a6e6eef04fedaa11bd72ef3b6a9bb254799ca2da
[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                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
550                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
551
552                 if (!__kfifo_get(session->cmdpool.queue,
553                                  (void*)&task, sizeof(void*)))
554                         return NULL;
555         }
556         /*
557          * released in complete pdu for task we expect a response for, and
558          * released by the lld when it has transmitted the task for
559          * pdus we do not expect a response for.
560          */
561         atomic_set(&task->refcount, 1);
562         task->conn = conn;
563         task->sc = NULL;
564
565         if (data_size) {
566                 memcpy(task->data, data, data_size);
567                 task->data_count = data_size;
568         } else
569                 task->data_count = 0;
570
571         if (conn->session->tt->alloc_pdu) {
572                 if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
573                         iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
574                                          "pdu for mgmt task.\n");
575                         goto requeue_task;
576                 }
577         }
578
579         itt = task->hdr->itt;
580         task->hdr_len = sizeof(struct iscsi_hdr);
581         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
582
583         if (hdr->itt != RESERVED_ITT) {
584                 if (session->tt->parse_pdu_itt)
585                         task->hdr->itt = itt;
586                 else
587                         task->hdr->itt = build_itt(task->itt,
588                                                    task->conn->session->age);
589         }
590
591         INIT_LIST_HEAD(&task->running);
592         list_add_tail(&task->running, &conn->mgmtqueue);
593
594         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
595                 if (iscsi_prep_mgmt_task(conn, task))
596                         goto free_task;
597
598                 if (session->tt->xmit_task(task))
599                         goto free_task;
600
601         } else
602                 iscsi_conn_queue_work(conn);
603
604         return task;
605
606 free_task:
607         __iscsi_put_task(task);
608         return NULL;
609
610 requeue_task:
611         if (task != conn->login_task)
612                 __kfifo_put(session->cmdpool.queue, (void*)&task,
613                             sizeof(void*));
614         return NULL;
615 }
616
617 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
618                         char *data, uint32_t data_size)
619 {
620         struct iscsi_conn *conn = cls_conn->dd_data;
621         struct iscsi_session *session = conn->session;
622         int err = 0;
623
624         spin_lock_bh(&session->lock);
625         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
626                 err = -EPERM;
627         spin_unlock_bh(&session->lock);
628         return err;
629 }
630 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
631
632 /**
633  * iscsi_cmd_rsp - SCSI Command Response processing
634  * @conn: iscsi connection
635  * @hdr: iscsi header
636  * @task: scsi command task
637  * @data: cmd data buffer
638  * @datalen: len of buffer
639  *
640  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
641  * then completes the command and task.
642  **/
643 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
644                                struct iscsi_task *task, char *data,
645                                int datalen)
646 {
647         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
648         struct iscsi_session *session = conn->session;
649         struct scsi_cmnd *sc = task->sc;
650
651         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
652         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
653
654         sc->result = (DID_OK << 16) | rhdr->cmd_status;
655
656         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
657                 sc->result = DID_ERROR << 16;
658                 goto out;
659         }
660
661         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
662                 uint16_t senselen;
663
664                 if (datalen < 2) {
665 invalid_datalen:
666                         iscsi_conn_printk(KERN_ERR,  conn,
667                                          "Got CHECK_CONDITION but invalid data "
668                                          "buffer size of %d\n", datalen);
669                         sc->result = DID_BAD_TARGET << 16;
670                         goto out;
671                 }
672
673                 senselen = get_unaligned_be16(data);
674                 if (datalen < senselen)
675                         goto invalid_datalen;
676
677                 memcpy(sc->sense_buffer, data + 2,
678                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
679                 ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
680                                   min_t(uint16_t, senselen,
681                                   SCSI_SENSE_BUFFERSIZE));
682         }
683
684         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
685                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
686                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
687
688                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
689                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
690                                  res_count <= scsi_in(sc)->length))
691                         scsi_in(sc)->resid = res_count;
692                 else
693                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
694         }
695
696         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
697                            ISCSI_FLAG_CMD_OVERFLOW)) {
698                 int res_count = be32_to_cpu(rhdr->residual_count);
699
700                 if (res_count > 0 &&
701                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
702                      res_count <= scsi_bufflen(sc)))
703                         /* write side for bidi or uni-io set_resid */
704                         scsi_set_resid(sc, res_count);
705                 else
706                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
707         }
708 out:
709         ISCSI_DBG_SESSION(session, "done [sc %p res %d itt 0x%x]\n",
710                           sc, sc->result, task->itt);
711         conn->scsirsp_pdus_cnt++;
712
713         __iscsi_put_task(task);
714 }
715
716 /**
717  * iscsi_data_in_rsp - SCSI Data-In Response processing
718  * @conn: iscsi connection
719  * @hdr:  iscsi pdu
720  * @task: scsi command task
721  **/
722 static void
723 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
724                   struct iscsi_task *task)
725 {
726         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
727         struct scsi_cmnd *sc = task->sc;
728
729         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
730                 return;
731
732         sc->result = (DID_OK << 16) | rhdr->cmd_status;
733         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
734         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
735                            ISCSI_FLAG_DATA_OVERFLOW)) {
736                 int res_count = be32_to_cpu(rhdr->residual_count);
737
738                 if (res_count > 0 &&
739                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
740                      res_count <= scsi_in(sc)->length))
741                         scsi_in(sc)->resid = res_count;
742                 else
743                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
744         }
745
746         conn->scsirsp_pdus_cnt++;
747         __iscsi_put_task(task);
748 }
749
750 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
751 {
752         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
753
754         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
755         conn->tmfrsp_pdus_cnt++;
756
757         if (conn->tmf_state != TMF_QUEUED)
758                 return;
759
760         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
761                 conn->tmf_state = TMF_SUCCESS;
762         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
763                 conn->tmf_state = TMF_NOT_FOUND;
764         else
765                 conn->tmf_state = TMF_FAILED;
766         wake_up(&conn->ehwait);
767 }
768
769 static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
770 {
771         struct iscsi_nopout hdr;
772         struct iscsi_task *task;
773
774         if (!rhdr && conn->ping_task)
775                 return;
776
777         memset(&hdr, 0, sizeof(struct iscsi_nopout));
778         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
779         hdr.flags = ISCSI_FLAG_CMD_FINAL;
780
781         if (rhdr) {
782                 memcpy(hdr.lun, rhdr->lun, 8);
783                 hdr.ttt = rhdr->ttt;
784                 hdr.itt = RESERVED_ITT;
785         } else
786                 hdr.ttt = RESERVED_ITT;
787
788         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
789         if (!task)
790                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
791         else if (!rhdr) {
792                 /* only track our nops */
793                 conn->ping_task = task;
794                 conn->last_ping = jiffies;
795         }
796 }
797
798 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
799                                char *data, int datalen)
800 {
801         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
802         struct iscsi_hdr rejected_pdu;
803
804         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
805
806         if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
807                 if (ntoh24(reject->dlength) > datalen)
808                         return ISCSI_ERR_PROTO;
809
810                 if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
811                         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
812                         iscsi_conn_printk(KERN_ERR, conn,
813                                           "pdu (op 0x%x) rejected "
814                                           "due to DataDigest error.\n",
815                                           rejected_pdu.opcode);
816                 }
817         }
818         return 0;
819 }
820
821 /**
822  * iscsi_itt_to_task - look up task by itt
823  * @conn: iscsi connection
824  * @itt: itt
825  *
826  * This should be used for mgmt tasks like login and nops, or if
827  * the LDD's itt space does not include the session age.
828  *
829  * The session lock must be held.
830  */
831 struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
832 {
833         struct iscsi_session *session = conn->session;
834         int i;
835
836         if (itt == RESERVED_ITT)
837                 return NULL;
838
839         if (session->tt->parse_pdu_itt)
840                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
841         else
842                 i = get_itt(itt);
843         if (i >= session->cmds_max)
844                 return NULL;
845
846         return session->cmds[i];
847 }
848 EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
849
850 /**
851  * __iscsi_complete_pdu - complete pdu
852  * @conn: iscsi conn
853  * @hdr: iscsi header
854  * @data: data buffer
855  * @datalen: len of data buffer
856  *
857  * Completes pdu processing by freeing any resources allocated at
858  * queuecommand or send generic. session lock must be held and verify
859  * itt must have been called.
860  */
861 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
862                          char *data, int datalen)
863 {
864         struct iscsi_session *session = conn->session;
865         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
866         struct iscsi_task *task;
867         uint32_t itt;
868
869         conn->last_recv = jiffies;
870         rc = iscsi_verify_itt(conn, hdr->itt);
871         if (rc)
872                 return rc;
873
874         if (hdr->itt != RESERVED_ITT)
875                 itt = get_itt(hdr->itt);
876         else
877                 itt = ~0U;
878
879         ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
880                           opcode, conn->id, itt, datalen);
881
882         if (itt == ~0U) {
883                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
884
885                 switch(opcode) {
886                 case ISCSI_OP_NOOP_IN:
887                         if (datalen) {
888                                 rc = ISCSI_ERR_PROTO;
889                                 break;
890                         }
891
892                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
893                                 break;
894
895                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
896                         break;
897                 case ISCSI_OP_REJECT:
898                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
899                         break;
900                 case ISCSI_OP_ASYNC_EVENT:
901                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
902                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
903                                 rc = ISCSI_ERR_CONN_FAILED;
904                         break;
905                 default:
906                         rc = ISCSI_ERR_BAD_OPCODE;
907                         break;
908                 }
909                 goto out;
910         }
911
912         switch(opcode) {
913         case ISCSI_OP_SCSI_CMD_RSP:
914         case ISCSI_OP_SCSI_DATA_IN:
915                 task = iscsi_itt_to_ctask(conn, hdr->itt);
916                 if (!task)
917                         return ISCSI_ERR_BAD_ITT;
918                 break;
919         case ISCSI_OP_R2T:
920                 /*
921                  * LLD handles R2Ts if they need to.
