212fe2027a8c942dd86c955fa9928d96b9bfdd69
[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;
42 module_param_named(debug_libiscsi, iscsi_dbg_lib, int, S_IRUGO | S_IWUSR);
43 MODULE_PARM_DESC(debug_libiscsi, "Turn on debugging for libiscsi module. "
44                  "Set to 1 to turn on, and zero to turn off. Default "
45                  "is off.");
46
47 #define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)                  \
48         do {                                                    \
49                 if (iscsi_dbg_lib)                              \
50                         iscsi_conn_printk(KERN_INFO, _conn,     \
51                                              "%s " dbg_fmt,     \
52                                              __func__, ##arg);  \
53         } while (0);
54
55 #define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)                    \
56         do {                                                            \
57                 if (iscsi_dbg_lib)                                      \
58                         iscsi_session_printk(KERN_INFO, _session,       \
59                                              "%s " dbg_fmt,             \
60                                              __func__, ##arg);          \
61         } while (0);
62
63 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
64 #define SNA32_CHECK 2147483648UL
65
66 static int iscsi_sna_lt(u32 n1, u32 n2)
67 {
68         return n1 != n2 && ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
69                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
70 }
71
72 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
73 static int iscsi_sna_lte(u32 n1, u32 n2)
74 {
75         return n1 == n2 || ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
76                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
77 }
78
79 inline void iscsi_conn_queue_work(struct iscsi_conn *conn)
80 {
81         struct Scsi_Host *shost = conn->session->host;
82         struct iscsi_host *ihost = shost_priv(shost);
83
84         queue_work(ihost->workq, &conn->xmitwork);
85 }
86 EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
87
88 void
89 iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
90 {
91         uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
92         uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);
93
94         /*
95          * standard specifies this check for when to update expected and
96          * max sequence numbers
97          */
98         if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
99                 return;
100
101         if (exp_cmdsn != session->exp_cmdsn &&
102             !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
103                 session->exp_cmdsn = exp_cmdsn;
104
105         if (max_cmdsn != session->max_cmdsn &&
106             !iscsi_sna_lt(max_cmdsn, session->max_cmdsn)) {
107                 session->max_cmdsn = max_cmdsn;
108                 /*
109                  * if the window closed with IO queued, then kick the
110                  * xmit thread
111                  */
112                 if (!list_empty(&session->leadconn->xmitqueue) ||
113                     !list_empty(&session->leadconn->mgmtqueue)) {
114                         if (!(session->tt->caps & CAP_DATA_PATH_OFFLOAD))
115                                 iscsi_conn_queue_work(session->leadconn);
116                 }
117         }
118 }
119 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
120
121 /**
122  * iscsi_prep_data_out_pdu - initialize Data-Out
123  * @task: scsi command task
124  * @r2t: R2T info
125  * @hdr: iscsi data in pdu
126  *
127  * Notes:
128  *      Initialize Data-Out within this R2T sequence and finds
129  *      proper data_offset within this SCSI command.
130  *
131  *      This function is called with connection lock taken.
132  **/
133 void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
134                            struct iscsi_data *hdr)
135 {
136         struct iscsi_conn *conn = task->conn;
137         unsigned int left = r2t->data_length - r2t->sent;
138
139         task->hdr_len = sizeof(struct iscsi_data);
140
141         memset(hdr, 0, sizeof(struct iscsi_data));
142         hdr->ttt = r2t->ttt;
143         hdr->datasn = cpu_to_be32(r2t->datasn);
144         r2t->datasn++;
145         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
146         memcpy(hdr->lun, task->lun, sizeof(hdr->lun));
147         hdr->itt = task->hdr_itt;
148         hdr->exp_statsn = r2t->exp_statsn;
149         hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
150         if (left > conn->max_xmit_dlength) {
151                 hton24(hdr->dlength, conn->max_xmit_dlength);
152                 r2t->data_count = conn->max_xmit_dlength;
153                 hdr->flags = 0;
154         } else {
155                 hton24(hdr->dlength, left);
156                 r2t->data_count = left;
157                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
158         }
159         conn->dataout_pdus_cnt++;
160 }
161 EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
162
163 static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
164 {
165         unsigned exp_len = task->hdr_len + len;
166
167         if (exp_len > task->hdr_max) {
168                 WARN_ON(1);
169                 return -EINVAL;
170         }
171
172         WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
173         task->hdr_len = exp_len;
174         return 0;
175 }
176
177 /*
178  * make an extended cdb AHS
179  */
180 static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
181 {
182         struct scsi_cmnd *cmd = task->sc;
183         unsigned rlen, pad_len;
184         unsigned short ahslength;
185         struct iscsi_ecdb_ahdr *ecdb_ahdr;
186         int rc;
187
188         ecdb_ahdr = iscsi_next_hdr(task);
189         rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
190
191         BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
192         ahslength = rlen + sizeof(ecdb_ahdr->reserved);
193
194         pad_len = iscsi_padding(rlen);
195
196         rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
197                            sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
198         if (rc)
199                 return rc;
200
201         if (pad_len)
202                 memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
203
204         ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
205         ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
206         ecdb_ahdr->reserved = 0;
207         memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
208
209         ISCSI_DBG_SESSION(task->conn->session,
210                           "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
211                           "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
212                           "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
213                           task->hdr_len);
214         return 0;
215 }
216
217 static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
218 {
219         struct scsi_cmnd *sc = task->sc;
220         struct iscsi_rlength_ahdr *rlen_ahdr;
221         int rc;
222
223         rlen_ahdr = iscsi_next_hdr(task);
224         rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
225         if (rc)
226                 return rc;
227
228         rlen_ahdr->ahslength =
229                 cpu_to_be16(sizeof(rlen_ahdr->read_length) +
230                                                   sizeof(rlen_ahdr->reserved));
231         rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
232         rlen_ahdr->reserved = 0;
233         rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
234
235         ISCSI_DBG_SESSION(task->conn->session,
236                           "bidi-in rlen_ahdr->read_length(%d) "
237                           "rlen_ahdr->ahslength(%d)\n",
238                           be32_to_cpu(rlen_ahdr->read_length),
239                           be16_to_cpu(rlen_ahdr->ahslength));
240         return 0;
241 }
242
243 /**
244  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
245  * @task: iscsi task
246  *
247  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
248  * fields like dlength or final based on how much data it sends
249  */
250 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
251 {
252         struct iscsi_conn *conn = task->conn;
253         struct iscsi_session *session = conn->session;
254         struct scsi_cmnd *sc = task->sc;
255         struct iscsi_cmd *hdr;
256         unsigned hdrlength, cmd_len;
257         itt_t itt;
258         int rc;
259
260         if (conn->session->tt->alloc_pdu) {
261                 rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
262                 if (rc)
263                         return rc;
264         }
265         hdr = (struct iscsi_cmd *) task->hdr;
266         itt = hdr->itt;
267         memset(hdr, 0, sizeof(*hdr));
268
269         if (session->tt->parse_pdu_itt)
270                 hdr->itt = task->hdr_itt = itt;
271         else
272                 hdr->itt = task->hdr_itt = build_itt(task->itt,
273                                                      task->conn->session->age);
274         task->hdr_len = 0;
275         rc = iscsi_add_hdr(task, sizeof(*hdr));
276         if (rc)
277                 return rc;
278         hdr->opcode = ISCSI_OP_SCSI_CMD;
279         hdr->flags = ISCSI_ATTR_SIMPLE;
280         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
281         memcpy(task->lun, hdr->lun, sizeof(task->lun));
282         hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
283         session->cmdsn++;
284         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
285         cmd_len = sc->cmd_len;
286         if (cmd_len < ISCSI_CDB_SIZE)
287                 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
288         else if (cmd_len > ISCSI_CDB_SIZE) {
289                 rc = iscsi_prep_ecdb_ahs(task);
290                 if (rc)
291                         return rc;
292                 cmd_len = ISCSI_CDB_SIZE;
293         }
294         memcpy(hdr->cdb, sc->cmnd, cmd_len);
295
296         task->imm_count = 0;
297         if (scsi_bidi_cmnd(sc)) {
298                 hdr->flags |= ISCSI_FLAG_CMD_READ;
299                 rc = iscsi_prep_bidi_ahs(task);
300                 if (rc)
301                         return rc;
302         }
303         if (sc->sc_data_direction == DMA_TO_DEVICE) {
304                 unsigned out_len = scsi_out(sc)->length;
305                 struct iscsi_r2t_info *r2t = &task->unsol_r2t;
306
307                 hdr->data_length = cpu_to_be32(out_len);
308                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
309                 /*
310                  * Write counters:
311                  *
312                  *      imm_count       bytes to be sent right after
313                  *                      SCSI PDU Header
314                  *
315                  *      unsol_count     bytes(as Data-Out) to be sent
316                  *                      without R2T ack right after
317                  *                      immediate data
318                  *
319                  *      r2t data_length bytes to be sent via R2T ack's
320                  *
321                  *      pad_count       bytes to be sent as zero-padding
322                  */
323                 memset(r2t, 0, sizeof(*r2t));
324
325                 if (session->imm_data_en) {
326                         if (out_len >= session->first_burst)
327                                 task->imm_count = min(session->first_burst,
328                                                         conn->max_xmit_dlength);
329                         else
330                                 task->imm_count = min(out_len,
331                                                         conn->max_xmit_dlength);
332                         hton24(hdr->dlength, task->imm_count);
333                 } else
334                         zero_data(hdr->dlength);
335
336                 if (!session->initial_r2t_en) {
337                         r2t->data_length = min(session->first_burst, out_len) -
338                                                task->imm_count;
339                         r2t->data_offset = task->imm_count;
340                         r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
341                         r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
342                 }
343
344                 if (!task->unsol_r2t.data_length)
345                         /* No unsolicit Data-Out's */
346                         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
347         } else {
348                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
349                 zero_data(hdr->dlength);
350                 hdr->data_length = cpu_to_be32(scsi_in(sc)->length);
351
352                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
353                         hdr->flags |= ISCSI_FLAG_CMD_READ;
354         }
355
356         /* calculate size of additional header segments (AHSs) */
357         hdrlength = task->hdr_len - sizeof(*hdr);
358
359         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
360         hdrlength /= ISCSI_PAD_LEN;
361
362         WARN_ON(hdrlength >= 256);
363         hdr->hlength = hdrlength & 0xFF;
364
365         if (session->tt->init_task && session->tt->init_task(task))
366                 return -EIO;
367
368         task->state = ISCSI_TASK_RUNNING;
369         list_move_tail(&task->running, &conn->run_list);
370
371         conn->scsicmd_pdus_cnt++;
372         ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
373                           "itt 0x%x len %d bidi_len %d cmdsn %d win %d]\n",
374                           scsi_bidi_cmnd(sc) ? "bidirectional" :
375                           sc->sc_data_direction == DMA_TO_DEVICE ?
376                           "write" : "read", conn->id, sc, sc->cmnd[0],
377                           task->itt, scsi_bufflen(sc),
378                           scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
379                           session->cmdsn,
380                           session->max_cmdsn - session->exp_cmdsn + 1);
381         return 0;
382 }
383
384 /**
385  * iscsi_complete_command - finish a task
386  * @task: iscsi cmd task
387  *
388  * Must be called with session lock.
389  * This function returns the scsi command to scsi-ml or cleans
390  * up mgmt tasks then returns the task to the pool.
