err.no Git - linux-2.6/blob - drivers/scsi/scsi_transport_iscsi.c

   1 /*
   2  * iSCSI transport class definitions
   3  *
   4  * Copyright (C) IBM Corporation, 2004
   5  * Copyright (C) Mike Christie, 2004 - 2005
   6  * Copyright (C) Dmitry Yusupov, 2004 - 2005
   7  * Copyright (C) Alex Aizman, 2004 - 2005
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  22  */
  23 #include <linux/module.h>
  24 #include <linux/mutex.h>
  25 #include <net/tcp.h>
  26 #include <scsi/scsi.h>
  27 #include <scsi/scsi_host.h>
  28 #include <scsi/scsi_device.h>
  29 #include <scsi/scsi_transport.h>
  30 #include <scsi/scsi_transport_iscsi.h>
  31 #include <scsi/iscsi_if.h>
  32
  33 #define ISCSI_SESSION_ATTRS 19
  34 #define ISCSI_CONN_ATTRS 13
  35 #define ISCSI_HOST_ATTRS 4
  36 #define ISCSI_TRANSPORT_VERSION "2.0-869"
  37
  38 struct iscsi_internal {
  39         int daemon_pid;
  40         struct scsi_transport_template t;
  41         struct iscsi_transport *iscsi_transport;
  42         struct list_head list;
  43         struct device dev;
  44
  45         struct device_attribute *host_attrs[ISCSI_HOST_ATTRS + 1];
  46         struct transport_container conn_cont;
  47         struct device_attribute *conn_attrs[ISCSI_CONN_ATTRS + 1];
  48         struct transport_container session_cont;
  49         struct device_attribute *session_attrs[ISCSI_SESSION_ATTRS + 1];
  50 };
  51
  52 static atomic_t iscsi_session_nr; /* sysfs session id for next new session */
  53 static struct workqueue_struct *iscsi_eh_timer_workq;
  54
  55 /*
  56  * list of registered transports and lock that must
  57  * be held while accessing list. The iscsi_transport_lock must
  58  * be acquired after the rx_queue_mutex.
  59  */
  60 static LIST_HEAD(iscsi_transports);
  61 static DEFINE_SPINLOCK(iscsi_transport_lock);
  62
  63 #define to_iscsi_internal(tmpl) \
  64         container_of(tmpl, struct iscsi_internal, t)
  65
  66 #define dev_to_iscsi_internal(_dev) \
  67         container_of(_dev, struct iscsi_internal, dev)
  68
  69 static void iscsi_transport_release(struct device *dev)
  70 {
  71         struct iscsi_internal *priv = dev_to_iscsi_internal(dev);
  72         kfree(priv);
  73 }
  74
  75 /*
  76  * iscsi_transport_class represents the iscsi_transports that are
  77  * registered.
  78  */
  79 static struct class iscsi_transport_class = {
  80         .name = "iscsi_transport",
  81         .dev_release = iscsi_transport_release,
  82 };
  83
  84 static ssize_t
  85 show_transport_handle(struct device *dev, struct device_attribute *attr,
  86                       char *buf)
  87 {
  88         struct iscsi_internal *priv = dev_to_iscsi_internal(dev);
  89         return sprintf(buf, "%llu\n", (unsigned long long)iscsi_handle(priv->iscsi_transport));
  90 }
  91 static DEVICE_ATTR(handle, S_IRUGO, show_transport_handle, NULL);
  92
  93 #define show_transport_attr(name, format)                               \
  94 static ssize_t                                                          \
  95 show_transport_##name(struct device *dev,                               \
  96                       struct device_attribute *attr,char *buf)          \
  97 {                                                                       \
  98         struct iscsi_internal *priv = dev_to_iscsi_internal(dev);       \
  99         return sprintf(buf, format"\n", priv->iscsi_transport->name);   \
 100 }                                                                       \
 101 static DEVICE_ATTR(name, S_IRUGO, show_transport_##name, NULL);
 102
 103 show_transport_attr(caps, "0x%x");
 104
 105 static struct attribute *iscsi_transport_attrs[] = {
 106         &dev_attr_handle.attr,
 107         &dev_attr_caps.attr,
 108         NULL,
 109 };
 110
 111 static struct attribute_group iscsi_transport_group = {
 112         .attrs = iscsi_transport_attrs,
 113 };
 114
 115 static int iscsi_setup_host(struct transport_container *tc, struct device *dev,
 116                             struct device *cdev)
 117 {
 118         struct Scsi_Host *shost = dev_to_shost(dev);
 119         struct iscsi_cls_host *ihost = shost->shost_data;
 120
 121         memset(ihost, 0, sizeof(*ihost));
 122         atomic_set(&ihost->nr_scans, 0);
 123         mutex_init(&ihost->mutex);
 124
 125         snprintf(ihost->scan_workq_name, KOBJ_NAME_LEN, "iscsi_scan_%d",
 126                 shost->host_no);
 127         ihost->scan_workq = create_singlethread_workqueue(
 128                                                 ihost->scan_workq_name);
 129         if (!ihost->scan_workq)
 130                 return -ENOMEM;
 131         return 0;
 132 }
 133
 134 static int iscsi_remove_host(struct transport_container *tc, struct device *dev,
 135                              struct device *cdev)
 136 {
 137         struct Scsi_Host *shost = dev_to_shost(dev);
 138         struct iscsi_cls_host *ihost = shost->shost_data;
 139
 140         destroy_workqueue(ihost->scan_workq);
 141         return 0;
 142 }
 143
 144 static DECLARE_TRANSPORT_CLASS(iscsi_host_class,
 145                                "iscsi_host",
 146                                iscsi_setup_host,
 147                                iscsi_remove_host,
 148                                NULL);
 149
 150 static DECLARE_TRANSPORT_CLASS(iscsi_session_class,
 151                                "iscsi_session",
 152                                NULL,
 153                                NULL,
 154                                NULL);
 155
 156 static DECLARE_TRANSPORT_CLASS(iscsi_connection_class,
 157                                "iscsi_connection",
 158                                NULL,
 159                                NULL,
 160                                NULL);
 161
 162 static struct sock *nls;
 163 static DEFINE_MUTEX(rx_queue_mutex);
 164
 165 static LIST_HEAD(sesslist);
 166 static DEFINE_SPINLOCK(sesslock);
 167 static LIST_HEAD(connlist);
 168 static DEFINE_SPINLOCK(connlock);
 169
 170 static uint32_t iscsi_conn_get_sid(struct iscsi_cls_conn *conn)
 171 {
 172         struct iscsi_cls_session *sess = iscsi_dev_to_session(conn->dev.parent);
 173         return sess->sid;
 174 }
 175
 176 /*
 177  * Returns the matching session to a given sid
 178  */
 179 static struct iscsi_cls_session *iscsi_session_lookup(uint32_t sid)
 180 {
 181         unsigned long flags;
 182         struct iscsi_cls_session *sess;
 183
 184         spin_lock_irqsave(&sesslock, flags);
 185         list_for_each_entry(sess, &sesslist, sess_list) {
 186                 if (sess->sid == sid) {
 187                         spin_unlock_irqrestore(&sesslock, flags);
 188                         return sess;
 189                 }
 190         }
 191         spin_unlock_irqrestore(&sesslock, flags);
 192         return NULL;
 193 }
 194
 195 /*
 196  * Returns the matching connection to a given sid / cid tuple
 197  */
 198 static struct iscsi_cls_conn *iscsi_conn_lookup(uint32_t sid, uint32_t cid)
 199 {
 200         unsigned long flags;
 201         struct iscsi_cls_conn *conn;
 202
 203         spin_lock_irqsave(&connlock, flags);
 204         list_for_each_entry(conn, &connlist, conn_list) {
 205                 if ((conn->cid == cid) && (iscsi_conn_get_sid(conn) == sid)) {
 206                         spin_unlock_irqrestore(&connlock, flags);
 207                         return conn;
 208                 }
 209         }
 210         spin_unlock_irqrestore(&connlock, flags);
 211         return NULL;
 212 }
 213
 214 /*
 215  * The following functions can be used by LLDs that allocate
 216  * their own scsi_hosts or by software iscsi LLDs
 217  */
 218 static struct {
 219         int value;
 220         char *name;
 221 } iscsi_session_state_names[] = {
 222         { ISCSI_SESSION_LOGGED_IN,      "LOGGED_IN" },
 223         { ISCSI_SESSION_FAILED,         "FAILED" },
 224         { ISCSI_SESSION_FREE,           "FREE" },
 225 };
 226
 227 static const char *iscsi_session_state_name(int state)
 228 {
 229         int i;
 230         char *name = NULL;
 231
 232         for (i = 0; i < ARRAY_SIZE(iscsi_session_state_names); i++) {
 233                 if (iscsi_session_state_names[i].value == state) {
 234                         name = iscsi_session_state_names[i].name;
 235                         break;
 236                 }
 237         }
 238         return name;
 239 }
 240
 241 int iscsi_session_chkready(struct iscsi_cls_session *session)
 242 {
 243         unsigned long flags;
 244         int err;
 245
 246         spin_lock_irqsave(&session->lock, flags);
 247         switch (session->state) {
 248         case ISCSI_SESSION_LOGGED_IN:
 249                 err = 0;
 250                 break;
 251         case ISCSI_SESSION_FAILED:
 252                 err = DID_IMM_RETRY << 16;
 253                 break;
 254         case ISCSI_SESSION_FREE:
 255                 err = DID_NO_CONNECT << 16;
 256                 break;
 257         default:
 258                 err = DID_NO_CONNECT << 16;
 259                 break;
 260         }
 261         spin_unlock_irqrestore(&session->lock, flags);
 262         return err;
 263 }
 264 EXPORT_SYMBOL_GPL(iscsi_session_chkready);
 265
 266 static void iscsi_session_release(struct device *dev)
 267 {
 268         struct iscsi_cls_session *session = iscsi_dev_to_session(dev);
 269         struct Scsi_Host *shost;
 270
 271         shost = iscsi_session_to_shost(session);
 272         scsi_host_put(shost);
 273         kfree(session);
 274 }
 275
 276 static int iscsi_is_session_dev(const struct device *dev)
 277 {
 278         return dev->release == iscsi_session_release;
 279 }
 280
 281 static int iscsi_iter_session_fn(struct device *dev, void *data)
 282 {
 283         void (* fn) (struct iscsi_cls_session *) = data;
 284
 285         if (!iscsi_is_session_dev(dev))
 286                 return 0;
 287         fn(iscsi_dev_to_session(dev));
 288         return 0;
 289 }
 290
 291 void iscsi_host_for_each_session(struct Scsi_Host *shost,
 292                                  void (*fn)(struct iscsi_cls_session *))
 293 {
 294         device_for_each_child(&shost->shost_gendev, fn,
 295                               iscsi_iter_session_fn);
 296 }
 297 EXPORT_SYMBOL_GPL(iscsi_host_for_each_session);
 298
 299 /**
 300  * iscsi_scan_finished - helper to report when running scans are done
 301  * @shost: scsi host
 302  * @time: scan run time
 303  *
 304  * This function can be used by drives like qla4xxx to report to the scsi
 305  * layer when the scans it kicked off at module load time are done.