922                  */
923                 return 0;
924         case ISCSI_OP_LOGOUT_RSP:
925         case ISCSI_OP_LOGIN_RSP:
926         case ISCSI_OP_TEXT_RSP:
927         case ISCSI_OP_SCSI_TMFUNC_RSP:
928         case ISCSI_OP_NOOP_IN:
929                 task = iscsi_itt_to_task(conn, hdr->itt);
930                 if (!task)
931                         return ISCSI_ERR_BAD_ITT;
932                 break;
933         default:
934                 return ISCSI_ERR_BAD_OPCODE;
935         }
936
937         switch(opcode) {
938         case ISCSI_OP_SCSI_CMD_RSP:
939                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
940                 break;
941         case ISCSI_OP_SCSI_DATA_IN:
942                 iscsi_data_in_rsp(conn, hdr, task);
943                 break;
944         case ISCSI_OP_LOGOUT_RSP:
945                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
946                 if (datalen) {
947                         rc = ISCSI_ERR_PROTO;
948                         break;
949                 }
950                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
951                 goto recv_pdu;
952         case ISCSI_OP_LOGIN_RSP:
953         case ISCSI_OP_TEXT_RSP:
954                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
955                 /*
956                  * login related PDU's exp_statsn is handled in
957                  * userspace
958                  */
959                 goto recv_pdu;
960         case ISCSI_OP_SCSI_TMFUNC_RSP:
961                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
962                 if (datalen) {
963                         rc = ISCSI_ERR_PROTO;
964                         break;
965                 }
966
967                 iscsi_tmf_rsp(conn, hdr);
968                 __iscsi_put_task(task);
969                 break;
970         case ISCSI_OP_NOOP_IN:
971                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
972                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
973                         rc = ISCSI_ERR_PROTO;
974                         break;
975                 }
976                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
977
978                 if (conn->ping_task != task)
979                         /*
980                          * If this is not in response to one of our
981                          * nops then it must be from userspace.
982                          */
983                         goto recv_pdu;
984
985                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
986                 __iscsi_put_task(task);
987                 break;
988         default:
989                 rc = ISCSI_ERR_BAD_OPCODE;
990                 break;
991         }
992
993 out:
994         return rc;
995 recv_pdu:
996         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
997                 rc = ISCSI_ERR_CONN_FAILED;
998         __iscsi_put_task(task);
999         return rc;
1000 }
1001 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1002
1003 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1004                        char *data, int datalen)
1005 {
1006         int rc;
1007
1008         spin_lock(&conn->session->lock);
1009         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1010         spin_unlock(&conn->session->lock);
1011         return rc;
1012 }
1013 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1014
1015 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1016 {
1017         struct iscsi_session *session = conn->session;
1018         int age = 0, i = 0;
1019
1020         if (itt == RESERVED_ITT)
1021                 return 0;
1022
1023         if (session->tt->parse_pdu_itt)
1024                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
1025         else {
1026                 i = get_itt(itt);
1027                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1028         }
1029
1030         if (age != session->age) {
1031                 iscsi_conn_printk(KERN_ERR, conn,
1032                                   "received itt %x expected session age (%x)\n",
1033                                   (__force u32)itt, session->age);
1034                 return ISCSI_ERR_BAD_ITT;
1035         }
1036
1037         if (i >= session->cmds_max) {
1038                 iscsi_conn_printk(KERN_ERR, conn,
1039                                   "received invalid itt index %u (max cmds "
1040                                    "%u.\n", i, session->cmds_max);
1041                 return ISCSI_ERR_BAD_ITT;
1042         }
1043         return 0;
1044 }
1045 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1046
1047 /**
1048  * iscsi_itt_to_ctask - look up ctask by itt
1049  * @conn: iscsi connection
1050  * @itt: itt
1051  *
1052  * This should be used for cmd tasks.
1053  *
1054  * The session lock must be held.
1055  */
1056 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1057 {
1058         struct iscsi_task *task;
1059
1060         if (iscsi_verify_itt(conn, itt))
1061                 return NULL;
1062
1063         task = iscsi_itt_to_task(conn, itt);
1064         if (!task || !task->sc)
1065                 return NULL;
1066
1067         if (task->sc->SCp.phase != conn->session->age) {
1068                 iscsi_session_printk(KERN_ERR, conn->session,
1069                                   "task's session age %d, expected %d\n",
1070                                   task->sc->SCp.phase, conn->session->age);
1071                 return NULL;
1072         }
1073
1074         return task;
1075 }
1076 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1077
1078 void iscsi_session_failure(struct iscsi_session *session,
1079                            enum iscsi_err err)
1080 {
1081         struct iscsi_conn *conn;
1082         struct device *dev;
1083         unsigned long flags;
1084
1085         spin_lock_irqsave(&session->lock, flags);
1086         conn = session->leadconn;
1087         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1088                 spin_unlock_irqrestore(&session->lock, flags);
1089                 return;
1090         }
1091
1092         dev = get_device(&conn->cls_conn->dev);
1093         spin_unlock_irqrestore(&session->lock, flags);
1094         if (!dev)
1095                 return;
1096         /*
1097          * if the host is being removed bypass the connection
1098          * recovery initialization because we are going to kill
1099          * the session.
1100          */
1101         if (err == ISCSI_ERR_INVALID_HOST)
1102                 iscsi_conn_error_event(conn->cls_conn, err);
1103         else
1104                 iscsi_conn_failure(conn, err);
1105         put_device(dev);
1106 }
1107 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1108
1109 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1110 {
1111         struct iscsi_session *session = conn->session;
1112         unsigned long flags;
1113
1114         spin_lock_irqsave(&session->lock, flags);
1115         if (session->state == ISCSI_STATE_FAILED) {
1116                 spin_unlock_irqrestore(&session->lock, flags);
1117                 return;
1118         }
1119
1120         if (conn->stop_stage == 0)
1121                 session->state = ISCSI_STATE_FAILED;
1122         spin_unlock_irqrestore(&session->lock, flags);
1123
1124         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1125         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1126         iscsi_conn_error_event(conn->cls_conn, err);
1127 }
1128 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1129
1130 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1131 {
1132         struct iscsi_session *session = conn->session;
1133
1134         /*
1135          * Check for iSCSI window and take care of CmdSN wrap-around
1136          */
1137         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1138                 ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1139                                   "%u MaxCmdSN %u CmdSN %u/%u\n",
1140                                   session->exp_cmdsn, session->max_cmdsn,
1141                                   session->cmdsn, session->queued_cmdsn);
1142                 return -ENOSPC;
1143         }
1144         return 0;
1145 }
1146
1147 static int iscsi_xmit_task(struct iscsi_conn *conn)
1148 {
1149         struct iscsi_task *task = conn->task;
1150         int rc;
1151
1152         __iscsi_get_task(task);
1153         spin_unlock_bh(&conn->session->lock);
1154         rc = conn->session->tt->xmit_task(task);
1155         spin_lock_bh(&conn->session->lock);
1156         __iscsi_put_task(task);
1157         if (!rc)
1158                 /* done with this task */
1159                 conn->task = NULL;
1160         return rc;
1161 }
1162
1163 /**
1164  * iscsi_requeue_task - requeue task to run from session workqueue
1165  * @task: task to requeue
1166  *
1167  * LLDs that need to run a task from the session workqueue should call
1168  * this. The session lock must be held. This should only be called
1169  * by software drivers.
1170  */
1171 void iscsi_requeue_task(struct iscsi_task *task)
1172 {
1173         struct iscsi_conn *conn = task->conn;
1174
1175         list_move_tail(&task->running, &conn->requeue);
1176         iscsi_conn_queue_work(conn);
1177 }
1178 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1179
1180 /**
1181  * iscsi_data_xmit - xmit any command into the scheduled connection
1182  * @conn: iscsi connection
1183  *
1184  * Notes:
1185  *      The function can return -EAGAIN in which case the caller must
1186  *      re-schedule it again later or recover. '0' return code means
1187  *      successful xmit.
1188  **/
1189 static int iscsi_data_xmit(struct iscsi_conn *conn)
1190 {
1191         int rc = 0;
1192
1193         spin_lock_bh(&conn->session->lock);
1194         if (unlikely(conn->suspend_tx)) {
1195                 ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1196                 spin_unlock_bh(&conn->session->lock);
1197                 return -ENODATA;
1198         }
1199
1200         if (conn->task) {
1201                 rc = iscsi_xmit_task(conn);
1202                 if (rc)
1203                         goto again;
1204         }
1205
1206         /*
1207          * process mgmt pdus like nops before commands since we should
1208          * only have one nop-out as a ping from us and targets should not
1209          * overflow us with nop-ins
1210          */
1211 check_mgmt:
1212         while (!list_empty(&conn->mgmtqueue)) {
1213                 conn->task = list_entry(conn->mgmtqueue.next,
1214                                          struct iscsi_task, running);
1215                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1216                         __iscsi_put_task(conn->task);
1217                         conn->task = NULL;
1218                         continue;
1219                 }
1220                 rc = iscsi_xmit_task(conn);
1221                 if (rc)
1222                         goto again;
1223         }
1224
1225         /* process pending command queue */
1226         while (!list_empty(&conn->xmitqueue)) {
1227                 if (conn->tmf_state == TMF_QUEUED)
1228                         break;
1229
1230                 conn->task = list_entry(conn->xmitqueue.next,
1231                                          struct iscsi_task, running);
1232                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1233                         fail_command(conn, conn->task, DID_IMM_RETRY << 16);
1234                         continue;
1235                 }
1236                 rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1237                 if (rc) {
1238                         if (rc == -ENOMEM) {
1239                                 conn->task = NULL;
1240                                 goto again;
1241                         } else
1242                                 fail_command(conn, conn->task, DID_ABORT << 16);
1243                         continue;
1244                 }
1245                 rc = iscsi_xmit_task(conn);
1246                 if (rc)
1247                         goto again;
1248                 /*
1249                  * we could continuously get new task requests so
1250                  * we need to check the mgmt queue for nops that need to
1251                  * be sent to aviod starvation
1252                  */
1253                 if (!list_empty(&conn->mgmtqueue))
1254                         goto check_mgmt;
1255         }
1256
1257         while (!list_empty(&conn->requeue)) {
1258                 if (conn->session->fast_abort && conn->tmf_state != TMF_INITIAL)
1259                         break;
1260
1261                 /*
1262                  * we always do fastlogout - conn stop code will clean up.
