[SCSI] libiscsi: add warm target reset tmf support
[linux-2.6.git] / drivers / scsi / libiscsi.c
1 /*
2  * iSCSI lib functions
3  *
4  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
5  * Copyright (C) 2004 - 2006 Mike Christie
6  * Copyright (C) 2004 - 2005 Dmitry Yusupov
7  * Copyright (C) 2004 - 2005 Alex Aizman
8  * maintained by open-iscsi@googlegroups.com
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23  */
24 #include <linux/types.h>
25 #include <linux/kfifo.h>
26 #include <linux/delay.h>
27 #include <linux/log2.h>
28 #include <asm/unaligned.h>
29 #include <net/tcp.h>
30 #include <scsi/scsi_cmnd.h>
31 #include <scsi/scsi_device.h>
32 #include <scsi/scsi_eh.h>
33 #include <scsi/scsi_tcq.h>
34 #include <scsi/scsi_host.h>
35 #include <scsi/scsi.h>
36 #include <scsi/iscsi_proto.h>
37 #include <scsi/scsi_transport.h>
38 #include <scsi/scsi_transport_iscsi.h>
39 #include <scsi/libiscsi.h>
40
41 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 static void __iscsi_update_cmdsn(struct iscsi_session *session,
113                                  uint32_t exp_cmdsn, uint32_t max_cmdsn)
114 {
115         /*
116          * standard specifies this check for when to update expected and
117          * max sequence numbers
118          */
119         if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
120                 return;
121
122         if (exp_cmdsn != session->exp_cmdsn &&
123             !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
124                 session->exp_cmdsn = exp_cmdsn;
125
126         if (max_cmdsn != session->max_cmdsn &&
127             !iscsi_sna_lt(max_cmdsn, session->max_cmdsn)) {
128                 session->max_cmdsn = max_cmdsn;
129                 /*
130                  * if the window closed with IO queued, then kick the
131                  * xmit thread
132                  */
133                 if (!list_empty(&session->leadconn->cmdqueue) ||
134                     !list_empty(&session->leadconn->mgmtqueue))
135                         iscsi_conn_queue_work(session->leadconn);
136         }
137 }
138
139 void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
140 {
141         __iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
142                              be32_to_cpu(hdr->max_cmdsn));
143 }
144 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
145
146 /**
147  * iscsi_prep_data_out_pdu - initialize Data-Out
148  * @task: scsi command task
149  * @r2t: R2T info
150  * @hdr: iscsi data in pdu
151  *
152  * Notes:
153  *      Initialize Data-Out within this R2T sequence and finds
154  *      proper data_offset within this SCSI command.
155  *
156  *      This function is called with connection lock taken.
157  **/
158 void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
159                            struct iscsi_data *hdr)
160 {
161         struct iscsi_conn *conn = task->conn;
162         unsigned int left = r2t->data_length - r2t->sent;
163
164         task->hdr_len = sizeof(struct iscsi_data);
165
166         memset(hdr, 0, sizeof(struct iscsi_data));
167         hdr->ttt = r2t->ttt;
168         hdr->datasn = cpu_to_be32(r2t->datasn);
169         r2t->datasn++;
170         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
171         memcpy(hdr->lun, task->lun, sizeof(hdr->lun));
172         hdr->itt = task->hdr_itt;
173         hdr->exp_statsn = r2t->exp_statsn;
174         hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
175         if (left > conn->max_xmit_dlength) {
176                 hton24(hdr->dlength, conn->max_xmit_dlength);
177                 r2t->data_count = conn->max_xmit_dlength;
178                 hdr->flags = 0;
179         } else {
180                 hton24(hdr->dlength, left);
181                 r2t->data_count = left;
182                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
183         }
184         conn->dataout_pdus_cnt++;
185 }
186 EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
187
188 static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
189 {
190         unsigned exp_len = task->hdr_len + len;
191
192         if (exp_len > task->hdr_max) {
193                 WARN_ON(1);
194                 return -EINVAL;
195         }
196
197         WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
198         task->hdr_len = exp_len;
199         return 0;
200 }
201
202 /*
203  * make an extended cdb AHS
204  */
205 static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
206 {
207         struct scsi_cmnd *cmd = task->sc;
208         unsigned rlen, pad_len;
209         unsigned short ahslength;
210         struct iscsi_ecdb_ahdr *ecdb_ahdr;
211         int rc;
212
213         ecdb_ahdr = iscsi_next_hdr(task);
214         rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
215
216         BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
217         ahslength = rlen + sizeof(ecdb_ahdr->reserved);
218
219         pad_len = iscsi_padding(rlen);
220
221         rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
222                            sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
223         if (rc)
224                 return rc;
225
226         if (pad_len)
227                 memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
228
229         ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
230         ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
231         ecdb_ahdr->reserved = 0;
232         memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
233
234         ISCSI_DBG_SESSION(task->conn->session,
235                           "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
236                           "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
237                           "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
238                           task->hdr_len);
239         return 0;
240 }
241
242 static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
243 {
244         struct scsi_cmnd *sc = task->sc;
245         struct iscsi_rlength_ahdr *rlen_ahdr;
246         int rc;
247
248         rlen_ahdr = iscsi_next_hdr(task);
249         rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
250         if (rc)
251                 return rc;
252
253         rlen_ahdr->ahslength =
254                 cpu_to_be16(sizeof(rlen_ahdr->read_length) +
255                                                   sizeof(rlen_ahdr->reserved));
256         rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
257         rlen_ahdr->reserved = 0;
258         rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
259
260         ISCSI_DBG_SESSION(task->conn->session,
261                           "bidi-in rlen_ahdr->read_length(%d) "
262                           "rlen_ahdr->ahslength(%d)\n",
263                           be32_to_cpu(rlen_ahdr->read_length),
264                           be16_to_cpu(rlen_ahdr->ahslength));
265         return 0;
266 }
267
268 /**
269  * iscsi_check_tmf_restrictions - check if a task is affected by TMF
270  * @task: iscsi task
271  * @opcode: opcode to check for
272  *
273  * During TMF a task has to be checked if it's affected.
274  * All unrelated I/O can be passed through, but I/O to the
275  * affected LUN should be restricted.
276  * If 'fast_abort' is set we won't be sending any I/O to the
277  * affected LUN.
278  * Otherwise the target is waiting for all TTTs to be completed,
279  * so we have to send all outstanding Data-Out PDUs to the target.
280  */
281 static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
282 {
283         struct iscsi_conn *conn = task->conn;
284         struct iscsi_tm *tmf = &conn->tmhdr;
285         unsigned int hdr_lun;
286
287         if (conn->tmf_state == TMF_INITIAL)
288                 return 0;
289
290         if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
291                 return 0;
292
293         switch (ISCSI_TM_FUNC_VALUE(tmf)) {
294         case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
295                 /*
296                  * Allow PDUs for unrelated LUNs
297                  */
298                 hdr_lun = scsilun_to_int((struct scsi_lun *)tmf->lun);
299                 if (hdr_lun != task->sc->device->lun)
300                         return 0;
301                 /* fall through */
302         case ISCSI_TM_FUNC_TARGET_WARM_RESET:
303                 /*
304                  * Fail all SCSI cmd PDUs
305                  */
306                 if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
307                         iscsi_conn_printk(KERN_INFO, conn,
308                                           "task [op %x/%x itt "
309                                           "0x%x/0x%x] "
310                                           "rejected.\n",
311                                           task->hdr->opcode, opcode,
312                                           task->itt, task->hdr_itt);
313                         return -EACCES;
314                 }
315                 /*
316                  * And also all data-out PDUs in response to R2T
317                  * if fast_abort is set.
318                  */
319                 if (conn->session->fast_abort) {
320                         iscsi_conn_printk(KERN_INFO, conn,
321                                           "task [op %x/%x itt "
322                                           "0x%x/0x%x] fast abort.\n",
323                                           task->hdr->opcode, opcode,
324                                           task->itt, task->hdr_itt);
325                         return -EACCES;
326                 }
327                 break;
328         case ISCSI_TM_FUNC_ABORT_TASK:
329                 /*
330                  * the caller has already checked if the task
331                  * they want to abort was in the pending queue so if
332                  * we are here the cmd pdu has gone out already, and
333                  * we will only hit this for data-outs
334                  */
335                 if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
336                     task->hdr_itt == tmf->rtt) {
337                         ISCSI_DBG_SESSION(conn->session,
338                                           "Preventing task %x/%x from sending "
339                                           "data-out due to abort task in "
340                                           "progress\n", task->itt,
341                                           task->hdr_itt);
342                         return -EACCES;
343                 }
344                 break;
345         }
346
347         return 0;
348 }
349
350 /**
351  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
352  * @task: iscsi task
353  *
354  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
355  * fields like dlength or final based on how much data it sends
356  */
357 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
358 {
359         struct iscsi_conn *conn = task->conn;
360         struct iscsi_session *session = conn->session;
361         struct scsi_cmnd *sc = task->sc;
362         struct iscsi_cmd *hdr;
363         unsigned hdrlength, cmd_len;
364         itt_t itt;
365         int rc;
366
367         rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
368         if (rc)
369                 return rc;
370
371         if (conn->session->tt->alloc_pdu) {
372                 rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
373                 if (rc)
374                         return rc;
375         }
376         hdr = (struct iscsi_cmd *) task->hdr;
377         itt = hdr->itt;
378         memset(hdr, 0, sizeof(*hdr));
379
380         if (session->tt->parse_pdu_itt)
381                 hdr->itt = task->hdr_itt = itt;
382         else
383                 hdr->itt = task->hdr_itt = build_itt(task->itt,
384                                                      task->conn->session->age);
385         task->hdr_len = 0;
386         rc = iscsi_add_hdr(task, sizeof(*hdr));
387         if (rc)
388                 return rc;
389         hdr->opcode = ISCSI_OP_SCSI_CMD;
390         hdr->flags = ISCSI_ATTR_SIMPLE;
391         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
392         memcpy(task->lun, hdr->lun, sizeof(task->lun));
393         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
394         cmd_len = sc->cmd_len;
395         if (cmd_len < ISCSI_CDB_SIZE)
396                 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
397         else if (cmd_len > ISCSI_CDB_SIZE) {
398                 rc = iscsi_prep_ecdb_ahs(task);
399                 if (rc)
400                         return rc;
401                 cmd_len = ISCSI_CDB_SIZE;
402         }
403         memcpy(hdr->cdb, sc->cmnd, cmd_len);
404
405         task->imm_count = 0;
406         if (scsi_bidi_cmnd(sc)) {
407                 hdr->flags |= ISCSI_FLAG_CMD_READ;
408                 rc = iscsi_prep_bidi_ahs(task);
409                 if (rc)
410                         return rc;
411         }
412         if (sc->sc_data_direction == DMA_TO_DEVICE) {
413                 unsigned out_len = scsi_out(sc)->length;
414                 struct iscsi_r2t_info *r2t = &task->unsol_r2t;
415
416                 hdr->data_length = cpu_to_be32(out_len);
417                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
418                 /*
419                  * Write counters:
420                  *
421                  *      imm_count       bytes to be sent right after
422                  *                      SCSI PDU Header
423                  *
424                  *      unsol_count     bytes(as Data-Out) to be sent
425                  *                      without R2T ack right after
426                  *                      immediate data
427                  *
428                  *      r2t data_length bytes to be sent via R2T ack's
429                  *
430                  *      pad_count       bytes to be sent as zero-padding
431                  */
432                 memset(r2t, 0, sizeof(*r2t));
433
434                 if (session->imm_data_en) {
435                         if (out_len >= session->first_burst)
436                                 task->imm_count = min(session->first_burst,
437                                                         conn->max_xmit_dlength);
438                         else
439                                 task->imm_count = min(out_len,
440                                                         conn->max_xmit_dlength);
441                         hton24(hdr->dlength, task->imm_count);
442                 } else
443                         zero_data(hdr->dlength);
444
445                 if (!session->initial_r2t_en) {
446                         r2t->data_length = min(session->first_burst, out_len) -
447                                                task->imm_count;
448                         r2t->data_offset = task->imm_count;
449                         r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
450                         r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
451                 }
452
453                 if (!task->unsol_r2t.data_length)
454                         /* No unsolicit Data-Out's */
455                         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
456         } else {
457                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
458                 zero_data(hdr->dlength);
459                 hdr->data_length = cpu_to_be32(scsi_in(sc)->length);
460
461                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
462                         hdr->flags |= ISCSI_FLAG_CMD_READ;
463         }
464
465         /* calculate size of additional header segments (AHSs) */
466         hdrlength = task->hdr_len - sizeof(*hdr);
467
468         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
469         hdrlength /= ISCSI_PAD_LEN;
470
471         WARN_ON(hdrlength >= 256);
472         hdr->hlength = hdrlength & 0xFF;
473
474         if (session->tt->init_task && session->tt->init_task(task))
475                 return -EIO;
476
477         task->state = ISCSI_TASK_RUNNING;
478         hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
479         session->cmdsn++;
480
481         conn->scsicmd_pdus_cnt++;
482         ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
483                           "itt 0x%x len %d bidi_len %d cmdsn %d win %d]\n",
484                           scsi_bidi_cmnd(sc) ? "bidirectional" :
485                           sc->sc_data_direction == DMA_TO_DEVICE ?