 306  */
 307 int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time)
 308 {
 309         struct iscsi_cls_host *ihost = shost->shost_data;
 310         /*
 311          * qla4xxx will have kicked off some session unblocks before calling
 312          * scsi_scan_host, so just wait for them to complete.
 313          */
 314         return !atomic_read(&ihost->nr_scans);
 315 }
 316 EXPORT_SYMBOL_GPL(iscsi_scan_finished);
 317
 318 struct iscsi_scan_data {
 319         unsigned int channel;
 320         unsigned int id;
 321         unsigned int lun;
 322 };
 323
 324 static int iscsi_user_scan_session(struct device *dev, void *data)
 325 {
 326         struct iscsi_scan_data *scan_data = data;
 327         struct iscsi_cls_session *session;
 328         struct Scsi_Host *shost;
 329         struct iscsi_cls_host *ihost;
 330         unsigned long flags;
 331         unsigned int id;
 332
 333         if (!iscsi_is_session_dev(dev))
 334                 return 0;
 335
 336         session = iscsi_dev_to_session(dev);
 337         shost = iscsi_session_to_shost(session);
 338         ihost = shost->shost_data;
 339
 340         mutex_lock(&ihost->mutex);
 341         spin_lock_irqsave(&session->lock, flags);
 342         if (session->state != ISCSI_SESSION_LOGGED_IN) {
 343                 spin_unlock_irqrestore(&session->lock, flags);
 344                 mutex_unlock(&ihost->mutex);
 345                 return 0;
 346         }
 347         id = session->target_id;
 348         spin_unlock_irqrestore(&session->lock, flags);
 349
 350         if (id != ISCSI_MAX_TARGET) {
 351                 if ((scan_data->channel == SCAN_WILD_CARD ||
 352                      scan_data->channel == 0) &&
 353                     (scan_data->id == SCAN_WILD_CARD ||
 354                      scan_data->id == id))
 355                         scsi_scan_target(&session->dev, 0, id,
 356                                          scan_data->lun, 1);
 357         }
 358         mutex_unlock(&ihost->mutex);
 359         return 0;
 360 }
 361
 362 static int iscsi_user_scan(struct Scsi_Host *shost, uint channel,
 363                            uint id, uint lun)
 364 {
 365         struct iscsi_scan_data scan_data;
 366
 367         scan_data.channel = channel;
 368         scan_data.id = id;
 369         scan_data.lun = lun;
 370
 371         return device_for_each_child(&shost->shost_gendev, &scan_data,
 372                                      iscsi_user_scan_session);
 373 }
 374
 375 static void iscsi_scan_session(struct work_struct *work)
 376 {
 377         struct iscsi_cls_session *session =
 378                         container_of(work, struct iscsi_cls_session, scan_work);
 379         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 380         struct iscsi_cls_host *ihost = shost->shost_data;
 381         struct iscsi_scan_data scan_data;
 382
 383         scan_data.channel = 0;
 384         scan_data.id = SCAN_WILD_CARD;
 385         scan_data.lun = SCAN_WILD_CARD;
 386
 387         iscsi_user_scan_session(&session->dev, &scan_data);
 388         atomic_dec(&ihost->nr_scans);
 389 }
 390
 391 static void session_recovery_timedout(struct work_struct *work)
 392 {
 393         struct iscsi_cls_session *session =
 394                 container_of(work, struct iscsi_cls_session,
 395                              recovery_work.work);
 396         unsigned long flags;
 397
 398         iscsi_cls_session_printk(KERN_INFO, session,
 399                                  "session recovery timed out after %d secs\n",
 400                                  session->recovery_tmo);
 401
 402         spin_lock_irqsave(&session->lock, flags);
 403         switch (session->state) {
 404         case ISCSI_SESSION_FAILED:
 405                 session->state = ISCSI_SESSION_FREE;
 406                 break;
 407         case ISCSI_SESSION_LOGGED_IN:
 408         case ISCSI_SESSION_FREE:
 409                 /* we raced with the unblock's flush */
 410                 spin_unlock_irqrestore(&session->lock, flags);
 411                 return;
 412         }
 413         spin_unlock_irqrestore(&session->lock, flags);
 414
 415         if (session->transport->session_recovery_timedout)
 416                 session->transport->session_recovery_timedout(session);
 417
 418         scsi_target_unblock(&session->dev);
 419 }
 420
 421 static void __iscsi_unblock_session(struct work_struct *work)
 422 {
 423         struct iscsi_cls_session *session =
 424                         container_of(work, struct iscsi_cls_session,
 425                                      unblock_work);
 426         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 427         struct iscsi_cls_host *ihost = shost->shost_data;
 428         unsigned long flags;
 429
 430         /*
 431          * The recovery and unblock work get run from the same workqueue,
 432          * so try to cancel it if it was going to run after this unblock.
 433          */
 434         cancel_delayed_work(&session->recovery_work);
 435         spin_lock_irqsave(&session->lock, flags);
 436         session->state = ISCSI_SESSION_LOGGED_IN;
 437         spin_unlock_irqrestore(&session->lock, flags);
 438         /* start IO */
 439         scsi_target_unblock(&session->dev);
 440         /*
 441          * Only do kernel scanning if the driver is properly hooked into
 442          * the async scanning code (drivers like iscsi_tcp do login and
 443          * scanning from userspace).
 444          */
 445         if (shost->hostt->scan_finished) {
 446                 if (queue_work(ihost->scan_workq, &session->scan_work))
 447                         atomic_inc(&ihost->nr_scans);
 448         }
 449 }
 450
 451 /**
 452  * iscsi_unblock_session - set a session as logged in and start IO.
 453  * @session: iscsi session
 454  *
 455  * Mark a session as ready to accept IO.