391  */
392 static void iscsi_complete_command(struct iscsi_task *task)
393 {
394         struct iscsi_conn *conn = task->conn;
395         struct iscsi_session *session = conn->session;
396         struct scsi_cmnd *sc = task->sc;
397
398         session->tt->cleanup_task(task);
399         list_del_init(&task->running);
400         task->state = ISCSI_TASK_COMPLETED;
401         task->sc = NULL;
402
403         if (conn->task == task)
404                 conn->task = NULL;
405         /*
406          * login task is preallocated so do not free
407          */
408         if (conn->login_task == task)
409                 return;
410
411         __kfifo_put(session->cmdpool.queue, (void*)&task, sizeof(void*));
412
413         if (conn->ping_task == task)
414                 conn->ping_task = NULL;
415
416         if (sc) {
417                 task->sc = NULL;
418                 /* SCSI eh reuses commands to verify us */
419                 sc->SCp.ptr = NULL;
420                 /*
421                  * queue command may call this to free the task, but
422                  * not have setup the sc callback
423                  */
424                 if (sc->scsi_done)
425                         sc->scsi_done(sc);
426         }
427 }
428
429 void __iscsi_get_task(struct iscsi_task *task)
430 {
431         atomic_inc(&task->refcount);
432 }
433 EXPORT_SYMBOL_GPL(__iscsi_get_task);
434
435 static void __iscsi_put_task(struct iscsi_task *task)
436 {
437         if (atomic_dec_and_test(&task->refcount))
438                 iscsi_complete_command(task);
439 }
440
441 void iscsi_put_task(struct iscsi_task *task)
442 {
443         struct iscsi_session *session = task->conn->session;
444
445         spin_lock_bh(&session->lock);
446         __iscsi_put_task(task);
447         spin_unlock_bh(&session->lock);
448 }
449 EXPORT_SYMBOL_GPL(iscsi_put_task);
450
451 /*
452  * session lock must be held
453  */
454 static void fail_command(struct iscsi_conn *conn, struct iscsi_task *task,
455                          int err)
456 {
457         struct scsi_cmnd *sc;
458
459         sc = task->sc;
460         if (!sc)
461                 return;
462
463         if (task->state == ISCSI_TASK_PENDING)
464                 /*
465                  * cmd never made it to the xmit thread, so we should not count
466                  * the cmd in the sequencing
467                  */
468                 conn->session->queued_cmdsn--;
469
470         sc->result = err;
471         if (!scsi_bidi_cmnd(sc))
472                 scsi_set_resid(sc, scsi_bufflen(sc));
473         else {
474                 scsi_out(sc)->resid = scsi_out(sc)->length;
475                 scsi_in(sc)->resid = scsi_in(sc)->length;
476         }
477
478         if (conn->task == task)
479                 conn->task = NULL;
480         /* release ref from queuecommand */
481         __iscsi_put_task(task);
482 }
483
484 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
485                                 struct iscsi_task *task)
486 {
487         struct iscsi_session *session = conn->session;
488         struct iscsi_hdr *hdr = task->hdr;
489         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
490
491         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
492                 return -ENOTCONN;
493
494         if (hdr->opcode != (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) &&
495             hdr->opcode != (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
496                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
497         /*
498          * pre-format CmdSN for outgoing PDU.
499          */
500         nop->cmdsn = cpu_to_be32(session->cmdsn);
501         if (hdr->itt != RESERVED_ITT) {
502                 /*
503                  * TODO: We always use immediate, so we never hit this.
504                  * If we start to send tmfs or nops as non-immediate then
505                  * we should start checking the cmdsn numbers for mgmt tasks.
506                  */
507                 if (conn->c_stage == ISCSI_CONN_STARTED &&
508                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
509                         session->queued_cmdsn++;
510                         session->cmdsn++;
511                 }
512         }
513
514         if (session->tt->init_task && session->tt->init_task(task))
515                 return -EIO;
516
517         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
518                 session->state = ISCSI_STATE_LOGGING_OUT;
519
520         task->state = ISCSI_TASK_RUNNING;
521         list_move_tail(&task->running, &conn->mgmt_run_list);
522         ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
523                           "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
524                           hdr->itt, task->data_count);
525         return 0;
526 }
527
528 static struct iscsi_task *
529 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
530                       char *data, uint32_t data_size)
531 {
532         struct iscsi_session *session = conn->session;
533         struct iscsi_task *task;
534         itt_t itt;
535
536         if (session->state == ISCSI_STATE_TERMINATE)
537                 return NULL;
538
539         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
540             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
541                 /*
542                  * Login and Text are sent serially, in
543                  * request-followed-by-response sequence.
544                  * Same task can be used. Same ITT must be used.
545                  * Note that login_task is preallocated at conn_create().
546                  */
547                 task = conn->login_task;
548         else {
549                 if (session->state != ISCSI_STATE_LOGGED_IN)
550                         return NULL;
551
552                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
553                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
554
555                 if (!__kfifo_get(session->cmdpool.queue,
556                                  (void*)&task, sizeof(void*)))
557                         return NULL;
558         }
559         /*
560          * released in complete pdu for task we expect a response for, and
561          * released by the lld when it has transmitted the task for
562          * pdus we do not expect a response for.
563          */
564         atomic_set(&task->refcount, 1);
565         task->conn = conn;
566         task->sc = NULL;
567
568         if (data_size) {
569                 memcpy(task->data, data, data_size);
570                 task->data_count = data_size;
571         } else
572                 task->data_count = 0;
573
574         if (conn->session->tt->alloc_pdu) {
575                 if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
576                         iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
577                                          "pdu for mgmt task.\n");
578                         goto requeue_task;
579                 }
580         }
581
582         itt = task->hdr->itt;
583         task->hdr_len = sizeof(struct iscsi_hdr);
584         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
585
586         if (hdr->itt != RESERVED_ITT) {
587                 if (session->tt->parse_pdu_itt)
588                         task->hdr->itt = itt;
589                 else
590                         task->hdr->itt = build_itt(task->itt,
591                                                    task->conn->session->age);
592         }
593
594         INIT_LIST_HEAD(&task->running);
595         list_add_tail(&task->running, &conn->mgmtqueue);
596
597         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
598                 if (iscsi_prep_mgmt_task(conn, task))
599                         goto free_task;
600
601                 if (session->tt->xmit_task(task))
602                         goto free_task;
603
604         } else
605                 iscsi_conn_queue_work(conn);
606
607         return task;
608
609 free_task:
610         __iscsi_put_task(task);
611         return NULL;
612
613 requeue_task:
614         if (task != conn->login_task)
615                 __kfifo_put(session->cmdpool.queue, (void*)&task,
616                             sizeof(void*));
617         return NULL;
618 }
619
620 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
621                         char *data, uint32_t data_size)
622 {
623         struct iscsi_conn *conn = cls_conn->dd_data;
624         struct iscsi_session *session = conn->session;
625         int err = 0;
626
627         spin_lock_bh(&session->lock);
628         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
629                 err = -EPERM;
630         spin_unlock_bh(&session->lock);
631         return err;
632 }
633 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
634
635 /**
636  * iscsi_cmd_rsp - SCSI Command Response processing
637  * @conn: iscsi connection
638  * @hdr: iscsi header
639  * @task: scsi command task
640  * @data: cmd data buffer
641  * @datalen: len of buffer
642  *
643  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
644  * then completes the command and task.
645  **/
646 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
647                                struct iscsi_task *task, char *data,
648                                int datalen)
649 {
650         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
651         struct iscsi_session *session = conn->session;
652         struct scsi_cmnd *sc = task->sc;
653
654         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
655         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
656
657         sc->result = (DID_OK << 16) | rhdr->cmd_status;
658
659         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
660                 sc->result = DID_ERROR << 16;
661                 goto out;
662         }
663
664         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
665                 uint16_t senselen;
666
667                 if (datalen < 2) {
668 invalid_datalen:
669                         iscsi_conn_printk(KERN_ERR,  conn,
670                                          "Got CHECK_CONDITION but invalid data "
671                                          "buffer size of %d\n", datalen);
672                         sc->result = DID_BAD_TARGET << 16;
673                         goto out;
674                 }
675
676                 senselen = get_unaligned_be16(data);
677                 if (datalen < senselen)
678                         goto invalid_datalen;
679
680                 memcpy(sc->sense_buffer, data + 2,
681                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
682                 ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
683                                   min_t(uint16_t, senselen,
684                                   SCSI_SENSE_BUFFERSIZE));
685         }
686
687         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
688                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
689                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
690
691                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
692                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
693                                  res_count <= scsi_in(sc)->length))
694                         scsi_in(sc)->resid = res_count;
695                 else
696                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
697         }
698
699         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
700                            ISCSI_FLAG_CMD_OVERFLOW)) {
701                 int res_count = be32_to_cpu(rhdr->residual_count);
702
703                 if (res_count > 0 &&
704                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
705                      res_count <= scsi_bufflen(sc)))
706                         /* write side for bidi or uni-io set_resid */
707                         scsi_set_resid(sc, res_count);
708                 else
709                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
710         }
711 out:
712         ISCSI_DBG_SESSION(session, "done [sc %p res %d itt 0x%x]\n",
713                           sc, sc->result, task->itt);
714         conn->scsirsp_pdus_cnt++;
715
716         __iscsi_put_task(task);
717 }
718
719 /**
720  * iscsi_data_in_rsp - SCSI Data-In Response processing
721  * @conn: iscsi connection
722  * @hdr:  iscsi pdu
723  * @task: scsi command task
724  **/
725 static void
726 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
727                   struct iscsi_task *task)
728 {
729         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
730         struct scsi_cmnd *sc = task->sc;
731
732         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
733                 return;
734
735         iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
736         sc->result = (DID_OK << 16) | rhdr->cmd_status;
737         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
738         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
739                            ISCSI_FLAG_DATA_OVERFLOW)) {
740                 int res_count = be32_to_cpu(rhdr->residual_count);
741
742                 if (res_count > 0 &&
743                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
744                      res_count <= scsi_in(sc)->length))
745                         scsi_in(sc)->resid = res_count;
746                 else
747                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
748         }
749
750         conn->scsirsp_pdus_cnt++;
751         __iscsi_put_task(task);
752 }
753
754 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
755 {
756         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
757
758         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
759         conn->tmfrsp_pdus_cnt++;
760
761         if (conn->tmf_state != TMF_QUEUED)
762                 return;
763
764         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
765                 conn->tmf_state = TMF_SUCCESS;
766         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
767                 conn->tmf_state = TMF_NOT_FOUND;
768         else
769                 conn->tmf_state = TMF_FAILED;
770         wake_up(&conn->ehwait);
771 }
772
773 static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
774 {
775         struct iscsi_nopout hdr;
776         struct iscsi_task *task;
777
778         if (!rhdr && conn->ping_task)
779                 return;
780
781         memset(&hdr, 0, sizeof(struct iscsi_nopout));
782         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
783         hdr.flags = ISCSI_FLAG_CMD_FINAL;
784
785         if (rhdr) {
786                 memcpy(hdr.lun, rhdr->lun, 8);
787                 hdr.ttt = rhdr->ttt;
788                 hdr.itt = RESERVED_ITT;
789         } else
790                 hdr.ttt = RESERVED_ITT;
791
792         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
793         if (!task)
794                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
795         else if (!rhdr) {
796                 /* only track our nops */
797                 conn->ping_task = task;
798                 conn->last_ping = jiffies;
799         }
800 }
801
802 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
803                                char *data, int datalen)
804 {
805         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
806         struct iscsi_hdr rejected_pdu;
807
808         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
809
810         if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
811                 if (ntoh24(reject->dlength) > datalen)
812                         return ISCSI_ERR_PROTO;
813
814                 if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
815                         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
816                         iscsi_conn_printk(KERN_ERR, conn,
817                                           "pdu (op 0x%x) rejected "
818                                           "due to DataDigest error.\n",
819                                           rejected_pdu.opcode);
820                 }
821         }
822         return 0;
823 }
824
825 /**
826  * iscsi_itt_to_task - look up task by itt
827  * @conn: iscsi connection
828  * @itt: itt
829  *
830  * This should be used for mgmt tasks like login and nops, or if
831  * the LDD's itt space does not include the session age.
832  *
833  * The session lock must be held.
