2 files changed, 118 insertions, 112 deletions

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index c648bd328a2..a9d7e520e55 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -109,7 +109,7 @@ iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
 		 * if the window closed with IO queued, then kick the
 		 * xmit thread
 		 */
-		if (!list_empty(&session->leadconn->xmitqueue) ||
+		if (!list_empty(&session->leadconn->cmdqueue) ||
 		    !list_empty(&session->leadconn->mgmtqueue)) {
 			if (!(session->tt->caps & CAP_DATA_PATH_OFFLOAD))
 				iscsi_conn_queue_work(session->leadconn);
@@ -366,7 +366,6 @@ static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 		return -EIO;
 
 	task->state = ISCSI_TASK_RUNNING;
-	list_move_tail(&task->running, &conn->run_list);
 
 	conn->scsicmd_pdus_cnt++;
 	ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
@@ -382,26 +381,23 @@ static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 }
 
 /**
- * iscsi_complete_command - finish a task
+ * iscsi_free_task - free a task
  * @task: iscsi cmd task
  *
  * Must be called with session lock.
  * This function returns the scsi command to scsi-ml or cleans
  * up mgmt tasks then returns the task to the pool.
  */
-static void iscsi_complete_command(struct iscsi_task *task)
+static void iscsi_free_task(struct iscsi_task *task)
 {
 	struct iscsi_conn *conn = task->conn;
 	struct iscsi_session *session = conn->session;
 	struct scsi_cmnd *sc = task->sc;
 
 	session->tt->cleanup_task(task);
-	list_del_init(&task->running);
-	task->state = ISCSI_TASK_COMPLETED;
+	task->state = ISCSI_TASK_FREE;
 	task->sc = NULL;
 
-	if (conn->task == task)
-		conn->task = NULL;
 	/*
 	 * login task is preallocated so do not free
 	 */
@@ -410,9 +406,6 @@ static void iscsi_complete_command(struct iscsi_task *task)
 
 	__kfifo_put(session->cmdpool.queue, (void*)&task, sizeof(void*));
 
-	if (conn->ping_task == task)
-		conn->ping_task = NULL;
-
 	if (sc) {
 		task->sc = NULL;
 		/* SCSI eh reuses commands to verify us */
@@ -435,7 +428,7 @@ EXPORT_SYMBOL_GPL(__iscsi_get_task);
 static void __iscsi_put_task(struct iscsi_task *task)
 {
 	if (atomic_dec_and_test(&task->refcount))
-		iscsi_complete_command(task);
+		iscsi_free_task(task);
 }
 
 void iscsi_put_task(struct iscsi_task *task)
@@ -448,14 +441,50 @@ void iscsi_put_task(struct iscsi_task *task)
 }
 EXPORT_SYMBOL_GPL(iscsi_put_task);
 
+/**
+ * iscsi_complete_task - finish a task
+ * @task: iscsi cmd task
+ *
+ * Must be called with session lock.
+ */
+static void iscsi_complete_task(struct iscsi_task *task)
+{
+	struct iscsi_conn *conn = task->conn;
+
+	if (task->state == ISCSI_TASK_COMPLETED)
+		return;
+	WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
+
+	task->state = ISCSI_TASK_COMPLETED;
+
+	if (!list_empty(&task->running))
+		list_del_init(&task->running);
+
+	if (conn->task == task)
+		conn->task = NULL;
+
+	if (conn->ping_task == task)
+		conn->ping_task = NULL;
+
+	/* release get from queueing */
+	__iscsi_put_task(task);
+}
+
 /*
- * session lock must be held
+ * session lock must be held and if not called for a task that is
+ * still pending or from the xmit thread, then xmit thread must
+ * be suspended.
  */
-static void fail_command(struct iscsi_conn *conn, struct iscsi_task *task,
-			 int err)
+static void fail_scsi_task(struct iscsi_task *task, int err)
 {
+	struct iscsi_conn *conn = task->conn;
 	struct scsi_cmnd *sc;
 
+	/*
+	 * if a command completes and we get a successful tmf response
+	 * we will hit this because the scsi eh abort code does not take
+	 * a ref to the task.
+	 */
 	sc = task->sc;
 	if (!sc)
 		return;
@@ -475,10 +504,7 @@ static void fail_command(struct iscsi_conn *conn, struct iscsi_task *task,
 		scsi_in(sc)->resid = scsi_in(sc)->length;
 	}
 
-	if (conn->task == task)
-		conn->task = NULL;
-	/* release ref from queuecommand */
-	__iscsi_put_task(task);
+	iscsi_complete_task(task);
 }
 