 456  */
 457 void iscsi_unblock_session(struct iscsi_cls_session *session)
 458 {
 459         queue_work(iscsi_eh_timer_workq, &session->unblock_work);
 460         /*
 461          * make sure all the events have completed before tell the driver
 462          * it is safe
 463          */
 464         flush_workqueue(iscsi_eh_timer_workq);
 465 }
 466 EXPORT_SYMBOL_GPL(iscsi_unblock_session);
 467
 468 static void __iscsi_block_session(struct work_struct *work)
 469 {
 470         struct iscsi_cls_session *session =
 471                         container_of(work, struct iscsi_cls_session,
 472                                      block_work);
 473         unsigned long flags;
 474
 475         spin_lock_irqsave(&session->lock, flags);
 476         session->state = ISCSI_SESSION_FAILED;
 477         spin_unlock_irqrestore(&session->lock, flags);
 478         scsi_target_block(&session->dev);
 479         queue_delayed_work(iscsi_eh_timer_workq, &session->recovery_work,
 480                            session->recovery_tmo * HZ);
 481 }
 482
 483 void iscsi_block_session(struct iscsi_cls_session *session)
 484 {
 485         queue_work(iscsi_eh_timer_workq, &session->block_work);
 486 }
 487 EXPORT_SYMBOL_GPL(iscsi_block_session);
 488
 489 static void __iscsi_unbind_session(struct work_struct *work)
 490 {
 491         struct iscsi_cls_session *session =
 492                         container_of(work, struct iscsi_cls_session,
 493                                      unbind_work);
 494         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 495         struct iscsi_cls_host *ihost = shost->shost_data;
 496         unsigned long flags;
 497
 498         /* Prevent new scans and make sure scanning is not in progress */
 499         mutex_lock(&ihost->mutex);
 500         spin_lock_irqsave(&session->lock, flags);
 501         if (session->target_id == ISCSI_MAX_TARGET) {
 502                 spin_unlock_irqrestore(&session->lock, flags);
 503                 mutex_unlock(&ihost->mutex);
 504                 return;
 505         }
 506         session->target_id = ISCSI_MAX_TARGET;
 507         spin_unlock_irqrestore(&session->lock, flags);
 508         mutex_unlock(&ihost->mutex);
 509
 510         scsi_remove_target(&session->dev);
 511         iscsi_session_event(session, ISCSI_KEVENT_UNBIND_SESSION);
 512 }
 513
 514 static int iscsi_unbind_session(struct iscsi_cls_session *session)
 515 {
 516         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 517         struct iscsi_cls_host *ihost = shost->shost_data;
 518
 519         return queue_work(ihost->scan_workq, &session->unbind_work);
 520 }
 521
 522 struct iscsi_cls_session *
 523 iscsi_alloc_session(struct Scsi_Host *shost, struct iscsi_transport *transport,
 524                     int dd_size)
 525 {
 526         struct iscsi_cls_session *session;
 527
 528         session = kzalloc(sizeof(*session) + dd_size,
 529                           GFP_KERNEL);
 530         if (!session)
 531                 return NULL;
 532
 533         session->transport = transport;
 534         session->recovery_tmo = 120;
 535         session->state = ISCSI_SESSION_FREE;
 536         INIT_DELAYED_WORK(&session->recovery_work, session_recovery_timedout);
 537         INIT_LIST_HEAD(&session->sess_list);
 538         INIT_WORK(&session->unblock_work, __iscsi_unblock_session);
 539         INIT_WORK(&session->block_work, __iscsi_block_session);
 540         INIT_WORK(&session->unbind_work, __iscsi_unbind_session);
 541         INIT_WORK(&session->scan_work, iscsi_scan_session);
 542         spin_lock_init(&session->lock);
 543
 544         /* this is released in the dev's release function */
 545         scsi_host_get(shost);
 546         session->dev.parent = &shost->shost_gendev;
 547         session->dev.release = iscsi_session_release;
 548         device_initialize(&session->dev);
 549         if (dd_size)
 550                 session->dd_data = &session[1];
 551         return session;
 552 }
 553 EXPORT_SYMBOL_GPL(iscsi_alloc_session);
 554
 555 static int iscsi_get_next_target_id(struct device *dev, void *data)
 556 {
 557         struct iscsi_cls_session *session;
 558         unsigned long flags;
 559         int err = 0;
 560
 561         if (!iscsi_is_session_dev(dev))
 562                 return 0;
 563
 564         session = iscsi_dev_to_session(dev);
 565         spin_lock_irqsave(&session->lock, flags);
 566         if (*((unsigned int *) data) == session->target_id)
 567                 err = -EEXIST;
 568         spin_unlock_irqrestore(&session->lock, flags);
 569         return err;
 570 }
 571
 572 int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id)
 573 {
 574         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 575         struct iscsi_cls_host *ihost;
 576         unsigned long flags;
 577         unsigned int id = target_id;
 578         int err;
 579
 580         ihost = shost->shost_data;
 581         session->sid = atomic_add_return(1, &iscsi_session_nr);
 582
 583         if (id == ISCSI_MAX_TARGET) {
 584                 for (id = 0; id < ISCSI_MAX_TARGET; id++) {
 585                         err = device_for_each_child(&shost->shost_gendev, &id,
 586                                                     iscsi_get_next_target_id);
 587                         if (!err)
 588                                 break;
 589                 }
 590
 591                 if (id == ISCSI_MAX_TARGET) {
 592                         iscsi_cls_session_printk(KERN_ERR, session,
 593                                                  "Too many iscsi targets. Max "
 594                                                  "number of targets is %d.\n",
 595                                                  ISCSI_MAX_TARGET - 1);
 596                         goto release_host;
 597                 }
 598         }
 599         session->target_id = id;
 600
 601         snprintf(session->dev.bus_id, BUS_ID_SIZE, "session%u",
 602                  session->sid);
 603         err = device_add(&session->dev);
 604         if (err) {
 605                 iscsi_cls_session_printk(KERN_ERR, session,
 606                                          "could not register session's dev\n");
 607                 goto release_host;
 608         }
 609         transport_register_device(&session->dev);
 610
 611         spin_lock_irqsave(&sesslock, flags);
 612         list_add(&session->sess_list, &sesslist);
 613         spin_unlock_irqrestore(&sesslock, flags);
 614
 615         iscsi_session_event(session, ISCSI_KEVENT_CREATE_SESSION);
 616         return 0;
 617
 618 release_host:
 619         scsi_host_put(shost);
 620         return err;
 621 }
 622 EXPORT_SYMBOL_GPL(iscsi_add_session);
 623
 624 /**
 625  * iscsi_create_session - create iscsi class session
 626  * @shost: scsi host
 627  * @transport: iscsi transport
 628  * @dd_size: private driver data size
 629  * @target_id: which target
 630  *
 631  * This can be called from a LLD or iscsi_transport.
 632  */
 633 struct iscsi_cls_session *
 634 iscsi_create_session(struct Scsi_Host *shost, struct iscsi_transport *transport,
 635                      int dd_size, unsigned int target_id)
 636 {
 637         struct iscsi_cls_session *session;
 638
 639         session = iscsi_alloc_session(shost, transport, dd_size);
 640         if (!session)
 641                 return NULL;
 642
 643         if (iscsi_add_session(session, target_id)) {
 644                 iscsi_free_session(session);
 645                 return NULL;
 646         }
 647         return session;
 648 }
 649 EXPORT_SYMBOL_GPL(iscsi_create_session);
 650
 651 static void iscsi_conn_release(struct device *dev)
 652 {
 653         struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev);
 654         struct device *parent = conn->dev.parent;
 655
 656         kfree(conn);
 657         put_device(parent);
 658 }
 659
 660 static int iscsi_is_conn_dev(const struct device *dev)
 661 {
 662         return dev->release == iscsi_conn_release;
 663 }
 664
 665 static int iscsi_iter_destroy_conn_fn(struct device *dev, void *data)
 666 {
 667         if (!iscsi_is_conn_dev(dev))
 668                 return 0;
 669         return iscsi_destroy_conn(iscsi_dev_to_conn(dev));
 670 }
 671
 672 void iscsi_remove_session(struct iscsi_cls_session *session)
 673 {
 674         struct Scsi_Host *shost = iscsi_session_to_shost(session);
 675         struct iscsi_cls_host *ihost = shost->shost_data;
 676         unsigned long flags;
 677         int err;
 678
 679         spin_lock_irqsave(&sesslock, flags);
 680         list_del(&session->sess_list);
 681         spin_unlock_irqrestore(&sesslock, flags);
 682
 683         /* make sure there are no blocks/unblocks queued */
 684         flush_workqueue(iscsi_eh_timer_workq);
 685         /* make sure the timedout callout is not running */
 686         if (!cancel_delayed_work(&session->recovery_work))
 687                 flush_workqueue(iscsi_eh_timer_workq);
 688         /*
 689          * If we are blocked let commands flow again. The lld or iscsi
 690          * layer should set up the queuecommand to fail commands.
 691          * We assume that LLD will not be calling block/unblock while
 692          * removing the session.
 693          */
 694         spin_lock_irqsave(&session->lock, flags);
 695         session->state = ISCSI_SESSION_FREE;
 696         spin_unlock_irqrestore(&session->lock, flags);
 697
 698         scsi_target_unblock(&session->dev);
 699         /* flush running scans then delete devices */
 700         flush_workqueue(ihost->scan_workq);
 701         __iscsi_unbind_session(&session->unbind_work);
 702
 703         /* hw iscsi may not have removed all connections from session */
 704         err = device_for_each_child(&session->dev, NULL,
 705                                     iscsi_iter_destroy_conn_fn);
 706         if (err)
 707                 iscsi_cls_session_printk(KERN_ERR, session,
 708                                          "Could not delete all connections "
 709                                          "for session. Error %d.\n", err);
 710
 711         transport_unregister_device(&session->dev);
 712         device_del(&session->dev);
 713 }
 714 EXPORT_SYMBOL_GPL(iscsi_remove_session);
 715
 716 void iscsi_free_session(struct iscsi_cls_session *session)
 717 {
 718         iscsi_session_event(session, ISCSI_KEVENT_DESTROY_SESSION);
 719         put_device(&session->dev);
 720 }
 721 EXPORT_SYMBOL_GPL(iscsi_free_session);
 722
 723 /**
 724  * iscsi_destroy_session - destroy iscsi session
 725  * @session: iscsi_session
 726  *
 727  * Can be called by a LLD or iscsi_transport. There must not be
 728  * any running connections.
 729  */
 730 int iscsi_destroy_session(struct iscsi_cls_session *session)
 731 {
 732         iscsi_remove_session(session);
 733         iscsi_free_session(session);
 734         return 0;
 735 }
 736 EXPORT_SYMBOL_GPL(iscsi_destroy_session);
 737
 738 /**
 739  * iscsi_create_conn - create iscsi class connection
 740  * @session: iscsi cls session
 741  * @dd_size: private driver data size
 742  * @cid: connection id
 743  *
 744  * This can be called from a LLD or iscsi_transport. The connection
 745  * is child of the session so cid must be unique for all connections
 746  * on the session.
 747  *
 748  * Since we do not support MCS, cid will normally be zero. In some cases
 749  * for software iscsi we could be trying to preallocate a connection struct
 750  * in which case there could be two connection structs and cid would be
 751  * non-zero.