1263                  */
1264                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1265                         break;
1266
1267                 conn->task = list_entry(conn->requeue.next,
1268                                          struct iscsi_task, running);
1269                 conn->task->state = ISCSI_TASK_RUNNING;
1270                 list_move_tail(conn->requeue.next, &conn->run_list);
1271                 rc = iscsi_xmit_task(conn);
1272                 if (rc)
1273                         goto again;
1274                 if (!list_empty(&conn->mgmtqueue))
1275                         goto check_mgmt;
1276         }
1277         spin_unlock_bh(&conn->session->lock);
1278         return -ENODATA;
1279
1280 again:
1281         if (unlikely(conn->suspend_tx))
1282                 rc = -ENODATA;
1283         spin_unlock_bh(&conn->session->lock);
1284         return rc;
1285 }
1286
1287 static void iscsi_xmitworker(struct work_struct *work)
1288 {
1289         struct iscsi_conn *conn =
1290                 container_of(work, struct iscsi_conn, xmitwork);
1291         int rc;
1292         /*
1293          * serialize Xmit worker on a per-connection basis.
1294          */
1295         do {
1296                 rc = iscsi_data_xmit(conn);
1297         } while (rc >= 0 || rc == -EAGAIN);
1298 }
1299
1300 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1301                                                   struct scsi_cmnd *sc)
1302 {
1303         struct iscsi_task *task;
1304
1305         if (!__kfifo_get(conn->session->cmdpool.queue,
1306                          (void *) &task, sizeof(void *)))
1307                 return NULL;
1308
1309         sc->SCp.phase = conn->session->age;
1310         sc->SCp.ptr = (char *) task;
1311
1312         atomic_set(&task->refcount, 1);
1313         task->state = ISCSI_TASK_PENDING;
1314         task->conn = conn;
1315         task->sc = sc;
1316         INIT_LIST_HEAD(&task->running);
1317         return task;
1318 }
1319
1320 enum {
1321         FAILURE_BAD_HOST = 1,
1322         FAILURE_SESSION_FAILED,
1323         FAILURE_SESSION_FREED,
1324         FAILURE_WINDOW_CLOSED,
1325         FAILURE_OOM,
1326         FAILURE_SESSION_TERMINATE,
1327         FAILURE_SESSION_IN_RECOVERY,
1328         FAILURE_SESSION_RECOVERY_TIMEOUT,
1329         FAILURE_SESSION_LOGGING_OUT,
1330         FAILURE_SESSION_NOT_READY,
1331 };
1332
1333 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
1334 {
1335         struct iscsi_cls_session *cls_session;
1336         struct Scsi_Host *host;
1337         int reason = 0;
1338         struct iscsi_session *session;
1339         struct iscsi_conn *conn;
1340         struct iscsi_task *task = NULL;
1341
1342         sc->scsi_done = done;
1343         sc->result = 0;
1344         sc->SCp.ptr = NULL;
1345
1346         host = sc->device->host;
1347         spin_unlock(host->host_lock);
1348
1349         cls_session = starget_to_session(scsi_target(sc->device));
1350         session = cls_session->dd_data;
1351         spin_lock(&session->lock);
1352
1353         reason = iscsi_session_chkready(cls_session);
1354         if (reason) {
1355                 sc->result = reason;
1356                 goto fault;
1357         }
1358
1359         /*
1360          * ISCSI_STATE_FAILED is a temp. state. The recovery
1361          * code will decide what is best to do with command queued
1362          * during this time
1363          */
1364         if (session->state != ISCSI_STATE_LOGGED_IN &&
1365             session->state != ISCSI_STATE_FAILED) {
1366                 /*
1367                  * to handle the race between when we set the recovery state
1368                  * and block the session we requeue here (commands could
1369                  * be entering our queuecommand while a block is starting
1370                  * up because the block code is not locked)
1371                  */
1372                 switch (session->state) {
1373                 case ISCSI_STATE_IN_RECOVERY:
1374                         reason = FAILURE_SESSION_IN_RECOVERY;
1375                         goto reject;
1376                 case ISCSI_STATE_LOGGING_OUT:
1377                         reason = FAILURE_SESSION_LOGGING_OUT;
1378                         goto reject;
1379                 case ISCSI_STATE_RECOVERY_FAILED:
1380                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1381                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1382                         break;
1383                 case ISCSI_STATE_TERMINATE:
1384                         reason = FAILURE_SESSION_TERMINATE;
1385                         sc->result = DID_NO_CONNECT << 16;
1386                         break;
1387                 default:
1388                         reason = FAILURE_SESSION_FREED;
1389                         sc->result = DID_NO_CONNECT << 16;
1390                 }
1391                 goto fault;
1392         }
1393
1394         conn = session->leadconn;
1395         if (!conn) {
1396                 reason = FAILURE_SESSION_FREED;
1397                 sc->result = DID_NO_CONNECT << 16;
1398                 goto fault;
1399         }
1400
1401         if (iscsi_check_cmdsn_window_closed(conn)) {
1402                 reason = FAILURE_WINDOW_CLOSED;
1403                 goto reject;
1404         }
1405
1406         task = iscsi_alloc_task(conn, sc);
1407         if (!task) {
1408                 reason = FAILURE_OOM;
1409                 goto reject;
1410         }
1411         list_add_tail(&task->running, &conn->xmitqueue);
1412
1413         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
1414                 reason = iscsi_prep_scsi_cmd_pdu(task);
1415                 if (reason) {
1416                         if (reason == -ENOMEM) {
1417                                 reason = FAILURE_OOM;
1418                                 goto prepd_reject;
1419                         } else {
1420                                 sc->result = DID_ABORT << 16;
1421                                 goto prepd_fault;
1422                         }
1423                 }
1424                 if (session->tt->xmit_task(task)) {
1425                         reason = FAILURE_SESSION_NOT_READY;
1426                         goto prepd_reject;
1427                 }
1428         } else
1429                 iscsi_conn_queue_work(conn);
1430
1431         session->queued_cmdsn++;
1432         spin_unlock(&session->lock);
1433         spin_lock(host->host_lock);
1434         return 0;
1435
1436 prepd_reject:
1437         sc->scsi_done = NULL;
1438         iscsi_complete_command(task);
1439 reject:
1440         spin_unlock(&session->lock);
1441         ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1442                           sc->cmnd[0], reason);
1443         spin_lock(host->host_lock);
1444         return SCSI_MLQUEUE_TARGET_BUSY;
1445
1446 prepd_fault:
1447         sc->scsi_done = NULL;
1448         iscsi_complete_command(task);
1449 fault:
1450         spin_unlock(&session->lock);
1451         ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1452                           sc->cmnd[0], reason);
1453         if (!scsi_bidi_cmnd(sc))
1454                 scsi_set_resid(sc, scsi_bufflen(sc));
1455         else {
1456                 scsi_out(sc)->resid = scsi_out(sc)->length;
1457                 scsi_in(sc)->resid = scsi_in(sc)->length;
1458         }
1459         done(sc);
1460         spin_lock(host->host_lock);
1461         return 0;
1462 }
1463 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1464
1465 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
1466 {
1467         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1468         return sdev->queue_depth;
1469 }
1470 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1471
1472 int iscsi_target_alloc(struct scsi_target *starget)
1473 {
1474         struct iscsi_cls_session *cls_session = starget_to_session(starget);
1475         struct iscsi_session *session = cls_session->dd_data;
1476
1477         starget->can_queue = session->scsi_cmds_max;
1478         return 0;
1479 }
1480 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1481
1482 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
1483 {
1484         struct iscsi_session *session = cls_session->dd_data;
1485
1486         spin_lock_bh(&session->lock);
1487         if (session->state != ISCSI_STATE_LOGGED_IN) {
1488                 session->state = ISCSI_STATE_RECOVERY_FAILED;
1489                 if (session->leadconn)
1490                         wake_up(&session->leadconn->ehwait);
1491         }
1492         spin_unlock_bh(&session->lock);
1493 }
1494 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
1495
1496 int iscsi_eh_target_reset(struct scsi_cmnd *sc)
1497 {
1498         struct iscsi_cls_session *cls_session;
1499         struct iscsi_session *session;
1500         struct iscsi_conn *conn;
1501
1502         cls_session = starget_to_session(scsi_target(sc->device));
1503         session = cls_session->dd_data;
1504         conn = session->leadconn;
1505
1506         mutex_lock(&session->eh_mutex);
1507         spin_lock_bh(&session->lock);
1508         if (session->state == ISCSI_STATE_TERMINATE) {
1509 failed:
1510                 iscsi_session_printk(KERN_INFO, session,
1511                                      "failing target reset: Could not log "
1512                                      "back into target [age %d]\n",
1513                                      session->age);
1514                 spin_unlock_bh(&session->lock);
1515                 mutex_unlock(&session->eh_mutex);
1516                 return FAILED;
1517         }
1518
1519         spin_unlock_bh(&session->lock);
1520         mutex_unlock(&session->eh_mutex);
1521         /*
1522          * we drop the lock here but the leadconn cannot be destoyed while
1523          * we are in the scsi eh
1524          */
1525         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1526
1527         ISCSI_DBG_SESSION(session, "wait for relogin\n");
1528         wait_event_interruptible(conn->ehwait,
1529                                  session->state == ISCSI_STATE_TERMINATE ||
1530                                  session->state == ISCSI_STATE_LOGGED_IN ||
1531                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
1532         if (signal_pending(current))
1533                 flush_signals(current);
1534
1535         mutex_lock(&session->eh_mutex);
1536         spin_lock_bh(&session->lock);
1537         if (session->state == ISCSI_STATE_LOGGED_IN)
1538                 iscsi_session_printk(KERN_INFO, session,
1539                                      "target reset succeeded\n");
1540         else
