+void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
+{
+ struct iscsi_session *session = cls_session->dd_data;
+
+ spin_lock_bh(&session->lock);
+ if (session->state != ISCSI_STATE_LOGGED_IN) {
+ session->state = ISCSI_STATE_RECOVERY_FAILED;
+ if (session->leadconn)
+ wake_up(&session->leadconn->ehwait);
+ }
+ spin_unlock_bh(&session->lock);
+}
+EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
+
+/**
+ * iscsi_eh_session_reset - drop session and attempt relogin
+ * @sc: scsi command
+ *
+ * This function will wait for a relogin, session termination from
+ * userspace, or a recovery/replacement timeout.
+ */
+static int iscsi_eh_session_reset(struct scsi_cmnd *sc)
+{
+ struct iscsi_cls_session *cls_session;
+ struct iscsi_session *session;
+ struct iscsi_conn *conn;
+
+ cls_session = starget_to_session(scsi_target(sc->device));
+ session = cls_session->dd_data;
+ conn = session->leadconn;
+
+ mutex_lock(&session->eh_mutex);
+ spin_lock_bh(&session->lock);
+ if (session->state == ISCSI_STATE_TERMINATE) {
+failed:
+ ISCSI_DBG_EH(session,
+ "failing session reset: Could not log back into "
+ "%s, %s [age %d]\n", session->targetname,
+ conn->persistent_address, session->age);
+ spin_unlock_bh(&session->lock);
+ mutex_unlock(&session->eh_mutex);
+ return FAILED;
+ }
+
+ spin_unlock_bh(&session->lock);
+ mutex_unlock(&session->eh_mutex);
+ /*
+ * we drop the lock here but the leadconn cannot be destoyed while
+ * we are in the scsi eh
+ */
+ iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+
+ ISCSI_DBG_EH(session, "wait for relogin\n");
+ wait_event_interruptible(conn->ehwait,
+ session->state == ISCSI_STATE_TERMINATE ||
+ session->state == ISCSI_STATE_LOGGED_IN ||
+ session->state == ISCSI_STATE_RECOVERY_FAILED);
+ if (signal_pending(current))
+ flush_signals(current);
+
+ mutex_lock(&session->eh_mutex);
+ spin_lock_bh(&session->lock);
+ if (session->state == ISCSI_STATE_LOGGED_IN) {
+ ISCSI_DBG_EH(session,
+ "session reset succeeded for %s,%s\n",
+ session->targetname, conn->persistent_address);
+ } else
+ goto failed;
+ spin_unlock_bh(&session->lock);
+ mutex_unlock(&session->eh_mutex);
+ return SUCCESS;
+}
+
+static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
+{
+ memset(hdr, 0, sizeof(*hdr));
+ hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
+ hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
+ hdr->flags |= ISCSI_FLAG_CMD_FINAL;
+ hdr->rtt = RESERVED_ITT;
+}
+
+/**
+ * iscsi_eh_target_reset - reset target
+ * @sc: scsi command
+ *
+ * This will attempt to send a warm target reset. If that fails
+ * then we will drop the session and attempt ERL0 recovery.
+ */
+int iscsi_eh_target_reset(struct scsi_cmnd *sc)
+{
+ struct iscsi_cls_session *cls_session;
+ struct iscsi_session *session;
+ struct iscsi_conn *conn;
+ struct iscsi_tm *hdr;
+ int rc = FAILED;
+
+ cls_session = starget_to_session(scsi_target(sc->device));
+ session = cls_session->dd_data;
+
+ ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
+ session->targetname);
+
+ mutex_lock(&session->eh_mutex);
+ spin_lock_bh(&session->lock);
+ /*
+ * Just check if we are not logged in. We cannot check for
+ * the phase because the reset could come from a ioctl.
+ */
+ if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
+ goto unlock;
+ conn = session->leadconn;
+
+ /* only have one tmf outstanding at a time */
+ if (conn->tmf_state != TMF_INITIAL)
+ goto unlock;
+ conn->tmf_state = TMF_QUEUED;
+
+ hdr = &conn->tmhdr;
+ iscsi_prep_tgt_reset_pdu(sc, hdr);
+
+ if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
+ session->tgt_reset_timeout)) {
+ rc = FAILED;
+ goto unlock;
+ }
+
+ switch (conn->tmf_state) {
+ case TMF_SUCCESS:
+ break;
+ case TMF_TIMEDOUT:
+ spin_unlock_bh(&session->lock);
+ iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+ goto done;
+ default:
+ conn->tmf_state = TMF_INITIAL;
+ goto unlock;
+ }
+
+ rc = SUCCESS;
+ spin_unlock_bh(&session->lock);
+
+ iscsi_suspend_tx(conn);
+
+ spin_lock_bh(&session->lock);
+ memset(hdr, 0, sizeof(*hdr));
+ fail_scsi_tasks(conn, -1, DID_ERROR);
+ conn->tmf_state = TMF_INITIAL;
+ spin_unlock_bh(&session->lock);
+
+ iscsi_start_tx(conn);
+ goto done;
+
+unlock:
+ spin_unlock_bh(&session->lock);
+done:
+ ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
+ rc == SUCCESS ? "SUCCESS" : "FAILED");
+ mutex_unlock(&session->eh_mutex);
+
+ if (rc == FAILED)
+ rc = iscsi_eh_session_reset(sc);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
+