 752  */
 753 struct iscsi_cls_conn *
 754 iscsi_create_conn(struct iscsi_cls_session *session, int dd_size, uint32_t cid)
 755 {
 756         struct iscsi_transport *transport = session->transport;
 757         struct iscsi_cls_conn *conn;
 758         unsigned long flags;
 759         int err;
 760
 761         conn = kzalloc(sizeof(*conn) + dd_size, GFP_KERNEL);
 762         if (!conn)
 763                 return NULL;
 764         if (dd_size)
 765                 conn->dd_data = &conn[1];
 766
 767         INIT_LIST_HEAD(&conn->conn_list);
 768         conn->transport = transport;
 769         conn->cid = cid;
 770
 771         /* this is released in the dev's release function */
 772         if (!get_device(&session->dev))
 773                 goto free_conn;
 774
 775         snprintf(conn->dev.bus_id, BUS_ID_SIZE, "connection%d:%u",
 776                  session->sid, cid);
 777         conn->dev.parent = &session->dev;
 778         conn->dev.release = iscsi_conn_release;
 779         err = device_register(&conn->dev);
 780         if (err) {
 781                 iscsi_cls_session_printk(KERN_ERR, session, "could not "
 782                                          "register connection's dev\n");
 783                 goto release_parent_ref;
 784         }
 785         transport_register_device(&conn->dev);
 786
 787         spin_lock_irqsave(&connlock, flags);
 788         list_add(&conn->conn_list, &connlist);
 789         conn->active = 1;
 790         spin_unlock_irqrestore(&connlock, flags);
 791         return conn;
 792
 793 release_parent_ref:
 794         put_device(&session->dev);
 795 free_conn:
 796         kfree(conn);
 797         return NULL;
 798 }
 799
 800 EXPORT_SYMBOL_GPL(iscsi_create_conn);
 801
 802 /**
 803  * iscsi_destroy_conn - destroy iscsi class connection
 804  * @conn: iscsi cls session
 805  *
 806  * This can be called from a LLD or iscsi_transport.
 807  */
 808 int iscsi_destroy_conn(struct iscsi_cls_conn *conn)
 809 {
 810         unsigned long flags;
 811
 812         spin_lock_irqsave(&connlock, flags);
 813         conn->active = 0;
 814         list_del(&conn->conn_list);
 815         spin_unlock_irqrestore(&connlock, flags);
 816
 817         transport_unregister_device(&conn->dev);
 818         device_unregister(&conn->dev);
 819         return 0;
 820 }
 821 EXPORT_SYMBOL_GPL(iscsi_destroy_conn);
 822
 823 /*
 824  * iscsi interface functions
 825  */
 826 static struct iscsi_internal *
 827 iscsi_if_transport_lookup(struct iscsi_transport *tt)
 828 {
 829         struct iscsi_internal *priv;
 830         unsigned long flags;
 831
 832         spin_lock_irqsave(&iscsi_transport_lock, flags);
 833         list_for_each_entry(priv, &iscsi_transports, list) {
 834                 if (tt == priv->iscsi_transport) {
 835                         spin_unlock_irqrestore(&iscsi_transport_lock, flags);
 836                         return priv;
 837                 }
 838         }
 839         spin_unlock_irqrestore(&iscsi_transport_lock, flags);
 840         return NULL;
 841 }
 842
 843 static int
 844 iscsi_broadcast_skb(struct sk_buff *skb, gfp_t gfp)
 845 {
 846         int rc;
 847
 848         rc = netlink_broadcast(nls, skb, 0, 1, gfp);
 849         if (rc < 0) {
 850                 printk(KERN_ERR "iscsi: can not broadcast skb (%d)\n", rc);
 851                 return rc;
 852         }
 853
 854         return 0;
 855 }
 856
 857 static int
 858 iscsi_unicast_skb(struct sk_buff *skb, int pid)
 859 {
 860         int rc;
 861
 862         rc = netlink_unicast(nls, skb, pid, MSG_DONTWAIT);
 863         if (rc < 0) {
 864                 printk(KERN_ERR "iscsi: can not unicast skb (%d)\n", rc);
 865                 return rc;
 866         }
 867
 868         return 0;
 869 }
 870
 871 int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 872                    char *data, uint32_t data_size)
 873 {
 874         struct nlmsghdr *nlh;
 875         struct sk_buff *skb;
 876         struct iscsi_uevent *ev;
 877         char *pdu;
 878         struct iscsi_internal *priv;
 879         int len = NLMSG_SPACE(sizeof(*ev) + sizeof(struct iscsi_hdr) +
 880                               data_size);
 881
 882         priv = iscsi_if_transport_lookup(conn->transport);
 883         if (!priv)
 884                 return -EINVAL;
 885
 886         skb = alloc_skb(len, GFP_ATOMIC);
 887         if (!skb) {
 888                 iscsi_conn_error(conn, ISCSI_ERR_CONN_FAILED);
 889                 iscsi_cls_conn_printk(KERN_ERR, conn, "can not deliver "
 890                                       "control PDU: OOM\n");
 891                 return -ENOMEM;
 892         }
 893
 894         nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
 895         ev = NLMSG_DATA(nlh);
 896         memset(ev, 0, sizeof(*ev));
 897         ev->transport_handle = iscsi_handle(conn->transport);
 898         ev->type = ISCSI_KEVENT_RECV_PDU;
 899         ev->r.recv_req.cid = conn->cid;
 900         ev->r.recv_req.sid = iscsi_conn_get_sid(conn);
 901         pdu = (char*)ev + sizeof(*ev);
 902         memcpy(pdu, hdr, sizeof(struct iscsi_hdr));
 903         memcpy(pdu + sizeof(struct iscsi_hdr), data, data_size);
 904
 905         return iscsi_unicast_skb(skb, priv->daemon_pid);
 906 }
 907 EXPORT_SYMBOL_GPL(iscsi_recv_pdu);
 908
 909 void iscsi_conn_error(struct iscsi_cls_conn *conn, enum iscsi_err error)
 910 {
 911         struct nlmsghdr *nlh;
 912         struct sk_buff  *skb;
 913         struct iscsi_uevent *ev;
 914         struct iscsi_internal *priv;
 915         int len = NLMSG_SPACE(sizeof(*ev));
 916
 917         priv = iscsi_if_transport_lookup(conn->transport);
 918         if (!priv)
 919                 return;
 920
 921         skb = alloc_skb(len, GFP_ATOMIC);
 922         if (!skb) {
 923                 iscsi_cls_conn_printk(KERN_ERR, conn, "gracefully ignored "
 924                                       "conn error (%d)\n", error);
 925                 return;
 926         }
 927
 928         nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
 929         ev = NLMSG_DATA(nlh);
 930         ev->transport_handle = iscsi_handle(conn->transport);
 931         ev->type = ISCSI_KEVENT_CONN_ERROR;
 932         ev->r.connerror.error = error;
 933         ev->r.connerror.cid = conn->cid;
 934         ev->r.connerror.sid = iscsi_conn_get_sid(conn);
 935
 936         iscsi_broadcast_skb(skb, GFP_ATOMIC);
 937
 938         iscsi_cls_conn_printk(KERN_INFO, conn, "detected conn error (%d)\n",
 939                               error);
 940 }
 941 EXPORT_SYMBOL_GPL(iscsi_conn_error);
 942
 943 static int
 944 iscsi_if_send_reply(int pid, int seq, int type, int done, int multi,
 945                       void *payload, int size)
 946 {
 947         struct sk_buff  *skb;
 948         struct nlmsghdr *nlh;
 949         int len = NLMSG_SPACE(size);
 950         int flags = multi ? NLM_F_MULTI : 0;
 951         int t = done ? NLMSG_DONE : type;
 952
 953         skb = alloc_skb(len, GFP_ATOMIC);
 954         if (!skb) {
 955                 printk(KERN_ERR "Could not allocate skb to send reply.\n");
 956                 return -ENOMEM;
 957         }
 958
 959         nlh = __nlmsg_put(skb, pid, seq, t, (len - sizeof(*nlh)), 0);
 960         nlh->nlmsg_flags = flags;
 961         memcpy(NLMSG_DATA(nlh), payload, size);
 962         return iscsi_unicast_skb(skb, pid);
 963 }
 964
 965 static int
 966 iscsi_if_get_stats(struct iscsi_transport *transport, struct nlmsghdr *nlh)
 967 {
 968         struct iscsi_uevent *ev = NLMSG_DATA(nlh);
 969         struct iscsi_stats *stats;
 970         struct sk_buff *skbstat;
 971         struct iscsi_cls_conn *conn;
 972         struct nlmsghdr *nlhstat;
 973         struct iscsi_uevent *evstat;
 974         struct iscsi_internal *priv;
 975         int len = NLMSG_SPACE(sizeof(*ev) +
 976                               sizeof(struct iscsi_stats) +
 977                               sizeof(struct iscsi_stats_custom) *
 978                               ISCSI_STATS_CUSTOM_MAX);
 979         int err = 0;
 980
 981         priv = iscsi_if_transport_lookup(transport);
 982         if (!priv)
 983                 return -EINVAL;
 984
 985         conn = iscsi_conn_lookup(ev->u.get_stats.sid, ev->u.get_stats.cid);
 986         if (!conn)
 987                 return -EEXIST;
 988
 989         do {
 990                 int actual_size;
 991
 992                 skbstat = alloc_skb(len, GFP_ATOMIC);
 993                 if (!skbstat) {
 994                         iscsi_cls_conn_printk(KERN_ERR, conn, "can not "
 995                                               "deliver stats: OOM\n");
 996                         return -ENOMEM;
 997                 }
 998
 999                 nlhstat = __nlmsg_put(skbstat, priv->daemon_pid, 0, 0,
1000                                       (len - sizeof(*nlhstat)), 0);
1001                 evstat = NLMSG_DATA(nlhstat);
1002                 memset(evstat, 0, sizeof(*evstat));
1003                 evstat->transport_handle = iscsi_handle(conn->transport);
1004                 evstat->type = nlh->nlmsg_type;
1005                 evstat->u.get_stats.cid =
1006                         ev->u.get_stats.cid;
1007                 evstat->u.get_stats.sid =
1008                         ev->u.get_stats.sid;
1009                 stats = (struct iscsi_stats *)
1010                         ((char*)evstat + sizeof(*evstat));
