+ if (!iscsi_is_session_dev(dev))
+ return 0;
+
+ session = iscsi_dev_to_session(dev);
+ shost = iscsi_session_to_shost(session);
+ ihost = shost->shost_data;
+
+ mutex_lock(&ihost->mutex);
+ spin_lock_irqsave(&session->lock, flags);
+ if (session->state != ISCSI_SESSION_LOGGED_IN) {
+ spin_unlock_irqrestore(&session->lock, flags);
+ mutex_unlock(&ihost->mutex);
+ return 0;
+ }
+ id = session->target_id;
+ spin_unlock_irqrestore(&session->lock, flags);
+
+ if (id != ISCSI_MAX_TARGET) {
+ if ((scan_data->channel == SCAN_WILD_CARD ||
+ scan_data->channel == 0) &&
+ (scan_data->id == SCAN_WILD_CARD ||
+ scan_data->id == id))
+ scsi_scan_target(&session->dev, 0, id,
+ scan_data->lun, 1);
+ }
+ mutex_unlock(&ihost->mutex);
+ return 0;
+}
+
+static int iscsi_user_scan(struct Scsi_Host *shost, uint channel,
+ uint id, uint lun)
+{
+ struct iscsi_scan_data scan_data;
+
+ scan_data.channel = channel;
+ scan_data.id = id;
+ scan_data.lun = lun;
+
+ return device_for_each_child(&shost->shost_gendev, &scan_data,
+ iscsi_user_scan_session);
+}
+
+static void iscsi_scan_session(struct work_struct *work)
+{
+ struct iscsi_cls_session *session =
+ container_of(work, struct iscsi_cls_session, scan_work);
+ struct Scsi_Host *shost = iscsi_session_to_shost(session);
+ struct iscsi_cls_host *ihost = shost->shost_data;
+ struct iscsi_scan_data scan_data;
+
+ scan_data.channel = 0;
+ scan_data.id = SCAN_WILD_CARD;
+ scan_data.lun = SCAN_WILD_CARD;
+
+ iscsi_user_scan_session(&session->dev, &scan_data);
+ atomic_dec(&ihost->nr_scans);
+}
+
+static void session_recovery_timedout(struct work_struct *work)
+{
+ struct iscsi_cls_session *session =
+ container_of(work, struct iscsi_cls_session,
+ recovery_work.work);
+ unsigned long flags;
+
+ iscsi_cls_session_printk(KERN_INFO, session,
+ "session recovery timed out after %d secs\n",
+ session->recovery_tmo);
+
+ spin_lock_irqsave(&session->lock, flags);
+ switch (session->state) {
+ case ISCSI_SESSION_FAILED:
+ session->state = ISCSI_SESSION_FREE;
+ break;
+ case ISCSI_SESSION_LOGGED_IN:
+ case ISCSI_SESSION_FREE:
+ /* we raced with the unblock's flush */
+ spin_unlock_irqrestore(&session->lock, flags);
+ return;
+ }
+ spin_unlock_irqrestore(&session->lock, flags);
+
+ if (session->transport->session_recovery_timedout)
+ session->transport->session_recovery_timedout(session);
+
+ scsi_target_unblock(&session->dev);
+}
+
+static void __iscsi_unblock_session(struct work_struct *work)
+{
+ struct iscsi_cls_session *session =
+ container_of(work, struct iscsi_cls_session,
+ unblock_work);
+ struct Scsi_Host *shost = iscsi_session_to_shost(session);
+ struct iscsi_cls_host *ihost = shost->shost_data;
+ unsigned long flags;
+
+ /*
+ * The recovery and unblock work get run from the same workqueue,
+ * so try to cancel it if it was going to run after this unblock.
+ */
+ cancel_delayed_work(&session->recovery_work);
+ spin_lock_irqsave(&session->lock, flags);
+ session->state = ISCSI_SESSION_LOGGED_IN;
+ spin_unlock_irqrestore(&session->lock, flags);
+ /* start IO */
+ scsi_target_unblock(&session->dev);
+ /*
+ * Only do kernel scanning if the driver is properly hooked into
+ * the async scanning code (drivers like iscsi_tcp do login and
+ * scanning from userspace).
+ */
+ if (shost->hostt->scan_finished) {
+ if (queue_work(ihost->scan_workq, &session->scan_work))
+ atomic_inc(&ihost->nr_scans);
+ }
+}
+
+/**
+ * iscsi_unblock_session - set a session as logged in and start IO.
+ * @session: iscsi session
+ *
+ * Mark a session as ready to accept IO.
+ */
+void iscsi_unblock_session(struct iscsi_cls_session *session)
+{
+ queue_work(iscsi_eh_timer_workq, &session->unblock_work);
+ /*
+ * make sure all the events have completed before tell the driver
+ * it is safe
+ */
+ flush_workqueue(iscsi_eh_timer_workq);
+}
+EXPORT_SYMBOL_GPL(iscsi_unblock_session);
+
+static void __iscsi_block_session(struct work_struct *work)
+{
+ struct iscsi_cls_session *session =
+ container_of(work, struct iscsi_cls_session,
+ block_work);
+ unsigned long flags;
+
+ spin_lock_irqsave(&session->lock, flags);
+ session->state = ISCSI_SESSION_FAILED;
+ spin_unlock_irqrestore(&session->lock, flags);
+ scsi_target_block(&session->dev);
+ queue_delayed_work(iscsi_eh_timer_workq, &session->recovery_work,
+ session->recovery_tmo * HZ);
+}
+
+void iscsi_block_session(struct iscsi_cls_session *session)
+{
+ queue_work(iscsi_eh_timer_workq, &session->block_work);
+}
+EXPORT_SYMBOL_GPL(iscsi_block_session);