834  */
835 struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
836 {
837         struct iscsi_session *session = conn->session;
838         int i;
839
840         if (itt == RESERVED_ITT)
841                 return NULL;
842
843         if (session->tt->parse_pdu_itt)
844                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
845         else
846                 i = get_itt(itt);
847         if (i >= session->cmds_max)
848                 return NULL;
849
850         return session->cmds[i];
851 }
852 EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
853
854 /**
855  * __iscsi_complete_pdu - complete pdu
856  * @conn: iscsi conn
857  * @hdr: iscsi header
858  * @data: data buffer
859  * @datalen: len of data buffer
860  *
861  * Completes pdu processing by freeing any resources allocated at
862  * queuecommand or send generic. session lock must be held and verify
863  * itt must have been called.
864  */
865 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
866                          char *data, int datalen)
867 {
868         struct iscsi_session *session = conn->session;
869         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
870         struct iscsi_task *task;
871         uint32_t itt;
872
873         conn->last_recv = jiffies;
874         rc = iscsi_verify_itt(conn, hdr->itt);
875         if (rc)
876                 return rc;
877
878         if (hdr->itt != RESERVED_ITT)
879                 itt = get_itt(hdr->itt);
880         else
881                 itt = ~0U;
882
883         ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
884                           opcode, conn->id, itt, datalen);
885
886         if (itt == ~0U) {
887                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
888
889                 switch(opcode) {
890                 case ISCSI_OP_NOOP_IN:
891                         if (datalen) {
892                                 rc = ISCSI_ERR_PROTO;
893                                 break;
894                         }
895
896                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
897                                 break;
898
899                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
900                         break;
901                 case ISCSI_OP_REJECT:
902                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
903                         break;
904                 case ISCSI_OP_ASYNC_EVENT:
905                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
906                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
907                                 rc = ISCSI_ERR_CONN_FAILED;
908                         break;
909                 default:
910                         rc = ISCSI_ERR_BAD_OPCODE;
911                         break;
912                 }
913                 goto out;
914         }
915
916         switch(opcode) {
917         case ISCSI_OP_SCSI_CMD_RSP:
918         case ISCSI_OP_SCSI_DATA_IN:
919                 task = iscsi_itt_to_ctask(conn, hdr->itt);
920                 if (!task)
921                         return ISCSI_ERR_BAD_ITT;
922                 break;
923         case ISCSI_OP_R2T:
924                 /*
925                  * LLD handles R2Ts if they need to.
926                  */
927                 return 0;
928         case ISCSI_OP_LOGOUT_RSP:
929         case ISCSI_OP_LOGIN_RSP:
930         case ISCSI_OP_TEXT_RSP:
931         case ISCSI_OP_SCSI_TMFUNC_RSP:
932         case ISCSI_OP_NOOP_IN:
933                 task = iscsi_itt_to_task(conn, hdr->itt);
934                 if (!task)
935                         return ISCSI_ERR_BAD_ITT;
936                 break;
937         default:
938                 return ISCSI_ERR_BAD_OPCODE;
939         }
940
941         switch(opcode) {
942         case ISCSI_OP_SCSI_CMD_RSP:
943                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
944                 break;
945         case ISCSI_OP_SCSI_DATA_IN:
946                 iscsi_data_in_rsp(conn, hdr, task);
947                 break;
948         case ISCSI_OP_LOGOUT_RSP:
949                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
950                 if (datalen) {
951                         rc = ISCSI_ERR_PROTO;
952                         break;
953                 }
954                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
955                 goto recv_pdu;
956         case ISCSI_OP_LOGIN_RSP:
957         case ISCSI_OP_TEXT_RSP:
958                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
959                 /*
960                  * login related PDU's exp_statsn is handled in
961                  * userspace
962                  */
963                 goto recv_pdu;
964         case ISCSI_OP_SCSI_TMFUNC_RSP:
965                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
966                 if (datalen) {
967                         rc = ISCSI_ERR_PROTO;
968                         break;
969                 }
970
971                 iscsi_tmf_rsp(conn, hdr);
972                 __iscsi_put_task(task);
973                 break;
974         case ISCSI_OP_NOOP_IN:
975                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
976                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
977                         rc = ISCSI_ERR_PROTO;
978                         break;
979                 }
980                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
981
982                 if (conn->ping_task != task)
983                         /*
984                          * If this is not in response to one of our
985                          * nops then it must be from userspace.
986                          */
987                         goto recv_pdu;
988
989                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
990                 __iscsi_put_task(task);
991                 break;
992         default:
993                 rc = ISCSI_ERR_BAD_OPCODE;
994                 break;
995         }
996
997 out:
998         return rc;
999 recv_pdu:
1000         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1001                 rc = ISCSI_ERR_CONN_FAILED;
1002         __iscsi_put_task(task);
1003         return rc;
1004 }
1005 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1006
1007 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1008                        char *data, int datalen)
1009 {
1010         int rc;
1011
1012         spin_lock(&conn->session->lock);
1013         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1014         spin_unlock(&conn->session->lock);
1015         return rc;
1016 }
1017 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1018
1019 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1020 {
1021         struct iscsi_session *session = conn->session;
1022         int age = 0, i = 0;
1023
1024         if (itt == RESERVED_ITT)
1025                 return 0;
1026
1027         if (session->tt->parse_pdu_itt)
1028                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
1029         else {
1030                 i = get_itt(itt);
1031                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1032         }
1033
1034         if (age != session->age) {
1035                 iscsi_conn_printk(KERN_ERR, conn,
1036                                   "received itt %x expected session age (%x)\n",
1037                                   (__force u32)itt, session->age);
1038                 return ISCSI_ERR_BAD_ITT;
1039         }
1040
1041         if (i >= session->cmds_max) {
1042                 iscsi_conn_printk(KERN_ERR, conn,
1043                                   "received invalid itt index %u (max cmds "
1044                                    "%u.\n", i, session->cmds_max);
1045                 return ISCSI_ERR_BAD_ITT;
1046         }
1047         return 0;
1048 }
1049 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1050
1051 /**
1052  * iscsi_itt_to_ctask - look up ctask by itt
1053  * @conn: iscsi connection
1054  * @itt: itt
1055  *
1056  * This should be used for cmd tasks.
1057  *
1058  * The session lock must be held.
1059  */
1060 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1061 {
1062         struct iscsi_task *task;
1063
1064         if (iscsi_verify_itt(conn, itt))
1065                 return NULL;
1066
1067         task = iscsi_itt_to_task(conn, itt);
1068         if (!task || !task->sc)
1069                 return NULL;
1070
1071         if (task->sc->SCp.phase != conn->session->age) {
1072                 iscsi_session_printk(KERN_ERR, conn->session,
1073                                   "task's session age %d, expected %d\n",
1074                                   task->sc->SCp.phase, conn->session->age);
1075                 return NULL;
1076         }
1077
1078         return task;
1079 }
1080 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1081
1082 void iscsi_session_failure(struct iscsi_session *session,
1083                            enum iscsi_err err)
1084 {
1085         struct iscsi_conn *conn;
1086         struct device *dev;
1087         unsigned long flags;
1088
1089         spin_lock_irqsave(&session->lock, flags);
1090         conn = session->leadconn;
1091         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1092                 spin_unlock_irqrestore(&session->lock, flags);
1093                 return;
1094         }
1095
1096         dev = get_device(&conn->cls_conn->dev);
1097         spin_unlock_irqrestore(&session->lock, flags);
1098         if (!dev)
1099                 return;
1100         /*
1101          * if the host is being removed bypass the connection
1102          * recovery initialization because we are going to kill
1103          * the session.
1104          */
1105         if (err == ISCSI_ERR_INVALID_HOST)
1106                 iscsi_conn_error_event(conn->cls_conn, err);
1107         else
1108                 iscsi_conn_failure(conn, err);
1109         put_device(dev);
1110 }
1111 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1112
1113 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1114 {
1115         struct iscsi_session *session = conn->session;
1116         unsigned long flags;
1117
1118         spin_lock_irqsave(&session->lock, flags);
1119         if (session->state == ISCSI_STATE_FAILED) {
1120                 spin_unlock_irqrestore(&session->lock, flags);
1121                 return;
1122         }
1123
1124         if (conn->stop_stage == 0)
1125                 session->state = ISCSI_STATE_FAILED;
1126         spin_unlock_irqrestore(&session->lock, flags);
1127
1128         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1129         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1130         iscsi_conn_error_event(conn->cls_conn, err);
1131 }
1132 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1133
1134 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1135 {
1136         struct iscsi_session *session = conn->session;
1137
1138         /*
1139          * Check for iSCSI window and take care of CmdSN wrap-around
1140          */
1141         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1142                 ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1143                                   "%u MaxCmdSN %u CmdSN %u/%u\n",
1144                                   session->exp_cmdsn, session->max_cmdsn,
1145                                   session->cmdsn, session->queued_cmdsn);
1146                 return -ENOSPC;
1147         }
1148         return 0;
1149 }
1150
1151 static int iscsi_xmit_task(struct iscsi_conn *conn)
1152 {
1153         struct iscsi_task *task = conn->task;
1154         int rc;
1155
1156         __iscsi_get_task(task);
1157         spin_unlock_bh(&conn->session->lock);
1158         rc = conn->session->tt->xmit_task(task);
1159         spin_lock_bh(&conn->session->lock);
1160         __iscsi_put_task(task);
1161         if (!rc)
1162                 /* done with this task */
1163                 conn->task = NULL;
1164         return rc;
1165 }
1166
1167 /**
1168  * iscsi_requeue_task - requeue task to run from session workqueue
1169  * @task: task to requeue
1170  *
1171  * LLDs that need to run a task from the session workqueue should call
1172  * this. The session lock must be held. This should only be called
1173  * by software drivers.
1174  */
1175 void iscsi_requeue_task(struct iscsi_task *task)
1176 {
1177         struct iscsi_conn *conn = task->conn;
1178
1179         list_move_tail(&task->running, &conn->requeue);
1180         iscsi_conn_queue_work(conn);
1181 }
1182 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1183
1184 /**
1185  * iscsi_data_xmit - xmit any command into the scheduled connection
1186  * @conn: iscsi connection
1187  *
1188  * Notes:
1189  *      The function can return -EAGAIN in which case the caller must
1190  *      re-schedule it again later or recover. '0' return code means
1191  *      successful xmit.
1192  **/
1193 static int iscsi_data_xmit(struct iscsi_conn *conn)
1194 {
1195         int rc = 0;
1196
1197         spin_lock_bh(&conn->session->lock);
1198         if (unlikely(conn->suspend_tx)) {
1199                 ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1200                 spin_unlock_bh(&conn->session->lock);
1201                 return -ENODATA;
1202         }
1203
1204         if (conn->task) {
1205                 rc = iscsi_xmit_task(conn);
1206                 if (rc)
1207                         goto again;
1208         }
1209
1210         /*
1211          * process mgmt pdus like nops before commands since we should
1212          * only have one nop-out as a ping from us and targets should not
1213          * overflow us with nop-ins
1214          */
1215 check_mgmt:
1216         while (!list_empty(&conn->mgmtqueue)) {
1217                 conn->task = list_entry(conn->mgmtqueue.next,
1218                                          struct iscsi_task, running);
1219                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1220                         __iscsi_put_task(conn->task);
1221                         conn->task = NULL;
1222                         continue;
1223                 }
1224                 rc = iscsi_xmit_task(conn);
1225                 if (rc)
1226                         goto again;
1227         }
1228
1229         /* process pending command queue */
1230         while (!list_empty(&conn->xmitqueue)) {
1231                 if (conn->tmf_state == TMF_QUEUED)
1232                         break;
1233
1234                 conn->task = list_entry(conn->xmitqueue.next,
1235                                          struct iscsi_task, running);
1236                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1237                         fail_command(conn, conn->task, DID_IMM_RETRY << 16);
1238                         continue;
1239                 }
1240                 rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1241                 if (rc) {
1242                         if (rc == -ENOMEM) {
1243                                 conn->task = NULL;
1244                                 goto again;
1245                         } else
1246                                 fail_command(conn, conn->task, DID_ABORT << 16);
1247                         continue;
1248                 }
1249                 rc = iscsi_xmit_task(conn);
1250                 if (rc)
1251                         goto again;
1252                 /*
1253                  * we could continuously get new task requests so
1254                  * we need to check the mgmt queue for nops that need to
1255                  * be sent to aviod starvation
1256                  */
1257                 if (!list_empty(&conn->mgmtqueue))
1258                         goto check_mgmt;
1259         }
1260
1261         while (!list_empty(&conn->requeue)) {
1262                 if (conn->session->fast_abort && conn->tmf_state != TMF_INITIAL)
1263                         break;
1264
1265                 /*
1266                  * we always do fastlogout - conn stop code will clean up.