486                           "write" : "read", conn->id, sc, sc->cmnd[0],
487                           task->itt, scsi_bufflen(sc),
488                           scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
489                           session->cmdsn,
490                           session->max_cmdsn - session->exp_cmdsn + 1);
491         return 0;
492 }
493
494 /**
495  * iscsi_free_task - free a task
496  * @task: iscsi cmd task
497  *
498  * Must be called with session lock.
499  * This function returns the scsi command to scsi-ml or cleans
500  * up mgmt tasks then returns the task to the pool.
501  */
502 static void iscsi_free_task(struct iscsi_task *task)
503 {
504         struct iscsi_conn *conn = task->conn;
505         struct iscsi_session *session = conn->session;
506         struct scsi_cmnd *sc = task->sc;
507
508         ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
509                           task->itt, task->state, task->sc);
510
511         session->tt->cleanup_task(task);
512         task->state = ISCSI_TASK_FREE;
513         task->sc = NULL;
514         /*
515          * login task is preallocated so do not free
516          */
517         if (conn->login_task == task)
518                 return;
519
520         __kfifo_put(session->cmdpool.queue, (void*)&task, sizeof(void*));
521
522         if (sc) {
523                 task->sc = NULL;
524                 /* SCSI eh reuses commands to verify us */
525                 sc->SCp.ptr = NULL;
526                 /*
527                  * queue command may call this to free the task, but
528                  * not have setup the sc callback
529                  */
530                 if (sc->scsi_done)
531                         sc->scsi_done(sc);
532         }
533 }
534
535 void __iscsi_get_task(struct iscsi_task *task)
536 {
537         atomic_inc(&task->refcount);
538 }
539 EXPORT_SYMBOL_GPL(__iscsi_get_task);
540
541 static void __iscsi_put_task(struct iscsi_task *task)
542 {
543         if (atomic_dec_and_test(&task->refcount))
544                 iscsi_free_task(task);
545 }
546
547 void iscsi_put_task(struct iscsi_task *task)
548 {
549         struct iscsi_session *session = task->conn->session;
550
551         spin_lock_bh(&session->lock);
552         __iscsi_put_task(task);
553         spin_unlock_bh(&session->lock);
554 }
555 EXPORT_SYMBOL_GPL(iscsi_put_task);
556
557 /**
558  * iscsi_complete_task - finish a task
559  * @task: iscsi cmd task
560  * @state: state to complete task with
561  *
562  * Must be called with session lock.
563  */
564 static void iscsi_complete_task(struct iscsi_task *task, int state)
565 {
566         struct iscsi_conn *conn = task->conn;
567
568         ISCSI_DBG_SESSION(conn->session,
569                           "complete task itt 0x%x state %d sc %p\n",
570                           task->itt, task->state, task->sc);
571         if (task->state == ISCSI_TASK_COMPLETED ||
572             task->state == ISCSI_TASK_ABRT_TMF ||
573             task->state == ISCSI_TASK_ABRT_SESS_RECOV)
574                 return;
575         WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
576         task->state = state;
577
578         if (!list_empty(&task->running))
579                 list_del_init(&task->running);
580
581         if (conn->task == task)
582                 conn->task = NULL;
583
584         if (conn->ping_task == task)
585                 conn->ping_task = NULL;
586
587         /* release get from queueing */
588         __iscsi_put_task(task);
589 }
590
591 /**
592  * iscsi_complete_scsi_task - finish scsi task normally
593  * @task: iscsi task for scsi cmd
594  * @exp_cmdsn: expected cmd sn in cpu format
595  * @max_cmdsn: max cmd sn in cpu format
596  *
597  * This is used when drivers do not need or cannot perform
598  * lower level pdu processing.
599  *
600  * Called with session lock
601  */
602 void iscsi_complete_scsi_task(struct iscsi_task *task,
603                               uint32_t exp_cmdsn, uint32_t max_cmdsn)
604 {
605         struct iscsi_conn *conn = task->conn;
606
607         ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
608
609         conn->last_recv = jiffies;
610         __iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
611         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
612 }
613 EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
614
615
616 /*
617  * session lock must be held and if not called for a task that is
618  * still pending or from the xmit thread, then xmit thread must
619  * be suspended.
620  */
621 static void fail_scsi_task(struct iscsi_task *task, int err)
622 {
623         struct iscsi_conn *conn = task->conn;
624         struct scsi_cmnd *sc;
625         int state;
626
627         /*
628          * if a command completes and we get a successful tmf response
629          * we will hit this because the scsi eh abort code does not take
630          * a ref to the task.
631          */
632         sc = task->sc;
633         if (!sc)
634                 return;
635
636         if (task->state == ISCSI_TASK_PENDING) {
637                 /*
638                  * cmd never made it to the xmit thread, so we should not count
639                  * the cmd in the sequencing
640                  */
641                 conn->session->queued_cmdsn--;
642                 /* it was never sent so just complete like normal */
643                 state = ISCSI_TASK_COMPLETED;
644         } else if (err == DID_TRANSPORT_DISRUPTED)
645                 state = ISCSI_TASK_ABRT_SESS_RECOV;
646         else
647                 state = ISCSI_TASK_ABRT_TMF;
648
649         sc->result = err << 16;
650         if (!scsi_bidi_cmnd(sc))
651                 scsi_set_resid(sc, scsi_bufflen(sc));
652         else {
653                 scsi_out(sc)->resid = scsi_out(sc)->length;
654                 scsi_in(sc)->resid = scsi_in(sc)->length;
655         }
656
657         iscsi_complete_task(task, state);
658 }
659
660 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
661                                 struct iscsi_task *task)
662 {
663         struct iscsi_session *session = conn->session;
664         struct iscsi_hdr *hdr = task->hdr;
665         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
666         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
667
668         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
669                 return -ENOTCONN;
670
671         if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
672                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
673         /*
674          * pre-format CmdSN for outgoing PDU.
675          */
676         nop->cmdsn = cpu_to_be32(session->cmdsn);
677         if (hdr->itt != RESERVED_ITT) {
678                 /*
679                  * TODO: We always use immediate for normal session pdus.
680                  * If we start to send tmfs or nops as non-immediate then
681                  * we should start checking the cmdsn numbers for mgmt tasks.
682                  *
683                  * During discovery sessions iscsid sends TEXT as non immediate,
684                  * but we always only send one PDU at a time.
685                  */
686                 if (conn->c_stage == ISCSI_CONN_STARTED &&
687                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
688                         session->queued_cmdsn++;
689                         session->cmdsn++;
690                 }
691         }
692
693         if (session->tt->init_task && session->tt->init_task(task))
694                 return -EIO;
695
696         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
697                 session->state = ISCSI_STATE_LOGGING_OUT;
698
699         task->state = ISCSI_TASK_RUNNING;
700         ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
701                           "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
702                           hdr->itt, task->data_count);
703         return 0;
704 }
705
706 static struct iscsi_task *
707 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
708                       char *data, uint32_t data_size)
709 {
710         struct iscsi_session *session = conn->session;
711         struct iscsi_host *ihost = shost_priv(session->host);
712         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
713         struct iscsi_task *task;
714         itt_t itt;
715
716         if (session->state == ISCSI_STATE_TERMINATE)
717                 return NULL;
718
719         if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
720                 /*
721                  * Login and Text are sent serially, in
722                  * request-followed-by-response sequence.
723                  * Same task can be used. Same ITT must be used.
724                  * Note that login_task is preallocated at conn_create().
725                  */
726                 if (conn->login_task->state != ISCSI_TASK_FREE) {
727                         iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
728                                           "progress. Cannot start new task.\n");
729                         return NULL;
730                 }
731
732                 task = conn->login_task;
733         } else {
734                 if (session->state != ISCSI_STATE_LOGGED_IN)
735                         return NULL;
736
737                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
738                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
739
740                 if (!__kfifo_get(session->cmdpool.queue,
741                                  (void*)&task, sizeof(void*)))
742                         return NULL;
743         }
744         /*
745          * released in complete pdu for task we expect a response for, and
746          * released by the lld when it has transmitted the task for
747          * pdus we do not expect a response for.
748          */
749         atomic_set(&task->refcount, 1);
750         task->conn = conn;
751         task->sc = NULL;
752         INIT_LIST_HEAD(&task->running);
753         task->state = ISCSI_TASK_PENDING;
754
755         if (data_size) {
756                 memcpy(task->data, data, data_size);
757                 task->data_count = data_size;
758         } else
759                 task->data_count = 0;
760
761         if (conn->session->tt->alloc_pdu) {
762                 if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
763                         iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
764                                          "pdu for mgmt task.\n");
765                         goto free_task;
766                 }
767         }
768
769         itt = task->hdr->itt;
770         task->hdr_len = sizeof(struct iscsi_hdr);
771         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
772
773         if (hdr->itt != RESERVED_ITT) {
774                 if (session->tt->parse_pdu_itt)
775                         task->hdr->itt = itt;
776                 else
777                         task->hdr->itt = build_itt(task->itt,
778                                                    task->conn->session->age);
779         }
780
781         if (!ihost->workq) {
782                 if (iscsi_prep_mgmt_task(conn, task))
783                         goto free_task;
784
785                 if (session->tt->xmit_task(task))
786                         goto free_task;
787         } else {
788                 list_add_tail(&task->running, &conn->mgmtqueue);
789                 iscsi_conn_queue_work(conn);
790         }
791
792         return task;
793
794 free_task:
795         __iscsi_put_task(task);
796         return NULL;
797 }
798
799 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
800                         char *data, uint32_t data_size)
801 {
802         struct iscsi_conn *conn = cls_conn->dd_data;
803         struct iscsi_session *session = conn->session;
804         int err = 0;
805
806         spin_lock_bh(&session->lock);
807         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
808                 err = -EPERM;
809         spin_unlock_bh(&session->lock);
810         return err;
811 }
812 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
813
814 /**
815  * iscsi_cmd_rsp - SCSI Command Response processing
816  * @conn: iscsi connection
817  * @hdr: iscsi header
818  * @task: scsi command task
819  * @data: cmd data buffer
820  * @datalen: len of buffer
821  *
822  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
823  * then completes the command and task.
824  **/
825 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
826                                struct iscsi_task *task, char *data,
827                                int datalen)
828 {
829         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
830         struct iscsi_session *session = conn->session;
831         struct scsi_cmnd *sc = task->sc;
832
833         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
834         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
835
836         sc->result = (DID_OK << 16) | rhdr->cmd_status;
837
838         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
839                 sc->result = DID_ERROR << 16;
840                 goto out;
841         }
842
843         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
844                 uint16_t senselen;
845
846                 if (datalen < 2) {
847 invalid_datalen:
848                         iscsi_conn_printk(KERN_ERR,  conn,
849                                          "Got CHECK_CONDITION but invalid data "
850                                          "buffer size of %d\n", datalen);
851                         sc->result = DID_BAD_TARGET << 16;
852                         goto out;
853                 }
854
855                 senselen = get_unaligned_be16(data);
856                 if (datalen < senselen)
857                         goto invalid_datalen;
858
859                 memcpy(sc->sense_buffer, data + 2,
860                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
861                 ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
862                                   min_t(uint16_t, senselen,
863                                   SCSI_SENSE_BUFFERSIZE));
864         }
865
866         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
867                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
868                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
869
870                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
871                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
872                                  res_count <= scsi_in(sc)->length))
873                         scsi_in(sc)->resid = res_count;
874                 else
875                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
876         }
877
878         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
879                            ISCSI_FLAG_CMD_OVERFLOW)) {
880                 int res_count = be32_to_cpu(rhdr->residual_count);
881
882                 if (res_count > 0 &&
883                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
884                      res_count <= scsi_bufflen(sc)))
885                         /* write side for bidi or uni-io set_resid */
886                         scsi_set_resid(sc, res_count);
887                 else
888                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
889         }
890 out:
891         ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
892                           sc, sc->result, task->itt);
893         conn->scsirsp_pdus_cnt++;
894         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
895 }
896
897 /**
898  * iscsi_data_in_rsp - SCSI Data-In Response processing
899  * @conn: iscsi connection
900  * @hdr:  iscsi pdu
901  * @task: scsi command task
902  **/
903 static void
904 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
905                   struct iscsi_task *task)
906 {
907         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
908         struct scsi_cmnd *sc = task->sc;
909
910         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
911                 return;
912
913         iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
914         sc->result = (DID_OK << 16) | rhdr->cmd_status;
915         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
916         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
917                            ISCSI_FLAG_DATA_OVERFLOW)) {
918                 int res_count = be32_to_cpu(rhdr->residual_count);
919
920                 if (res_count > 0 &&
921                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
922                      res_count <= scsi_in(sc)->length))
923                         scsi_in(sc)->resid = res_count;
924                 else
925                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
926         }
927
928         ISCSI_DBG_SESSION(conn->session, "data in with status done "
929                           "[sc %p res %d itt 0x%x]\n",
930                           sc, sc->result, task->itt);
931         conn->scsirsp_pdus_cnt++;
932         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
933 }
934
935 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
936 {
937         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
938
939         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
940         conn->tmfrsp_pdus_cnt++;
941
942         if (conn->tmf_state != TMF_QUEUED)
943                 return;
944
945         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
946                 conn->tmf_state = TMF_SUCCESS;
947         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
948                 conn->tmf_state = TMF_NOT_FOUND;
949         else
950                 conn->tmf_state = TMF_FAILED;
951         wake_up(&conn->ehwait);
952 }
953
954 static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
955 {
956         struct iscsi_nopout hdr;
957         struct iscsi_task *task;
958
959         if (!rhdr && conn->ping_task)
960                 return;
961
962         memset(&hdr, 0, sizeof(struct iscsi_nopout));
963         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
964         hdr.flags = ISCSI_FLAG_CMD_FINAL;
965
966         if (rhdr) {
967                 memcpy(hdr.lun, rhdr->lun, 8);
968                 hdr.ttt = rhdr->ttt;
969                 hdr.itt = RESERVED_ITT;
970         } else
971                 hdr.ttt = RESERVED_ITT;
972
973         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
974         if (!task)
975                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
976         else if (!rhdr) {
977                 /* only track our nops */
978                 conn->ping_task = task;
979                 conn->last_ping = jiffies;
980         }
981 }
982
983 static int iscsi_nop_out_rsp(struct iscsi_task *task,
984                              struct iscsi_nopin *nop, char *data, int datalen)
985 {
986         struct iscsi_conn *conn = task->conn;
987         int rc = 0;
988
989         if (conn->ping_task != task) {
990                 /*
991                  * If this is not in response to one of our
992                  * nops then it must be from userspace.