 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
@@ -518,7 +544,6 @@ static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 		session->state = ISCSI_STATE_LOGGING_OUT;
 
 	task->state = ISCSI_TASK_RUNNING;
-	list_move_tail(&task->running, &conn->mgmt_run_list);
 	ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 			  "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 			  hdr->itt, task->data_count);
@@ -564,6 +589,8 @@ __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 	atomic_set(&task->refcount, 1);
 	task->conn = conn;
 	task->sc = NULL;
+	INIT_LIST_HEAD(&task->running);
+	task->state = ISCSI_TASK_PENDING;
 
 	if (data_size) {
 		memcpy(task->data, data, data_size);
@@ -575,7 +602,7 @@ __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 		if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 			iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 					 "pdu for mgmt task.\n");
-			goto requeue_task;
+			goto free_task;
 		}
 	}
 
@@ -591,30 +618,22 @@ __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 						   task->conn->session->age);
 	}
 
-	INIT_LIST_HEAD(&task->running);
-	list_add_tail(&task->running, &conn->mgmtqueue);
-
 	if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
 		if (iscsi_prep_mgmt_task(conn, task))
 			goto free_task;
 
 		if (session->tt->xmit_task(task))
 			goto free_task;
-
-	} else
+	} else {
+		list_add_tail(&task->running, &conn->mgmtqueue);
 		iscsi_conn_queue_work(conn);
+	}
 
 	return task;
 
 free_task:
 	__iscsi_put_task(task);
 	return NULL;
-
-requeue_task:
-	if (task != conn->login_task)
-		__kfifo_put(session->cmdpool.queue, (void*)&task,
-			    sizeof(void*));
-	return NULL;
 }
 
 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
@@ -709,11 +728,10 @@ invalid_datalen:
 			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 	}
 out:
-	ISCSI_DBG_SESSION(session, "done [sc %p res %d itt 0x%x]\n",
+	ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 			  sc, sc->result, task->itt);
 	conn->scsirsp_pdus_cnt++;
-
-	__iscsi_put_task(task);
+	iscsi_complete_task(task);
 }
 
 /**
@@ -747,8 +765,11 @@ iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 	}
 
+	ISCSI_DBG_SESSION(conn->session, "data in with status done "
+			  "[sc %p res %d itt 0x%x]\n",
+			  sc, sc->result, task->itt);
 	conn->scsirsp_pdus_cnt++;
-	__iscsi_put_task(task);
+	iscsi_complete_task(task);
 }
 
 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
@@ -969,7 +990,7 @@ int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 		}
 
 		iscsi_tmf_rsp(conn, hdr);
-		__iscsi_put_task(task);
+		iscsi_complete_task(task);
 		break;
 	case ISCSI_OP_NOOP_IN:
 		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
@@ -987,7 +1008,7 @@ int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 			goto recv_pdu;
 
 		mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
-		__iscsi_put_task(task);
+		iscsi_complete_task(task);
 		break;
 	default:
 		rc = ISCSI_ERR_BAD_OPCODE;
@@ -999,7 +1020,7 @@ out:
 recv_pdu:
 	if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 		rc = ISCSI_ERR_CONN_FAILED;
-	__iscsi_put_task(task);
+	iscsi_complete_task(task);
 	return rc;
 }
 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
@@ -1176,7 +1197,12 @@ void iscsi_requeue_task(struct iscsi_task *task)
 {
 	struct iscsi_conn *conn = task->conn;
 
-	list_move_tail(&task->running, &conn->requeue);
+	/*
+	 * this may be on the requeue list already if the xmit_task callout
+	 * is handling the r2ts while we are adding new ones
+	 */
+	if (list_empty(&task->running))
+		list_add_tail(&task->running, &conn->requeue);
 	iscsi_conn_queue_work(conn);
 }
 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
@@ -1216,6 +1242,7 @@ check_mgmt:
 	while (!list_empty(&conn->mgmtqueue)) {
 		conn->task = list_entry(conn->mgmtqueue.next,
 					 struct iscsi_task, running);
+		list_del_init(&conn->task->running);
 		if (iscsi_prep_mgmt_task(conn, conn->task)) {
 			__iscsi_put_task(conn->task);
 			conn->task = NULL;
@@ -1227,23 +1254,26 @@ check_mgmt:
 	}
 
 	/* process pending command queue */
-	while (!list_empty(&conn->xmitqueue)) {
+	while (!list_empty(&conn->cmdqueue)) {
 		if (conn->tmf_state == TMF_QUEUED)
 			break;
 