1267                  */
1268                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1269                         break;
1270
1271                 conn->task = list_entry(conn->requeue.next,
1272                                          struct iscsi_task, running);
1273                 conn->task->state = ISCSI_TASK_RUNNING;
1274                 list_move_tail(conn->requeue.next, &conn->run_list);
1275                 rc = iscsi_xmit_task(conn);
1276                 if (rc)
1277                         goto again;
1278                 if (!list_empty(&conn->mgmtqueue))
1279                         goto check_mgmt;
1280         }
1281         spin_unlock_bh(&conn->session->lock);
1282         return -ENODATA;
1283
1284 again:
1285         if (unlikely(conn->suspend_tx))
1286                 rc = -ENODATA;
1287         spin_unlock_bh(&conn->session->lock);
1288         return rc;
1289 }
1290
1291 static void iscsi_xmitworker(struct work_struct *work)
1292 {
1293         struct iscsi_conn *conn =
1294                 container_of(work, struct iscsi_conn, xmitwork);
1295         int rc;
1296         /*
1297          * serialize Xmit worker on a per-connection basis.
1298          */
1299         do {
1300                 rc = iscsi_data_xmit(conn);
1301         } while (rc >= 0 || rc == -EAGAIN);
1302 }
1303
1304 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1305                                                   struct scsi_cmnd *sc)
1306 {
1307         struct iscsi_task *task;
1308
1309         if (!__kfifo_get(conn->session->cmdpool.queue,
1310                          (void *) &task, sizeof(void *)))
1311                 return NULL;
1312
1313         sc->SCp.phase = conn->session->age;
1314         sc->SCp.ptr = (char *) task;
1315
1316         atomic_set(&task->refcount, 1);
1317         task->state = ISCSI_TASK_PENDING;
1318         task->conn = conn;
1319         task->sc = sc;
1320         INIT_LIST_HEAD(&task->running);
1321         return task;
1322 }
1323
1324 enum {
1325         FAILURE_BAD_HOST = 1,
1326         FAILURE_SESSION_FAILED,
1327         FAILURE_SESSION_FREED,
1328         FAILURE_WINDOW_CLOSED,
1329         FAILURE_OOM,
1330         FAILURE_SESSION_TERMINATE,
1331         FAILURE_SESSION_IN_RECOVERY,
1332         FAILURE_SESSION_RECOVERY_TIMEOUT,
1333         FAILURE_SESSION_LOGGING_OUT,
1334         FAILURE_SESSION_NOT_READY,
1335 };
1336
1337 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
1338 {
1339         struct iscsi_cls_session *cls_session;
1340         struct Scsi_Host *host;
1341         int reason = 0;
1342         struct iscsi_session *session;
1343         struct iscsi_conn *conn;
1344         struct iscsi_task *task = NULL;
1345
1346         sc->scsi_done = done;
1347         sc->result = 0;
1348         sc->SCp.ptr = NULL;
1349
1350         host = sc->device->host;
1351         spin_unlock(host->host_lock);
1352
1353         cls_session = starget_to_session(scsi_target(sc->device));
1354         session = cls_session->dd_data;
1355         spin_lock(&session->lock);
1356
1357         reason = iscsi_session_chkready(cls_session);
1358         if (reason) {
1359                 sc->result = reason;
1360                 goto fault;
1361         }
1362
1363         /*
1364          * ISCSI_STATE_FAILED is a temp. state. The recovery
1365          * code will decide what is best to do with command queued
1366          * during this time
1367          */
1368         if (session->state != ISCSI_STATE_LOGGED_IN &&
1369             session->state != ISCSI_STATE_FAILED) {
1370                 /*
1371                  * to handle the race between when we set the recovery state
1372                  * and block the session we requeue here (commands could
1373                  * be entering our queuecommand while a block is starting
1374                  * up because the block code is not locked)
1375                  */
1376                 switch (session->state) {
1377                 case ISCSI_STATE_IN_RECOVERY:
1378                         reason = FAILURE_SESSION_IN_RECOVERY;
1379                         goto reject;
1380                 case ISCSI_STATE_LOGGING_OUT:
1381                         reason = FAILURE_SESSION_LOGGING_OUT;
1382                         goto reject;
1383                 case ISCSI_STATE_RECOVERY_FAILED:
1384                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1385                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1386                         break;
1387                 case ISCSI_STATE_TERMINATE:
1388                         reason = FAILURE_SESSION_TERMINATE;
1389                         sc->result = DID_NO_CONNECT << 16;
1390                         break;
1391                 default:
1392                         reason = FAILURE_SESSION_FREED;
1393                         sc->result = DID_NO_CONNECT << 16;
1394                 }
1395                 goto fault;
1396         }
1397
1398         conn = session->leadconn;
1399         if (!conn) {
1400                 reason = FAILURE_SESSION_FREED;
1401                 sc->result = DID_NO_CONNECT << 16;
1402                 goto fault;
1403         }
1404
1405         if (iscsi_check_cmdsn_window_closed(conn)) {
1406                 reason = FAILURE_WINDOW_CLOSED;
1407                 goto reject;
1408         }
1409
1410         task = iscsi_alloc_task(conn, sc);
1411         if (!task) {
1412                 reason = FAILURE_OOM;
1413                 goto reject;
1414         }
1415         list_add_tail(&task->running, &conn->xmitqueue);
1416
1417         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
1418                 reason = iscsi_prep_scsi_cmd_pdu(task);
1419                 if (reason) {
1420                         if (reason == -ENOMEM) {
1421                                 reason = FAILURE_OOM;
1422                                 goto prepd_reject;
1423                         } else {
1424                                 sc->result = DID_ABORT << 16;
1425                                 goto prepd_fault;
1426                         }
1427                 }
1428                 if (session->tt->xmit_task(task)) {
1429                         reason = FAILURE_SESSION_NOT_READY;
1430                         goto prepd_reject;
1431                 }
1432         } else
1433                 iscsi_conn_queue_work(conn);
1434
1435         session->queued_cmdsn++;
1436         spin_unlock(&session->lock);
1437         spin_lock(host->host_lock);
1438         return 0;
1439
1440 prepd_reject:
1441         sc->scsi_done = NULL;
1442         iscsi_complete_command(task);
1443 reject:
1444         spin_unlock(&session->lock);
1445         ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1446                           sc->cmnd[0], reason);
1447         spin_lock(host->host_lock);
1448         return SCSI_MLQUEUE_TARGET_BUSY;
1449
1450 prepd_fault:
1451         sc->scsi_done = NULL;
1452         iscsi_complete_command(task);
1453 fault:
1454         spin_unlock(&session->lock);
1455         ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1456                           sc->cmnd[0], reason);
1457         if (!scsi_bidi_cmnd(sc))
1458                 scsi_set_resid(sc, scsi_bufflen(sc));
1459         else {
1460                 scsi_out(sc)->resid = scsi_out(sc)->length;
1461                 scsi_in(sc)->resid = scsi_in(sc)->length;
1462         }
1463         done(sc);
1464         spin_lock(host->host_lock);
1465         return 0;
1466 }
1467 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1468
1469 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
1470 {
1471         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1472         return sdev->queue_depth;
1473 }
1474 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1475
1476 int iscsi_target_alloc(struct scsi_target *starget)
1477 {
1478         struct iscsi_cls_session *cls_session = starget_to_session(starget);
1479         struct iscsi_session *session = cls_session->dd_data;
1480
1481         starget->can_queue = session->scsi_cmds_max;
1482         return 0;
1483 }
1484 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1485
1486 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
1487 {
1488         struct iscsi_session *session = cls_session->dd_data;
1489
1490         spin_lock_bh(&session->lock);
1491         if (session->state != ISCSI_STATE_LOGGED_IN) {
1492                 session->state = ISCSI_STATE_RECOVERY_FAILED;
1493                 if (session->leadconn)
1494                         wake_up(&session->leadconn->ehwait);
1495         }
1496         spin_unlock_bh(&session->lock);
1497 }
1498 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
1499
1500 int iscsi_eh_target_reset(struct scsi_cmnd *sc)
1501 {
1502         struct iscsi_cls_session *cls_session;
1503         struct iscsi_session *session;
1504         struct iscsi_conn *conn;
1505
1506         cls_session = starget_to_session(scsi_target(sc->device));
1507         session = cls_session->dd_data;
1508         conn = session->leadconn;
1509
1510         mutex_lock(&session->eh_mutex);
1511         spin_lock_bh(&session->lock);
1512         if (session->state == ISCSI_STATE_TERMINATE) {
1513 failed:
1514                 iscsi_session_printk(KERN_INFO, session,
1515                                      "failing target reset: Could not log "
1516                                      "back into target [age %d]\n",
1517                                      session->age);
1518                 spin_unlock_bh(&session->lock);
1519                 mutex_unlock(&session->eh_mutex);
1520                 return FAILED;
1521         }
1522
1523         spin_unlock_bh(&session->lock);
1524         mutex_unlock(&session->eh_mutex);
1525         /*
1526          * we drop the lock here but the leadconn cannot be destoyed while
1527          * we are in the scsi eh
1528          */
1529         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1530
1531         ISCSI_DBG_SESSION(session, "wait for relogin\n");
1532         wait_event_interruptible(conn->ehwait,
1533                                  session->state == ISCSI_STATE_TERMINATE ||
1534                                  session->state == ISCSI_STATE_LOGGED_IN ||
1535                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
1536         if (signal_pending(current))
1537                 flush_signals(current);
1538
1539         mutex_lock(&session->eh_mutex);
1540         spin_lock_bh(&session->lock);
1541         if (session->state == ISCSI_STATE_LOGGED_IN)
1542                 iscsi_session_printk(KERN_INFO, session,
1543                                      "target reset succeeded\n");
1544         else
1545                 goto failed;
1546         spin_unlock_bh(&session->lock);
1547         mutex_unlock(&session->eh_mutex);
1548         return SUCCESS;
1549 }
1550 EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
1551
1552 static void iscsi_tmf_timedout(unsigned long data)
1553 {
1554         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1555         struct iscsi_session *session = conn->session;
1556
1557         spin_lock(&session->lock);
1558         if (conn->tmf_state == TMF_QUEUED) {
1559                 conn->tmf_state = TMF_TIMEDOUT;
1560                 ISCSI_DBG_SESSION(session, "tmf timedout\n");
1561                 /* unblock eh_abort() */
1562                 wake_up(&conn->ehwait);
1563         }
1564         spin_unlock(&session->lock);
1565 }
1566
1567 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1568                                    struct iscsi_tm *hdr, int age,
1569                                    int timeout)
1570 {
1571         struct iscsi_session *session = conn->session;
1572         struct iscsi_task *task;
1573
1574         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1575                                       NULL, 0);
1576         if (!task) {
1577                 spin_unlock_bh(&session->lock);
1578                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1579                 spin_lock_bh(&session->lock);
1580                 ISCSI_DBG_SESSION(session, "tmf exec failure\n");
1581                 return -EPERM;
1582         }
1583         conn->tmfcmd_pdus_cnt++;
1584         conn->tmf_timer.expires = timeout * HZ + jiffies;
1585         conn->tmf_timer.function = iscsi_tmf_timedout;
1586         conn->tmf_timer.data = (unsigned long)conn;
1587         add_timer(&conn->tmf_timer);
1588         ISCSI_DBG_SESSION(session, "tmf set timeout\n");
1589
1590         spin_unlock_bh(&session->lock);
1591         mutex_unlock(&session->eh_mutex);
1592
1593         /*
1594          * block eh thread until:
1595          *
1596          * 1) tmf response
1597          * 2) tmf timeout
1598          * 3) session is terminated or restarted or userspace has
1599          * given up on recovery
1600          */
1601         wait_event_interruptible(conn->ehwait, age != session->age ||
1602                                  session->state != ISCSI_STATE_LOGGED_IN ||
1603                                  conn->tmf_state != TMF_QUEUED);
1604         if (signal_pending(current))
1605                 flush_signals(current);
1606         del_timer_sync(&conn->tmf_timer);
1607
1608         mutex_lock(&session->eh_mutex);
1609         spin_lock_bh(&session->lock);
1610         /* if the session drops it will clean up the task */
1611         if (age != session->age ||