993                  */
994                 if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
995                                    data, datalen))
996                         rc = ISCSI_ERR_CONN_FAILED;
997         } else
998                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
999         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1000         return rc;
1001 }
1002
1003 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1004                                char *data, int datalen)
1005 {
1006         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1007         struct iscsi_hdr rejected_pdu;
1008         int opcode, rc = 0;
1009
1010         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1011
1012         if (ntoh24(reject->dlength) > datalen ||
1013             ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1014                 iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1015                                   "pdu. Invalid data length (pdu dlength "
1016                                   "%u, datalen %d\n", ntoh24(reject->dlength),
1017                                   datalen);
1018                 return ISCSI_ERR_PROTO;
1019         }
1020         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1021         opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1022
1023         switch (reject->reason) {
1024         case ISCSI_REASON_DATA_DIGEST_ERROR:
1025                 iscsi_conn_printk(KERN_ERR, conn,
1026                                   "pdu (op 0x%x itt 0x%x) rejected "
1027                                   "due to DataDigest error.\n",
1028                                   rejected_pdu.itt, opcode);
1029                 break;
1030         case ISCSI_REASON_IMM_CMD_REJECT:
1031                 iscsi_conn_printk(KERN_ERR, conn,
1032                                   "pdu (op 0x%x itt 0x%x) rejected. Too many "
1033                                   "immediate commands.\n",
1034                                   rejected_pdu.itt, opcode);
1035                 /*
1036                  * We only send one TMF at a time so if the target could not
1037                  * handle it, then it should get fixed (RFC mandates that
1038                  * a target can handle one immediate TMF per conn).
1039                  *
1040                  * For nops-outs, we could have sent more than one if
1041                  * the target is sending us lots of nop-ins
1042                  */
1043                 if (opcode != ISCSI_OP_NOOP_OUT)
1044                         return 0;
1045
1046                  if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG))
1047                         /*
1048                          * nop-out in response to target's nop-out rejected.
1049                          * Just resend.
1050                          */
1051                         iscsi_send_nopout(conn,
1052                                           (struct iscsi_nopin*)&rejected_pdu);
1053                 else {
1054                         struct iscsi_task *task;
1055                         /*
1056                          * Our nop as ping got dropped. We know the target
1057                          * and transport are ok so just clean up
1058                          */
1059                         task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1060                         if (!task) {
1061                                 iscsi_conn_printk(KERN_ERR, conn,
1062                                                  "Invalid pdu reject. Could "
1063                                                  "not lookup rejected task.\n");
1064                                 rc = ISCSI_ERR_BAD_ITT;
1065                         } else
1066                                 rc = iscsi_nop_out_rsp(task,
1067                                         (struct iscsi_nopin*)&rejected_pdu,
1068                                         NULL, 0);
1069                 }
1070                 break;
1071         default:
1072                 iscsi_conn_printk(KERN_ERR, conn,
1073                                   "pdu (op 0x%x itt 0x%x) rejected. Reason "
1074                                   "code 0x%x\n", rejected_pdu.itt,
1075                                   rejected_pdu.opcode, reject->reason);
1076                 break;
1077         }
1078         return rc;
1079 }
1080
1081 /**
1082  * iscsi_itt_to_task - look up task by itt
1083  * @conn: iscsi connection
1084  * @itt: itt
1085  *
1086  * This should be used for mgmt tasks like login and nops, or if
1087  * the LDD's itt space does not include the session age.
1088  *
1089  * The session lock must be held.
1090  */
1091 struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1092 {
1093         struct iscsi_session *session = conn->session;
1094         int i;
1095
1096         if (itt == RESERVED_ITT)
1097                 return NULL;
1098
1099         if (session->tt->parse_pdu_itt)
1100                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1101         else
1102                 i = get_itt(itt);
1103         if (i >= session->cmds_max)
1104                 return NULL;
1105
1106         return session->cmds[i];
1107 }
1108 EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1109
1110 /**
1111  * __iscsi_complete_pdu - complete pdu
1112  * @conn: iscsi conn
1113  * @hdr: iscsi header
1114  * @data: data buffer
1115  * @datalen: len of data buffer
1116  *
1117  * Completes pdu processing by freeing any resources allocated at
1118  * queuecommand or send generic. session lock must be held and verify
1119  * itt must have been called.
1120  */
1121 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1122                          char *data, int datalen)
1123 {
1124         struct iscsi_session *session = conn->session;
1125         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1126         struct iscsi_task *task;
1127         uint32_t itt;
1128
1129         conn->last_recv = jiffies;
1130         rc = iscsi_verify_itt(conn, hdr->itt);
1131         if (rc)
1132                 return rc;
1133
1134         if (hdr->itt != RESERVED_ITT)
1135                 itt = get_itt(hdr->itt);
1136         else
1137                 itt = ~0U;
1138
1139         ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1140                           opcode, conn->id, itt, datalen);
1141
1142         if (itt == ~0U) {
1143                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1144
1145                 switch(opcode) {
1146                 case ISCSI_OP_NOOP_IN:
1147                         if (datalen) {
1148                                 rc = ISCSI_ERR_PROTO;
1149                                 break;
1150                         }
1151
1152                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1153                                 break;
1154
1155                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1156                         break;
1157                 case ISCSI_OP_REJECT:
1158                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
1159                         break;
1160                 case ISCSI_OP_ASYNC_EVENT:
1161                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1162                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1163                                 rc = ISCSI_ERR_CONN_FAILED;
1164                         break;
1165                 default:
1166                         rc = ISCSI_ERR_BAD_OPCODE;
1167                         break;
1168                 }
1169                 goto out;
1170         }
1171
1172         switch(opcode) {
1173         case ISCSI_OP_SCSI_CMD_RSP:
1174         case ISCSI_OP_SCSI_DATA_IN:
1175                 task = iscsi_itt_to_ctask(conn, hdr->itt);
1176                 if (!task)
1177                         return ISCSI_ERR_BAD_ITT;
1178                 task->last_xfer = jiffies;
1179                 break;
1180         case ISCSI_OP_R2T:
1181                 /*
1182                  * LLD handles R2Ts if they need to.
1183                  */
1184                 return 0;
1185         case ISCSI_OP_LOGOUT_RSP:
1186         case ISCSI_OP_LOGIN_RSP:
1187         case ISCSI_OP_TEXT_RSP:
1188         case ISCSI_OP_SCSI_TMFUNC_RSP:
1189         case ISCSI_OP_NOOP_IN:
1190                 task = iscsi_itt_to_task(conn, hdr->itt);
1191                 if (!task)
1192                         return ISCSI_ERR_BAD_ITT;
1193                 break;
1194         default:
1195                 return ISCSI_ERR_BAD_OPCODE;
1196         }
1197
1198         switch(opcode) {
1199         case ISCSI_OP_SCSI_CMD_RSP:
1200                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1201                 break;
1202         case ISCSI_OP_SCSI_DATA_IN:
1203                 iscsi_data_in_rsp(conn, hdr, task);
1204                 break;
1205         case ISCSI_OP_LOGOUT_RSP:
1206                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1207                 if (datalen) {
1208                         rc = ISCSI_ERR_PROTO;
1209                         break;
1210                 }
1211                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1212                 goto recv_pdu;
1213         case ISCSI_OP_LOGIN_RSP:
1214         case ISCSI_OP_TEXT_RSP:
1215                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1216                 /*
1217                  * login related PDU's exp_statsn is handled in
1218                  * userspace
1219                  */
1220                 goto recv_pdu;
1221         case ISCSI_OP_SCSI_TMFUNC_RSP:
1222                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1223                 if (datalen) {
1224                         rc = ISCSI_ERR_PROTO;
1225                         break;
1226                 }
1227
1228                 iscsi_tmf_rsp(conn, hdr);
1229                 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1230                 break;
1231         case ISCSI_OP_NOOP_IN:
1232                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1233                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1234                         rc = ISCSI_ERR_PROTO;
1235                         break;
1236                 }
1237                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1238
1239                 rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1240                                        data, datalen);
1241                 break;
1242         default:
1243                 rc = ISCSI_ERR_BAD_OPCODE;
1244                 break;
1245         }
1246
1247 out:
1248         return rc;
1249 recv_pdu:
1250         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1251                 rc = ISCSI_ERR_CONN_FAILED;
1252         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1253         return rc;
1254 }
1255 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1256
1257 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1258                        char *data, int datalen)
1259 {
1260         int rc;
1261
1262         spin_lock(&conn->session->lock);
1263         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1264         spin_unlock(&conn->session->lock);
1265         return rc;
1266 }
1267 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1268
1269 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1270 {
1271         struct iscsi_session *session = conn->session;
1272         int age = 0, i = 0;
1273
1274         if (itt == RESERVED_ITT)
1275                 return 0;
1276
1277         if (session->tt->parse_pdu_itt)
1278                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
1279         else {
1280                 i = get_itt(itt);
1281                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1282         }
1283
1284         if (age != session->age) {
1285                 iscsi_conn_printk(KERN_ERR, conn,
1286                                   "received itt %x expected session age (%x)\n",
1287                                   (__force u32)itt, session->age);
1288                 return ISCSI_ERR_BAD_ITT;
1289         }
1290
1291         if (i >= session->cmds_max) {
1292                 iscsi_conn_printk(KERN_ERR, conn,
1293                                   "received invalid itt index %u (max cmds "
1294                                    "%u.\n", i, session->cmds_max);
1295                 return ISCSI_ERR_BAD_ITT;
1296         }
1297         return 0;
1298 }
1299 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1300
1301 /**
1302  * iscsi_itt_to_ctask - look up ctask by itt
1303  * @conn: iscsi connection
1304  * @itt: itt
1305  *
1306  * This should be used for cmd tasks.
1307  *
1308  * The session lock must be held.
1309  */
1310 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1311 {
1312         struct iscsi_task *task;
1313
1314         if (iscsi_verify_itt(conn, itt))
1315                 return NULL;
1316
1317         task = iscsi_itt_to_task(conn, itt);
1318         if (!task || !task->sc)
1319                 return NULL;
1320
1321         if (task->sc->SCp.phase != conn->session->age) {
1322                 iscsi_session_printk(KERN_ERR, conn->session,
1323                                   "task's session age %d, expected %d\n",
1324                                   task->sc->SCp.phase, conn->session->age);
1325                 return NULL;
1326         }
1327
1328         return task;
1329 }
1330 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1331
1332 void iscsi_session_failure(struct iscsi_session *session,
1333                            enum iscsi_err err)
1334 {
1335         struct iscsi_conn *conn;
1336         struct device *dev;
1337         unsigned long flags;
1338
1339         spin_lock_irqsave(&session->lock, flags);
1340         conn = session->leadconn;
1341         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1342                 spin_unlock_irqrestore(&session->lock, flags);
1343                 return;
1344         }
1345
1346         dev = get_device(&conn->cls_conn->dev);
1347         spin_unlock_irqrestore(&session->lock, flags);
1348         if (!dev)
1349                 return;
1350         /*
1351          * if the host is being removed bypass the connection
1352          * recovery initialization because we are going to kill
1353          * the session.
1354          */
1355         if (err == ISCSI_ERR_INVALID_HOST)
1356                 iscsi_conn_error_event(conn->cls_conn, err);
1357         else
1358                 iscsi_conn_failure(conn, err);
1359         put_device(dev);
1360 }
1361 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1362
1363 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1364 {
1365         struct iscsi_session *session = conn->session;
1366         unsigned long flags;
1367
1368         spin_lock_irqsave(&session->lock, flags);
1369         if (session->state == ISCSI_STATE_FAILED) {
1370                 spin_unlock_irqrestore(&session->lock, flags);
1371                 return;
1372         }
1373
1374         if (conn->stop_stage == 0)
1375                 session->state = ISCSI_STATE_FAILED;
1376         spin_unlock_irqrestore(&session->lock, flags);
1377
1378         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1379         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1380         iscsi_conn_error_event(conn->cls_conn, err);
1381 }
1382 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1383
1384 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1385 {
1386         struct iscsi_session *session = conn->session;
1387
1388         /*
1389          * Check for iSCSI window and take care of CmdSN wrap-around
1390          */
1391         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1392                 ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1393                                   "%u MaxCmdSN %u CmdSN %u/%u\n",
1394                                   session->exp_cmdsn, session->max_cmdsn,
1395                                   session->cmdsn, session->queued_cmdsn);
1396                 return -ENOSPC;
1397         }
1398         return 0;
1399 }
1400
1401 static int iscsi_xmit_task(struct iscsi_conn *conn)
1402 {
1403         struct iscsi_task *task = conn->task;
1404         int rc;
1405
1406         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
1407                 return -ENODATA;
1408
1409         __iscsi_get_task(task);
1410         spin_unlock_bh(&conn->session->lock);
1411         rc = conn->session->tt->xmit_task(task);
1412         spin_lock_bh(&conn->session->lock);
1413         if (!rc) {
1414                 /* done with this task */
1415                 task->last_xfer = jiffies;
1416                 conn->task = NULL;
1417         }
1418         __iscsi_put_task(task);
1419         return rc;
1420 }
1421
1422 /**
1423  * iscsi_requeue_task - requeue task to run from session workqueue
1424  * @task: task to requeue
1425  *
1426  * LLDs that need to run a task from the session workqueue should call
1427  * this. The session lock must be held. This should only be called
1428  * by software drivers.