1011                 memset(stats, 0, sizeof(*stats));
1012
1013                 transport->get_stats(conn, stats);
1014                 actual_size = NLMSG_SPACE(sizeof(struct iscsi_uevent) +
1015                                           sizeof(struct iscsi_stats) +
1016                                           sizeof(struct iscsi_stats_custom) *
1017                                           stats->custom_length);
1018                 actual_size -= sizeof(*nlhstat);
1019                 actual_size = NLMSG_LENGTH(actual_size);
1020                 skb_trim(skbstat, NLMSG_ALIGN(actual_size));
1021                 nlhstat->nlmsg_len = actual_size;
1022
1023                 err = iscsi_unicast_skb(skbstat, priv->daemon_pid);
1024         } while (err < 0 && err != -ECONNREFUSED);
1025
1026         return err;
1027 }
1028
1029 /**
1030  * iscsi_session_event - send session destr. completion event
1031  * @session: iscsi class session
1032  * @event: type of event
1033  */
1034 int iscsi_session_event(struct iscsi_cls_session *session,
1035                         enum iscsi_uevent_e event)
1036 {
1037         struct iscsi_internal *priv;
1038         struct Scsi_Host *shost;
1039         struct iscsi_uevent *ev;
1040         struct sk_buff  *skb;
1041         struct nlmsghdr *nlh;
1042         int rc, len = NLMSG_SPACE(sizeof(*ev));
1043
1044         priv = iscsi_if_transport_lookup(session->transport);
1045         if (!priv)
1046                 return -EINVAL;
1047         shost = iscsi_session_to_shost(session);
1048
1049         skb = alloc_skb(len, GFP_KERNEL);
1050         if (!skb) {
1051                 iscsi_cls_session_printk(KERN_ERR, session,
1052                                          "Cannot notify userspace of session "
1053                                          "event %u\n", event);
1054                 return -ENOMEM;
1055         }
1056
1057         nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
1058         ev = NLMSG_DATA(nlh);
1059         ev->transport_handle = iscsi_handle(session->transport);
1060
1061         ev->type = event;
1062         switch (event) {
1063         case ISCSI_KEVENT_DESTROY_SESSION:
1064                 ev->r.d_session.host_no = shost->host_no;
1065                 ev->r.d_session.sid = session->sid;
1066                 break;
1067         case ISCSI_KEVENT_CREATE_SESSION:
1068                 ev->r.c_session_ret.host_no = shost->host_no;
1069                 ev->r.c_session_ret.sid = session->sid;
1070                 break;
1071         case ISCSI_KEVENT_UNBIND_SESSION:
1072                 ev->r.unbind_session.host_no = shost->host_no;
1073                 ev->r.unbind_session.sid = session->sid;
1074                 break;
1075         default:
1076                 iscsi_cls_session_printk(KERN_ERR, session, "Invalid event "
1077                                          "%u.\n", event);
1078                 kfree_skb(skb);
1079                 return -EINVAL;
1080         }
1081
1082         /*
1083          * this will occur if the daemon is not up, so we just warn
1084          * the user and when the daemon is restarted it will handle it
1085          */
1086         rc = iscsi_broadcast_skb(skb, GFP_KERNEL);
1087         if (rc < 0)
1088                 iscsi_cls_session_printk(KERN_ERR, session,
1089                                          "Cannot notify userspace of session "
1090                                          "event %u. Check iscsi daemon\n",
1091                                          event);
1092         return rc;
1093 }
1094 EXPORT_SYMBOL_GPL(iscsi_session_event);
1095
1096 static int
1097 iscsi_if_create_session(struct iscsi_internal *priv, struct iscsi_uevent *ev,
1098                         uint32_t host_no, uint32_t initial_cmdsn,
1099                         uint16_t cmds_max, uint16_t queue_depth)
1100 {
1101         struct iscsi_transport *transport = priv->iscsi_transport;
1102         struct iscsi_cls_session *session;
1103         struct Scsi_Host *shost = NULL;
1104
1105         /*
1106          * Software iscsi allocates a host per session, but
1107          * offload drivers (and possibly iser one day) allocate a host per
1108          * hba/nic/rnic. Offload will match a host here, but software will
1109          * return a new hostno after the create_session callback has returned.
1110          */
1111         if (host_no != UINT_MAX) {
1112                 shost = scsi_host_lookup(host_no);
1113                 if (IS_ERR(shost)) {
1114                         printk(KERN_ERR "Could not find host no %u to "
1115                                "create session\n", host_no);
1116                         return -ENODEV;
1117                 }
1118         }
1119
1120         session = transport->create_session(shost, cmds_max, queue_depth,
1121                                             initial_cmdsn, &host_no);
1122         if (shost)
1123                 scsi_host_put(shost);
1124         if (!session)
1125                 return -ENOMEM;
1126
1127         ev->r.c_session_ret.host_no = host_no;
1128         ev->r.c_session_ret.sid = session->sid;
1129         return 0;
1130 }
1131
1132 static int
1133 iscsi_if_create_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1134 {
1135         struct iscsi_cls_conn *conn;
1136         struct iscsi_cls_session *session;
1137
1138         session = iscsi_session_lookup(ev->u.c_conn.sid);
1139         if (!session) {
1140                 printk(KERN_ERR "iscsi: invalid session %d.\n",
1141                        ev->u.c_conn.sid);
1142                 return -EINVAL;
1143         }
1144
1145         conn = transport->create_conn(session, ev->u.c_conn.cid);
1146         if (!conn) {
1147                 iscsi_cls_session_printk(KERN_ERR, session,
1148                                          "couldn't create a new connection.");
1149                 return -ENOMEM;
1150         }
1151
1152         ev->r.c_conn_ret.sid = session->sid;
1153         ev->r.c_conn_ret.cid = conn->cid;
1154         return 0;
1155 }
1156
1157 static int
1158 iscsi_if_destroy_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1159 {
1160         struct iscsi_cls_conn *conn;
1161
1162         conn = iscsi_conn_lookup(ev->u.d_conn.sid, ev->u.d_conn.cid);
1163         if (!conn)
1164                 return -EINVAL;
1165
1166         if (transport->destroy_conn)
1167                 transport->destroy_conn(conn);
1168         return 0;
1169 }
1170
1171 static int
1172 iscsi_set_param(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1173 {
1174         char *data = (char*)ev + sizeof(*ev);
1175         struct iscsi_cls_conn *conn;
1176         struct iscsi_cls_session *session;
1177         int err = 0, value = 0;
1178
1179         session = iscsi_session_lookup(ev->u.set_param.sid);
1180         conn = iscsi_conn_lookup(ev->u.set_param.sid, ev->u.set_param.cid);
1181         if (!conn || !session)
1182                 return -EINVAL;
1183
1184         switch (ev->u.set_param.param) {
1185         case ISCSI_PARAM_SESS_RECOVERY_TMO:
1186                 sscanf(data, "%d", &value);
1187                 if (value != 0)
1188                         session->recovery_tmo = value;
1189                 break;
1190         default:
1191                 err = transport->set_param(conn, ev->u.set_param.param,
1192                                            data, ev->u.set_param.len);
1193         }
1194
1195         return err;
1196 }
1197
1198 static int
1199 iscsi_if_transport_ep(struct iscsi_transport *transport,
1200                       struct iscsi_uevent *ev, int msg_type)
1201 {
1202         struct sockaddr *dst_addr;
1203         int rc = 0;
1204
1205         switch (msg_type) {
1206         case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
1207                 if (!transport->ep_connect)
1208                         return -EINVAL;
1209
1210                 dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
1211                 rc = transport->ep_connect(dst_addr,
1212                                            ev->u.ep_connect.non_blocking,
1213                                            &ev->r.ep_connect_ret.handle);
1214                 break;
1215         case ISCSI_UEVENT_TRANSPORT_EP_POLL:
1216                 if (!transport->ep_poll)
1217                         return -EINVAL;
1218
1219                 ev->r.retcode = transport->ep_poll(ev->u.ep_poll.ep_handle,
1220                                                    ev->u.ep_poll.timeout_ms);
1221                 break;
1222         case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
1223                 if (!transport->ep_disconnect)
1224                         return -EINVAL;
1225
1226                 transport->ep_disconnect(ev->u.ep_disconnect.ep_handle);
1227                 break;
1228         }
1229         return rc;
1230 }
1231
1232 static int
1233 iscsi_tgt_dscvr(struct iscsi_transport *transport,
1234                 struct iscsi_uevent *ev)
1235 {
1236         struct Scsi_Host *shost;
1237         struct sockaddr *dst_addr;
1238         int err;
1239
1240         if (!transport->tgt_dscvr)
1241                 return -EINVAL;
1242
1243         shost = scsi_host_lookup(ev->u.tgt_dscvr.host_no);
1244         if (IS_ERR(shost)) {
1245                 printk(KERN_ERR "target discovery could not find host no %u\n",
1246                        ev->u.tgt_dscvr.host_no);