1612             session->state != ISCSI_STATE_LOGGED_IN)
1613                 return -ENOTCONN;
1614         return 0;
1615 }
1616
1617 /*
1618  * Fail commands. session lock held and recv side suspended and xmit
1619  * thread flushed
1620  */
1621 static void fail_all_commands(struct iscsi_conn *conn, unsigned lun,
1622                               int error)
1623 {
1624         struct iscsi_task *task, *tmp;
1625
1626         if (conn->task) {
1627                 if (lun == -1 ||
1628                     (conn->task->sc && conn->task->sc->device->lun == lun))
1629                         conn->task = NULL;
1630         }
1631
1632         /* flush pending */
1633         list_for_each_entry_safe(task, tmp, &conn->xmitqueue, running) {
1634                 if (lun == task->sc->device->lun || lun == -1) {
1635                         ISCSI_DBG_SESSION(conn->session,
1636                                           "failing pending sc %p itt 0x%x\n",
1637                                           task->sc, task->itt);
1638                         fail_command(conn, task, error << 16);
1639                 }
1640         }
1641
1642         list_for_each_entry_safe(task, tmp, &conn->requeue, running) {
1643                 if (lun == task->sc->device->lun || lun == -1) {
1644                         ISCSI_DBG_SESSION(conn->session,
1645                                           "failing requeued sc %p itt 0x%x\n",
1646                                           task->sc, task->itt);
1647                         fail_command(conn, task, error << 16);
1648                 }
1649         }
1650
1651         /* fail all other running */
1652         list_for_each_entry_safe(task, tmp, &conn->run_list, running) {
1653                 if (lun == task->sc->device->lun || lun == -1) {
1654                         ISCSI_DBG_SESSION(conn->session,
1655                                          "failing in progress sc %p itt 0x%x\n",
1656                                          task->sc, task->itt);
1657                         fail_command(conn, task, error << 16);
1658                 }
1659         }
1660 }
1661
1662 void iscsi_suspend_tx(struct iscsi_conn *conn)
1663 {
1664         struct Scsi_Host *shost = conn->session->host;
1665         struct iscsi_host *ihost = shost_priv(shost);
1666
1667         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1668         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1669                 flush_workqueue(ihost->workq);
1670 }
1671 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1672
1673 static void iscsi_start_tx(struct iscsi_conn *conn)
1674 {
1675         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1676         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1677                 iscsi_conn_queue_work(conn);
1678 }
1679
1680 static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *scmd)
1681 {
1682         struct iscsi_cls_session *cls_session;
1683         struct iscsi_session *session;
1684         struct iscsi_conn *conn;
1685         enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1686
1687         cls_session = starget_to_session(scsi_target(scmd->device));
1688         session = cls_session->dd_data;
1689
1690         ISCSI_DBG_SESSION(session, "scsi cmd %p timedout\n", scmd);
1691
1692         spin_lock(&session->lock);
1693         if (session->state != ISCSI_STATE_LOGGED_IN) {
1694                 /*
1695                  * We are probably in the middle of iscsi recovery so let
1696                  * that complete and handle the error.
1697                  */
1698                 rc = BLK_EH_RESET_TIMER;
1699                 goto done;
1700         }
1701
1702         conn = session->leadconn;
1703         if (!conn) {
1704                 /* In the middle of shuting down */
1705                 rc = BLK_EH_RESET_TIMER;
1706                 goto done;
1707         }
1708
1709         if (!conn->recv_timeout && !conn->ping_timeout)
1710                 goto done;
1711         /*
1712          * if the ping timedout then we are in the middle of cleaning up
1713          * and can let the iscsi eh handle it
1714          */
1715         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1716                             (conn->ping_timeout * HZ), jiffies))
1717                 rc = BLK_EH_RESET_TIMER;
1718         /*
1719          * if we are about to check the transport then give the command
1720          * more time
1721          */
1722         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ),
1723                            jiffies))
1724                 rc = BLK_EH_RESET_TIMER;
1725         /* if in the middle of checking the transport then give us more time */
1726         if (conn->ping_task)
1727                 rc = BLK_EH_RESET_TIMER;
1728 done:
1729         spin_unlock(&session->lock);
1730         ISCSI_DBG_SESSION(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
1731                           "timer reset" : "nh");
1732         return rc;
1733 }
1734
1735 static void iscsi_check_transport_timeouts(unsigned long data)
1736 {
1737         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1738         struct iscsi_session *session = conn->session;
1739         unsigned long recv_timeout, next_timeout = 0, last_recv;
1740
1741         spin_lock(&session->lock);
1742         if (session->state != ISCSI_STATE_LOGGED_IN)
1743                 goto done;
1744
1745         recv_timeout = conn->recv_timeout;
1746         if (!recv_timeout)
1747                 goto done;
1748
1749         recv_timeout *= HZ;
1750         last_recv = conn->last_recv;
1751         if (conn->ping_task &&
1752             time_before_eq(conn->last_ping + (conn->ping_timeout * HZ),
1753                            jiffies)) {
1754                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
1755                                   "expired, last rx %lu, last ping %lu, "
1756                                   "now %lu\n", conn->ping_timeout, last_recv,
1757                                   conn->last_ping, jiffies);
1758                 spin_unlock(&session->lock);
1759                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1760                 return;
1761         }
1762
1763         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
1764                 /* send a ping to try to provoke some traffic */
1765                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
1766                 iscsi_send_nopout(conn, NULL);
1767                 next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
1768         } else
1769                 next_timeout = last_recv + recv_timeout;
1770
1771         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
1772         mod_timer(&conn->transport_timer, next_timeout);
1773 done:
1774         spin_unlock(&session->lock);
1775 }
1776
1777 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
1778                                       struct iscsi_tm *hdr)
1779 {
1780         memset(hdr, 0, sizeof(*hdr));
1781         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1782         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
1783         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1784         memcpy(hdr->lun, task->lun, sizeof(hdr->lun));
1785         hdr->rtt = task->hdr_itt;
1786         hdr->refcmdsn = task->cmdsn;
1787 }
1788
1789 int iscsi_eh_abort(struct scsi_cmnd *sc)
1790 {
1791         struct iscsi_cls_session *cls_session;
1792         struct iscsi_session *session;
1793         struct iscsi_conn *conn;
1794         struct iscsi_task *task;
1795         struct iscsi_tm *hdr;
1796         int rc, age;
1797
1798         cls_session = starget_to_session(scsi_target(sc->device));
1799         session = cls_session->dd_data;
1800
1801         mutex_lock(&session->eh_mutex);
1802         spin_lock_bh(&session->lock);
1803         /*
1804          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1805          * got the command.
1806          */
1807         if (!sc->SCp.ptr) {
1808                 ISCSI_DBG_SESSION(session, "sc never reached iscsi layer or "
1809                                   "it completed.\n");
1810                 spin_unlock_bh(&session->lock);
1811                 mutex_unlock(&session->eh_mutex);
1812                 return SUCCESS;
1813         }
1814
1815         /*
1816          * If we are not logged in or we have started a new session
1817          * then let the host reset code handle this
1818          */
1819         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
1820             sc->SCp.phase != session->age) {
1821                 spin_unlock_bh(&session->lock);
1822                 mutex_unlock(&session->eh_mutex);
1823                 return FAILED;
1824         }
1825
1826         conn = session->leadconn;
1827         conn->eh_abort_cnt++;
1828         age = session->age;
1829
1830         task = (struct iscsi_task *)sc->SCp.ptr;
1831         ISCSI_DBG_SESSION(session, "aborting [sc %p itt 0x%x]\n",
1832                           sc, task->itt);
1833
1834         /* task completed before time out */
1835         if (!task->sc) {
1836                 ISCSI_DBG_SESSION(session, "sc completed while abort in "
1837                                   "progress\n");
1838                 goto success;
1839         }
1840
1841         if (task->state == ISCSI_TASK_PENDING) {
1842                 fail_command(conn, task, DID_ABORT << 16);
1843                 goto success;
1844         }
1845
1846         /* only have one tmf outstanding at a time */
1847         if (conn->tmf_state != TMF_INITIAL)
1848                 goto failed;
1849         conn->tmf_state = TMF_QUEUED;
1850
1851         hdr = &conn->tmhdr;
1852         iscsi_prep_abort_task_pdu(task, hdr);
1853
1854         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
1855                 rc = FAILED;
1856                 goto failed;
1857         }
1858
1859         switch (conn->tmf_state) {
1860         case TMF_SUCCESS:
1861                 spin_unlock_bh(&session->lock);
1862                 /*
1863                  * stop tx side incase the target had sent a abort rsp but
1864                  * the initiator was still writing out data.
1865                  */
1866                 iscsi_suspend_tx(conn);
1867                 /*
1868                  * we do not stop the recv side because targets have been
1869                  * good and have never sent us a successful tmf response
1870                  * then sent more data for the cmd.
1871                  */
1872                 spin_lock(&session->lock);
1873                 fail_command(conn, task, DID_ABORT << 16);
1874                 conn->tmf_state = TMF_INITIAL;
1875                 spin_unlock(&session->lock);
1876                 iscsi_start_tx(conn);
1877                 goto success_unlocked;
1878         case TMF_TIMEDOUT:
1879                 spin_unlock_bh(&session->lock);
1880                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1881                 goto failed_unlocked;
1882         case TMF_NOT_FOUND:
1883                 if (!sc->SCp.ptr) {
1884                         conn->tmf_state = TMF_INITIAL;
1885                         /* task completed before tmf abort response */
1886                         ISCSI_DBG_SESSION(session, "sc completed while abort "
1887                                           "in progress\n");
1888                         goto success;
1889                 }
1890                 /* fall through */
1891         default:
1892                 conn->tmf_state = TMF_INITIAL;
1893                 goto failed;
1894         }
1895
1896 success:
1897         spin_unlock_bh(&session->lock);
1898 success_unlocked:
1899         ISCSI_DBG_SESSION(session, "abort success [sc %p itt 0x%x]\n",
1900                           sc, task->itt);
1901         mutex_unlock(&session->eh_mutex);
1902         return SUCCESS;
1903
1904 failed:
1905         spin_unlock_bh(&session->lock);
1906 failed_unlocked:
1907         ISCSI_DBG_SESSION(session, "abort failed [sc %p itt 0x%x]\n", sc,
1908                           task ? task->itt : 0);
1909         mutex_unlock(&session->eh_mutex);
1910         return FAILED;
1911 }
1912 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1913
1914 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
1915 {
1916         memset(hdr, 0, sizeof(*hdr));
1917         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1918         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
1919         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1920         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
1921         hdr->rtt = RESERVED_ITT;
1922 }
1923
1924 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
1925 {
1926         struct iscsi_cls_session *cls_session;
1927         struct iscsi_session *session;
1928         struct iscsi_conn *conn;
1929         struct iscsi_tm *hdr;
1930         int rc = FAILED;
1931
1932         cls_session = starget_to_session(scsi_target(sc->device));
1933         session = cls_session->dd_data;
1934
1935         ISCSI_DBG_SESSION(session, "LU Reset [sc %p lun %u]\n",
1936                           sc, sc->device->lun);
1937
1938         mutex_lock(&session->eh_mutex);
1939         spin_lock_bh(&session->lock);
1940         /*
1941          * Just check if we are not logged in. We cannot check for
1942          * the phase because the reset could come from a ioctl.