1429  */
1430 void iscsi_requeue_task(struct iscsi_task *task)
1431 {
1432         struct iscsi_conn *conn = task->conn;
1433
1434         /*
1435          * this may be on the requeue list already if the xmit_task callout
1436          * is handling the r2ts while we are adding new ones
1437          */
1438         if (list_empty(&task->running))
1439                 list_add_tail(&task->running, &conn->requeue);
1440         iscsi_conn_queue_work(conn);
1441 }
1442 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1443
1444 /**
1445  * iscsi_data_xmit - xmit any command into the scheduled connection
1446  * @conn: iscsi connection
1447  *
1448  * Notes:
1449  *      The function can return -EAGAIN in which case the caller must
1450  *      re-schedule it again later or recover. '0' return code means
1451  *      successful xmit.
1452  **/
1453 static int iscsi_data_xmit(struct iscsi_conn *conn)
1454 {
1455         struct iscsi_task *task;
1456         int rc = 0;
1457
1458         spin_lock_bh(&conn->session->lock);
1459         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1460                 ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1461                 spin_unlock_bh(&conn->session->lock);
1462                 return -ENODATA;
1463         }
1464
1465         if (conn->task) {
1466                 rc = iscsi_xmit_task(conn);
1467                 if (rc)
1468                         goto done;
1469         }
1470
1471         /*
1472          * process mgmt pdus like nops before commands since we should
1473          * only have one nop-out as a ping from us and targets should not
1474          * overflow us with nop-ins
1475          */
1476 check_mgmt:
1477         while (!list_empty(&conn->mgmtqueue)) {
1478                 conn->task = list_entry(conn->mgmtqueue.next,
1479                                          struct iscsi_task, running);
1480                 list_del_init(&conn->task->running);
1481                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1482                         __iscsi_put_task(conn->task);
1483                         conn->task = NULL;
1484                         continue;
1485                 }
1486                 rc = iscsi_xmit_task(conn);
1487                 if (rc)
1488                         goto done;
1489         }
1490
1491         /* process pending command queue */
1492         while (!list_empty(&conn->cmdqueue)) {
1493                 conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1494                                         running);
1495                 list_del_init(&conn->task->running);
1496                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1497                         fail_scsi_task(conn->task, DID_IMM_RETRY);
1498                         continue;
1499                 }
1500                 rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1501                 if (rc) {
1502                         if (rc == -ENOMEM || rc == -EACCES) {
1503                                 list_add_tail(&conn->task->running,
1504                                               &conn->cmdqueue);
1505                                 conn->task = NULL;
1506                                 goto done;
1507                         } else
1508                                 fail_scsi_task(conn->task, DID_ABORT);
1509                         continue;
1510                 }
1511                 rc = iscsi_xmit_task(conn);
1512                 if (rc)
1513                         goto done;
1514                 /*
1515                  * we could continuously get new task requests so
1516                  * we need to check the mgmt queue for nops that need to
1517                  * be sent to aviod starvation
1518                  */
1519                 if (!list_empty(&conn->mgmtqueue))
1520                         goto check_mgmt;
1521         }
1522
1523         while (!list_empty(&conn->requeue)) {
1524                 /*
1525                  * we always do fastlogout - conn stop code will clean up.
1526                  */
1527                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1528                         break;
1529
1530                 task = list_entry(conn->requeue.next, struct iscsi_task,
1531                                   running);
1532                 if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1533                         break;
1534
1535                 conn->task = task;
1536                 list_del_init(&conn->task->running);
1537                 conn->task->state = ISCSI_TASK_RUNNING;
1538                 rc = iscsi_xmit_task(conn);
1539                 if (rc)
1540                         goto done;
1541                 if (!list_empty(&conn->mgmtqueue))
1542                         goto check_mgmt;
1543         }
1544         spin_unlock_bh(&conn->session->lock);
1545         return -ENODATA;
1546
1547 done:
1548         spin_unlock_bh(&conn->session->lock);
1549         return rc;
1550 }
1551
1552 static void iscsi_xmitworker(struct work_struct *work)
1553 {
1554         struct iscsi_conn *conn =
1555                 container_of(work, struct iscsi_conn, xmitwork);
1556         int rc;
1557         /*
1558          * serialize Xmit worker on a per-connection basis.
1559          */
1560         do {
1561                 rc = iscsi_data_xmit(conn);
1562         } while (rc >= 0 || rc == -EAGAIN);
1563 }
1564
1565 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1566                                                   struct scsi_cmnd *sc)
1567 {
1568         struct iscsi_task *task;
1569
1570         if (!__kfifo_get(conn->session->cmdpool.queue,
1571                          (void *) &task, sizeof(void *)))
1572                 return NULL;
1573
1574         sc->SCp.phase = conn->session->age;
1575         sc->SCp.ptr = (char *) task;
1576
1577         atomic_set(&task->refcount, 1);
1578         task->state = ISCSI_TASK_PENDING;
1579         task->conn = conn;
1580         task->sc = sc;
1581         task->have_checked_conn = false;
1582         task->last_timeout = jiffies;
1583         task->last_xfer = jiffies;
1584         INIT_LIST_HEAD(&task->running);
1585         return task;
1586 }
1587
1588 enum {
1589         FAILURE_BAD_HOST = 1,
1590         FAILURE_SESSION_FAILED,
1591         FAILURE_SESSION_FREED,
1592         FAILURE_WINDOW_CLOSED,
1593         FAILURE_OOM,
1594         FAILURE_SESSION_TERMINATE,
1595         FAILURE_SESSION_IN_RECOVERY,
1596         FAILURE_SESSION_RECOVERY_TIMEOUT,
1597         FAILURE_SESSION_LOGGING_OUT,
1598         FAILURE_SESSION_NOT_READY,
1599 };
1600
1601 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
1602 {
1603         struct iscsi_cls_session *cls_session;
1604         struct Scsi_Host *host;
1605         struct iscsi_host *ihost;
1606         int reason = 0;
1607         struct iscsi_session *session;
1608         struct iscsi_conn *conn;
1609         struct iscsi_task *task = NULL;
1610
1611         sc->scsi_done = done;
1612         sc->result = 0;
1613         sc->SCp.ptr = NULL;
1614
1615         host = sc->device->host;
1616         ihost = shost_priv(host);
1617         spin_unlock(host->host_lock);
1618
1619         cls_session = starget_to_session(scsi_target(sc->device));
1620         session = cls_session->dd_data;
1621         spin_lock(&session->lock);
1622
1623         reason = iscsi_session_chkready(cls_session);
1624         if (reason) {
1625                 sc->result = reason;
1626                 goto fault;
1627         }
1628
1629         if (session->state != ISCSI_STATE_LOGGED_IN) {
1630                 /*
1631                  * to handle the race between when we set the recovery state
1632                  * and block the session we requeue here (commands could
1633                  * be entering our queuecommand while a block is starting
1634                  * up because the block code is not locked)
1635                  */
1636                 switch (session->state) {
1637                 case ISCSI_STATE_FAILED:
1638                 case ISCSI_STATE_IN_RECOVERY:
1639                         reason = FAILURE_SESSION_IN_RECOVERY;
1640                         sc->result = DID_IMM_RETRY << 16;
1641                         break;
1642                 case ISCSI_STATE_LOGGING_OUT:
1643                         reason = FAILURE_SESSION_LOGGING_OUT;
1644                         sc->result = DID_IMM_RETRY << 16;
1645                         break;
1646                 case ISCSI_STATE_RECOVERY_FAILED:
1647                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1648                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1649                         break;
1650                 case ISCSI_STATE_TERMINATE:
1651                         reason = FAILURE_SESSION_TERMINATE;
1652                         sc->result = DID_NO_CONNECT << 16;
1653                         break;
1654                 default:
1655                         reason = FAILURE_SESSION_FREED;
1656                         sc->result = DID_NO_CONNECT << 16;
1657                 }
1658                 goto fault;
1659         }
1660
1661         conn = session->leadconn;
1662         if (!conn) {
1663                 reason = FAILURE_SESSION_FREED;
1664                 sc->result = DID_NO_CONNECT << 16;
1665                 goto fault;
1666         }
1667
1668         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1669                 reason = FAILURE_SESSION_IN_RECOVERY;
1670                 sc->result = DID_REQUEUE;
1671                 goto fault;
1672         }
1673
1674         if (iscsi_check_cmdsn_window_closed(conn)) {
1675                 reason = FAILURE_WINDOW_CLOSED;
1676                 goto reject;
1677         }
1678
1679         task = iscsi_alloc_task(conn, sc);
1680         if (!task) {
1681                 reason = FAILURE_OOM;
1682                 goto reject;
1683         }
1684
1685         if (!ihost->workq) {
1686                 reason = iscsi_prep_scsi_cmd_pdu(task);
1687                 if (reason) {
1688                         if (reason == -ENOMEM ||  reason == -EACCES) {
1689                                 reason = FAILURE_OOM;
1690                                 goto prepd_reject;
1691                         } else {
1692                                 sc->result = DID_ABORT << 16;
1693                                 goto prepd_fault;
1694                         }
1695                 }
1696                 if (session->tt->xmit_task(task)) {
1697                         session->cmdsn--;
1698                         reason = FAILURE_SESSION_NOT_READY;
1699                         goto prepd_reject;
1700                 }
1701         } else {
1702                 list_add_tail(&task->running, &conn->cmdqueue);
1703                 iscsi_conn_queue_work(conn);
1704         }
1705
1706         session->queued_cmdsn++;
1707         spin_unlock(&session->lock);
1708         spin_lock(host->host_lock);
1709         return 0;
1710
1711 prepd_reject:
1712         sc->scsi_done = NULL;
1713         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1714 reject:
1715         spin_unlock(&session->lock);
1716         ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1717                           sc->cmnd[0], reason);
1718         spin_lock(host->host_lock);
1719         return SCSI_MLQUEUE_TARGET_BUSY;
1720
1721 prepd_fault:
1722         sc->scsi_done = NULL;
1723         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1724 fault:
1725         spin_unlock(&session->lock);
1726         ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1727                           sc->cmnd[0], reason);
1728         if (!scsi_bidi_cmnd(sc))
1729                 scsi_set_resid(sc, scsi_bufflen(sc));
1730         else {
1731                 scsi_out(sc)->resid = scsi_out(sc)->length;
1732                 scsi_in(sc)->resid = scsi_in(sc)->length;
1733         }
1734         done(sc);
1735         spin_lock(host->host_lock);
1736         return 0;
1737 }
1738 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1739
1740 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth, int reason)
1741 {
1742         if (reason != SCSI_QDEPTH_DEFAULT)
1743                 return -EOPNOTSUPP;
1744
1745         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1746         return sdev->queue_depth;
1747 }
1748 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1749
1750 int iscsi_target_alloc(struct scsi_target *starget)
1751 {
1752         struct iscsi_cls_session *cls_session = starget_to_session(starget);
1753         struct iscsi_session *session = cls_session->dd_data;
1754
1755         starget->can_queue = session->scsi_cmds_max;
1756         return 0;
1757 }
1758 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1759
1760 static void iscsi_tmf_timedout(unsigned long data)
1761 {
1762         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1763         struct iscsi_session *session = conn->session;
1764
1765         spin_lock(&session->lock);
1766         if (conn->tmf_state == TMF_QUEUED) {
1767                 conn->tmf_state = TMF_TIMEDOUT;
1768                 ISCSI_DBG_EH(session, "tmf timedout\n");
1769                 /* unblock eh_abort() */
1770                 wake_up(&conn->ehwait);
1771         }
1772         spin_unlock(&session->lock);
1773 }
1774
1775 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1776                                    struct iscsi_tm *hdr, int age,
1777                                    int timeout)
1778 {
1779         struct iscsi_session *session = conn->session;
1780         struct iscsi_task *task;
1781
1782         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1783                                       NULL, 0);
1784         if (!task) {
1785                 spin_unlock_bh(&session->lock);
1786                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1787                 spin_lock_bh(&session->lock);
1788                 ISCSI_DBG_EH(session, "tmf exec failure\n");
1789                 return -EPERM;
1790         }
1791         conn->tmfcmd_pdus_cnt++;
1792         conn->tmf_timer.expires = timeout * HZ + jiffies;
1793         conn->tmf_timer.function = iscsi_tmf_timedout;
1794         conn->tmf_timer.data = (unsigned long)conn;
1795         add_timer(&conn->tmf_timer);
1796         ISCSI_DBG_EH(session, "tmf set timeout\n");
1797
1798         spin_unlock_bh(&session->lock);
1799         mutex_unlock(&session->eh_mutex);
1800
1801         /*
1802          * block eh thread until:
1803          *
1804          * 1) tmf response
1805          * 2) tmf timeout
1806          * 3) session is terminated or restarted or userspace has
1807          * given up on recovery
1808          */
1809         wait_event_interruptible(conn->ehwait, age != session->age ||
1810                                  session->state != ISCSI_STATE_LOGGED_IN ||
1811                                  conn->tmf_state != TMF_QUEUED);
1812         if (signal_pending(current))
1813                 flush_signals(current);
1814         del_timer_sync(&conn->tmf_timer);
1815
1816         mutex_lock(&session->eh_mutex);
1817         spin_lock_bh(&session->lock);
1818         /* if the session drops it will clean up the task */
1819         if (age != session->age ||
1820             session->state != ISCSI_STATE_LOGGED_IN)
1821                 return -ENOTCONN;
1822         return 0;
1823 }
1824
1825 /*
1826  * Fail commands. session lock held and recv side suspended and xmit
1827  * thread flushed
1828  */
1829 static void fail_scsi_tasks(struct iscsi_conn *conn, unsigned lun,
1830                             int error)
1831 {
1832         struct iscsi_task *task;
1833         int i;
1834
1835         for (i = 0; i < conn->session->cmds_max; i++) {
1836                 task = conn->session->cmds[i];
1837                 if (!task->sc || task->state == ISCSI_TASK_FREE)
1838                         continue;
1839
1840                 if (lun != -1 && lun != task->sc->device->lun)
1841                         continue;
1842
1843                 ISCSI_DBG_SESSION(conn->session,
1844                                   "failing sc %p itt 0x%x state %d\n",
1845                                   task->sc, task->itt, task->state);
1846                 fail_scsi_task(task, error);
1847         }
1848 }
1849
1850 /**
1851  * iscsi_suspend_queue - suspend iscsi_queuecommand
1852  * @conn: iscsi conn to stop queueing IO on
1853  *
1854  * This grabs the session lock to make sure no one is in
1855  * xmit_task/queuecommand, and then sets suspend to prevent
1856  * new commands from being queued. This only needs to be called
1857  * by offload drivers that need to sync a path like ep disconnect
1858  * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1859  * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1860  */
1861 void iscsi_suspend_queue(struct iscsi_conn *conn)
1862 {
1863         spin_lock_bh(&conn->session->lock);
1864         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1865         spin_unlock_bh(&conn->session->lock);
1866 }
1867 EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1868
1869 /**
1870  * iscsi_suspend_tx - suspend iscsi_data_xmit
1871  * @conn: iscsi conn tp stop processing IO on.