1247                 return -ENODEV;
1248         }
1249
1250
1251         dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
1252         err = transport->tgt_dscvr(shost, ev->u.tgt_dscvr.type,
1253                                    ev->u.tgt_dscvr.enable, dst_addr);
1254         scsi_host_put(shost);
1255         return err;
1256 }
1257
1258 static int
1259 iscsi_set_host_param(struct iscsi_transport *transport,
1260                      struct iscsi_uevent *ev)
1261 {
1262         char *data = (char*)ev + sizeof(*ev);
1263         struct Scsi_Host *shost;
1264         int err;
1265
1266         if (!transport->set_host_param)
1267                 return -ENOSYS;
1268
1269         shost = scsi_host_lookup(ev->u.set_host_param.host_no);
1270         if (IS_ERR(shost)) {
1271                 printk(KERN_ERR "set_host_param could not find host no %u\n",
1272                        ev->u.set_host_param.host_no);
1273                 return -ENODEV;
1274         }
1275
1276         err = transport->set_host_param(shost, ev->u.set_host_param.param,
1277                                         data, ev->u.set_host_param.len);
1278         scsi_host_put(shost);
1279         return err;
1280 }
1281
1282 static int
1283 iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
1284 {
1285         int err = 0;
1286         uint32_t host_no = UINT_MAX;
1287         struct iscsi_uevent *ev = NLMSG_DATA(nlh);
1288         struct iscsi_transport *transport = NULL;
1289         struct iscsi_internal *priv;
1290         struct iscsi_cls_session *session;
1291         struct iscsi_cls_conn *conn;
1292
1293         priv = iscsi_if_transport_lookup(iscsi_ptr(ev->transport_handle));
1294         if (!priv)
1295                 return -EINVAL;
1296         transport = priv->iscsi_transport;
1297
1298         if (!try_module_get(transport->owner))
1299                 return -EINVAL;
1300
1301         priv->daemon_pid = NETLINK_CREDS(skb)->pid;
1302
1303         switch (nlh->nlmsg_type) {
1304         case ISCSI_UEVENT_CREATE_SESSION:
1305                 err = iscsi_if_create_session(priv, ev, host_no,
1306                                               ev->u.c_session.initial_cmdsn,
1307                                               ev->u.c_session.cmds_max,
1308                                               ev->u.c_session.queue_depth);
1309                 break;
1310         case ISCSI_UEVENT_CREATE_BOUND_SESSION:
1311                 err = iscsi_if_create_session(priv, ev,
1312                                         ev->u.c_bound_session.host_no,
1313                                         ev->u.c_bound_session.initial_cmdsn,
1314                                         ev->u.c_bound_session.cmds_max,
1315                                         ev->u.c_bound_session.queue_depth);
1316                 break;
1317         case ISCSI_UEVENT_DESTROY_SESSION:
1318                 session = iscsi_session_lookup(ev->u.d_session.sid);
1319                 if (session)
1320                         transport->destroy_session(session);
1321                 else
1322                         err = -EINVAL;
1323                 break;
1324         case ISCSI_UEVENT_UNBIND_SESSION:
1325                 session = iscsi_session_lookup(ev->u.d_session.sid);
1326                 if (session)
1327                         iscsi_unbind_session(session);
1328                 else
1329                         err = -EINVAL;
1330                 break;
1331         case ISCSI_UEVENT_CREATE_CONN:
1332                 err = iscsi_if_create_conn(transport, ev);
1333                 break;
1334         case ISCSI_UEVENT_DESTROY_CONN:
1335                 err = iscsi_if_destroy_conn(transport, ev);
1336                 break;
1337         case ISCSI_UEVENT_BIND_CONN:
1338                 session = iscsi_session_lookup(ev->u.b_conn.sid);
1339                 conn = iscsi_conn_lookup(ev->u.b_conn.sid, ev->u.b_conn.cid);
1340
1341                 if (session && conn)
1342                         ev->r.retcode = transport->bind_conn(session, conn,
1343                                         ev->u.b_conn.transport_eph,
1344                                         ev->u.b_conn.is_leading);
1345                 else
1346                         err = -EINVAL;
1347                 break;
1348         case ISCSI_UEVENT_SET_PARAM:
1349                 err = iscsi_set_param(transport, ev);
1350                 break;
1351         case ISCSI_UEVENT_START_CONN:
1352                 conn = iscsi_conn_lookup(ev->u.start_conn.sid, ev->u.start_conn.cid);
1353                 if (conn)
1354                         ev->r.retcode = transport->start_conn(conn);
1355                 else
1356                         err = -EINVAL;
1357                 break;
1358         case ISCSI_UEVENT_STOP_CONN:
1359                 conn = iscsi_conn_lookup(ev->u.stop_conn.sid, ev->u.stop_conn.cid);
1360                 if (conn)
1361                         transport->stop_conn(conn, ev->u.stop_conn.flag);
1362                 else
1363                         err = -EINVAL;
1364                 break;
1365         case ISCSI_UEVENT_SEND_PDU:
1366                 conn = iscsi_conn_lookup(ev->u.send_pdu.sid, ev->u.send_pdu.cid);
1367                 if (conn)
1368                         ev->r.retcode = transport->send_pdu(conn,
1369                                 (struct iscsi_hdr*)((char*)ev + sizeof(*ev)),
1370                                 (char*)ev + sizeof(*ev) + ev->u.send_pdu.hdr_size,
1371                                 ev->u.send_pdu.data_size);
1372                 else
1373                         err = -EINVAL;
1374                 break;
1375         case ISCSI_UEVENT_GET_STATS:
1376                 err = iscsi_if_get_stats(transport, nlh);
1377                 break;
1378         case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
1379         case ISCSI_UEVENT_TRANSPORT_EP_POLL:
1380         case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
1381                 err = iscsi_if_transport_ep(transport, ev, nlh->nlmsg_type);
1382                 break;
1383         case ISCSI_UEVENT_TGT_DSCVR:
1384                 err = iscsi_tgt_dscvr(transport, ev);
1385                 break;
1386         case ISCSI_UEVENT_SET_HOST_PARAM:
1387                 err = iscsi_set_host_param(transport, ev);
1388                 break;
1389         default:
1390                 err = -ENOSYS;
1391                 break;
1392         }
1393
1394         module_put(transport->owner);
1395         return err;
1396 }
1397
1398 /*
1399  * Get message from skb.  Each message is processed by iscsi_if_recv_msg.
1400  * Malformed skbs with wrong lengths or invalid creds are not processed.
1401  */
1402 static void
1403 iscsi_if_rx(struct sk_buff *skb)
1404 {
1405         mutex_lock(&rx_queue_mutex);
1406         while (skb->len >= NLMSG_SPACE(0)) {
1407                 int err;
1408                 uint32_t rlen;
1409                 struct nlmsghdr *nlh;
1410                 struct iscsi_uevent *ev;
1411
1412                 nlh = nlmsg_hdr(skb);
1413                 if (nlh->nlmsg_len < sizeof(*nlh) ||
1414                     skb->len < nlh->nlmsg_len) {
1415                         break;
1416                 }
1417
1418                 ev = NLMSG_DATA(nlh);
1419                 rlen = NLMSG_ALIGN(nlh->nlmsg_len);
1420                 if (rlen > skb->len)
1421                         rlen = skb->len;
1422
1423                 err = iscsi_if_recv_msg(skb, nlh);
1424                 if (err) {
1425                         ev->type = ISCSI_KEVENT_IF_ERROR;
1426                         ev->iferror = err;
1427                 }
1428                 do {
1429                         /*
1430                          * special case for GET_STATS:
1431                          * on success - sending reply and stats from
1432                          * inside of if_recv_msg(),
1433                          * on error - fall through.
1434                          */
1435                         if (ev->type == ISCSI_UEVENT_GET_STATS && !err)
1436                                 break;
1437                         err = iscsi_if_send_reply(
1438                                 NETLINK_CREDS(skb)->pid, nlh->nlmsg_seq,
1439                                 nlh->nlmsg_type, 0, 0, ev, sizeof(*ev));
1440                 } while (err < 0 && err != -ECONNREFUSED);
1441                 skb_pull(skb, rlen);
1442         }
1443         mutex_unlock(&rx_queue_mutex);
1444 }
1445
1446 #define ISCSI_CLASS_ATTR(_prefix,_name,_mode,_show,_store)              \
1447 struct device_attribute dev_attr_##_prefix##_##_name =  \
1448         __ATTR(_name,_mode,_show,_store)
1449
1450 /*
1451  * iSCSI connection attrs
1452  */
1453 #define iscsi_conn_attr_show(param)                                     \
1454 static ssize_t                                                          \
1455 show_conn_param_##param(struct device *dev,                             \
1456                         struct device_attribute *attr, char *buf)       \
1457 {                                                                       \
1458         struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev->parent);   \
1459         struct iscsi_transport *t = conn->transport;                    \
1460         return t->get_conn_param(conn, param, buf);                     \
1461 }
1462