1943          */
1944         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
1945                 goto unlock;
1946         conn = session->leadconn;
1947
1948         /* only have one tmf outstanding at a time */
1949         if (conn->tmf_state != TMF_INITIAL)
1950                 goto unlock;
1951         conn->tmf_state = TMF_QUEUED;
1952
1953         hdr = &conn->tmhdr;
1954         iscsi_prep_lun_reset_pdu(sc, hdr);
1955
1956         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
1957                                     session->lu_reset_timeout)) {
1958                 rc = FAILED;
1959                 goto unlock;
1960         }
1961
1962         switch (conn->tmf_state) {
1963         case TMF_SUCCESS:
1964                 break;
1965         case TMF_TIMEDOUT:
1966                 spin_unlock_bh(&session->lock);
1967                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1968                 goto done;
1969         default:
1970                 conn->tmf_state = TMF_INITIAL;
1971                 goto unlock;
1972         }
1973
1974         rc = SUCCESS;
1975         spin_unlock_bh(&session->lock);
1976
1977         iscsi_suspend_tx(conn);
1978
1979         spin_lock_bh(&session->lock);
1980         fail_all_commands(conn, sc->device->lun, DID_ERROR);
1981         conn->tmf_state = TMF_INITIAL;
1982         spin_unlock_bh(&session->lock);
1983
1984         iscsi_start_tx(conn);
1985         goto done;
1986
1987 unlock:
1988         spin_unlock_bh(&session->lock);
1989 done:
1990         ISCSI_DBG_SESSION(session, "dev reset result = %s\n",
1991                          rc == SUCCESS ? "SUCCESS" : "FAILED");
1992         mutex_unlock(&session->eh_mutex);
1993         return rc;
1994 }
1995 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
1996
1997 /*
1998  * Pre-allocate a pool of @max items of @item_size. By default, the pool
1999  * should be accessed via kfifo_{get,put} on q->queue.
2000  * Optionally, the caller can obtain the array of object pointers
2001  * by passing in a non-NULL @items pointer
2002  */
2003 int
2004 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2005 {
2006         int i, num_arrays = 1;
2007
2008         memset(q, 0, sizeof(*q));
2009
2010         q->max = max;
2011
2012         /* If the user passed an items pointer, he wants a copy of
2013          * the array. */
2014         if (items)
2015                 num_arrays++;
2016         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
2017         if (q->pool == NULL)
2018                 return -ENOMEM;
2019
2020         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
2021                               GFP_KERNEL, NULL);
2022         if (IS_ERR(q->queue)) {
2023                 q->queue = NULL;
2024                 goto enomem;
2025         }
2026
2027         for (i = 0; i < max; i++) {
2028                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2029                 if (q->pool[i] == NULL) {
2030                         q->max = i;
2031                         goto enomem;
2032                 }
2033                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
2034         }
2035
2036         if (items) {
2037                 *items = q->pool + max;
2038                 memcpy(*items, q->pool, max * sizeof(void *));
2039         }
2040
2041         return 0;
2042
2043 enomem:
2044         iscsi_pool_free(q);
2045         return -ENOMEM;
2046 }
2047 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2048
2049 void iscsi_pool_free(struct iscsi_pool *q)
2050 {
2051         int i;
2052
2053         for (i = 0; i < q->max; i++)
2054                 kfree(q->pool[i]);
2055         kfree(q->pool);
2056         kfree(q->queue);
2057 }
2058 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2059
2060 /**
2061  * iscsi_host_add - add host to system
2062  * @shost: scsi host
2063  * @pdev: parent device
2064  *
2065  * This should be called by partial offload and software iscsi drivers
2066  * to add a host to the system.
2067  */
2068 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2069 {
2070         if (!shost->can_queue)
2071                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2072
2073         if (!shost->cmd_per_lun)
2074                 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2075
2076         if (!shost->transportt->eh_timed_out)
2077                 shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
2078         return scsi_add_host(shost, pdev);
2079 }
2080 EXPORT_SYMBOL_GPL(iscsi_host_add);
2081
2082 /**
2083  * iscsi_host_alloc - allocate a host and driver data
2084  * @sht: scsi host template
2085  * @dd_data_size: driver host data size
2086  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2087  *
2088  * This should be called by partial offload and software iscsi drivers.
2089  * To access the driver specific memory use the iscsi_host_priv() macro.
2090  */
2091 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2092                                    int dd_data_size, bool xmit_can_sleep)
2093 {
2094         struct Scsi_Host *shost;
2095         struct iscsi_host *ihost;
2096
2097         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2098         if (!shost)
2099                 return NULL;
2100         ihost = shost_priv(shost);
2101
2102         if (xmit_can_sleep) {
2103                 snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2104                         "iscsi_q_%d", shost->host_no);
2105                 ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2106                 if (!ihost->workq)
2107                         goto free_host;
2108         }
2109
2110         spin_lock_init(&ihost->lock);
2111         ihost->state = ISCSI_HOST_SETUP;
2112         ihost->num_sessions = 0;
2113         init_waitqueue_head(&ihost->session_removal_wq);
2114         return shost;
2115
2116 free_host:
2117         scsi_host_put(shost);
2118         return NULL;
2119 }
2120 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2121
2122 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2123 {
2124         iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2125 }
2126
2127 /**
2128  * iscsi_host_remove - remove host and sessions
2129  * @shost: scsi host
2130  *
2131  * If there are any sessions left, this will initiate the removal and wait
2132  * for the completion.
2133  */
2134 void iscsi_host_remove(struct Scsi_Host *shost)
2135 {
2136         struct iscsi_host *ihost = shost_priv(shost);
2137         unsigned long flags;
2138
2139         spin_lock_irqsave(&ihost->lock, flags);
2140         ihost->state = ISCSI_HOST_REMOVED;
2141         spin_unlock_irqrestore(&ihost->lock, flags);
2142
2143         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2144         wait_event_interruptible(ihost->session_removal_wq,
2145                                  ihost->num_sessions == 0);
2146         if (signal_pending(current))
2147                 flush_signals(current);
2148
2149         scsi_remove_host(shost);
2150         if (ihost->workq)
2151                 destroy_workqueue(ihost->workq);
2152 }
2153 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2154
2155 void iscsi_host_free(struct Scsi_Host *shost)
2156 {
2157         struct iscsi_host *ihost = shost_priv(shost);
2158
2159         kfree(ihost->netdev);
2160         kfree(ihost->hwaddress);
2161         kfree(ihost->initiatorname);
2162         scsi_host_put(shost);
2163 }
2164 EXPORT_SYMBOL_GPL(iscsi_host_free);
2165
2166 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2167 {
2168         struct iscsi_host *ihost = shost_priv(shost);
2169         unsigned long flags;
2170
2171         shost = scsi_host_get(shost);
2172         if (!shost) {
2173                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2174                       "of session teardown event because host already "
2175                       "removed.\n");
2176                 return;
2177         }
2178
2179         spin_lock_irqsave(&ihost->lock, flags);
2180         ihost->num_sessions--;
2181         if (ihost->num_sessions == 0)
2182                 wake_up(&ihost->session_removal_wq);
2183         spin_unlock_irqrestore(&ihost->lock, flags);
2184         scsi_host_put(shost);
2185 }
2186
2187 /**
2188  * iscsi_session_setup - create iscsi cls session and host and session
2189  * @iscsit: iscsi transport template
2190  * @shost: scsi host
2191  * @cmds_max: session can queue
2192  * @cmd_task_size: LLD task private data size
2193  * @initial_cmdsn: initial CmdSN
2194  *
2195  * This can be used by software iscsi_transports that allocate
2196  * a session per scsi host.
2197  *
2198  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2199  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2200  * for nop handling and login/logout requests.
2201  */
2202 struct iscsi_cls_session *
2203 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2204                     uint16_t cmds_max, int cmd_task_size,
2205                     uint32_t initial_cmdsn, unsigned int id)
2206 {
2207         struct iscsi_host *ihost = shost_priv(shost);
2208         struct iscsi_session *session;
2209         struct iscsi_cls_session *cls_session;
2210         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2211         unsigned long flags;
2212
2213         spin_lock_irqsave(&ihost->lock, flags);
2214         if (ihost->state == ISCSI_HOST_REMOVED) {
2215                 spin_unlock_irqrestore(&ihost->lock, flags);
2216                 return NULL;
2217         }
2218         ihost->num_sessions++;
2219         spin_unlock_irqrestore(&ihost->lock, flags);
2220
2221         if (!total_cmds)
2222                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2223         /*
2224          * The iscsi layer needs some tasks for nop handling and tmfs,
2225          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2226          * + 1 command for scsi IO.
2227          */
2228         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2229                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2230                        "must be a power of two that is at least %d.\n",
2231                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2232                 goto dec_session_count;
2233         }
2234
2235         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2236                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2237                        "must be a power of 2 less than or equal to %d.\n",
2238                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2239                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2240         }
2241
2242         if (!is_power_of_2(total_cmds)) {
2243                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2244                        "must be a power of 2.\n", total_cmds);
2245                 total_cmds = rounddown_pow_of_two(total_cmds);
2246                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2247                         return NULL;
2248                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2249                        total_cmds);
2250         }
2251         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2252
2253         cls_session = iscsi_alloc_session(shost, iscsit,
2254                                           sizeof(struct iscsi_session));
2255         if (!cls_session)
2256                 goto dec_session_count;
2257         session = cls_session->dd_data;
2258         session->cls_session = cls_session;
2259         session->host = shost;
2260         session->state = ISCSI_STATE_FREE;
2261         session->fast_abort = 1;
2262         session->lu_reset_timeout = 15;
2263         session->abort_timeout = 10;
2264         session->scsi_cmds_max = scsi_cmds;
2265         session->cmds_max = total_cmds;
2266         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2267         session->exp_cmdsn = initial_cmdsn + 1;
2268         session->max_cmdsn = initial_cmdsn + 1;
2269         session->max_r2t = 1;
2270         session->tt = iscsit;
2271         mutex_init(&session->eh_mutex);
2272         spin_lock_init(&session->lock);
2273
2274         /* initialize SCSI PDU commands pool */
2275         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2276                             (void***)&session->cmds,
2277                             cmd_task_size + sizeof(struct iscsi_task)))
2278                 goto cmdpool_alloc_fail;
2279
2280         /* pre-format cmds pool with ITT */
2281         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2282                 struct iscsi_task *task = session->cmds[cmd_i];
2283
2284                 if (cmd_task_size)
2285                         task->dd_data = &task[1];
2286                 task->itt = cmd_i;
2287                 INIT_LIST_HEAD(&task->running);
2288         }
2289
2290         if (!try_module_get(iscsit->owner))
2291                 goto module_get_fail;
2292
2293         if (iscsi_add_session(cls_session, id))
2294                 goto cls_session_fail;
2295
2296         return cls_session;
2297
2298 cls_session_fail:
2299         module_put(iscsit->owner);
2300 module_get_fail:
2301         iscsi_pool_free(&session->cmdpool);
2302 cmdpool_alloc_fail:
2303         iscsi_free_session(cls_session);
2304 dec_session_count:
2305         iscsi_host_dec_session_cnt(shost);
2306         return NULL;
2307 }
2308 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2309
2310 /**
2311  * iscsi_session_teardown - destroy session, host, and cls_session
2312  * @cls_session: iscsi session
2313  *
2314  * The driver must have called iscsi_remove_session before
2315  * calling this.