1541                 goto failed;
1542         spin_unlock_bh(&session->lock);
1543         mutex_unlock(&session->eh_mutex);
1544         return SUCCESS;
1545 }
1546 EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
1547
1548 static void iscsi_tmf_timedout(unsigned long data)
1549 {
1550         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1551         struct iscsi_session *session = conn->session;
1552
1553         spin_lock(&session->lock);
1554         if (conn->tmf_state == TMF_QUEUED) {
1555                 conn->tmf_state = TMF_TIMEDOUT;
1556                 ISCSI_DBG_SESSION(session, "tmf timedout\n");
1557                 /* unblock eh_abort() */
1558                 wake_up(&conn->ehwait);
1559         }
1560         spin_unlock(&session->lock);
1561 }
1562
1563 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1564                                    struct iscsi_tm *hdr, int age,
1565                                    int timeout)
1566 {
1567         struct iscsi_session *session = conn->session;
1568         struct iscsi_task *task;
1569
1570         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1571                                       NULL, 0);
1572         if (!task) {
1573                 spin_unlock_bh(&session->lock);
1574                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1575                 spin_lock_bh(&session->lock);
1576                 ISCSI_DBG_SESSION(session, "tmf exec failure\n");
1577                 return -EPERM;
1578         }
1579         conn->tmfcmd_pdus_cnt++;
1580         conn->tmf_timer.expires = timeout * HZ + jiffies;
1581         conn->tmf_timer.function = iscsi_tmf_timedout;
1582         conn->tmf_timer.data = (unsigned long)conn;
1583         add_timer(&conn->tmf_timer);
1584         ISCSI_DBG_SESSION(session, "tmf set timeout\n");
1585
1586         spin_unlock_bh(&session->lock);
1587         mutex_unlock(&session->eh_mutex);
1588
1589         /*
1590          * block eh thread until:
1591          *
1592          * 1) tmf response
1593          * 2) tmf timeout
1594          * 3) session is terminated or restarted or userspace has
1595          * given up on recovery
1596          */
1597         wait_event_interruptible(conn->ehwait, age != session->age ||
1598                                  session->state != ISCSI_STATE_LOGGED_IN ||
1599                                  conn->tmf_state != TMF_QUEUED);
1600         if (signal_pending(current))
1601                 flush_signals(current);
1602         del_timer_sync(&conn->tmf_timer);
1603
1604         mutex_lock(&session->eh_mutex);
1605         spin_lock_bh(&session->lock);
1606         /* if the session drops it will clean up the task */
1607         if (age != session->age ||
1608             session->state != ISCSI_STATE_LOGGED_IN)
1609                 return -ENOTCONN;
1610         return 0;
1611 }
1612
1613 /*
1614  * Fail commands. session lock held and recv side suspended and xmit
1615  * thread flushed
1616  */
1617 static void fail_all_commands(struct iscsi_conn *conn, unsigned lun,
1618                               int error)
1619 {
1620         struct iscsi_task *task, *tmp;
1621
1622         if (conn->task) {
1623                 if (lun == -1 ||
1624                     (conn->task->sc && conn->task->sc->device->lun == lun))
1625                         conn->task = NULL;
1626         }
1627
1628         /* flush pending */
1629         list_for_each_entry_safe(task, tmp, &conn->xmitqueue, running) {
1630                 if (lun == task->sc->device->lun || lun == -1) {
1631                         ISCSI_DBG_SESSION(conn->session,
1632                                           "failing pending sc %p itt 0x%x\n",
1633                                           task->sc, task->itt);
1634                         fail_command(conn, task, error << 16);
1635                 }
1636         }
1637
1638         list_for_each_entry_safe(task, tmp, &conn->requeue, running) {
1639                 if (lun == task->sc->device->lun || lun == -1) {
1640                         ISCSI_DBG_SESSION(conn->session,
1641                                           "failing requeued sc %p itt 0x%x\n",
1642                                           task->sc, task->itt);
1643                         fail_command(conn, task, error << 16);
1644                 }
1645         }
1646
1647         /* fail all other running */
1648         list_for_each_entry_safe(task, tmp, &conn->run_list, running) {
1649                 if (lun == task->sc->device->lun || lun == -1) {
1650                         ISCSI_DBG_SESSION(conn->session,
1651                                          "failing in progress sc %p itt 0x%x\n",
1652                                          task->sc, task->itt);
1653                         fail_command(conn, task, error << 16);
1654                 }
1655         }
1656 }
1657
1658 void iscsi_suspend_tx(struct iscsi_conn *conn)
1659 {
1660         struct Scsi_Host *shost = conn->session->host;
1661         struct iscsi_host *ihost = shost_priv(shost);
1662
1663         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1664         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1665                 flush_workqueue(ihost->workq);
1666 }
1667 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1668
1669 static void iscsi_start_tx(struct iscsi_conn *conn)
1670 {
1671         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1672         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1673                 iscsi_conn_queue_work(conn);
1674 }
1675
1676 static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *scmd)
1677 {
1678         struct iscsi_cls_session *cls_session;
1679         struct iscsi_session *session;
1680         struct iscsi_conn *conn;
1681         enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1682
1683         cls_session = starget_to_session(scsi_target(scmd->device));
1684         session = cls_session->dd_data;
1685
1686         ISCSI_DBG_SESSION(session, "scsi cmd %p timedout\n", scmd);
1687
1688         spin_lock(&session->lock);
1689         if (session->state != ISCSI_STATE_LOGGED_IN) {
1690                 /*
1691                  * We are probably in the middle of iscsi recovery so let
1692                  * that complete and handle the error.
1693                  */
1694                 rc = BLK_EH_RESET_TIMER;
1695                 goto done;
1696         }
1697
1698         conn = session->leadconn;
1699         if (!conn) {
1700                 /* In the middle of shuting down */
1701                 rc = BLK_EH_RESET_TIMER;
1702                 goto done;
1703         }
1704
1705         if (!conn->recv_timeout && !conn->ping_timeout)
1706                 goto done;
1707         /*
1708          * if the ping timedout then we are in the middle of cleaning up
1709          * and can let the iscsi eh handle it
1710          */
1711         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1712                             (conn->ping_timeout * HZ), jiffies))
1713                 rc = BLK_EH_RESET_TIMER;
1714         /*
1715          * if we are about to check the transport then give the command
1716          * more time
1717          */
1718         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ),
1719                            jiffies))
1720                 rc = BLK_EH_RESET_TIMER;
1721         /* if in the middle of checking the transport then give us more time */
1722         if (conn->ping_task)
1723                 rc = BLK_EH_RESET_TIMER;
1724 done:
1725         spin_unlock(&session->lock);
1726         ISCSI_DBG_SESSION(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
1727                           "timer reset" : "nh");
1728         return rc;
1729 }
1730
1731 static void iscsi_check_transport_timeouts(unsigned long data)
1732 {
1733         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1734         struct iscsi_session *session = conn->session;
1735         unsigned long recv_timeout, next_timeout = 0, last_recv;
1736
1737         spin_lock(&session->lock);
1738         if (session->state != ISCSI_STATE_LOGGED_IN)
1739                 goto done;
1740
1741         recv_timeout = conn->recv_timeout;
1742         if (!recv_timeout)
1743                 goto done;
1744
1745         recv_timeout *= HZ;
1746         last_recv = conn->last_recv;
1747         if (conn->ping_task &&
1748             time_before_eq(conn->last_ping + (conn->ping_timeout * HZ),
1749                            jiffies)) {
1750                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
1751                                   "expired, last rx %lu, last ping %lu, "
1752                                   "now %lu\n", conn->ping_timeout, last_recv,
1753                                   conn->last_ping, jiffies);
1754                 spin_unlock(&session->lock);
1755                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1756                 return;
1757         }
1758
1759         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
1760                 /* send a ping to try to provoke some traffic */
1761                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
1762                 iscsi_send_nopout(conn, NULL);
1763                 next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
1764         } else
1765                 next_timeout = last_recv + recv_timeout;
1766
1767         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
1768         mod_timer(&conn->transport_timer, next_timeout);
1769 done:
1770         spin_unlock(&session->lock);
1771 }
1772
1773 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
1774                                       struct iscsi_tm *hdr)
1775 {
1776         memset(hdr, 0, sizeof(*hdr));
1777         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1778         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
1779         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1780         memcpy(hdr->lun, task->lun, sizeof(hdr->lun));
1781         hdr->rtt = task->hdr_itt;
1782         hdr->refcmdsn = task->cmdsn;
1783 }
1784
1785 int iscsi_eh_abort(struct scsi_cmnd *sc)
1786 {
1787         struct iscsi_cls_session *cls_session;
1788         struct iscsi_session *session;
1789         struct iscsi_conn *conn;
1790         struct iscsi_task *task;
1791         struct iscsi_tm *hdr;
1792         int rc, age;
1793
1794         cls_session = starget_to_session(scsi_target(sc->device));
1795         session = cls_session->dd_data;
1796
1797         mutex_lock(&session->eh_mutex);
1798         spin_lock_bh(&session->lock);
1799         /*
1800          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1801          * got the command.