1463 #define iscsi_conn_attr(field, param)                                   \
1464         iscsi_conn_attr_show(param)                                     \
1465 static ISCSI_CLASS_ATTR(conn, field, S_IRUGO, show_conn_param_##param,  \
1466                         NULL);
1467
1468 iscsi_conn_attr(max_recv_dlength, ISCSI_PARAM_MAX_RECV_DLENGTH);
1469 iscsi_conn_attr(max_xmit_dlength, ISCSI_PARAM_MAX_XMIT_DLENGTH);
1470 iscsi_conn_attr(header_digest, ISCSI_PARAM_HDRDGST_EN);
1471 iscsi_conn_attr(data_digest, ISCSI_PARAM_DATADGST_EN);
1472 iscsi_conn_attr(ifmarker, ISCSI_PARAM_IFMARKER_EN);
1473 iscsi_conn_attr(ofmarker, ISCSI_PARAM_OFMARKER_EN);
1474 iscsi_conn_attr(persistent_port, ISCSI_PARAM_PERSISTENT_PORT);
1475 iscsi_conn_attr(port, ISCSI_PARAM_CONN_PORT);
1476 iscsi_conn_attr(exp_statsn, ISCSI_PARAM_EXP_STATSN);
1477 iscsi_conn_attr(persistent_address, ISCSI_PARAM_PERSISTENT_ADDRESS);
1478 iscsi_conn_attr(address, ISCSI_PARAM_CONN_ADDRESS);
1479 iscsi_conn_attr(ping_tmo, ISCSI_PARAM_PING_TMO);
1480 iscsi_conn_attr(recv_tmo, ISCSI_PARAM_RECV_TMO);
1481
1482 /*
1483  * iSCSI session attrs
1484  */
1485 #define iscsi_session_attr_show(param, perm)                            \
1486 static ssize_t                                                          \
1487 show_session_param_##param(struct device *dev,                          \
1488                            struct device_attribute *attr, char *buf)    \
1489 {                                                                       \
1490         struct iscsi_cls_session *session =                             \
1491                 iscsi_dev_to_session(dev->parent);                      \
1492         struct iscsi_transport *t = session->transport;                 \
1493                                                                         \
1494         if (perm && !capable(CAP_SYS_ADMIN))                            \
1495                 return -EACCES;                                         \
1496         return t->get_session_param(session, param, buf);               \
1497 }
1498
1499 #define iscsi_session_attr(field, param, perm)                          \
1500         iscsi_session_attr_show(param, perm)                            \
1501 static ISCSI_CLASS_ATTR(sess, field, S_IRUGO, show_session_param_##param, \
1502                         NULL);
1503
1504 iscsi_session_attr(targetname, ISCSI_PARAM_TARGET_NAME, 0);
1505 iscsi_session_attr(initial_r2t, ISCSI_PARAM_INITIAL_R2T_EN, 0);
1506 iscsi_session_attr(max_outstanding_r2t, ISCSI_PARAM_MAX_R2T, 0);
1507 iscsi_session_attr(immediate_data, ISCSI_PARAM_IMM_DATA_EN, 0);
1508 iscsi_session_attr(first_burst_len, ISCSI_PARAM_FIRST_BURST, 0);
1509 iscsi_session_attr(max_burst_len, ISCSI_PARAM_MAX_BURST, 0);
1510 iscsi_session_attr(data_pdu_in_order, ISCSI_PARAM_PDU_INORDER_EN, 0);
1511 iscsi_session_attr(data_seq_in_order, ISCSI_PARAM_DATASEQ_INORDER_EN, 0);
1512 iscsi_session_attr(erl, ISCSI_PARAM_ERL, 0);
1513 iscsi_session_attr(tpgt, ISCSI_PARAM_TPGT, 0);
1514 iscsi_session_attr(username, ISCSI_PARAM_USERNAME, 1);
1515 iscsi_session_attr(username_in, ISCSI_PARAM_USERNAME_IN, 1);
1516 iscsi_session_attr(password, ISCSI_PARAM_PASSWORD, 1);
1517 iscsi_session_attr(password_in, ISCSI_PARAM_PASSWORD_IN, 1);
1518 iscsi_session_attr(fast_abort, ISCSI_PARAM_FAST_ABORT, 0);
1519 iscsi_session_attr(abort_tmo, ISCSI_PARAM_ABORT_TMO, 0);
1520 iscsi_session_attr(lu_reset_tmo, ISCSI_PARAM_LU_RESET_TMO, 0);
1521
1522 static ssize_t
1523 show_priv_session_state(struct device *dev, struct device_attribute *attr,
1524                         char *buf)
1525 {
1526         struct iscsi_cls_session *session = iscsi_dev_to_session(dev->parent);
1527         return sprintf(buf, "%s\n", iscsi_session_state_name(session->state));
1528 }
1529 static ISCSI_CLASS_ATTR(priv_sess, state, S_IRUGO, show_priv_session_state,
1530                         NULL);
1531
1532 #define iscsi_priv_session_attr_show(field, format)                     \
1533 static ssize_t                                                          \
1534 show_priv_session_##field(struct device *dev,                           \
1535                           struct device_attribute *attr, char *buf)     \
1536 {                                                                       \
1537         struct iscsi_cls_session *session =                             \
1538                         iscsi_dev_to_session(dev->parent);              \
1539         return sprintf(buf, format"\n", session->field);                \
1540 }
1541
1542 #define iscsi_priv_session_attr(field, format)                          \
1543         iscsi_priv_session_attr_show(field, format)                     \
1544 static ISCSI_CLASS_ATTR(priv_sess, field, S_IRUGO, show_priv_session_##field, \
1545                         NULL)
1546 iscsi_priv_session_attr(recovery_tmo, "%d");
1547
1548 /*
1549  * iSCSI host attrs
1550  */
1551 #define iscsi_host_attr_show(param)                                     \
1552 static ssize_t                                                          \
1553 show_host_param_##param(struct device *dev,                             \
1554                         struct device_attribute *attr, char *buf)       \
1555 {                                                                       \
1556         struct Scsi_Host *shost = transport_class_to_shost(dev);        \
1557         struct iscsi_internal *priv = to_iscsi_internal(shost->transportt); \
1558         return priv->iscsi_transport->get_host_param(shost, param, buf); \
1559 }
1560
1561 #define iscsi_host_attr(field, param)                                   \
1562         iscsi_host_attr_show(param)                                     \
1563 static ISCSI_CLASS_ATTR(host, field, S_IRUGO, show_host_param_##param,  \
1564                         NULL);
1565
1566 iscsi_host_attr(netdev, ISCSI_HOST_PARAM_NETDEV_NAME);
1567 iscsi_host_attr(hwaddress, ISCSI_HOST_PARAM_HWADDRESS);
1568 iscsi_host_attr(ipaddress, ISCSI_HOST_PARAM_IPADDRESS);
1569 iscsi_host_attr(initiatorname, ISCSI_HOST_PARAM_INITIATOR_NAME);
1570
1571 #define SETUP_PRIV_SESSION_RD_ATTR(field)                               \
1572 do {                                                                    \
1573         priv->session_attrs[count] = &dev_attr_priv_sess_##field; \
1574         count++;                                                        \
1575 } while (0)
1576
1577
1578 #define SETUP_SESSION_RD_ATTR(field, param_flag)                        \
1579 do {                                                                    \
1580         if (tt->param_mask & param_flag) {                              \
1581                 priv->session_attrs[count] = &dev_attr_sess_##field; \
1582                 count++;                                                \
1583         }                                                               \
1584 } while (0)
1585
1586 #define SETUP_CONN_RD_ATTR(field, param_flag)                           \
1587 do {                                                                    \
1588         if (tt->param_mask & param_flag) {                              \
1589                 priv->conn_attrs[count] = &dev_attr_conn_##field; \
1590                 count++;                                                \
1591         }                                                               \
1592 } while (0)
1593
1594 #define SETUP_HOST_RD_ATTR(field, param_flag)                           \
1595 do {                                                                    \
1596         if (tt->host_param_mask & param_flag) {                         \
1597                 priv->host_attrs[count] = &dev_attr_host_##field; \
1598                 count++;                                                \
1599         }                                                               \
1600 } while (0)
1601
1602 static int iscsi_session_match(struct attribute_container *cont,
1603                            struct device *dev)
1604 {
1605         struct iscsi_cls_session *session;
1606         struct Scsi_Host *shost;
1607         struct iscsi_internal *priv;
1608
1609         if (!iscsi_is_session_dev(dev))
1610                 return 0;
1611
1612         session = iscsi_dev_to_session(dev);
1613         shost = iscsi_session_to_shost(session);
1614         if (!shost->transportt)
1615                 return 0;
1616
1617         priv = to_iscsi_internal(shost->transportt);
1618         if (priv->session_cont.ac.class != &iscsi_session_class.class)
1619                 return 0;
1620
1621         return &priv->session_cont.ac == cont;
1622 }
1623
1624 static int iscsi_conn_match(struct attribute_container *cont,
1625                            struct device *dev)
1626 {
1627         struct iscsi_cls_session *session;
1628         struct iscsi_cls_conn *conn;
1629         struct Scsi_Host *shost;
1630         struct iscsi_internal *priv;
1631
1632         if (!iscsi_is_conn_dev(dev))
1633                 return 0;
1634
1635         conn = iscsi_dev_to_conn(dev);
1636         session = iscsi_dev_to_session(conn->dev.parent);
1637         shost = iscsi_session_to_shost(session);
1638
1639         if (!shost->transportt)
1640                 return 0;
1641
1642         priv = to_iscsi_internal(shost->transportt);
1643         if (priv->conn_cont.ac.class != &iscsi_connection_class.class)
1644                 return 0;
1645
1646         return &priv->conn_cont.ac == cont;