1872  *
1873  * This function sets the suspend bit to prevent iscsi_data_xmit
1874  * from sending new IO, and if work is queued on the xmit thread
1875  * it will wait for it to be completed.
1876  */
1877 void iscsi_suspend_tx(struct iscsi_conn *conn)
1878 {
1879         struct Scsi_Host *shost = conn->session->host;
1880         struct iscsi_host *ihost = shost_priv(shost);
1881
1882         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1883         if (ihost->workq)
1884                 flush_workqueue(ihost->workq);
1885 }
1886 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1887
1888 static void iscsi_start_tx(struct iscsi_conn *conn)
1889 {
1890         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1891         iscsi_conn_queue_work(conn);
1892 }
1893
1894 /*
1895  * We want to make sure a ping is in flight. It has timed out.
1896  * And we are not busy processing a pdu that is making
1897  * progress but got started before the ping and is taking a while
1898  * to complete so the ping is just stuck behind it in a queue.
1899  */
1900 static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1901 {
1902         if (conn->ping_task &&
1903             time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1904                            (conn->ping_timeout * HZ), jiffies))
1905                 return 1;
1906         else
1907                 return 0;
1908 }
1909
1910 static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1911 {
1912         enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1913         struct iscsi_task *task = NULL;
1914         struct iscsi_cls_session *cls_session;
1915         struct iscsi_session *session;
1916         struct iscsi_conn *conn;
1917
1918         cls_session = starget_to_session(scsi_target(sc->device));
1919         session = cls_session->dd_data;
1920
1921         ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1922
1923         spin_lock(&session->lock);
1924         if (session->state != ISCSI_STATE_LOGGED_IN) {
1925                 /*
1926                  * We are probably in the middle of iscsi recovery so let
1927                  * that complete and handle the error.
1928                  */
1929                 rc = BLK_EH_RESET_TIMER;
1930                 goto done;
1931         }
1932
1933         conn = session->leadconn;
1934         if (!conn) {
1935                 /* In the middle of shuting down */
1936                 rc = BLK_EH_RESET_TIMER;
1937                 goto done;
1938         }
1939
1940         task = (struct iscsi_task *)sc->SCp.ptr;
1941         if (!task)
1942                 goto done;
1943         /*
1944          * If we have sent (at least queued to the network layer) a pdu or
1945          * recvd one for the task since the last timeout ask for
1946          * more time. If on the next timeout we have not made progress
1947          * we can check if it is the task or connection when we send the
1948          * nop as a ping.
1949          */
1950         if (time_after_eq(task->last_xfer, task->last_timeout)) {
1951                 ISCSI_DBG_EH(session, "Command making progress. Asking "
1952                              "scsi-ml for more time to complete. "
1953                              "Last data recv at %lu. Last timeout was at "
1954                              "%lu\n.", task->last_xfer, task->last_timeout);
1955                 task->have_checked_conn = false;
1956                 rc = BLK_EH_RESET_TIMER;
1957                 goto done;
1958         }
1959
1960         if (!conn->recv_timeout && !conn->ping_timeout)
1961                 goto done;
1962         /*
1963          * if the ping timedout then we are in the middle of cleaning up
1964          * and can let the iscsi eh handle it
1965          */
1966         if (iscsi_has_ping_timed_out(conn)) {
1967                 rc = BLK_EH_RESET_TIMER;
1968                 goto done;
1969         }
1970
1971         /* Assumes nop timeout is shorter than scsi cmd timeout */
1972         if (task->have_checked_conn)
1973                 goto done;
1974
1975         /*
1976          * Checking the transport already or nop from a cmd timeout still
1977          * running
1978          */
1979         if (conn->ping_task) {
1980                 task->have_checked_conn = true;
1981                 rc = BLK_EH_RESET_TIMER;
1982                 goto done;
1983         }
1984
1985         /* Make sure there is a transport check done */
1986         iscsi_send_nopout(conn, NULL);
1987         task->have_checked_conn = true;
1988         rc = BLK_EH_RESET_TIMER;
1989
1990 done:
1991         if (task)
1992                 task->last_timeout = jiffies;
1993         spin_unlock(&session->lock);
1994         ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
1995                      "timer reset" : "nh");
1996         return rc;
1997 }
1998
1999 static void iscsi_check_transport_timeouts(unsigned long data)
2000 {
2001         struct iscsi_conn *conn = (struct iscsi_conn *)data;
2002         struct iscsi_session *session = conn->session;
2003         unsigned long recv_timeout, next_timeout = 0, last_recv;
2004
2005         spin_lock(&session->lock);
2006         if (session->state != ISCSI_STATE_LOGGED_IN)
2007                 goto done;
2008
2009         recv_timeout = conn->recv_timeout;
2010         if (!recv_timeout)
2011                 goto done;
2012
2013         recv_timeout *= HZ;
2014         last_recv = conn->last_recv;
2015
2016         if (iscsi_has_ping_timed_out(conn)) {
2017                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2018                                   "expired, recv timeout %d, last rx %lu, "
2019                                   "last ping %lu, now %lu\n",
2020                                   conn->ping_timeout, conn->recv_timeout,
2021                                   last_recv, conn->last_ping, jiffies);
2022                 spin_unlock(&session->lock);
2023                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
2024                 return;
2025         }
2026
2027         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2028                 /* send a ping to try to provoke some traffic */
2029                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2030                 iscsi_send_nopout(conn, NULL);
2031                 next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2032         } else
2033                 next_timeout = last_recv + recv_timeout;
2034
2035         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2036         mod_timer(&conn->transport_timer, next_timeout);
2037 done:
2038         spin_unlock(&session->lock);
2039 }
2040
2041 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2042                                       struct iscsi_tm *hdr)
2043 {
2044         memset(hdr, 0, sizeof(*hdr));
2045         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2046         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2047         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2048         memcpy(hdr->lun, task->lun, sizeof(hdr->lun));
2049         hdr->rtt = task->hdr_itt;
2050         hdr->refcmdsn = task->cmdsn;
2051 }
2052
2053 int iscsi_eh_abort(struct scsi_cmnd *sc)
2054 {
2055         struct iscsi_cls_session *cls_session;
2056         struct iscsi_session *session;
2057         struct iscsi_conn *conn;
2058         struct iscsi_task *task;
2059         struct iscsi_tm *hdr;
2060         int rc, age;
2061
2062         cls_session = starget_to_session(scsi_target(sc->device));
2063         session = cls_session->dd_data;
2064
2065         ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2066
2067         mutex_lock(&session->eh_mutex);
2068         spin_lock_bh(&session->lock);
2069         /*
2070          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2071          * got the command.
2072          */
2073         if (!sc->SCp.ptr) {
2074                 ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2075                                       "it completed.\n");
2076                 spin_unlock_bh(&session->lock);
2077                 mutex_unlock(&session->eh_mutex);
2078                 return SUCCESS;
2079         }
2080
2081         /*
2082          * If we are not logged in or we have started a new session
2083          * then let the host reset code handle this
2084          */
2085         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2086             sc->SCp.phase != session->age) {
2087                 spin_unlock_bh(&session->lock);
2088                 mutex_unlock(&session->eh_mutex);
2089                 ISCSI_DBG_EH(session, "failing abort due to dropped "
2090                                   "session.\n");
2091                 return FAILED;
2092         }
2093
2094         conn = session->leadconn;
2095         conn->eh_abort_cnt++;
2096         age = session->age;
2097
2098         task = (struct iscsi_task *)sc->SCp.ptr;
2099         ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2100                      sc, task->itt);
2101
2102         /* task completed before time out */
2103         if (!task->sc) {
2104                 ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2105                 goto success;
2106         }
2107
2108         if (task->state == ISCSI_TASK_PENDING) {
2109                 fail_scsi_task(task, DID_ABORT);
2110                 goto success;
2111         }
2112
2113         /* only have one tmf outstanding at a time */
2114         if (conn->tmf_state != TMF_INITIAL)
2115                 goto failed;
2116         conn->tmf_state = TMF_QUEUED;
2117
2118         hdr = &conn->tmhdr;
2119         iscsi_prep_abort_task_pdu(task, hdr);
2120
2121         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
2122                 rc = FAILED;
2123                 goto failed;
2124         }
2125
2126         switch (conn->tmf_state) {
2127         case TMF_SUCCESS:
2128                 spin_unlock_bh(&session->lock);
2129                 /*
2130                  * stop tx side incase the target had sent a abort rsp but
2131                  * the initiator was still writing out data.
2132                  */
2133                 iscsi_suspend_tx(conn);
2134                 /*
2135                  * we do not stop the recv side because targets have been
2136                  * good and have never sent us a successful tmf response
2137                  * then sent more data for the cmd.
2138                  */
2139                 spin_lock_bh(&session->lock);
2140                 fail_scsi_task(task, DID_ABORT);
2141                 conn->tmf_state = TMF_INITIAL;
2142                 memset(hdr, 0, sizeof(*hdr));
2143                 spin_unlock_bh(&session->lock);
2144                 iscsi_start_tx(conn);
2145                 goto success_unlocked;
2146         case TMF_TIMEDOUT:
2147                 spin_unlock_bh(&session->lock);
2148                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
2149                 goto failed_unlocked;
2150         case TMF_NOT_FOUND:
2151                 if (!sc->SCp.ptr) {
2152                         conn->tmf_state = TMF_INITIAL;
2153                         memset(hdr, 0, sizeof(*hdr));
2154                         /* task completed before tmf abort response */
2155                         ISCSI_DBG_EH(session, "sc completed while abort in "
2156                                               "progress\n");
2157                         goto success;
2158                 }
2159                 /* fall through */
2160         default:
2161                 conn->tmf_state = TMF_INITIAL;
2162                 goto failed;
2163         }
2164
2165 success:
2166         spin_unlock_bh(&session->lock);
2167 success_unlocked:
2168         ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2169                      sc, task->itt);
2170         mutex_unlock(&session->eh_mutex);
2171         return SUCCESS;
2172
2173 failed:
2174         spin_unlock_bh(&session->lock);
2175 failed_unlocked:
2176         ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2177                      task ? task->itt : 0);
2178         mutex_unlock(&session->eh_mutex);
2179         return FAILED;
2180 }
2181 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2182
2183 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2184 {
2185         memset(hdr, 0, sizeof(*hdr));
2186         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2187         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2188         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2189         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
2190         hdr->rtt = RESERVED_ITT;
2191 }
2192
2193 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2194 {
2195         struct iscsi_cls_session *cls_session;
2196         struct iscsi_session *session;
2197         struct iscsi_conn *conn;
2198         struct iscsi_tm *hdr;
2199         int rc = FAILED;
2200
2201         cls_session = starget_to_session(scsi_target(sc->device));
2202         session = cls_session->dd_data;
2203
2204         ISCSI_DBG_EH(session, "LU Reset [sc %p lun %u]\n", sc, sc->device->lun);
2205
2206         mutex_lock(&session->eh_mutex);
2207         spin_lock_bh(&session->lock);
2208         /*
2209          * Just check if we are not logged in. We cannot check for
2210          * the phase because the reset could come from a ioctl.