1802          */
1803         if (!sc->SCp.ptr) {
1804                 ISCSI_DBG_SESSION(session, "sc never reached iscsi layer or "
1805                                   "it completed.\n");
1806                 spin_unlock_bh(&session->lock);
1807                 mutex_unlock(&session->eh_mutex);
1808                 return SUCCESS;
1809         }
1810
1811         /*
1812          * If we are not logged in or we have started a new session
1813          * then let the host reset code handle this
1814          */
1815         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
1816             sc->SCp.phase != session->age) {
1817                 spin_unlock_bh(&session->lock);
1818                 mutex_unlock(&session->eh_mutex);
1819                 return FAILED;
1820         }
1821
1822         conn = session->leadconn;
1823         conn->eh_abort_cnt++;
1824         age = session->age;
1825
1826         task = (struct iscsi_task *)sc->SCp.ptr;
1827         ISCSI_DBG_SESSION(session, "aborting [sc %p itt 0x%x]\n",
1828                           sc, task->itt);
1829
1830         /* task completed before time out */
1831         if (!task->sc) {
1832                 ISCSI_DBG_SESSION(session, "sc completed while abort in "
1833                                   "progress\n");
1834                 goto success;
1835         }
1836
1837         if (task->state == ISCSI_TASK_PENDING) {
1838                 fail_command(conn, task, DID_ABORT << 16);
1839                 goto success;
1840         }
1841
1842         /* only have one tmf outstanding at a time */
1843         if (conn->tmf_state != TMF_INITIAL)
1844                 goto failed;
1845         conn->tmf_state = TMF_QUEUED;
1846
1847         hdr = &conn->tmhdr;
1848         iscsi_prep_abort_task_pdu(task, hdr);
1849
1850         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
1851                 rc = FAILED;
1852                 goto failed;
1853         }
1854
1855         switch (conn->tmf_state) {
1856         case TMF_SUCCESS:
1857                 spin_unlock_bh(&session->lock);
1858                 /*
1859                  * stop tx side incase the target had sent a abort rsp but
1860                  * the initiator was still writing out data.
1861                  */
1862                 iscsi_suspend_tx(conn);
1863                 /*
1864                  * we do not stop the recv side because targets have been
1865                  * good and have never sent us a successful tmf response
1866                  * then sent more data for the cmd.
1867                  */
1868                 spin_lock(&session->lock);
1869                 fail_command(conn, task, DID_ABORT << 16);
1870                 conn->tmf_state = TMF_INITIAL;
1871                 spin_unlock(&session->lock);
1872                 iscsi_start_tx(conn);
1873                 goto success_unlocked;
1874         case TMF_TIMEDOUT:
1875                 spin_unlock_bh(&session->lock);
1876                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1877                 goto failed_unlocked;
1878         case TMF_NOT_FOUND:
1879                 if (!sc->SCp.ptr) {
1880                         conn->tmf_state = TMF_INITIAL;
1881                         /* task completed before tmf abort response */
1882                         ISCSI_DBG_SESSION(session, "sc completed while abort "
1883                                           "in progress\n");
1884                         goto success;
1885                 }
1886                 /* fall through */
1887         default:
1888                 conn->tmf_state = TMF_INITIAL;
1889                 goto failed;
1890         }
1891
1892 success:
1893         spin_unlock_bh(&session->lock);
1894 success_unlocked:
1895         ISCSI_DBG_SESSION(session, "abort success [sc %p itt 0x%x]\n",
1896                           sc, task->itt);
1897         mutex_unlock(&session->eh_mutex);
1898         return SUCCESS;
1899
1900 failed:
1901         spin_unlock_bh(&session->lock);
1902 failed_unlocked:
1903         ISCSI_DBG_SESSION(session, "abort failed [sc %p itt 0x%x]\n", sc,
1904                           task ? task->itt : 0);
1905         mutex_unlock(&session->eh_mutex);
1906         return FAILED;
1907 }
1908 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1909
1910 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
1911 {
1912         memset(hdr, 0, sizeof(*hdr));
1913         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1914         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
1915         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1916         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
1917         hdr->rtt = RESERVED_ITT;
1918 }
1919
1920 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
1921 {
1922         struct iscsi_cls_session *cls_session;
1923         struct iscsi_session *session;
1924         struct iscsi_conn *conn;
1925         struct iscsi_tm *hdr;
1926         int rc = FAILED;
1927
1928         cls_session = starget_to_session(scsi_target(sc->device));
1929         session = cls_session->dd_data;
1930
1931         ISCSI_DBG_SESSION(session, "LU Reset [sc %p lun %u]\n",
1932                           sc, sc->device->lun);
1933
1934         mutex_lock(&session->eh_mutex);
1935         spin_lock_bh(&session->lock);
1936         /*
1937          * Just check if we are not logged in. We cannot check for
1938          * the phase because the reset could come from a ioctl.
1939          */
1940         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
1941                 goto unlock;
1942         conn = session->leadconn;
1943
1944         /* only have one tmf outstanding at a time */
1945         if (conn->tmf_state != TMF_INITIAL)
1946                 goto unlock;
1947         conn->tmf_state = TMF_QUEUED;
1948
1949         hdr = &conn->tmhdr;
1950         iscsi_prep_lun_reset_pdu(sc, hdr);
1951
1952         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
1953                                     session->lu_reset_timeout)) {
1954                 rc = FAILED;
1955                 goto unlock;
1956         }
1957
1958         switch (conn->tmf_state) {
1959         case TMF_SUCCESS:
1960                 break;
1961         case TMF_TIMEDOUT:
1962                 spin_unlock_bh(&session->lock);
1963                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1964                 goto done;
1965         default:
1966                 conn->tmf_state = TMF_INITIAL;
1967                 goto unlock;
1968         }
1969
1970         rc = SUCCESS;
1971         spin_unlock_bh(&session->lock);
1972
1973         iscsi_suspend_tx(conn);
1974
1975         spin_lock_bh(&session->lock);
1976         fail_all_commands(conn, sc->device->lun, DID_ERROR);
1977         conn->tmf_state = TMF_INITIAL;
1978         spin_unlock_bh(&session->lock);
1979
1980         iscsi_start_tx(conn);
1981         goto done;
1982
1983 unlock:
1984         spin_unlock_bh(&session->lock);
1985 done:
1986         ISCSI_DBG_SESSION(session, "dev reset result = %s\n",
1987                          rc == SUCCESS ? "SUCCESS" : "FAILED");
1988         mutex_unlock(&session->eh_mutex);
1989         return rc;
1990 }
1991 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
1992
1993 /*
1994  * Pre-allocate a pool of @max items of @item_size. By default, the pool
1995  * should be accessed via kfifo_{get,put} on q->queue.
1996  * Optionally, the caller can obtain the array of object pointers
1997  * by passing in a non-NULL @items pointer
1998  */
1999 int
2000 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2001 {
2002         int i, num_arrays = 1;
2003
2004         memset(q, 0, sizeof(*q));
2005
2006         q->max = max;
2007
2008         /* If the user passed an items pointer, he wants a copy of
2009          * the array. */
2010         if (items)
2011                 num_arrays++;
2012         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
2013         if (q->pool == NULL)
2014                 return -ENOMEM;
2015
2016         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
2017                               GFP_KERNEL, NULL);
2018         if (IS_ERR(q->queue)) {
2019                 q->queue = NULL;
2020                 goto enomem;
2021         }
2022
2023         for (i = 0; i < max; i++) {
2024                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2025                 if (q->pool[i] == NULL) {
2026                         q->max = i;
2027                         goto enomem;
2028                 }
2029                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
2030         }
2031
2032         if (items) {
2033                 *items = q->pool + max;
2034                 memcpy(*items, q->pool, max * sizeof(void *));
2035         }
2036
2037         return 0;
2038
2039 enomem:
2040         iscsi_pool_free(q);
2041         return -ENOMEM;
2042 }
2043 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2044
2045 void iscsi_pool_free(struct iscsi_pool *q)
2046 {
2047         int i;
2048
2049         for (i = 0; i < q->max; i++)
2050                 kfree(q->pool[i]);
2051         kfree(q->pool);
2052         kfree(q->queue);
2053 }
2054 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2055
2056 /**
2057  * iscsi_host_add - add host to system
2058  * @shost: scsi host
2059  * @pdev: parent device
2060  *
2061  * This should be called by partial offload and software iscsi drivers
2062  * to add a host to the system.
2063  */
2064 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2065 {
2066         if (!shost->can_queue)
2067                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2068
2069         if (!shost->cmd_per_lun)
2070                 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2071
2072         if (!shost->transportt->eh_timed_out)
2073                 shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
2074         return scsi_add_host(shost, pdev);
2075 }
2076 EXPORT_SYMBOL_GPL(iscsi_host_add);
2077
2078 /**
2079  * iscsi_host_alloc - allocate a host and driver data
2080  * @sht: scsi host template
2081  * @dd_data_size: driver host data size
2082  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2083  *
2084  * This should be called by partial offload and software iscsi drivers.
2085  * To access the driver specific memory use the iscsi_host_priv() macro.
2086  */
2087 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2088                                    int dd_data_size, bool xmit_can_sleep)
2089 {
2090         struct Scsi_Host *shost;
2091         struct iscsi_host *ihost;
2092
2093         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2094         if (!shost)
2095                 return NULL;
2096         ihost = shost_priv(shost);
2097
2098         if (xmit_can_sleep) {
2099                 snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2100                         "iscsi_q_%d", shost->host_no);
2101                 ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2102                 if (!ihost->workq)
2103                         goto free_host;
2104         }
2105
2106         spin_lock_init(&ihost->lock);
2107         ihost->state = ISCSI_HOST_SETUP;
2108         ihost->num_sessions = 0;
2109         init_waitqueue_head(&ihost->session_removal_wq);
2110         return shost;
2111
2112 free_host:
2113         scsi_host_put(shost);
2114         return NULL;
2115 }
2116 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2117
2118 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2119 {
2120         iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2121 }
2122
2123 /**
2124  * iscsi_host_remove - remove host and sessions
2125  * @shost: scsi host
2126  *
2127  * If there are any sessions left, this will initiate the removal and wait
2128  * for the completion.