2316  */
2317 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2318 {
2319         struct iscsi_session *session = cls_session->dd_data;
2320         struct module *owner = cls_session->transport->owner;
2321         struct Scsi_Host *shost = session->host;
2322
2323         iscsi_pool_free(&session->cmdpool);
2324
2325         kfree(session->password);
2326         kfree(session->password_in);
2327         kfree(session->username);
2328         kfree(session->username_in);
2329         kfree(session->targetname);
2330         kfree(session->initiatorname);
2331         kfree(session->ifacename);
2332
2333         iscsi_destroy_session(cls_session);
2334         iscsi_host_dec_session_cnt(shost);
2335         module_put(owner);
2336 }
2337 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2338
2339 /**
2340  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2341  * @cls_session: iscsi_cls_session
2342  * @dd_size: private driver data size
2343  * @conn_idx: cid
2344  */
2345 struct iscsi_cls_conn *
2346 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2347                  uint32_t conn_idx)
2348 {
2349         struct iscsi_session *session = cls_session->dd_data;
2350         struct iscsi_conn *conn;
2351         struct iscsi_cls_conn *cls_conn;
2352         char *data;
2353
2354         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2355                                      conn_idx);
2356         if (!cls_conn)
2357                 return NULL;
2358         conn = cls_conn->dd_data;
2359         memset(conn, 0, sizeof(*conn) + dd_size);
2360
2361         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2362         conn->session = session;
2363         conn->cls_conn = cls_conn;
2364         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2365         conn->id = conn_idx;
2366         conn->exp_statsn = 0;
2367         conn->tmf_state = TMF_INITIAL;
2368
2369         init_timer(&conn->transport_timer);
2370         conn->transport_timer.data = (unsigned long)conn;
2371         conn->transport_timer.function = iscsi_check_transport_timeouts;
2372
2373         INIT_LIST_HEAD(&conn->run_list);
2374         INIT_LIST_HEAD(&conn->mgmt_run_list);
2375         INIT_LIST_HEAD(&conn->mgmtqueue);
2376         INIT_LIST_HEAD(&conn->xmitqueue);
2377         INIT_LIST_HEAD(&conn->requeue);
2378         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2379
2380         /* allocate login_task used for the login/text sequences */
2381         spin_lock_bh(&session->lock);
2382         if (!__kfifo_get(session->cmdpool.queue,
2383                          (void*)&conn->login_task,
2384                          sizeof(void*))) {
2385                 spin_unlock_bh(&session->lock);
2386                 goto login_task_alloc_fail;
2387         }
2388         spin_unlock_bh(&session->lock);
2389
2390         data = (char *) __get_free_pages(GFP_KERNEL,
2391                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2392         if (!data)
2393                 goto login_task_data_alloc_fail;
2394         conn->login_task->data = conn->data = data;
2395
2396         init_timer(&conn->tmf_timer);
2397         init_waitqueue_head(&conn->ehwait);
2398
2399         return cls_conn;
2400
2401 login_task_data_alloc_fail:
2402         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2403                     sizeof(void*));
2404 login_task_alloc_fail:
2405         iscsi_destroy_conn(cls_conn);
2406         return NULL;
2407 }
2408 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2409
2410 /**
2411  * iscsi_conn_teardown - teardown iscsi connection
2412  * cls_conn: iscsi class connection
2413  *
2414  * TODO: we may need to make this into a two step process
2415  * like scsi-mls remove + put host
2416  */
2417 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2418 {
2419         struct iscsi_conn *conn = cls_conn->dd_data;
2420         struct iscsi_session *session = conn->session;
2421         unsigned long flags;
2422
2423         del_timer_sync(&conn->transport_timer);
2424
2425         spin_lock_bh(&session->lock);
2426         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2427         if (session->leadconn == conn) {
2428                 /*
2429                  * leading connection? then give up on recovery.
2430                  */
2431                 session->state = ISCSI_STATE_TERMINATE;
2432                 wake_up(&conn->ehwait);
2433         }
2434         spin_unlock_bh(&session->lock);
2435
2436         /*
2437          * Block until all in-progress commands for this connection
2438          * time out or fail.
2439          */
2440         for (;;) {
2441                 spin_lock_irqsave(session->host->host_lock, flags);
2442                 if (!session->host->host_busy) { /* OK for ERL == 0 */
2443                         spin_unlock_irqrestore(session->host->host_lock, flags);
2444                         break;
2445                 }
2446                 spin_unlock_irqrestore(session->host->host_lock, flags);
2447                 msleep_interruptible(500);
2448                 iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2449                                   "host_busy %d host_failed %d\n",
2450                                   session->host->host_busy,
2451                                   session->host->host_failed);
2452                 /*
2453                  * force eh_abort() to unblock
2454                  */
2455                 wake_up(&conn->ehwait);
2456         }
2457
2458         /* flush queued up work because we free the connection below */
2459         iscsi_suspend_tx(conn);
2460
2461         spin_lock_bh(&session->lock);
2462         free_pages((unsigned long) conn->data,
2463                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2464         kfree(conn->persistent_address);
2465         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2466                     sizeof(void*));
2467         if (session->leadconn == conn)
2468                 session->leadconn = NULL;
2469         spin_unlock_bh(&session->lock);
2470
2471         iscsi_destroy_conn(cls_conn);
2472 }
2473 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2474
2475 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2476 {
2477         struct iscsi_conn *conn = cls_conn->dd_data;
2478         struct iscsi_session *session = conn->session;
2479
2480         if (!session) {
2481                 iscsi_conn_printk(KERN_ERR, conn,
2482                                   "can't start unbound connection\n");
2483                 return -EPERM;
2484         }
2485
2486         if ((session->imm_data_en || !session->initial_r2t_en) &&
2487              session->first_burst > session->max_burst) {
2488                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2489                                   "first_burst %d max_burst %d\n",
2490                                   session->first_burst, session->max_burst);
2491                 return -EINVAL;
2492         }
2493
2494         if (conn->ping_timeout && !conn->recv_timeout) {
2495                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
2496                                   "zero. Using 5 seconds\n.");
2497                 conn->recv_timeout = 5;
2498         }
2499
2500         if (conn->recv_timeout && !conn->ping_timeout) {
2501                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
2502                                   "zero. Using 5 seconds.\n");
2503                 conn->ping_timeout = 5;
2504         }
2505
2506         spin_lock_bh(&session->lock);
2507         conn->c_stage = ISCSI_CONN_STARTED;
2508         session->state = ISCSI_STATE_LOGGED_IN;
2509         session->queued_cmdsn = session->cmdsn;
2510
2511         conn->last_recv = jiffies;
2512         conn->last_ping = jiffies;
2513         if (conn->recv_timeout && conn->ping_timeout)
2514                 mod_timer(&conn->transport_timer,
2515                           jiffies + (conn->recv_timeout * HZ));
2516
2517         switch(conn->stop_stage) {
2518         case STOP_CONN_RECOVER:
2519                 /*
2520                  * unblock eh_abort() if it is blocked. re-try all
2521                  * commands after successful recovery
2522                  */
2523                 conn->stop_stage = 0;
2524                 conn->tmf_state = TMF_INITIAL;
2525                 session->age++;
2526                 if (session->age == 16)
2527                         session->age = 0;
2528                 break;
2529         case STOP_CONN_TERM:
2530                 conn->stop_stage = 0;
2531                 break;
2532         default:
2533                 break;
2534         }
2535         spin_unlock_bh(&session->lock);
2536
2537         iscsi_unblock_session(session->cls_session);
2538         wake_up(&conn->ehwait);
2539         return 0;
2540 }
2541 EXPORT_SYMBOL_GPL(iscsi_conn_start);
2542
2543 static void
2544 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
2545 {
2546         struct iscsi_task *task, *tmp;
2547
2548         /* handle pending */
2549         list_for_each_entry_safe(task, tmp, &conn->mgmtqueue, running) {
2550                 ISCSI_DBG_SESSION(session, "flushing pending mgmt task "
2551                                   "itt 0x%x\n", task->itt);
2552                 /* release ref from prep task */
2553                 __iscsi_put_task(task);
2554         }
2555
2556         /* handle running */
2557         list_for_each_entry_safe(task, tmp, &conn->mgmt_run_list, running) {
2558                 ISCSI_DBG_SESSION(session, "flushing running mgmt task "
2559                                   "itt 0x%x\n", task->itt);
2560                 /* release ref from prep task */
2561                 __iscsi_put_task(task);
2562         }
2563
2564         conn->task = NULL;
2565 }
2566
2567 static void iscsi_start_session_recovery(struct iscsi_session *session,
2568                                          struct iscsi_conn *conn, int flag)
2569 {
2570         int old_stop_stage;
2571
2572         mutex_lock(&session->eh_mutex);
2573         spin_lock_bh(&session->lock);
2574         if (conn->stop_stage == STOP_CONN_TERM) {
2575                 spin_unlock_bh(&session->lock);
2576                 mutex_unlock(&session->eh_mutex);
2577                 return;
2578         }
2579
2580         /*
2581          * When this is called for the in_login state, we only want to clean
2582          * up the login task and connection. We do not need to block and set
2583          * the recovery state again
2584          */
2585         if (flag == STOP_CONN_TERM)
2586                 session->state = ISCSI_STATE_TERMINATE;
2587         else if (conn->stop_stage != STOP_CONN_RECOVER)
2588                 session->state = ISCSI_STATE_IN_RECOVERY;
2589         spin_unlock_bh(&session->lock);
2590
2591         del_timer_sync(&conn->transport_timer);
2592         iscsi_suspend_tx(conn);
2593
2594         spin_lock_bh(&session->lock);
2595         old_stop_stage = conn->stop_stage;
2596         conn->stop_stage = flag;
2597         conn->c_stage = ISCSI_CONN_STOPPED;
2598         spin_unlock_bh(&session->lock);
2599
2600         /*
2601          * for connection level recovery we should not calculate
2602          * header digest. conn->hdr_size used for optimization
2603          * in hdr_extract() and will be re-negotiated at
2604          * set_param() time.
2605          */
2606         if (flag == STOP_CONN_RECOVER) {
2607                 conn->hdrdgst_en = 0;
2608                 conn->datadgst_en = 0;
2609                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
2610                     old_stop_stage != STOP_CONN_RECOVER) {
2611                         ISCSI_DBG_SESSION(session, "blocking session\n");
2612                         iscsi_block_session(session->cls_session);
2613                 }
2614         }
2615
2616         /*
2617          * flush queues.
2618          */
2619         spin_lock_bh(&session->lock);
2620         if (flag == STOP_CONN_RECOVER)
2621                 fail_all_commands(conn, -1, DID_TRANSPORT_DISRUPTED);
2622         else
2623                 fail_all_commands(conn, -1, DID_ERROR);
2624         flush_control_queues(session, conn);
2625         spin_unlock_bh(&session->lock);
2626         mutex_unlock(&session->eh_mutex);
2627 }
2628
2629 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
2630 {
2631         struct iscsi_conn *conn = cls_conn->dd_data;
2632         struct iscsi_session *session = conn->session;
2633
2634         switch (flag) {
2635         case STOP_CONN_RECOVER:
2636         case STOP_CONN_TERM:
2637                 iscsi_start_session_recovery(session, conn, flag);
2638                 break;
2639         default:
2640                 iscsi_conn_printk(KERN_ERR, conn,
2641                                   "invalid stop flag %d\n", flag);
2642         }
2643 }
2644 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
2645
2646 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
2647                     struct iscsi_cls_conn *cls_conn, int is_leading)
2648 {
2649         struct iscsi_session *session = cls_session->dd_data;
2650         struct iscsi_conn *conn = cls_conn->dd_data;
2651
2652         spin_lock_bh(&session->lock);
2653         if (is_leading)
2654                 session->leadconn = conn;
2655         spin_unlock_bh(&session->lock);
2656
2657         /*
2658          * Unblock xmitworker(), Login Phase will pass through.