2211          */
2212         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2213                 goto unlock;
2214         conn = session->leadconn;
2215
2216         /* only have one tmf outstanding at a time */
2217         if (conn->tmf_state != TMF_INITIAL)
2218                 goto unlock;
2219         conn->tmf_state = TMF_QUEUED;
2220
2221         hdr = &conn->tmhdr;
2222         iscsi_prep_lun_reset_pdu(sc, hdr);
2223
2224         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2225                                     session->lu_reset_timeout)) {
2226                 rc = FAILED;
2227                 goto unlock;
2228         }
2229
2230         switch (conn->tmf_state) {
2231         case TMF_SUCCESS:
2232                 break;
2233         case TMF_TIMEDOUT:
2234                 spin_unlock_bh(&session->lock);
2235                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
2236                 goto done;
2237         default:
2238                 conn->tmf_state = TMF_INITIAL;
2239                 goto unlock;
2240         }
2241
2242         rc = SUCCESS;
2243         spin_unlock_bh(&session->lock);
2244
2245         iscsi_suspend_tx(conn);
2246
2247         spin_lock_bh(&session->lock);
2248         memset(hdr, 0, sizeof(*hdr));
2249         fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2250         conn->tmf_state = TMF_INITIAL;
2251         spin_unlock_bh(&session->lock);
2252
2253         iscsi_start_tx(conn);
2254         goto done;
2255
2256 unlock:
2257         spin_unlock_bh(&session->lock);
2258 done:
2259         ISCSI_DBG_EH(session, "dev reset result = %s\n",
2260                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2261         mutex_unlock(&session->eh_mutex);
2262         return rc;
2263 }
2264 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2265
2266 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2267 {
2268         struct iscsi_session *session = cls_session->dd_data;
2269
2270         spin_lock_bh(&session->lock);
2271         if (session->state != ISCSI_STATE_LOGGED_IN) {
2272                 session->state = ISCSI_STATE_RECOVERY_FAILED;
2273                 if (session->leadconn)
2274                         wake_up(&session->leadconn->ehwait);
2275         }
2276         spin_unlock_bh(&session->lock);
2277 }
2278 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2279
2280 /**
2281  * iscsi_eh_session_reset - drop session and attempt relogin
2282  * @sc: scsi command
2283  *
2284  * This function will wait for a relogin, session termination from
2285  * userspace, or a recovery/replacement timeout.
2286  */
2287 static int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2288 {
2289         struct iscsi_cls_session *cls_session;
2290         struct iscsi_session *session;
2291         struct iscsi_conn *conn;
2292
2293         cls_session = starget_to_session(scsi_target(sc->device));
2294         session = cls_session->dd_data;
2295         conn = session->leadconn;
2296
2297         mutex_lock(&session->eh_mutex);
2298         spin_lock_bh(&session->lock);
2299         if (session->state == ISCSI_STATE_TERMINATE) {
2300 failed:
2301                 ISCSI_DBG_EH(session,
2302                              "failing session reset: Could not log back into "
2303                              "%s, %s [age %d]\n", session->targetname,
2304                              conn->persistent_address, session->age);
2305                 spin_unlock_bh(&session->lock);
2306                 mutex_unlock(&session->eh_mutex);
2307                 return FAILED;
2308         }
2309
2310         spin_unlock_bh(&session->lock);
2311         mutex_unlock(&session->eh_mutex);
2312         /*
2313          * we drop the lock here but the leadconn cannot be destoyed while
2314          * we are in the scsi eh
2315          */
2316         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
2317
2318         ISCSI_DBG_EH(session, "wait for relogin\n");
2319         wait_event_interruptible(conn->ehwait,
2320                                  session->state == ISCSI_STATE_TERMINATE ||
2321                                  session->state == ISCSI_STATE_LOGGED_IN ||
2322                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
2323         if (signal_pending(current))
2324                 flush_signals(current);
2325
2326         mutex_lock(&session->eh_mutex);
2327         spin_lock_bh(&session->lock);
2328         if (session->state == ISCSI_STATE_LOGGED_IN) {
2329                 ISCSI_DBG_EH(session,
2330                              "session reset succeeded for %s,%s\n",
2331                              session->targetname, conn->persistent_address);
2332         } else
2333                 goto failed;
2334         spin_unlock_bh(&session->lock);
2335         mutex_unlock(&session->eh_mutex);
2336         return SUCCESS;
2337 }
2338
2339 static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2340 {
2341         memset(hdr, 0, sizeof(*hdr));
2342         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2343         hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2344         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2345         hdr->rtt = RESERVED_ITT;
2346 }
2347
2348 /**
2349  * iscsi_eh_target_reset - reset target
2350  * @sc: scsi command
2351  *
2352  * This will attempt to send a warm target reset. If that fails
2353  * then we will drop the session and attempt ERL0 recovery.
2354  */
2355 int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2356 {
2357         struct iscsi_cls_session *cls_session;
2358         struct iscsi_session *session;
2359         struct iscsi_conn *conn;
2360         struct iscsi_tm *hdr;
2361         int rc = FAILED;
2362
2363         cls_session = starget_to_session(scsi_target(sc->device));
2364         session = cls_session->dd_data;
2365
2366         ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2367                      session->targetname);
2368
2369         mutex_lock(&session->eh_mutex);
2370         spin_lock_bh(&session->lock);
2371         /*
2372          * Just check if we are not logged in. We cannot check for
2373          * the phase because the reset could come from a ioctl.
2374          */
2375         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2376                 goto unlock;
2377         conn = session->leadconn;
2378
2379         /* only have one tmf outstanding at a time */
2380         if (conn->tmf_state != TMF_INITIAL)
2381                 goto unlock;
2382         conn->tmf_state = TMF_QUEUED;
2383
2384         hdr = &conn->tmhdr;
2385         iscsi_prep_tgt_reset_pdu(sc, hdr);
2386
2387         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2388                                     session->tgt_reset_timeout)) {
2389                 rc = FAILED;
2390                 goto unlock;
2391         }
2392
2393         switch (conn->tmf_state) {
2394         case TMF_SUCCESS:
2395                 break;
2396         case TMF_TIMEDOUT:
2397                 spin_unlock_bh(&session->lock);
2398                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
2399                 goto done;
2400         default:
2401                 conn->tmf_state = TMF_INITIAL;
2402                 goto unlock;
2403         }
2404
2405         rc = SUCCESS;
2406         spin_unlock_bh(&session->lock);
2407
2408         iscsi_suspend_tx(conn);
2409
2410         spin_lock_bh(&session->lock);
2411         memset(hdr, 0, sizeof(*hdr));
2412         fail_scsi_tasks(conn, -1, DID_ERROR);
2413         conn->tmf_state = TMF_INITIAL;
2414         spin_unlock_bh(&session->lock);
2415
2416         iscsi_start_tx(conn);
2417         goto done;
2418
2419 unlock:
2420         spin_unlock_bh(&session->lock);
2421 done:
2422         ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2423                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2424         mutex_unlock(&session->eh_mutex);
2425
2426         if (rc == FAILED)
2427                 rc = iscsi_eh_session_reset(sc);
2428         return rc;
2429 }
2430 EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
2431
2432 /*
2433  * Pre-allocate a pool of @max items of @item_size. By default, the pool
2434  * should be accessed via kfifo_{get,put} on q->queue.
2435  * Optionally, the caller can obtain the array of object pointers
2436  * by passing in a non-NULL @items pointer
2437  */
2438 int
2439 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2440 {
2441         int i, num_arrays = 1;
2442
2443         memset(q, 0, sizeof(*q));
2444
2445         q->max = max;
2446
2447         /* If the user passed an items pointer, he wants a copy of
2448          * the array. */
2449         if (items)
2450                 num_arrays++;
2451         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
2452         if (q->pool == NULL)
2453                 return -ENOMEM;
2454
2455         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
2456                               GFP_KERNEL, NULL);
2457         if (IS_ERR(q->queue)) {
2458                 q->queue = NULL;
2459                 goto enomem;
2460         }
2461
2462         for (i = 0; i < max; i++) {
2463                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2464                 if (q->pool[i] == NULL) {
2465                         q->max = i;
2466                         goto enomem;
2467                 }
2468                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
2469         }
2470
2471         if (items) {
2472                 *items = q->pool + max;
2473                 memcpy(*items, q->pool, max * sizeof(void *));
2474         }
2475
2476         return 0;
2477
2478 enomem:
2479         iscsi_pool_free(q);
2480         return -ENOMEM;
2481 }
2482 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2483
2484 void iscsi_pool_free(struct iscsi_pool *q)
2485 {
2486         int i;
2487
2488         for (i = 0; i < q->max; i++)
2489                 kfree(q->pool[i]);
2490         kfree(q->pool);
2491         kfree(q->queue);
2492 }
2493 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2494
2495 /**
2496  * iscsi_host_add - add host to system
2497  * @shost: scsi host
2498  * @pdev: parent device
2499  *
2500  * This should be called by partial offload and software iscsi drivers
2501  * to add a host to the system.
2502  */
2503 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2504 {
2505         if (!shost->can_queue)
2506                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2507
2508         if (!shost->cmd_per_lun)
2509                 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2510
2511         if (!shost->transportt->eh_timed_out)
2512                 shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
2513         return scsi_add_host(shost, pdev);
2514 }
2515 EXPORT_SYMBOL_GPL(iscsi_host_add);
2516
2517 /**
2518  * iscsi_host_alloc - allocate a host and driver data
2519  * @sht: scsi host template
2520  * @dd_data_size: driver host data size
2521  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2522  *
2523  * This should be called by partial offload and software iscsi drivers.
2524  * To access the driver specific memory use the iscsi_host_priv() macro.
2525  */
2526 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2527                                    int dd_data_size, bool xmit_can_sleep)
2528 {
2529         struct Scsi_Host *shost;
2530         struct iscsi_host *ihost;
2531
2532         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2533         if (!shost)
2534                 return NULL;
2535         ihost = shost_priv(shost);
2536
2537         if (xmit_can_sleep) {
2538                 snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2539                         "iscsi_q_%d", shost->host_no);
2540                 ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2541                 if (!ihost->workq)
2542                         goto free_host;
2543         }
2544
2545         spin_lock_init(&ihost->lock);
2546         ihost->state = ISCSI_HOST_SETUP;
2547         ihost->num_sessions = 0;
2548         init_waitqueue_head(&ihost->session_removal_wq);
2549         return shost;
2550
2551 free_host:
2552         scsi_host_put(shost);
2553         return NULL;
2554 }
2555 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2556
2557 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2558 {
2559         iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2560 }
2561
2562 /**
2563  * iscsi_host_remove - remove host and sessions
2564  * @shost: scsi host
2565  *
2566  * If there are any sessions left, this will initiate the removal and wait
2567  * for the completion.
2568  */
2569 void iscsi_host_remove(struct Scsi_Host *shost)
2570 {
2571         struct iscsi_host *ihost = shost_priv(shost);
2572         unsigned long flags;
2573
2574         spin_lock_irqsave(&ihost->lock, flags);
2575         ihost->state = ISCSI_HOST_REMOVED;
2576         spin_unlock_irqrestore(&ihost->lock, flags);
2577
2578         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2579         wait_event_interruptible(ihost->session_removal_wq,
2580                                  ihost->num_sessions == 0);
2581         if (signal_pending(current))
2582                 flush_signals(current);
2583
2584         scsi_remove_host(shost);
2585         if (ihost->workq)
2586                 destroy_workqueue(ihost->workq);
2587 }
2588 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2589
2590 void iscsi_host_free(struct Scsi_Host *shost)
2591 {
2592         struct iscsi_host *ihost = shost_priv(shost);
2593
2594         kfree(ihost->netdev);
2595         kfree(ihost->hwaddress);
2596         kfree(ihost->initiatorname);
2597         scsi_host_put(shost);
2598 }
2599 EXPORT_SYMBOL_GPL(iscsi_host_free);
2600
2601 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2602 {
2603         struct iscsi_host *ihost = shost_priv(shost);
2604         unsigned long flags;
2605
2606         shost = scsi_host_get(shost);
2607         if (!shost) {
2608                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2609                       "of session teardown event because host already "
2610                       "removed.\n");
2611                 return;
2612         }
2613
2614         spin_lock_irqsave(&ihost->lock, flags);
2615         ihost->num_sessions--;
2616         if (ihost->num_sessions == 0)
2617                 wake_up(&ihost->session_removal_wq);
2618         spin_unlock_irqrestore(&ihost->lock, flags);
2619         scsi_host_put(shost);
2620 }
2621
2622 /**
2623  * iscsi_session_setup - create iscsi cls session and host and session
2624  * @iscsit: iscsi transport template
2625  * @shost: scsi host
2626  * @cmds_max: session can queue
2627  * @cmd_task_size: LLD task private data size
2628  * @initial_cmdsn: initial CmdSN
2629  *
2630  * This can be used by software iscsi_transports that allocate
2631  * a session per scsi host.
2632  *
2633  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2634  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2635  * for nop handling and login/logout requests.