2129  */
2130 void iscsi_host_remove(struct Scsi_Host *shost)
2131 {
2132         struct iscsi_host *ihost = shost_priv(shost);
2133         unsigned long flags;
2134
2135         spin_lock_irqsave(&ihost->lock, flags);
2136         ihost->state = ISCSI_HOST_REMOVED;
2137         spin_unlock_irqrestore(&ihost->lock, flags);
2138
2139         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2140         wait_event_interruptible(ihost->session_removal_wq,
2141                                  ihost->num_sessions == 0);
2142         if (signal_pending(current))
2143                 flush_signals(current);
2144
2145         scsi_remove_host(shost);
2146         if (ihost->workq)
2147                 destroy_workqueue(ihost->workq);
2148 }
2149 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2150
2151 void iscsi_host_free(struct Scsi_Host *shost)
2152 {
2153         struct iscsi_host *ihost = shost_priv(shost);
2154
2155         kfree(ihost->netdev);
2156         kfree(ihost->hwaddress);
2157         kfree(ihost->initiatorname);
2158         scsi_host_put(shost);
2159 }
2160 EXPORT_SYMBOL_GPL(iscsi_host_free);
2161
2162 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2163 {
2164         struct iscsi_host *ihost = shost_priv(shost);
2165         unsigned long flags;
2166
2167         shost = scsi_host_get(shost);
2168         if (!shost) {
2169                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2170                       "of session teardown event because host already "
2171                       "removed.\n");
2172                 return;
2173         }
2174
2175         spin_lock_irqsave(&ihost->lock, flags);
2176         ihost->num_sessions--;
2177         if (ihost->num_sessions == 0)
2178                 wake_up(&ihost->session_removal_wq);
2179         spin_unlock_irqrestore(&ihost->lock, flags);
2180         scsi_host_put(shost);
2181 }
2182
2183 /**
2184  * iscsi_session_setup - create iscsi cls session and host and session
2185  * @iscsit: iscsi transport template
2186  * @shost: scsi host
2187  * @cmds_max: session can queue
2188  * @cmd_task_size: LLD task private data size
2189  * @initial_cmdsn: initial CmdSN
2190  *
2191  * This can be used by software iscsi_transports that allocate
2192  * a session per scsi host.
2193  *
2194  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2195  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2196  * for nop handling and login/logout requests.
2197  */
2198 struct iscsi_cls_session *
2199 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2200                     uint16_t cmds_max, int cmd_task_size,
2201                     uint32_t initial_cmdsn, unsigned int id)
2202 {
2203         struct iscsi_host *ihost = shost_priv(shost);
2204         struct iscsi_session *session;
2205         struct iscsi_cls_session *cls_session;
2206         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2207         unsigned long flags;
2208
2209         spin_lock_irqsave(&ihost->lock, flags);
2210         if (ihost->state == ISCSI_HOST_REMOVED) {
2211                 spin_unlock_irqrestore(&ihost->lock, flags);
2212                 return NULL;
2213         }
2214         ihost->num_sessions++;
2215         spin_unlock_irqrestore(&ihost->lock, flags);
2216
2217         if (!total_cmds)
2218                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2219         /*
2220          * The iscsi layer needs some tasks for nop handling and tmfs,
2221          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2222          * + 1 command for scsi IO.
2223          */
2224         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2225                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2226                        "must be a power of two that is at least %d.\n",
2227                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2228                 goto dec_session_count;
2229         }
2230
2231         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2232                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2233                        "must be a power of 2 less than or equal to %d.\n",
2234                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2235                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2236         }
2237
2238         if (!is_power_of_2(total_cmds)) {
2239                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2240                        "must be a power of 2.\n", total_cmds);
2241                 total_cmds = rounddown_pow_of_two(total_cmds);
2242                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2243                         return NULL;
2244                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2245                        total_cmds);
2246         }
2247         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2248
2249         cls_session = iscsi_alloc_session(shost, iscsit,
2250                                           sizeof(struct iscsi_session));
2251         if (!cls_session)
2252                 goto dec_session_count;
2253         session = cls_session->dd_data;
2254         session->cls_session = cls_session;
2255         session->host = shost;
2256         session->state = ISCSI_STATE_FREE;
2257         session->fast_abort = 1;
2258         session->lu_reset_timeout = 15;
2259         session->abort_timeout = 10;
2260         session->scsi_cmds_max = scsi_cmds;
2261         session->cmds_max = total_cmds;
2262         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2263         session->exp_cmdsn = initial_cmdsn + 1;
2264         session->max_cmdsn = initial_cmdsn + 1;
2265         session->max_r2t = 1;
2266         session->tt = iscsit;
2267         mutex_init(&session->eh_mutex);
2268         spin_lock_init(&session->lock);
2269
2270         /* initialize SCSI PDU commands pool */
2271         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2272                             (void***)&session->cmds,
2273                             cmd_task_size + sizeof(struct iscsi_task)))
2274                 goto cmdpool_alloc_fail;
2275
2276         /* pre-format cmds pool with ITT */
2277         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2278                 struct iscsi_task *task = session->cmds[cmd_i];
2279
2280                 if (cmd_task_size)
2281                         task->dd_data = &task[1];
2282                 task->itt = cmd_i;
2283                 INIT_LIST_HEAD(&task->running);
2284         }
2285
2286         if (!try_module_get(iscsit->owner))
2287                 goto module_get_fail;
2288
2289         if (iscsi_add_session(cls_session, id))
2290                 goto cls_session_fail;
2291
2292         return cls_session;
2293
2294 cls_session_fail:
2295         module_put(iscsit->owner);
2296 module_get_fail:
2297         iscsi_pool_free(&session->cmdpool);
2298 cmdpool_alloc_fail:
2299         iscsi_free_session(cls_session);
2300 dec_session_count:
2301         iscsi_host_dec_session_cnt(shost);
2302         return NULL;
2303 }
2304 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2305
2306 /**
2307  * iscsi_session_teardown - destroy session, host, and cls_session
2308  * @cls_session: iscsi session
2309  *
2310  * The driver must have called iscsi_remove_session before
2311  * calling this.
2312  */
2313 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2314 {
2315         struct iscsi_session *session = cls_session->dd_data;
2316         struct module *owner = cls_session->transport->owner;
2317         struct Scsi_Host *shost = session->host;
2318
2319         iscsi_pool_free(&session->cmdpool);
2320
2321         kfree(session->password);
2322         kfree(session->password_in);
2323         kfree(session->username);
2324         kfree(session->username_in);
2325         kfree(session->targetname);
2326         kfree(session->initiatorname);
2327         kfree(session->ifacename);
2328
2329         iscsi_destroy_session(cls_session);
2330         iscsi_host_dec_session_cnt(shost);
2331         module_put(owner);
2332 }
2333 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2334
2335 /**
2336  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2337  * @cls_session: iscsi_cls_session
2338  * @dd_size: private driver data size
2339  * @conn_idx: cid
2340  */
2341 struct iscsi_cls_conn *
2342 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2343                  uint32_t conn_idx)
2344 {
2345         struct iscsi_session *session = cls_session->dd_data;
2346         struct iscsi_conn *conn;
2347         struct iscsi_cls_conn *cls_conn;
2348         char *data;
2349
2350         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2351                                      conn_idx);
2352         if (!cls_conn)
2353                 return NULL;
2354         conn = cls_conn->dd_data;
2355         memset(conn, 0, sizeof(*conn) + dd_size);
2356
2357         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2358         conn->session = session;
2359         conn->cls_conn = cls_conn;
2360         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2361         conn->id = conn_idx;
2362         conn->exp_statsn = 0;
2363         conn->tmf_state = TMF_INITIAL;
2364
2365         init_timer(&conn->transport_timer);
2366         conn->transport_timer.data = (unsigned long)conn;
2367         conn->transport_timer.function = iscsi_check_transport_timeouts;
2368
2369         INIT_LIST_HEAD(&conn->run_list);
2370         INIT_LIST_HEAD(&conn->mgmt_run_list);
2371         INIT_LIST_HEAD(&conn->mgmtqueue);
2372         INIT_LIST_HEAD(&conn->xmitqueue);
2373         INIT_LIST_HEAD(&conn->requeue);
2374         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2375
2376         /* allocate login_task used for the login/text sequences */
2377         spin_lock_bh(&session->lock);
2378         if (!__kfifo_get(session->cmdpool.queue,
2379                          (void*)&conn->login_task,
2380                          sizeof(void*))) {
2381                 spin_unlock_bh(&session->lock);
2382                 goto login_task_alloc_fail;
2383         }
2384         spin_unlock_bh(&session->lock);
2385
2386         data = (char *) __get_free_pages(GFP_KERNEL,
2387                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2388         if (!data)
2389                 goto login_task_data_alloc_fail;
2390         conn->login_task->data = conn->data = data;
2391
2392         init_timer(&conn->tmf_timer);
2393         init_waitqueue_head(&conn->ehwait);
2394
2395         return cls_conn;
2396
2397 login_task_data_alloc_fail:
2398         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2399                     sizeof(void*));
2400 login_task_alloc_fail:
2401         iscsi_destroy_conn(cls_conn);
2402         return NULL;
2403 }
2404 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2405
2406 /**
2407  * iscsi_conn_teardown - teardown iscsi connection
2408  * cls_conn: iscsi class connection
2409  *
2410  * TODO: we may need to make this into a two step process
2411  * like scsi-mls remove + put host
2412  */
2413 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2414 {
2415         struct iscsi_conn *conn = cls_conn->dd_data;
2416         struct iscsi_session *session = conn->session;
2417         unsigned long flags;
2418
2419         del_timer_sync(&conn->transport_timer);
2420
2421         spin_lock_bh(&session->lock);
2422         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2423         if (session->leadconn == conn) {
2424                 /*
2425                  * leading connection? then give up on recovery.
