprintf(buf, "%d\n", session->tpgt);
2930                 break;
2931         case ISCSI_PARAM_USERNAME:
2932                 len = sprintf(buf, "%s\n", session->username);
2933                 break;
2934         case ISCSI_PARAM_USERNAME_IN:
2935                 len = sprintf(buf, "%s\n", session->username_in);
2936                 break;
2937         case ISCSI_PARAM_PASSWORD:
2938                 len = sprintf(buf, "%s\n", session->password);
2939                 break;
2940         case ISCSI_PARAM_PASSWORD_IN:
2941                 len = sprintf(buf, "%s\n", session->password_in);
2942                 break;
2943         case ISCSI_PARAM_IFACE_NAME:
2944                 len = sprintf(buf, "%s\n", session->ifacename);
2945                 break;
2946         case ISCSI_PARAM_INITIATOR_NAME:
2947                 len = sprintf(buf, "%s\n", session->initiatorname);
2948                 break;
2949         default:
2950                 return -ENOSYS;
2951         }
2952
2953         return len;
2954 }
2955 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
2956
2957 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2958                          enum iscsi_param param, char *buf)
2959 {
2960         struct iscsi_conn *conn = cls_conn->dd_data;
2961         int len;
2962
2963         switch(param) {
2964         case ISCSI_PARAM_PING_TMO:
2965                 len = sprintf(buf, "%u\n", conn->ping_timeout);
2966                 break;
2967         case ISCSI_PARAM_RECV_TMO:
2968                 len = sprintf(buf, "%u\n", conn->recv_timeout);
2969                 break;
2970         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2971                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
2972                 break;
2973         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2974                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
2975                 break;
2976         case ISCSI_PARAM_HDRDGST_EN:
2977                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
2978                 break;
2979         case ISCSI_PARAM_DATADGST_EN:
2980                 len = sprintf(buf, "%d\n", conn->datadgst_en);
2981                 break;
2982         case ISCSI_PARAM_IFMARKER_EN:
2983                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
2984                 break;
2985         case ISCSI_PARAM_OFMARKER_EN:
2986                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
2987                 break;
2988         case ISCSI_PARAM_EXP_STATSN:
2989                 len = sprintf(buf, "%u\n", conn->exp_statsn);
2990                 break;
2991         case ISCSI_PARAM_PERSISTENT_PORT:
2992                 len = sprintf(buf, "%d\n", conn->persistent_port);
2993                 break;
2994         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2995                 len = sprintf(buf, "%s\n", conn->persistent_address);
2996                 break;
2997         default:
2998                 return -ENOSYS;
2999         }
3000
3001         return len;
3002 }
3003 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3004
3005 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3006                          char *buf)
3007 {
3008         struct iscsi_host *ihost = shost_priv(shost);
3009         int len;
3010
3011         switch (param) {
3012         case ISCSI_HOST_PARAM_NETDEV_NAME:
3013                 len = sprintf(buf, "%s\n", ihost->netdev);
3014                 break;
3015         case ISCSI_HOST_PARAM_HWADDRESS:
3016                 len = sprintf(buf, "%s\n", ihost->hwaddress);
3017                 break;
3018         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3019                 len = sprintf(buf, "%s\n", ihost->initiatorname);
3020                 break;
3021         case ISCSI_HOST_PARAM_IPADDRESS:
3022                 len = sprintf(buf, "%s\n", ihost->local_address);
3023                 break;
3024         default:
3025                 return -ENOSYS;
3026         }
3027
3028         return len;
3029 }
3030 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3031
3032 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3033                          char *buf, int buflen)
3034 {
3035         struct iscsi_host *ihost = shost_priv(shost);
3036
3037         switch (param) {
3038         case ISCSI_HOST_PARAM_NETDEV_NAME:
3039                 return iscsi_switch_str_param(&ihost->netdev, buf);
3040         case ISCSI_HOST_PARAM_HWADDRESS:
3041                 return iscsi_switch_str_param(&ihost->hwaddress, buf);
3042         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3043                 return iscsi_switch_str_param(&ihost->initiatorname, buf);
3044         default:
3045                 return -ENOSYS;
3046         }
3047
3048         return 0;
3049 }
3050 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3051
3052 MODULE_AUTHOR("Mike Christie");
3053 MODULE_DESCRIPTION("iSCSI library functions");
3054 MODULE_LICENSE("GPL");