-		conn->task = list_entry(conn->xmitqueue.next,
+		conn->task = list_entry(conn->cmdqueue.next,
 					 struct iscsi_task, running);
+		list_del_init(&conn->task->running);
 		if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
-			fail_command(conn, conn->task, DID_IMM_RETRY << 16);
+			fail_scsi_task(conn->task, DID_IMM_RETRY << 16);
 			continue;
 		}
 		rc = iscsi_prep_scsi_cmd_pdu(conn->task);
 		if (rc) {
 			if (rc == -ENOMEM) {
+				list_add_tail(&conn->task->running,
+					      &conn->cmdqueue);
 				conn->task = NULL;
 				goto again;
 			} else
-				fail_command(conn, conn->task, DID_ABORT << 16);
+				fail_scsi_task(conn->task, DID_ABORT << 16);
 			continue;
 		}
 		rc = iscsi_xmit_task(conn);
@@ -1270,8 +1300,8 @@ check_mgmt:
 
 		conn->task = list_entry(conn->requeue.next,
 					 struct iscsi_task, running);
+		list_del_init(&conn->task->running);
 		conn->task->state = ISCSI_TASK_RUNNING;
-		list_move_tail(conn->requeue.next, &conn->run_list);
 		rc = iscsi_xmit_task(conn);
 		if (rc)
 			goto again;
@@ -1412,7 +1442,6 @@ int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
 		reason = FAILURE_OOM;
 		goto reject;
 	}
-	list_add_tail(&task->running, &conn->xmitqueue);
 
 	if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
 		reason = iscsi_prep_scsi_cmd_pdu(task);
@@ -1429,8 +1458,10 @@ int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
 			reason = FAILURE_SESSION_NOT_READY;
 			goto prepd_reject;
 		}
-	} else
+	} else {
+		list_add_tail(&task->running, &conn->cmdqueue);
 		iscsi_conn_queue_work(conn);
+	}
 
 	session->queued_cmdsn++;
 	spin_unlock(&session->lock);
@@ -1439,7 +1470,7 @@ int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
 
 prepd_reject:
 	sc->scsi_done = NULL;
-	iscsi_complete_command(task);
+	iscsi_complete_task(task);
 reject:
 	spin_unlock(&session->lock);
 	ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
@@ -1449,7 +1480,7 @@ reject:
 
 prepd_fault:
 	sc->scsi_done = NULL;
-	iscsi_complete_command(task);
+	iscsi_complete_task(task);
 fault:
 	spin_unlock(&session->lock);
 	ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
@@ -1618,44 +1649,24 @@ static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
  * Fail commands. session lock held and recv side suspended and xmit
  * thread flushed
  */
-static void fail_all_commands(struct iscsi_conn *conn, unsigned lun,
-			      int error)
+static void fail_scsi_tasks(struct iscsi_conn *conn, unsigned lun,
+			    int error)
 {
-	struct iscsi_task *task, *tmp;
-
-	if (conn->task) {
-		if (lun == -1 ||
-		    (conn->task->sc && conn->task->sc->device->lun == lun))
-			conn->task = NULL;
-	}
+	struct iscsi_task *task;
+	int i;
 
-	/* flush pending */
-	list_for_each_entry_safe(task, tmp, &conn->xmitqueue, running) {
-		if (lun == task->sc->device->lun || lun == -1) {
-			ISCSI_DBG_SESSION(conn->session,
-					  "failing pending sc %p itt 0x%x\n",
-					  task->sc, task->itt);
-			fail_command(conn, task, error << 16);
-		}
-	}
+	for (i = 0; i < conn->session->cmds_max; i++) {
+		task = conn->session->cmds[i];
+		if (!task->sc || task->state == ISCSI_TASK_FREE)
+			continue;
 
-	list_for_each_entry_safe(task, tmp, &conn->requeue, running) {
-		if (lun == task->sc->device->lun || lun == -1) {
-			ISCSI_DBG_SESSION(conn->session,
-					  "failing requeued sc %p itt 0x%x\n",
-					  task->sc, task->itt);
-			fail_command(conn, task, error << 16);
-		}
-	}
+		if (lun != -1 && lun != task->sc->device->lun)
+			continue;
 
-	/* fail all other running */
-	list_for_each_entry_safe(task, tmp, &conn->run_list, running) {
-		if (lun == task->sc->device->lun || lun == -1) {
-			ISCSI_DBG_SESSION(conn->session,
-					 "failing in progress sc %p itt 0x%x\n",
-					 task->sc, task->itt);
-			fail_command(conn, task, error << 16);
-		}
+		ISCSI_DBG_SESSION(conn->session,
+				  "failing sc %p itt 0x%x state %d\n",
+				  task->sc, task->itt, task->state);
+		fail_scsi_task(task, error << 16);
 	}
 }
 
@@ -1859,7 +1870,7 @@ int iscsi_eh_abort(struct scsi_cmnd *sc)
 	}
 
 	if (task->state == ISCSI_TASK_PENDING) {
-		fail_command(conn, task, DID_ABORT << 16);
+		fail_scsi_task(task, DID_ABORT << 16);
 		goto success;
 	}
 