2426                  */
2427                 session->state = ISCSI_STATE_TERMINATE;
2428                 wake_up(&conn->ehwait);
2429         }
2430         spin_unlock_bh(&session->lock);
2431
2432         /*
2433          * Block until all in-progress commands for this connection
2434          * time out or fail.
2435          */
2436         for (;;) {
2437                 spin_lock_irqsave(session->host->host_lock, flags);
2438                 if (!session->host->host_busy) { /* OK for ERL == 0 */
2439                         spin_unlock_irqrestore(session->host->host_lock, flags);
2440                         break;
2441                 }
2442                 spin_unlock_irqrestore(session->host->host_lock, flags);
2443                 msleep_interruptible(500);
2444                 iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2445                                   "host_busy %d host_failed %d\n",
2446                                   session->host->host_busy,
2447                                   session->host->host_failed);
2448                 /*
2449                  * force eh_abort() to unblock
2450                  */
2451                 wake_up(&conn->ehwait);
2452         }
2453
2454         /* flush queued up work because we free the connection below */
2455         iscsi_suspend_tx(conn);
2456
2457         spin_lock_bh(&session->lock);
2458         free_pages((unsigned long) conn->data,
2459                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2460         kfree(conn->persistent_address);
2461         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2462                     sizeof(void*));
2463         if (session->leadconn == conn)
2464                 session->leadconn = NULL;
2465         spin_unlock_bh(&session->lock);
2466
2467         iscsi_destroy_conn(cls_conn);
2468 }
2469 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2470
2471 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2472 {
2473         struct iscsi_conn *conn = cls_conn->dd_data;
2474         struct iscsi_session *session = conn->session;
2475
2476         if (!session) {
2477                 iscsi_conn_printk(KERN_ERR, conn,
2478                                   "can't start unbound connection\n");
2479                 return -EPERM;
2480         }
2481
2482         if ((session->imm_data_en || !session->initial_r2t_en) &&
2483              session->first_burst > session->max_burst) {
2484                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2485                                   "first_burst %d max_burst %d\n",
2486                                   session->first_burst, session->max_burst);
2487                 return -EINVAL;
2488         }
2489
2490         if (conn->ping_timeout && !conn->recv_timeout) {
2491                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
2492                                   "zero. Using 5 seconds\n.");
2493                 conn->recv_timeout = 5;
2494         }
2495
2496         if (conn->recv_timeout && !conn->ping_timeout) {
2497                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
2498                                   "zero. Using 5 seconds.\n");
2499                 conn->ping_timeout = 5;
2500         }
2501
2502         spin_lock_bh(&session->lock);
2503         conn->c_stage = ISCSI_CONN_STARTED;
2504         session->state = ISCSI_STATE_LOGGED_IN;
2505         session->queued_cmdsn = session->cmdsn;
2506
2507         conn->last_recv = jiffies;
2508         conn->last_ping = jiffies;
2509         if (conn->recv_timeout && conn->ping_timeout)
2510                 mod_timer(&conn->transport_timer,
2511                           jiffies + (conn->recv_timeout * HZ));
2512
2513         switch(conn->stop_stage) {
2514         case STOP_CONN_RECOVER:
2515                 /*
2516                  * unblock eh_abort() if it is blocked. re-try all
2517                  * commands after successful recovery
2518                  */
2519                 conn->stop_stage = 0;
2520                 conn->tmf_state = TMF_INITIAL;
2521                 session->age++;
2522                 if (session->age == 16)
2523                         session->age = 0;
2524                 break;
2525         case STOP_CONN_TERM:
2526                 conn->stop_stage = 0;
2527                 break;
2528         default:
2529                 break;
2530         }
2531         spin_unlock_bh(&session->lock);
2532
2533         iscsi_unblock_session(session->cls_session);
2534         wake_up(&conn->ehwait);
2535         return 0;
2536 }
2537 EXPORT_SYMBOL_GPL(iscsi_conn_start);
2538
2539 static void
2540 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
2541 {
2542         struct iscsi_task *task, *tmp;
2543
2544         /* handle pending */
2545         list_for_each_entry_safe(task, tmp, &conn->mgmtqueue, running) {
2546                 ISCSI_DBG_SESSION(session, "flushing pending mgmt task "
2547                                   "itt 0x%x\n", task->itt);
2548                 /* release ref from prep task */
2549                 __iscsi_put_task(task);
2550         }
2551
2552         /* handle running */
2553         list_for_each_entry_safe(task, tmp, &conn->mgmt_run_list, running) {
2554                 ISCSI_DBG_SESSION(session, "flushing running mgmt task "
2555                                   "itt 0x%x\n", task->itt);
2556                 /* release ref from prep task */
2557                 __iscsi_put_task(task);
2558         }
2559
2560         conn->task = NULL;
2561 }
2562
2563 static void iscsi_start_session_recovery(struct iscsi_session *session,
2564                                          struct iscsi_conn *conn, int flag)
2565 {
2566         int old_stop_stage;
2567
2568         del_timer_sync(&conn->transport_timer);
2569
2570         mutex_lock(&session->eh_mutex);
2571         spin_lock_bh(&session->lock);
2572         if (conn->stop_stage == STOP_CONN_TERM) {
2573                 spin_unlock_bh(&session->lock);
2574                 mutex_unlock(&session->eh_mutex);
2575                 return;
2576         }
2577
2578         /*
2579          * When this is called for the in_login state, we only want to clean
2580          * up the login task and connection. We do not need to block and set
2581          * the recovery state again
2582          */
2583         if (flag == STOP_CONN_TERM)
2584                 session->state = ISCSI_STATE_TERMINATE;
2585         else if (conn->stop_stage != STOP_CONN_RECOVER)
2586                 session->state = ISCSI_STATE_IN_RECOVERY;
2587
2588         old_stop_stage = conn->stop_stage;
2589         conn->stop_stage = flag;
2590         conn->c_stage = ISCSI_CONN_STOPPED;
2591         spin_unlock_bh(&session->lock);
2592
2593         iscsi_suspend_tx(conn);
2594         /*
2595          * for connection level recovery we should not calculate
2596          * header digest. conn->hdr_size used for optimization
2597          * in hdr_extract() and will be re-negotiated at
2598          * set_param() time.
2599          */
2600         if (flag == STOP_CONN_RECOVER) {
2601                 conn->hdrdgst_en = 0;
2602                 conn->datadgst_en = 0;
2603                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
2604                     old_stop_stage != STOP_CONN_RECOVER) {
2605                         ISCSI_DBG_SESSION(session, "blocking session\n");
2606                         iscsi_block_session(session->cls_session);
2607                 }
2608         }
2609
2610         /*
2611          * flush queues.
2612          */
2613         spin_lock_bh(&session->lock);
2614         if (flag == STOP_CONN_RECOVER)
2615                 fail_all_commands(conn, -1, DID_TRANSPORT_DISRUPTED);
2616         else
2617                 fail_all_commands(conn, -1, DID_ERROR);
2618         flush_control_queues(session, conn);
2619         spin_unlock_bh(&session->lock);
2620         mutex_unlock(&session->eh_mutex);
2621 }
2622
2623 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
2624 {
2625         struct iscsi_conn *conn = cls_conn->dd_data;
2626         struct iscsi_session *session = conn->session;
2627
2628         switch (flag) {
2629         case STOP_CONN_RECOVER:
2630         case STOP_CONN_TERM:
2631                 iscsi_start_session_recovery(session, conn, flag);
2632                 break;
2633         default:
2634                 iscsi_conn_printk(KERN_ERR, conn,
2635                                   "invalid stop flag %d\n", flag);
2636         }
2637 }
2638 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
2639
2640 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
2641                     struct iscsi_cls_conn *cls_conn, int is_leading)
2642 {
2643         struct iscsi_session *session = cls_session->dd_data;
2644         struct iscsi_conn *conn = cls_conn->dd_data;
2645
2646         spin_lock_bh(&session->lock);
2647         if (is_leading)
2648                 session->leadconn = conn;
2649         spin_unlock_bh(&session->lock);
2650
2651         /*
2652          * Unblock xmitworker(), Login Phase will pass through.