1647 }
1648
1649 static int iscsi_host_match(struct attribute_container *cont,
1650                             struct device *dev)
1651 {
1652         struct Scsi_Host *shost;
1653         struct iscsi_internal *priv;
1654
1655         if (!scsi_is_host_device(dev))
1656                 return 0;
1657
1658         shost = dev_to_shost(dev);
1659         if (!shost->transportt  ||
1660             shost->transportt->host_attrs.ac.class != &iscsi_host_class.class)
1661                 return 0;
1662
1663         priv = to_iscsi_internal(shost->transportt);
1664         return &priv->t.host_attrs.ac == cont;
1665 }
1666
1667 struct scsi_transport_template *
1668 iscsi_register_transport(struct iscsi_transport *tt)
1669 {
1670         struct iscsi_internal *priv;
1671         unsigned long flags;
1672         int count = 0, err;
1673
1674         BUG_ON(!tt);
1675
1676         priv = iscsi_if_transport_lookup(tt);
1677         if (priv)
1678                 return NULL;
1679
1680         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1681         if (!priv)
1682                 return NULL;
1683         INIT_LIST_HEAD(&priv->list);
1684         priv->daemon_pid = -1;
1685         priv->iscsi_transport = tt;
1686         priv->t.user_scan = iscsi_user_scan;
1687         if (!(tt->caps & CAP_DATA_PATH_OFFLOAD))
1688                 priv->t.create_work_queue = 1;
1689
1690         priv->dev.class = &iscsi_transport_class;
1691         snprintf(priv->dev.bus_id, BUS_ID_SIZE, "%s", tt->name);
1692         err = device_register(&priv->dev);
1693         if (err)
1694                 goto free_priv;
1695
1696         err = sysfs_create_group(&priv->dev.kobj, &iscsi_transport_group);
1697         if (err)
1698                 goto unregister_dev;
1699
1700         /* host parameters */
1701         priv->t.host_attrs.ac.attrs = &priv->host_attrs[0];
1702         priv->t.host_attrs.ac.class = &iscsi_host_class.class;
1703         priv->t.host_attrs.ac.match = iscsi_host_match;
1704         priv->t.host_size = sizeof(struct iscsi_cls_host);
1705         transport_container_register(&priv->t.host_attrs);
1706
1707         SETUP_HOST_RD_ATTR(netdev, ISCSI_HOST_NETDEV_NAME);
1708         SETUP_HOST_RD_ATTR(ipaddress, ISCSI_HOST_IPADDRESS);
1709         SETUP_HOST_RD_ATTR(hwaddress, ISCSI_HOST_HWADDRESS);
1710         SETUP_HOST_RD_ATTR(initiatorname, ISCSI_HOST_INITIATOR_NAME);
1711         BUG_ON(count > ISCSI_HOST_ATTRS);
1712         priv->host_attrs[count] = NULL;
1713         count = 0;
1714
1715         /* connection parameters */
1716         priv->conn_cont.ac.attrs = &priv->conn_attrs[0];
1717         priv->conn_cont.ac.class = &iscsi_connection_class.class;
1718         priv->conn_cont.ac.match = iscsi_conn_match;
1719         transport_container_register(&priv->conn_cont);
1720
1721         SETUP_CONN_RD_ATTR(max_recv_dlength, ISCSI_MAX_RECV_DLENGTH);
1722         SETUP_CONN_RD_ATTR(max_xmit_dlength, ISCSI_MAX_XMIT_DLENGTH);
1723         SETUP_CONN_RD_ATTR(header_digest, ISCSI_HDRDGST_EN);
1724         SETUP_CONN_RD_ATTR(data_digest, ISCSI_DATADGST_EN);
1725         SETUP_CONN_RD_ATTR(ifmarker, ISCSI_IFMARKER_EN);
1726         SETUP_CONN_RD_ATTR(ofmarker, ISCSI_OFMARKER_EN);
1727         SETUP_CONN_RD_ATTR(address, ISCSI_CONN_ADDRESS);
1728         SETUP_CONN_RD_ATTR(port, ISCSI_CONN_PORT);
1729         SETUP_CONN_RD_ATTR(exp_statsn, ISCSI_EXP_STATSN);
1730         SETUP_CONN_RD_ATTR(persistent_address, ISCSI_PERSISTENT_ADDRESS);
1731         SETUP_CONN_RD_ATTR(persistent_port, ISCSI_PERSISTENT_PORT);
1732         SETUP_CONN_RD_ATTR(ping_tmo, ISCSI_PING_TMO);
1733         SETUP_CONN_RD_ATTR(recv_tmo, ISCSI_RECV_TMO);
1734
1735         BUG_ON(count > ISCSI_CONN_ATTRS);
1736         priv->conn_attrs[count] = NULL;
1737         count = 0;
1738
1739         /* session parameters */
1740         priv->session_cont.ac.attrs = &priv->session_attrs[0];
1741         priv->session_cont.ac.class = &iscsi_session_class.class;
1742         priv->session_cont.ac.match = iscsi_session_match;
1743         transport_container_register(&priv->session_cont);
1744
1745         SETUP_SESSION_RD_ATTR(initial_r2t, ISCSI_INITIAL_R2T_EN);
1746         SETUP_SESSION_RD_ATTR(max_outstanding_r2t, ISCSI_MAX_R2T);
1747         SETUP_SESSION_RD_ATTR(immediate_data, ISCSI_IMM_DATA_EN);
1748         SETUP_SESSION_RD_ATTR(first_burst_len, ISCSI_FIRST_BURST);
1749         SETUP_SESSION_RD_ATTR(max_burst_len, ISCSI_MAX_BURST);
1750         SETUP_SESSION_RD_ATTR(data_pdu_in_order, ISCSI_PDU_INORDER_EN);
1751         SETUP_SESSION_RD_ATTR(data_seq_in_order, ISCSI_DATASEQ_INORDER_EN);
1752         SETUP_SESSION_RD_ATTR(erl, ISCSI_ERL);
1753         SETUP_SESSION_RD_ATTR(targetname, ISCSI_TARGET_NAME);
1754         SETUP_SESSION_RD_ATTR(tpgt, ISCSI_TPGT);
1755         SETUP_SESSION_RD_ATTR(password, ISCSI_USERNAME);
1756         SETUP_SESSION_RD_ATTR(password_in, ISCSI_USERNAME_IN);
1757         SETUP_SESSION_RD_ATTR(username, ISCSI_PASSWORD);
1758         SETUP_SESSION_RD_ATTR(username_in, ISCSI_PASSWORD_IN);
1759         SETUP_SESSION_RD_ATTR(fast_abort, ISCSI_FAST_ABORT);
1760         SETUP_SESSION_RD_ATTR(abort_tmo, ISCSI_ABORT_TMO);
1761         SETUP_SESSION_RD_ATTR(lu_reset_tmo,ISCSI_LU_RESET_TMO);
1762         SETUP_PRIV_SESSION_RD_ATTR(recovery_tmo);
1763         SETUP_PRIV_SESSION_RD_ATTR(state);
1764
1765         BUG_ON(count > ISCSI_SESSION_ATTRS);
1766         priv->session_attrs[count] = NULL;
1767
1768         spin_lock_irqsave(&iscsi_transport_lock, flags);
1769         list_add(&priv->list, &iscsi_transports);
1770         spin_unlock_irqrestore(&iscsi_transport_lock, flags);
1771
1772         printk(KERN_NOTICE "iscsi: registered transport (%s)\n", tt->name);
1773         return &priv->t;
1774
1775 unregister_dev:
1776         device_unregister(&priv->dev);
1777 free_priv:
1778         kfree(priv);
1779         return NULL;
1780 }
1781 EXPORT_SYMBOL_GPL(iscsi_register_transport);
1782
1783 int iscsi_unregister_transport(struct iscsi_transport *tt)
1784 {
1785         struct iscsi_internal *priv;
1786         unsigned long flags;
1787
1788         BUG_ON(!tt);
1789
1790         mutex_lock(&rx_queue_mutex);
1791
1792         priv = iscsi_if_transport_lookup(tt);
1793         BUG_ON (!priv);
1794
1795         spin_lock_irqsave(&iscsi_transport_lock, flags);
1796         list_del(&priv->list);
1797         spin_unlock_irqrestore(&iscsi_transport_lock, flags);
1798
1799         transport_container_unregister(&priv->conn_cont);
1800         transport_container_unregister(&priv->session_cont);
1801         transport_container_unregister(&priv->t.host_attrs);
1802
1803         sysfs_remove_group(&priv->dev.kobj, &iscsi_transport_group);
1804         device_unregister(&priv->dev);
1805         mutex_unlock(&rx_queue_mutex);
1806
1807         return 0;
1808 }
1809 EXPORT_SYMBOL_GPL(iscsi_unregister_transport);
1810
1811 static __init int iscsi_transport_init(void)
1812 {
1813         int err;
1814
1815         printk(KERN_INFO "Loading iSCSI transport class v%s.\n",
1816                 ISCSI_TRANSPORT_VERSION);
1817
1818         atomic_set(&iscsi_session_nr, 0);
1819
1820         err = class_register(&iscsi_transport_class);
1821         if (err)
1822                 return err;
1823
1824         err = transport_class_register(&iscsi_host_class);
1825         if (err)
1826                 goto unregister_transport_class;
1827
1828         err = transport_class_register(&iscsi_connection_class);
1829         if (err)
1830                 goto unregister_host_class;
1831
1832         err = transport_class_register(&iscsi_session_class);
1833         if (err)
1834                 goto unregister_conn_class;
1835
1836         nls = netlink_kernel_create(&init_net, NETLINK_ISCSI, 1, iscsi_if_rx, NULL,
1837                         THIS_MODULE);
1838         if (!nls) {
1839                 err = -ENOBUFS;
1840                 goto unregister_session_class;
1841         }
1842
1843         iscsi_eh_timer_workq = create_singlethread_workqueue("iscsi_eh");
1844         if (!iscsi_eh_timer_workq)
1845                 goto release_nls;
1846
1847         return 0;
1848
1849 release_nls:
1850         netlink_kernel_release(nls);
1851 unregister_session_class:
1852         transport_class_unregister(&iscsi_session_class);
1853 unregister_conn_class:
1854         transport_class_unregister(&iscsi_connection_class);
1855 unregister_host_class:
1856         transport_class_unregister(&iscsi_host_class);
1857 unregister_transport_class:
1858         class_unregister(&iscsi_transport_class);
1859         return err;
1860 }
1861
1862 static void __exit iscsi_transport_exit(void)
1863 {
1864         destroy_workqueue(iscsi_eh_timer_workq);
1865         netlink_kernel_release(nls);
1866         transport_class_unregister(&iscsi_connection_class);
1867         transport_class_unregister(&iscsi_session_class);
1868         transport_class_unregister(&iscsi_host_class);
1869         class_unregister(&iscsi_transport_class);
1870 }
1871
1872 module_init(iscsi_transport_init);
1873 module_exit(iscsi_transport_exit);
1874
1875 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
1876               "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
1877               "Alex Aizman <itn780@yahoo.com>");
1878 MODULE_DESCRIPTION("iSCSI Transport Interface");
1879 MODULE_LICENSE("GPL");
1880 MODULE_VERSION(ISCSI_TRANSPORT_VERSION);