2636  */
2637 struct iscsi_cls_session *
2638 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2639                     uint16_t cmds_max, int dd_size, int cmd_task_size,
2640                     uint32_t initial_cmdsn, unsigned int id)
2641 {
2642         struct iscsi_host *ihost = shost_priv(shost);
2643         struct iscsi_session *session;
2644         struct iscsi_cls_session *cls_session;
2645         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2646         unsigned long flags;
2647
2648         spin_lock_irqsave(&ihost->lock, flags);
2649         if (ihost->state == ISCSI_HOST_REMOVED) {
2650                 spin_unlock_irqrestore(&ihost->lock, flags);
2651                 return NULL;
2652         }
2653         ihost->num_sessions++;
2654         spin_unlock_irqrestore(&ihost->lock, flags);
2655
2656         if (!total_cmds)
2657                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2658         /*
2659          * The iscsi layer needs some tasks for nop handling and tmfs,
2660          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2661          * + 1 command for scsi IO.
2662          */
2663         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2664                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2665                        "must be a power of two that is at least %d.\n",
2666                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2667                 goto dec_session_count;
2668         }
2669
2670         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2671                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2672                        "must be a power of 2 less than or equal to %d.\n",
2673                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2674                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2675         }
2676
2677         if (!is_power_of_2(total_cmds)) {
2678                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2679                        "must be a power of 2.\n", total_cmds);
2680                 total_cmds = rounddown_pow_of_two(total_cmds);
2681                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2682                         return NULL;
2683                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2684                        total_cmds);
2685         }
2686         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2687
2688         cls_session = iscsi_alloc_session(shost, iscsit,
2689                                           sizeof(struct iscsi_session) +
2690                                           dd_size);
2691         if (!cls_session)
2692                 goto dec_session_count;
2693         session = cls_session->dd_data;
2694         session->cls_session = cls_session;
2695         session->host = shost;
2696         session->state = ISCSI_STATE_FREE;
2697         session->fast_abort = 1;
2698         session->tgt_reset_timeout = 30;
2699         session->lu_reset_timeout = 15;
2700         session->abort_timeout = 10;
2701         session->scsi_cmds_max = scsi_cmds;
2702         session->cmds_max = total_cmds;
2703         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2704         session->exp_cmdsn = initial_cmdsn + 1;
2705         session->max_cmdsn = initial_cmdsn + 1;
2706         session->max_r2t = 1;
2707         session->tt = iscsit;
2708         session->dd_data = cls_session->dd_data + sizeof(*session);
2709         mutex_init(&session->eh_mutex);
2710         spin_lock_init(&session->lock);
2711
2712         /* initialize SCSI PDU commands pool */
2713         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2714                             (void***)&session->cmds,
2715                             cmd_task_size + sizeof(struct iscsi_task)))
2716                 goto cmdpool_alloc_fail;
2717
2718         /* pre-format cmds pool with ITT */
2719         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2720                 struct iscsi_task *task = session->cmds[cmd_i];
2721
2722                 if (cmd_task_size)
2723                         task->dd_data = &task[1];
2724                 task->itt = cmd_i;
2725                 task->state = ISCSI_TASK_FREE;
2726                 INIT_LIST_HEAD(&task->running);
2727         }
2728
2729         if (!try_module_get(iscsit->owner))
2730                 goto module_get_fail;
2731
2732         if (iscsi_add_session(cls_session, id))
2733                 goto cls_session_fail;
2734
2735         return cls_session;
2736
2737 cls_session_fail:
2738         module_put(iscsit->owner);
2739 module_get_fail:
2740         iscsi_pool_free(&session->cmdpool);
2741 cmdpool_alloc_fail:
2742         iscsi_free_session(cls_session);
2743 dec_session_count:
2744         iscsi_host_dec_session_cnt(shost);
2745         return NULL;
2746 }
2747 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2748
2749 /**
2750  * iscsi_session_teardown - destroy session, host, and cls_session
2751  * @cls_session: iscsi session
2752  *
2753  * The driver must have called iscsi_remove_session before
2754  * calling this.
2755  */
2756 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2757 {
2758         struct iscsi_session *session = cls_session->dd_data;
2759         struct module *owner = cls_session->transport->owner;
2760         struct Scsi_Host *shost = session->host;
2761
2762         iscsi_pool_free(&session->cmdpool);
2763
2764         kfree(session->password);
2765         kfree(session->password_in);
2766         kfree(session->username);
2767         kfree(session->username_in);
2768         kfree(session->targetname);
2769         kfree(session->initiatorname);
2770         kfree(session->ifacename);
2771
2772         iscsi_destroy_session(cls_session);
2773         iscsi_host_dec_session_cnt(shost);
2774         module_put(owner);
2775 }
2776 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2777
2778 /**
2779  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2780  * @cls_session: iscsi_cls_session
2781  * @dd_size: private driver data size
2782  * @conn_idx: cid
2783  */
2784 struct iscsi_cls_conn *
2785 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2786                  uint32_t conn_idx)
2787 {
2788         struct iscsi_session *session = cls_session->dd_data;
2789         struct iscsi_conn *conn;
2790         struct iscsi_cls_conn *cls_conn;
2791         char *data;
2792
2793         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2794                                      conn_idx);
2795         if (!cls_conn)
2796                 return NULL;
2797         conn = cls_conn->dd_data;
2798         memset(conn, 0, sizeof(*conn) + dd_size);
2799
2800         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2801         conn->session = session;
2802         conn->cls_conn = cls_conn;
2803         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2804         conn->id = conn_idx;
2805         conn->exp_statsn = 0;
2806         conn->tmf_state = TMF_INITIAL;
2807
2808         init_timer(&conn->transport_timer);
2809         conn->transport_timer.data = (unsigned long)conn;
2810         conn->transport_timer.function = iscsi_check_transport_timeouts;
2811
2812         INIT_LIST_HEAD(&conn->mgmtqueue);
2813         INIT_LIST_HEAD(&conn->cmdqueue);
2814         INIT_LIST_HEAD(&conn->requeue);
2815         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2816
2817         /* allocate login_task used for the login/text sequences */
2818         spin_lock_bh(&session->lock);
2819         if (!__kfifo_get(session->cmdpool.queue,
2820                          (void*)&conn->login_task,
2821                          sizeof(void*))) {
2822                 spin_unlock_bh(&session->lock);
2823                 goto login_task_alloc_fail;
2824         }
2825         spin_unlock_bh(&session->lock);
2826
2827         data = (char *) __get_free_pages(GFP_KERNEL,
2828                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2829         if (!data)
2830                 goto login_task_data_alloc_fail;
2831         conn->login_task->data = conn->data = data;
2832
2833         init_timer(&conn->tmf_timer);
2834         init_waitqueue_head(&conn->ehwait);
2835
2836         return cls_conn;
2837
2838 login_task_data_alloc_fail:
2839         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2840                     sizeof(void*));
2841 login_task_alloc_fail:
2842         iscsi_destroy_conn(cls_conn);
2843         return NULL;
2844 }
2845 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2846
2847 /**
2848  * iscsi_conn_teardown - teardown iscsi connection
2849  * cls_conn: iscsi class connection
2850  *
2851  * TODO: we may need to make this into a two step process
2852  * like scsi-mls remove + put host
2853  */
2854 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2855 {
2856         struct iscsi_conn *conn = cls_conn->dd_data;
2857         struct iscsi_session *session = conn->session;
2858         unsigned long flags;
2859
2860         del_timer_sync(&conn->transport_timer);
2861
2862         spin_lock_bh(&session->lock);
2863         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2864         if (session->leadconn == conn) {
2865                 /*
2866                  * leading connection? then give up on recovery.
2867                  */
2868                 session->state = ISCSI_STATE_TERMINATE;
2869                 wake_up(&conn->ehwait);
2870         }
2871         spin_unlock_bh(&session->lock);
2872
2873         /*
2874          * Block until all in-progress commands for this connection
2875          * time out or fail.
2876          */
2877         for (;;) {
2878                 spin_lock_irqsave(session->host->host_lock, flags);
2879                 if (!session->host->host_busy) { /* OK for ERL == 0 */
2880                         spin_unlock_irqrestore(session->host->host_lock, flags);
2881                         break;
2882                 }
2883                 spin_unlock_irqrestore(session->host->host_lock, flags);
2884                 msleep_interruptible(500);
2885                 iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2886                                   "host_busy %d host_failed %d\n",
2887                                   session->host->host_busy,
2888                                   session->host->host_failed);
2889                 /*
2890                  * force eh_abort() to unblock
2891                  */
2892                 wake_up(&conn->ehwait);
2893         }
2894
2895         /* flush queued up work because we free the connection below */
2896         iscsi_suspend_tx(conn);
2897
2898         spin_lock_bh(&session->lock);
2899         free_pages((unsigned long) conn->data,
2900                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2901         kfree(conn->persistent_address);
2902         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2903                     sizeof(void*));
2904         if (session->leadconn == conn)
2905                 session->leadconn = NULL;
2906         spin_unlock_bh(&session->lock);
2907
2908         iscsi_destroy_conn(cls_conn);
2909 }
2910 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2911
2912 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2913 {
2914         struct iscsi_conn *conn = cls_conn->dd_data;
2915         struct iscsi_session *session = conn->session;
2916
2917         if (!session) {
2918                 iscsi_conn_printk(KERN_ERR, conn,
2919                                   "can't start unbound connection\n");
2920                 return -EPERM;
2921         }
2922
2923         if ((session->imm_data_en || !session->initial_r2t_en) &&
2924              session->first_burst > session->max_burst) {
2925                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2926                                   "first_burst %d max_burst %d\n",
2927                                   session->first_burst, session->max_burst);
2928                 return -EINVAL;
2929         }
2930
2931         if (conn->ping_timeout && !conn->recv_timeout) {
2932                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
2933                                   "zero. Using 5 seconds\n.");
2934                 conn->recv_timeout = 5;
2935         }
2936
2937         if (conn->recv_timeout && !conn->ping_timeout) {
2938                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
2939                                   "zero. Using 5 seconds.\n");
2940                 conn->ping_timeout = 5;
2941         }
2942
2943         spin_lock_bh(&session->lock);
2944         conn->c_stage = ISCSI_CONN_STARTED;
2945         session->state = ISCSI_STATE_LOGGED_IN;
2946         session->queued_cmdsn = session->cmdsn;
2947
2948         conn->last_recv = jiffies;
2949         conn->last_ping = jiffies;
2950         if (conn->recv_timeout && conn->ping_timeout)
2951                 mod_timer(&conn->transport_timer,
2952                           jiffies + (conn->recv_timeout * HZ));
2953
2954         switch(conn->stop_stage) {
2955         case STOP_CONN_RECOVER:
2956                 /*
2957                  * unblock eh_abort() if it is blocked. re-try all
2958                  * commands after successful recovery
2959                  */
2960                 conn->stop_stage = 0;
2961                 conn->tmf_state = TMF_INITIAL;
2962                 session->age++;
2963                 if (session->age == 16)
2964                         session->age = 0;
2965                 break;
2966         case STOP_CONN_TERM:
2967                 conn->stop_stage = 0;
2968                 break;
2969         default:
2970                 break;
2971         }
2972         spin_unlock_bh(&session->lock);
2973
2974         iscsi_unblock_session(session->cls_session);
2975         wake_up(&conn->ehwait);
2976         return 0;
2977 }
2978 EXPORT_SYMBOL_GPL(iscsi_conn_start);
2979
2980 static void
2981 fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
2982 {
2983         struct iscsi_task *task;
2984         int i, state;
2985
2986         for (i = 0; i < conn->session->cmds_max; i++) {
2987                 task = conn->session->cmds[i];
2988                 if (task->sc)
2989                         continue;
2990
2991                 if (task->state == ISCSI_TASK_FREE)
2992                         continue;
2993
2994                 ISCSI_DBG_SESSION(conn->session,
2995                                   "failing mgmt itt 0x%x state %d\n",
2996                                   task->itt, task->state);
2997                 state = ISCSI_TASK_ABRT_SESS_RECOV;
2998                 if (task->state == ISCSI_TASK_PENDING)
2999                         state = ISCSI_TASK_COMPLETED;
3000                 iscsi_complete_task(task, state);
3001
3002         }
3003 }
3004
3005 static void iscsi_start_session_recovery(struct iscsi_session *session,
3006                                          struct iscsi_conn *conn, int flag)
3007 {
3008         int old_stop_stage;
3009
3010         mutex_lock(&session->eh_mutex);
3011         spin_lock_bh(&session->lock);
3012         if (conn->stop_stage == STOP_CONN_TERM) {
3013                 spin_unlock_bh(&session->lock);
3014                 mutex_unlock(&session->eh_mutex);
3015                 return;
3016         }
3017
3018         /*
3019          * When this is called for the in_login state, we only want to clean
3020          * up the login task and connection. We do not need to block and set
3021          * the recovery state again
3022          */
3023         if (flag == STOP_CONN_TERM)
3024                 session->state = ISCSI_STATE_TERMINATE;
3025         else if (conn->stop_stage != STOP_CONN_RECOVER)
3026                 session->state = ISCSI_STATE_IN_RECOVERY;
3027         spin_unlock_bh(&session->lock);
3028
3029         del_timer_sync(&conn->transport_timer);
3030         iscsi_suspend_tx(conn);
3031
3032         spin_lock_bh(&session->lock);
3033         old_stop_stage = conn->stop_stage;
3034         conn->stop_stage = flag;
3035         conn->c_stage = ISCSI_CONN_STOPPED;
3036         spin_unlock_bh(&session->lock);
3037
3038         /*
3039          * for connection level recovery we should not calculate
3040          * header digest. conn->hdr_size used for optimization
3041          * in hdr_extract() and will be re-negotiated at
3042          * set_param() time.