2659          */
2660         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
2661         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
2662         return 0;
2663 }
2664 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
2665
2666 static int iscsi_switch_str_param(char **param, char *new_val_buf)
2667 {
2668         char *new_val;
2669
2670         if (*param) {
2671                 if (!strcmp(*param, new_val_buf))
2672                         return 0;
2673         }
2674
2675         new_val = kstrdup(new_val_buf, GFP_NOIO);
2676         if (!new_val)
2677                 return -ENOMEM;
2678
2679         kfree(*param);
2680         *param = new_val;
2681         return 0;
2682 }
2683
2684 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
2685                     enum iscsi_param param, char *buf, int buflen)
2686 {
2687         struct iscsi_conn *conn = cls_conn->dd_data;
2688         struct iscsi_session *session = conn->session;
2689         uint32_t value;
2690
2691         switch(param) {
2692         case ISCSI_PARAM_FAST_ABORT:
2693                 sscanf(buf, "%d", &session->fast_abort);
2694                 break;
2695         case ISCSI_PARAM_ABORT_TMO:
2696                 sscanf(buf, "%d", &session->abort_timeout);
2697                 break;
2698         case ISCSI_PARAM_LU_RESET_TMO:
2699                 sscanf(buf, "%d", &session->lu_reset_timeout);
2700                 break;
2701         case ISCSI_PARAM_PING_TMO:
2702                 sscanf(buf, "%d", &conn->ping_timeout);
2703                 break;
2704         case ISCSI_PARAM_RECV_TMO:
2705                 sscanf(buf, "%d", &conn->recv_timeout);
2706                 break;
2707         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2708                 sscanf(buf, "%d", &conn->max_recv_dlength);
2709                 break;
2710         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2711                 sscanf(buf, "%d", &conn->max_xmit_dlength);
2712                 break;
2713         case ISCSI_PARAM_HDRDGST_EN:
2714                 sscanf(buf, "%d", &conn->hdrdgst_en);
2715                 break;
2716         case ISCSI_PARAM_DATADGST_EN:
2717                 sscanf(buf, "%d", &conn->datadgst_en);
2718                 break;
2719         case ISCSI_PARAM_INITIAL_R2T_EN:
2720                 sscanf(buf, "%d", &session->initial_r2t_en);
2721                 break;
2722         case ISCSI_PARAM_MAX_R2T:
2723                 sscanf(buf, "%d", &session->max_r2t);
2724                 break;
2725         case ISCSI_PARAM_IMM_DATA_EN:
2726                 sscanf(buf, "%d", &session->imm_data_en);
2727                 break;
2728         case ISCSI_PARAM_FIRST_BURST:
2729                 sscanf(buf, "%d", &session->first_burst);
2730                 break;
2731         case ISCSI_PARAM_MAX_BURST:
2732                 sscanf(buf, "%d", &session->max_burst);
2733                 break;
2734         case ISCSI_PARAM_PDU_INORDER_EN:
2735                 sscanf(buf, "%d", &session->pdu_inorder_en);
2736                 break;
2737         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2738                 sscanf(buf, "%d", &session->dataseq_inorder_en);
2739                 break;
2740         case ISCSI_PARAM_ERL:
2741                 sscanf(buf, "%d", &session->erl);
2742                 break;
2743         case ISCSI_PARAM_IFMARKER_EN:
2744                 sscanf(buf, "%d", &value);
2745                 BUG_ON(value);
2746                 break;
2747         case ISCSI_PARAM_OFMARKER_EN:
2748                 sscanf(buf, "%d", &value);
2749                 BUG_ON(value);
2750                 break;
2751         case ISCSI_PARAM_EXP_STATSN:
2752                 sscanf(buf, "%u", &conn->exp_statsn);
2753                 break;
2754         case ISCSI_PARAM_USERNAME:
2755                 return iscsi_switch_str_param(&session->username, buf);
2756         case ISCSI_PARAM_USERNAME_IN:
2757                 return iscsi_switch_str_param(&session->username_in, buf);
2758         case ISCSI_PARAM_PASSWORD:
2759                 return iscsi_switch_str_param(&session->password, buf);
2760         case ISCSI_PARAM_PASSWORD_IN:
2761                 return iscsi_switch_str_param(&session->password_in, buf);
2762         case ISCSI_PARAM_TARGET_NAME:
2763                 return iscsi_switch_str_param(&session->targetname, buf);
2764         case ISCSI_PARAM_TPGT:
2765                 sscanf(buf, "%d", &session->tpgt);
2766                 break;
2767         case ISCSI_PARAM_PERSISTENT_PORT:
2768                 sscanf(buf, "%d", &conn->persistent_port);
2769                 break;
2770         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2771                 return iscsi_switch_str_param(&conn->persistent_address, buf);
2772         case ISCSI_PARAM_IFACE_NAME:
2773                 return iscsi_switch_str_param(&session->ifacename, buf);
2774         case ISCSI_PARAM_INITIATOR_NAME:
2775                 return iscsi_switch_str_param(&session->initiatorname, buf);
2776         default:
2777                 return -ENOSYS;
2778         }
2779
2780         return 0;
2781 }
2782 EXPORT_SYMBOL_GPL(iscsi_set_param);
2783
2784 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
2785                             enum iscsi_param param, char *buf)
2786 {
2787         struct iscsi_session *session = cls_session->dd_data;
2788         int len;
2789
2790         switch(param) {
2791         case ISCSI_PARAM_FAST_ABORT:
2792                 len = sprintf(buf, "%d\n", session->fast_abort);
2793                 break;
2794         case ISCSI_PARAM_ABORT_TMO:
2795                 len = sprintf(buf, "%d\n", session->abort_timeout);
2796                 break;
2797         case ISCSI_PARAM_LU_RESET_TMO:
2798                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
2799                 break;
2800         case ISCSI_PARAM_INITIAL_R2T_EN:
2801                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
2802                 break;
2803         case ISCSI_PARAM_MAX_R2T:
2804                 len = sprintf(buf, "%hu\n", session->max_r2t);
2805                 break;
2806         case ISCSI_PARAM_IMM_DATA_EN:
2807                 len = sprintf(buf, "%d\n", session->imm_data_en);
2808                 break;
2809         case ISCSI_PARAM_FIRST_BURST:
2810                 len = sprintf(buf, "%u\n", session->first_burst);
2811                 break;
2812         case ISCSI_PARAM_MAX_BURST:
2813                 len = sprintf(buf, "%u\n", session->max_burst);
2814                 break;
2815         case ISCSI_PARAM_PDU_INORDER_EN:
2816                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
2817                 break;
2818         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2819                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
2820                 break;
2821         case ISCSI_PARAM_ERL:
2822                 len = sprintf(buf, "%d\n", session->erl);
2823                 break;
2824         case ISCSI_PARAM_TARGET_NAME:
2825                 len = sprintf(buf, "%s\n", session->targetname);
2826                 break;
2827         case ISCSI_PARAM_TPGT:
2828                 len = sprintf(buf, "%d\n", session->tpgt);
2829                 break;
2830         case ISCSI_PARAM_USERNAME:
2831                 len = sprintf(buf, "%s\n", session->username);
2832                 break;
2833         case ISCSI_PARAM_USERNAME_IN:
2834                 len = sprintf(buf, "%s\n", session->username_in);
2835                 break;
2836         case ISCSI_PARAM_PASSWORD:
2837                 len = sprintf(buf, "%s\n", session->password);
2838                 break;
2839         case ISCSI_PARAM_PASSWORD_IN:
2840                 len = sprintf(buf, "%s\n", session->password_in);
2841                 break;
2842         case ISCSI_PARAM_IFACE_NAME:
2843                 len = sprintf(buf, "%s\n", session->ifacename);
2844                 break;
2845         case ISCSI_PARAM_INITIATOR_NAME:
2846                 len = sprintf(buf, "%s\n", session->initiatorname);
2847                 break;
2848         default:
2849                 return -ENOSYS;
2850         }
2851
2852         return len;
2853 }
2854 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
2855
2856 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2857                          enum iscsi_param param, char *buf)
2858 {
2859         struct iscsi_conn *conn = cls_conn->dd_data;
2860         int len;
2861
2862         switch(param) {
2863         case ISCSI_PARAM_PING_TMO:
2864                 len = sprintf(buf, "%u\n", conn->ping_timeout);
2865                 break;
2866         case ISCSI_PARAM_RECV_TMO:
2867                 len = sprintf(buf, "%u\n", conn->recv_timeout);
2868                 break;
2869         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2870                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
2871                 break;
2872         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2873                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
2874                 break;
2875         case ISCSI_PARAM_HDRDGST_EN:
2876                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
2877                 break;
2878         case ISCSI_PARAM_DATADGST_EN:
2879                 len = sprintf(buf, "%d\n", conn->datadgst_en);
2880                 break;
2881         case ISCSI_PARAM_IFMARKER_EN:
2882                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
2883                 break;
2884         case ISCSI_PARAM_OFMARKER_EN:
2885                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
2886                 break;
2887         case ISCSI_PARAM_EXP_STATSN:
2888                 len = sprintf(buf, "%u\n", conn->exp_statsn);
2889                 break;
2890         case ISCSI_PARAM_PERSISTENT_PORT:
2891                 len = sprintf(buf, "%d\n", conn->persistent_port);
2892                 break;
2893         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2894                 len = sprintf(buf, "%s\n", conn->persistent_address);
2895                 break;
2896         default:
2897                 return -ENOSYS;
2898         }
2899
2900         return len;
2901 }
2902 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
2903
2904 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2905                          char *buf)
2906 {
2907         struct iscsi_host *ihost = shost_priv(shost);
2908         int len;
2909
2910         switch (param) {
2911         case ISCSI_HOST_PARAM_NETDEV_NAME:
2912                 len = sprintf(buf, "%s\n", ihost->netdev);
2913                 break;
2914         case ISCSI_HOST_PARAM_HWADDRESS:
2915                 len = sprintf(buf, "%s\n", ihost->hwaddress);
2916                 break;
2917         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2918                 len = sprintf(buf, "%s\n", ihost->initiatorname);
2919                 break;
2920         case ISCSI_HOST_PARAM_IPADDRESS:
2921                 len = sprintf(buf, "%s\n", ihost->local_address);
2922                 break;
2923         default:
2924                 return -ENOSYS;
2925         }
2926
2927         return len;
2928 }
2929 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
2930
2931 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2932                          char *buf, int buflen)
2933 {
2934         struct iscsi_host *ihost = shost_priv(shost);
2935
2936         switch (param) {
2937         case ISCSI_HOST_PARAM_NETDEV_NAME:
2938                 return iscsi_switch_str_param(&ihost->netdev, buf);
2939         case ISCSI_HOST_PARAM_HWADDRESS:
2940                 return iscsi_switch_str_param(&ihost->hwaddress, buf);
2941         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2942                 return iscsi_switch_str_param(&ihost->initiatorname, buf);
2943         default:
2944                 return -ENOSYS;
2945         }
2946
2947         return 0;
2948 }
2949 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
2950
2951 MODULE_AUTHOR("Mike Christie");
2952 MODULE_DESCRIPTION("iSCSI library functions");
2953 MODULE_LICENSE("GPL");