@@ -1890,7 +1901,7 @@ int iscsi_eh_abort(struct scsi_cmnd *sc)
 		 * then sent more data for the cmd.
 		 */
 		spin_lock(&session->lock);
-		fail_command(conn, task, DID_ABORT << 16);
+		fail_scsi_task(task, DID_ABORT << 16);
 		conn->tmf_state = TMF_INITIAL;
 		spin_unlock(&session->lock);
 		iscsi_start_tx(conn);
@@ -1997,7 +2008,7 @@ int iscsi_eh_device_reset(struct scsi_cmnd *sc)
 	iscsi_suspend_tx(conn);
 
 	spin_lock_bh(&session->lock);
-	fail_all_commands(conn, sc->device->lun, DID_ERROR);
+	fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
 	conn->tmf_state = TMF_INITIAL;
 	spin_unlock_bh(&session->lock);
 
@@ -2304,6 +2315,7 @@ iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
 		if (cmd_task_size)
 			task->dd_data = &task[1];
 		task->itt = cmd_i;
+		task->state = ISCSI_TASK_FREE;
 		INIT_LIST_HEAD(&task->running);
 	}
 
@@ -2390,10 +2402,8 @@ iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
 	conn->transport_timer.data = (unsigned long)conn;
 	conn->transport_timer.function = iscsi_check_transport_timeouts;
 
-	INIT_LIST_HEAD(&conn->run_list);
-	INIT_LIST_HEAD(&conn->mgmt_run_list);
 	INIT_LIST_HEAD(&conn->mgmtqueue);
-	INIT_LIST_HEAD(&conn->xmitqueue);
+	INIT_LIST_HEAD(&conn->cmdqueue);
 	INIT_LIST_HEAD(&conn->requeue);
 	INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
 
@@ -2561,27 +2571,24 @@ int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
 EXPORT_SYMBOL_GPL(iscsi_conn_start);
 
 static void
-flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
+fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
 {
-	struct iscsi_task *task, *tmp;
+	struct iscsi_task *task;
+	int i;
 
-	/* handle pending */
-	list_for_each_entry_safe(task, tmp, &conn->mgmtqueue, running) {
-		ISCSI_DBG_SESSION(session, "flushing pending mgmt task "
-				  "itt 0x%x\n", task->itt);
-		/* release ref from prep task */
-		__iscsi_put_task(task);
-	}
+	for (i = 0; i < conn->session->cmds_max; i++) {
+		task = conn->session->cmds[i];
+		if (task->sc)
+			continue;
 
-	/* handle running */
-	list_for_each_entry_safe(task, tmp, &conn->mgmt_run_list, running) {
-		ISCSI_DBG_SESSION(session, "flushing running mgmt task "
-				  "itt 0x%x\n", task->itt);
-		/* release ref from prep task */
-		__iscsi_put_task(task);
-	}
+		if (task->state == ISCSI_TASK_FREE)
+			continue;
 
-	conn->task = NULL;
+		ISCSI_DBG_SESSION(conn->session,
+				  "failing mgmt itt 0x%x state %d\n",
+				  task->itt, task->state);
+		iscsi_complete_task(task);
+	}
 }
 
 static void iscsi_start_session_recovery(struct iscsi_session *session,
@@ -2638,10 +2645,10 @@ static void iscsi_start_session_recovery(struct iscsi_session *session,
 	 */
 	spin_lock_bh(&session->lock);
 	if (flag == STOP_CONN_RECOVER)
-		fail_all_commands(conn, -1, DID_TRANSPORT_DISRUPTED);
+		fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
 	else
-		fail_all_commands(conn, -1, DID_ERROR);
-	flush_control_queues(session, conn);
+		fail_scsi_tasks(conn, -1, DID_ERROR);
+	fail_mgmt_tasks(session, conn);
 	spin_unlock_bh(&session->lock);
 	mutex_unlock(&session->eh_mutex);
 }
diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
index 88d33a46efa..facae71183a 100644
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -82,6 +82,7 @@ enum {
 
 
 enum {
+	ISCSI_TASK_FREE,
 	ISCSI_TASK_COMPLETED,
 	ISCSI_TASK_PENDING,
 	ISCSI_TASK_RUNNING,
@@ -181,9 +182,7 @@ struct iscsi_conn {
 
 	/* xmit */
 	struct list_head	mgmtqueue;	/* mgmt (control) xmit queue */
-	struct list_head	mgmt_run_list;	/* list of control tasks */
-	struct list_head	xmitqueue;	/* data-path cmd queue */
-	struct list_head	run_list;	/* list of cmds in progress */
+	struct list_head	cmdqueue;	/* data-path cmd queue */
 	struct list_head	requeue;	/* tasks needing another run */
 	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
 	unsigned long		suspend_tx;	/* suspend Tx */