3043          */
3044         if (flag == STOP_CONN_RECOVER) {
3045                 conn->hdrdgst_en = 0;
3046                 conn->datadgst_en = 0;
3047                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
3048                     old_stop_stage != STOP_CONN_RECOVER) {
3049                         ISCSI_DBG_SESSION(session, "blocking session\n");
3050                         iscsi_block_session(session->cls_session);
3051                 }
3052         }
3053
3054         /*
3055          * flush queues.
3056          */
3057         spin_lock_bh(&session->lock);
3058         fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3059         fail_mgmt_tasks(session, conn);
3060         memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3061         spin_unlock_bh(&session->lock);
3062         mutex_unlock(&session->eh_mutex);
3063 }
3064
3065 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3066 {
3067         struct iscsi_conn *conn = cls_conn->dd_data;
3068         struct iscsi_session *session = conn->session;
3069
3070         switch (flag) {
3071         case STOP_CONN_RECOVER:
3072         case STOP_CONN_TERM:
3073                 iscsi_start_session_recovery(session, conn, flag);
3074                 break;
3075         default:
3076                 iscsi_conn_printk(KERN_ERR, conn,
3077                                   "invalid stop flag %d\n", flag);
3078         }
3079 }
3080 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3081
3082 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3083                     struct iscsi_cls_conn *cls_conn, int is_leading)
3084 {
3085         struct iscsi_session *session = cls_session->dd_data;
3086         struct iscsi_conn *conn = cls_conn->dd_data;
3087
3088         spin_lock_bh(&session->lock);
3089         if (is_leading)
3090                 session->leadconn = conn;
3091         spin_unlock_bh(&session->lock);
3092
3093         /*
3094          * Unblock xmitworker(), Login Phase will pass through.
3095          */
3096         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3097         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3098         return 0;
3099 }
3100 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3101
3102 static int iscsi_switch_str_param(char **param, char *new_val_buf)
3103 {
3104         char *new_val;
3105
3106         if (*param) {
3107                 if (!strcmp(*param, new_val_buf))
3108                         return 0;
3109         }
3110
3111         new_val = kstrdup(new_val_buf, GFP_NOIO);
3112         if (!new_val)
3113                 return -ENOMEM;
3114
3115         kfree(*param);
3116         *param = new_val;
3117         return 0;
3118 }
3119
3120 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3121                     enum iscsi_param param, char *buf, int buflen)
3122 {
3123         struct iscsi_conn *conn = cls_conn->dd_data;
3124         struct iscsi_session *session = conn->session;
3125         uint32_t value;
3126
3127         switch(param) {
3128         case ISCSI_PARAM_FAST_ABORT:
3129                 sscanf(buf, "%d", &session->fast_abort);
3130                 break;
3131         case ISCSI_PARAM_ABORT_TMO:
3132                 sscanf(buf, "%d", &session->abort_timeout);
3133                 break;
3134         case ISCSI_PARAM_LU_RESET_TMO:
3135                 sscanf(buf, "%d", &session->lu_reset_timeout);
3136                 break;
3137         case ISCSI_PARAM_TGT_RESET_TMO:
3138                 sscanf(buf, "%d", &session->tgt_reset_timeout);
3139                 break;
3140         case ISCSI_PARAM_PING_TMO:
3141                 sscanf(buf, "%d", &conn->ping_timeout);
3142                 break;
3143         case ISCSI_PARAM_RECV_TMO:
3144                 sscanf(buf, "%d", &conn->recv_timeout);
3145                 break;
3146         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3147                 sscanf(buf, "%d", &conn->max_recv_dlength);
3148                 break;
3149         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3150                 sscanf(buf, "%d", &conn->max_xmit_dlength);
3151                 break;
3152         case ISCSI_PARAM_HDRDGST_EN:
3153                 sscanf(buf, "%d", &conn->hdrdgst_en);
3154                 break;
3155         case ISCSI_PARAM_DATADGST_EN:
3156                 sscanf(buf, "%d", &conn->datadgst_en);
3157                 break;
3158         case ISCSI_PARAM_INITIAL_R2T_EN:
3159                 sscanf(buf, "%d", &session->initial_r2t_en);
3160                 break;
3161         case ISCSI_PARAM_MAX_R2T:
3162                 sscanf(buf, "%d", &session->max_r2t);
3163                 break;
3164         case ISCSI_PARAM_IMM_DATA_EN:
3165                 sscanf(buf, "%d", &session->imm_data_en);
3166                 break;
3167         case ISCSI_PARAM_FIRST_BURST:
3168                 sscanf(buf, "%d", &session->first_burst);
3169                 break;
3170         case ISCSI_PARAM_MAX_BURST:
3171                 sscanf(buf, "%d", &session->max_burst);
3172                 break;
3173         case ISCSI_PARAM_PDU_INORDER_EN:
3174                 sscanf(buf, "%d", &session->pdu_inorder_en);
3175                 break;
3176         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3177                 sscanf(buf, "%d", &session->dataseq_inorder_en);
3178                 break;
3179         case ISCSI_PARAM_ERL:
3180                 sscanf(buf, "%d", &session->erl);
3181                 break;
3182         case ISCSI_PARAM_IFMARKER_EN:
3183                 sscanf(buf, "%d", &value);
3184                 BUG_ON(value);
3185                 break;
3186         case ISCSI_PARAM_OFMARKER_EN:
3187                 sscanf(buf, "%d", &value);
3188                 BUG_ON(value);
3189                 break;
3190         case ISCSI_PARAM_EXP_STATSN:
3191                 sscanf(buf, "%u", &conn->exp_statsn);
3192                 break;
3193         case ISCSI_PARAM_USERNAME:
3194                 return iscsi_switch_str_param(&session->username, buf);
3195         case ISCSI_PARAM_USERNAME_IN:
3196                 return iscsi_switch_str_param(&session->username_in, buf);
3197         case ISCSI_PARAM_PASSWORD:
3198                 return iscsi_switch_str_param(&session->password, buf);
3199         case ISCSI_PARAM_PASSWORD_IN:
3200                 return iscsi_switch_str_param(&session->password_in, buf);
3201         case ISCSI_PARAM_TARGET_NAME:
3202                 return iscsi_switch_str_param(&session->targetname, buf);
3203         case ISCSI_PARAM_TPGT:
3204                 sscanf(buf, "%d", &session->tpgt);
3205                 break;
3206         case ISCSI_PARAM_PERSISTENT_PORT:
3207                 sscanf(buf, "%d", &conn->persistent_port);
3208                 break;
3209         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3210                 return iscsi_switch_str_param(&conn->persistent_address, buf);
3211         case ISCSI_PARAM_IFACE_NAME:
3212                 return iscsi_switch_str_param(&session->ifacename, buf);
3213         case ISCSI_PARAM_INITIATOR_NAME:
3214                 return iscsi_switch_str_param(&session->initiatorname, buf);
3215         default:
3216                 return -ENOSYS;
3217         }
3218
3219         return 0;
3220 }
3221 EXPORT_SYMBOL_GPL(iscsi_set_param);
3222
3223 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3224                             enum iscsi_param param, char *buf)
3225 {
3226         struct iscsi_session *session = cls_session->dd_data;
3227         int len;
3228
3229         switch(param) {
3230         case ISCSI_PARAM_FAST_ABORT:
3231                 len = sprintf(buf, "%d\n", session->fast_abort);
3232                 break;
3233         case ISCSI_PARAM_ABORT_TMO:
3234                 len = sprintf(buf, "%d\n", session->abort_timeout);
3235                 break;
3236         case ISCSI_PARAM_LU_RESET_TMO:
3237                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
3238                 break;
3239         case ISCSI_PARAM_TGT_RESET_TMO:
3240                 len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
3241                 break;
3242         case ISCSI_PARAM_INITIAL_R2T_EN:
3243                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
3244                 break;
3245         case ISCSI_PARAM_MAX_R2T:
3246                 len = sprintf(buf, "%hu\n", session->max_r2t);
3247                 break;
3248         case ISCSI_PARAM_IMM_DATA_EN:
3249                 len = sprintf(buf, "%d\n", session->imm_data_en);
3250                 break;
3251         case ISCSI_PARAM_FIRST_BURST:
3252                 len = sprintf(buf, "%u\n", session->first_burst);
3253                 break;
3254         case ISCSI_PARAM_MAX_BURST:
3255                 len = sprintf(buf, "%u\n", session->max_burst);
3256                 break;
3257         case ISCSI_PARAM_PDU_INORDER_EN:
3258                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
3259                 break;
3260         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3261                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
3262                 break;
3263         case ISCSI_PARAM_ERL:
3264                 len = sprintf(buf, "%d\n", session->erl);
3265                 break;
3266         case ISCSI_PARAM_TARGET_NAME:
3267                 len = sprintf(buf, "%s\n", session->targetname);
3268                 break;
3269         case ISCSI_PARAM_TPGT:
3270                 len = sprintf(buf, "%d\n", session->tpgt);
3271                 break;
3272         case ISCSI_PARAM_USERNAME:
3273                 len = sprintf(buf, "%s\n", session->username);
3274                 break;
3275         case ISCSI_PARAM_USERNAME_IN:
3276                 len = sprintf(buf, "%s\n", session->username_in);
3277                 break;
3278         case ISCSI_PARAM_PASSWORD:
3279                 len = sprintf(buf, "%s\n", session->password);
3280                 break;
3281         case ISCSI_PARAM_PASSWORD_IN:
3282                 len = sprintf(buf, "%s\n", session->password_in);
3283                 break;
3284         case ISCSI_PARAM_IFACE_NAME:
3285                 len = sprintf(buf, "%s\n", session->ifacename);
3286                 break;
3287         case ISCSI_PARAM_INITIATOR_NAME:
3288                 len = sprintf(buf, "%s\n", session->initiatorname);
3289                 break;
3290         default:
3291                 return -ENOSYS;
3292         }
3293
3294         return len;
3295 }
3296 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3297
3298 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3299                          enum iscsi_param param, char *buf)
3300 {
3301         struct iscsi_conn *conn = cls_conn->dd_data;
3302         int len;
3303
3304         switch(param) {
3305         case ISCSI_PARAM_PING_TMO:
3306                 len = sprintf(buf, "%u\n", conn->ping_timeout);
3307                 break;
3308         case ISCSI_PARAM_RECV_TMO:
3309                 len = sprintf(buf, "%u\n", conn->recv_timeout);
3310                 break;
3311         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3312                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
3313                 break;
3314         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3315                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
3316                 break;
3317         case ISCSI_PARAM_HDRDGST_EN:
3318                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
3319                 break;
3320         case ISCSI_PARAM_DATADGST_EN:
3321                 len = sprintf(buf, "%d\n", conn->datadgst_en);
3322                 break;
3323         case ISCSI_PARAM_IFMARKER_EN:
3324                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
3325                 break;
3326         case ISCSI_PARAM_OFMARKER_EN:
3327                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
3328                 break;
3329         case ISCSI_PARAM_EXP_STATSN:
3330                 len = sprintf(buf, "%u\n", conn->exp_statsn);
3331                 break;
3332         case ISCSI_PARAM_PERSISTENT_PORT:
3333                 len = sprintf(buf, "%d\n", conn->persistent_port);
3334                 break;
3335         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3336                 len = sprintf(buf, "%s\n", conn->persistent_address);
3337                 break;
3338         default:
3339                 return -ENOSYS;
3340         }
3341
3342         return len;
3343 }
3344 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3345
3346 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3347                          char *buf)
3348 {
3349         struct iscsi_host *ihost = shost_priv(shost);
3350         int len;
3351
3352         switch (param) {
3353         case ISCSI_HOST_PARAM_NETDEV_NAME:
3354                 len = sprintf(buf, "%s\n", ihost->netdev);
3355                 break;
3356         case ISCSI_HOST_PARAM_HWADDRESS:
3357                 len = sprintf(buf, "%s\n", ihost->hwaddress);
3358                 break;
3359         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3360                 len = sprintf(buf, "%s\n", ihost->initiatorname);
3361                 break;
3362         case ISCSI_HOST_PARAM_IPADDRESS:
3363                 len = sprintf(buf, "%s\n", ihost->local_address);
3364                 break;
3365         default:
3366                 return -ENOSYS;
3367         }
3368
3369         return len;
3370 }
3371 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3372
3373 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3374                          char *buf, int buflen)
3375 {
3376         struct iscsi_host *ihost = shost_priv(shost);
3377
3378         switch (param) {
3379         case ISCSI_HOST_PARAM_NETDEV_NAME:
3380                 return iscsi_switch_str_param(&ihost->netdev, buf);
3381         case ISCSI_HOST_PARAM_HWADDRESS:
3382                 return iscsi_switch_str_param(&ihost->hwaddress, buf);
3383         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3384                 return iscsi_switch_str_param(&ihost->initiatorname, buf);
3385         default:
3386                 return -ENOSYS;
3387         }
3388
3389         return 0;
3390 }
3391 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3392
3393 MODULE_AUTHOR("Mike Christie");
3394 MODULE_DESCRIPTION("iSCSI library functions");
3395 MODULE_LICENSE("GPL");