2653          */
2654         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
2655         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
2656         return 0;
2657 }
2658 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
2659
2660 static int iscsi_switch_str_param(char **param, char *new_val_buf)
2661 {
2662         char *new_val;
2663
2664         if (*param) {
2665                 if (!strcmp(*param, new_val_buf))
2666                         return 0;
2667         }
2668
2669         new_val = kstrdup(new_val_buf, GFP_NOIO);
2670         if (!new_val)
2671                 return -ENOMEM;
2672
2673         kfree(*param);
2674         *param = new_val;
2675         return 0;
2676 }
2677
2678 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
2679                     enum iscsi_param param, char *buf, int buflen)
2680 {
2681         struct iscsi_conn *conn = cls_conn->dd_data;
2682         struct iscsi_session *session = conn->session;
2683         uint32_t value;
2684
2685         switch(param) {
2686         case ISCSI_PARAM_FAST_ABORT:
2687                 sscanf(buf, "%d", &session->fast_abort);
2688                 break;
2689         case ISCSI_PARAM_ABORT_TMO:
2690                 sscanf(buf, "%d", &session->abort_timeout);
2691                 break;
2692         case ISCSI_PARAM_LU_RESET_TMO:
2693                 sscanf(buf, "%d", &session->lu_reset_timeout);
2694                 break;
2695         case ISCSI_PARAM_PING_TMO:
2696                 sscanf(buf, "%d", &conn->ping_timeout);
2697                 break;
2698         case ISCSI_PARAM_RECV_TMO:
2699                 sscanf(buf, "%d", &conn->recv_timeout);
2700                 break;
2701         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2702                 sscanf(buf, "%d", &conn->max_recv_dlength);
2703                 break;
2704         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2705                 sscanf(buf, "%d", &conn->max_xmit_dlength);
2706                 break;
2707         case ISCSI_PARAM_HDRDGST_EN:
2708                 sscanf(buf, "%d", &conn->hdrdgst_en);
2709                 break;
2710         case ISCSI_PARAM_DATADGST_EN:
2711                 sscanf(buf, "%d", &conn->datadgst_en);
2712                 break;
2713         case ISCSI_PARAM_INITIAL_R2T_EN:
2714                 sscanf(buf, "%d", &session->initial_r2t_en);
2715                 break;
2716         case ISCSI_PARAM_MAX_R2T:
2717                 sscanf(buf, "%d", &session->max_r2t);
2718                 break;
2719         case ISCSI_PARAM_IMM_DATA_EN:
2720                 sscanf(buf, "%d", &session->imm_data_en);
2721                 break;
2722         case ISCSI_PARAM_FIRST_BURST:
2723                 sscanf(buf, "%d", &session->first_burst);
2724                 break;
2725         case ISCSI_PARAM_MAX_BURST:
2726                 sscanf(buf, "%d", &session->max_burst);
2727                 break;
2728         case ISCSI_PARAM_PDU_INORDER_EN:
2729                 sscanf(buf, "%d", &session->pdu_inorder_en);
2730                 break;
2731         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2732                 sscanf(buf, "%d", &session->dataseq_inorder_en);
2733                 break;
2734         case ISCSI_PARAM_ERL:
2735                 sscanf(buf, "%d", &session->erl);
2736                 break;
2737         case ISCSI_PARAM_IFMARKER_EN:
2738                 sscanf(buf, "%d", &value);
2739                 BUG_ON(value);
2740                 break;
2741         case ISCSI_PARAM_OFMARKER_EN:
2742                 sscanf(buf, "%d", &value);
2743                 BUG_ON(value);
2744                 break;
2745         case ISCSI_PARAM_EXP_STATSN:
2746                 sscanf(buf, "%u", &conn->exp_statsn);
2747                 break;
2748         case ISCSI_PARAM_USERNAME:
2749                 return iscsi_switch_str_param(&session->username, buf);
2750         case ISCSI_PARAM_USERNAME_IN:
2751                 return iscsi_switch_str_param(&session->username_in, buf);
2752         case ISCSI_PARAM_PASSWORD:
2753                 return iscsi_switch_str_param(&session->password, buf);
2754         case ISCSI_PARAM_PASSWORD_IN:
2755                 return iscsi_switch_str_param(&session->password_in, buf);
2756         case ISCSI_PARAM_TARGET_NAME:
2757                 return iscsi_switch_str_param(&session->targetname, buf);
2758         case ISCSI_PARAM_TPGT:
2759                 sscanf(buf, "%d", &session->tpgt);
2760                 break;
2761         case ISCSI_PARAM_PERSISTENT_PORT:
2762                 sscanf(buf, "%d", &conn->persistent_port);
2763                 break;
2764         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2765                 return iscsi_switch_str_param(&conn->persistent_address, buf);
2766         case ISCSI_PARAM_IFACE_NAME:
2767                 return iscsi_switch_str_param(&session->ifacename, buf);
2768         case ISCSI_PARAM_INITIATOR_NAME:
2769                 return iscsi_switch_str_param(&session->initiatorname, buf);
2770         default:
2771                 return -ENOSYS;
2772         }
2773
2774         return 0;
2775 }
2776 EXPORT_SYMBOL_GPL(iscsi_set_param);
2777
2778 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
2779                             enum iscsi_param param, char *buf)
2780 {
2781         struct iscsi_session *session = cls_session->dd_data;
2782         int len;
2783
2784         switch(param) {
2785         case ISCSI_PARAM_FAST_ABORT:
2786                 len = sprintf(buf, "%d\n", session->fast_abort);
2787                 break;
2788         case ISCSI_PARAM_ABORT_TMO:
2789                 len = sprintf(buf, "%d\n", session->abort_timeout);
2790                 break;
2791         case ISCSI_PARAM_LU_RESET_TMO:
2792                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
2793                 break;
2794         case ISCSI_PARAM_INITIAL_R2T_EN:
2795                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
2796                 break;
2797         case ISCSI_PARAM_MAX_R2T:
2798                 len = sprintf(buf, "%hu\n", session->max_r2t);
2799                 break;
2800         case ISCSI_PARAM_IMM_DATA_EN:
2801                 len = sprintf(buf, "%d\n", session->imm_data_en);
2802                 break;
2803         case ISCSI_PARAM_FIRST_BURST:
2804                 len = sprintf(buf, "%u\n", session->first_burst);
2805                 break;
2806         case ISCSI_PARAM_MAX_BURST:
2807                 len = sprintf(buf, "%u\n", session->max_burst);
2808                 break;
2809         case ISCSI_PARAM_PDU_INORDER_EN:
2810                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
2811                 break;
2812         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2813                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
2814                 break;
2815         case ISCSI_PARAM_ERL:
2816                 len = sprintf(buf, "%d\n", session->erl);
2817                 break;
2818         case ISCSI_PARAM_TARGET_NAME:
2819                 len = sprintf(buf, "%s\n", session->targetname);
2820                 break;
2821         case ISCSI_PARAM_TPGT:
2822                 len = sprintf(buf, "%d\n", session->tpgt);
2823                 break;
2824         case ISCSI_PARAM_USERNAME:
2825                 len = sprintf(buf, "%s\n", session->username);
2826                 break;
2827         case ISCSI_PARAM_USERNAME_IN:
2828                 len = sprintf(buf, "%s\n", session->username_in);
2829                 break;
2830         case ISCSI_PARAM_PASSWORD:
2831                 len = sprintf(buf, "%s\n", session->password);
2832                 break;
2833         case ISCSI_PARAM_PASSWORD_IN:
2834                 len = sprintf(buf, "%s\n", session->password_in);
2835                 break;
2836         case ISCSI_PARAM_IFACE_NAME:
2837                 len = sprintf(buf, "%s\n", session->ifacename);
2838                 break;
2839         case ISCSI_PARAM_INITIATOR_NAME:
2840                 len = sprintf(buf, "%s\n", session->initiatorname);
2841                 break;
2842         default:
2843                 return -ENOSYS;
2844         }
2845
2846         return len;
2847 }
2848 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
2849
2850 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2851                          enum iscsi_param param, char *buf)
2852 {
2853         struct iscsi_conn *conn = cls_conn->dd_data;
2854         int len;
2855
2856         switch(param) {
2857         case ISCSI_PARAM_PING_TMO:
2858                 len = sprintf(buf, "%u\n", conn->ping_timeout);
2859                 break;
2860         case ISCSI_PARAM_RECV_TMO:
2861                 len = sprintf(buf, "%u\n", conn->recv_timeout);
2862                 break;
2863         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2864                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
2865                 break;
2866         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2867                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
2868                 break;
2869         case ISCSI_PARAM_HDRDGST_EN:
2870                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
2871                 break;
2872         case ISCSI_PARAM_DATADGST_EN:
2873                 len = sprintf(buf, "%d\n", conn->datadgst_en);
2874                 break;
2875         case ISCSI_PARAM_IFMARKER_EN:
2876                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
2877                 break;
2878         case ISCSI_PARAM_OFMARKER_EN:
2879                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
2880                 break;
2881         case ISCSI_PARAM_EXP_STATSN:
2882                 len = sprintf(buf, "%u\n", conn->exp_statsn);
2883                 break;
2884         case ISCSI_PARAM_PERSISTENT_PORT:
2885                 len = sprintf(buf, "%d\n", conn->persistent_port);
2886                 break;
2887         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2888                 len = sprintf(buf, "%s\n", conn->persistent_address);
2889                 break;
2890         default:
2891                 return -ENOSYS;
2892         }
2893
2894         return len;
2895 }
2896 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
2897
2898 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2899                          char *buf)
2900 {
2901         struct iscsi_host *ihost = shost_priv(shost);
2902         int len;
2903
2904         switch (param) {
2905         case ISCSI_HOST_PARAM_NETDEV_NAME:
2906                 len = sprintf(buf, "%s\n", ihost->netdev);
2907                 break;
2908         case ISCSI_HOST_PARAM_HWADDRESS:
2909                 len = sprintf(buf, "%s\n", ihost->hwaddress);
2910                 break;
2911         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2912                 len = sprintf(buf, "%s\n", ihost->initiatorname);
2913                 break;
2914         case ISCSI_HOST_PARAM_IPADDRESS:
2915                 len = sprintf(buf, "%s\n", ihost->local_address);
2916                 break;
2917         default:
2918                 return -ENOSYS;
2919         }
2920
2921         return len;
2922 }
2923 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
2924
2925 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2926                          char *buf, int buflen)
2927 {
2928         struct iscsi_host *ihost = shost_priv(shost);
2929
2930         switch (param) {
2931         case ISCSI_HOST_PARAM_NETDEV_NAME:
2932                 return iscsi_switch_str_param(&ihost->netdev, buf);
2933         case ISCSI_HOST_PARAM_HWADDRESS:
2934                 return iscsi_switch_str_param(&ihost->hwaddress, buf);
2935         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2936                 return iscsi_switch_str_param(&ihost->initiatorname, buf);
2937         default:
2938                 return -ENOSYS;
2939         }
2940
2941         return 0;
2942 }
2943 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
2944
2945 MODULE_AUTHOR("Mike Christie");
2946 MODULE_DESCRIPTION("iSCSI library functions");
2947 MODULE_LICENSE("GPL");