isci: Check IDEV_GONE before performing abort path operations.

In the link fail path, set IDEV_GONE for every device on the domain
when the last link in the port fails.

In the abort path functions like isci_reset_device, make sure that
there has not already been a detected domain failure with the device
by checking IDEV_GONE, before performing any kind of hard reset, SMP
phy control, or TMF operation.

The check for IDEV_GONE makes sure that the device in the abort path
really has control of the port with which it is associated.  This
prevents starting hard resets at incorrect times and scheduling
unnecessary LUN resets for SATA devices.
Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/scsi/isci/port.c

@@ -240,9 +240,32 @@ static void isci_port_link_down(struct isci_host *isci_host,
 				struct isci_phy *isci_phy,
 				struct isci_port *isci_port)
 {
+	struct isci_remote_device *isci_device;
+
 	dev_dbg(&isci_host->pdev->dev,
 		"%s: isci_port = %p\n", __func__, isci_port);
 
+	if (isci_port) {
+
+		/* check to see if this is the last phy on this port. */
+		if (isci_phy->sas_phy.port &&
+		    isci_phy->sas_phy.port->num_phys == 1) {
+			/* change the state for all devices on this port.  The
+			* next task sent to this device will be returned as
+			* SAS_TASK_UNDELIVERED, and the scsi mid layer will
+			* remove the target
+			*/
+			list_for_each_entry(isci_device,
+					    &isci_port->remote_dev_list,
+					    node) {
+				dev_dbg(&isci_host->pdev->dev,
+					"%s: isci_device = %p\n",
+					__func__, isci_device);
+				set_bit(IDEV_GONE, &isci_device->flags);
+			}
+		}
+	}
+
 	/* Notify libsas of the borken link, this will trigger calls to our
 	 * isci_port_deformed and isci_dev_gone functions.
 	 */

drivers/scsi/isci/task.c

@@ -421,7 +421,7 @@ int isci_task_lu_reset(struct domain_device *dev, u8 *lun)
 	struct isci_host *ihost = dev_to_ihost(dev);
 	struct isci_remote_device *idev;
 	unsigned long flags;
-	int ret;
+	int ret = TMF_RESP_FUNC_COMPLETE;
 
 	spin_lock_irqsave(&ihost->scic_lock, flags);
 	idev = isci_get_device(dev->lldd_dev);
@@ -447,12 +447,12 @@ int isci_task_lu_reset(struct domain_device *dev, u8 *lun)
 		goto out;
 	}
 	/* All pending I/Os have been terminated and cleaned up. */
-	if (dev_is_sata(dev)) {
-		sas_ata_schedule_reset(dev);
-		ret = TMF_RESP_FUNC_COMPLETE;
-	} else {
-		/* Send the task management part of the reset. */
-		ret = isci_task_send_lu_reset_sas(ihost, idev, lun);
+	if (!test_bit(IDEV_GONE, &idev->flags)) {
+		if (dev_is_sata(dev))
+			sas_ata_schedule_reset(dev);
+		else
+			/* Send the task management part of the reset. */
+			ret = isci_task_send_lu_reset_sas(ihost, idev, lun);
 	}
  out:
 	isci_put_device(idev);
@@ -512,8 +512,17 @@ int isci_task_abort_task(struct sas_task *task)
 	spin_unlock_irqrestore(&ihost->scic_lock, flags);
 
 	dev_warn(&ihost->pdev->dev,
-		 "%s: dev = %p, task = %p, old_request == %p\n",
-		 __func__, idev, task, old_request);
+		 "%s: dev = %p (%s%s), task = %p, old_request == %p\n",
+		 __func__, idev,
+		 (dev_is_sata(task->dev) ? "STP/SATA"
+					 : ((dev_is_expander(task->dev))
+						? "SMP"
+						: "SSP")),
+		 ((idev) ? ((test_bit(IDEV_GONE, &idev->flags))
+			   ? " IDEV_GONE"
+			   : "")
+			 : " <NULL>"),
+		 task, old_request);
 
 	/* Device reset conditions signalled in task_state_flags are the
 	 * responsbility of libsas to observe at the start of the error
@@ -552,7 +561,8 @@ int isci_task_abort_task(struct sas_task *task)
 
 	if (task->task_proto == SAS_PROTOCOL_SMP ||
 	    sas_protocol_ata(task->task_proto) ||
-	    test_bit(IREQ_COMPLETE_IN_TARGET, &old_request->flags)) {
+	    test_bit(IREQ_COMPLETE_IN_TARGET, &old_request->flags) ||
+	    test_bit(IDEV_GONE, &idev->flags)) {
 
 		spin_unlock_irqrestore(&ihost->scic_lock, flags);
 
@@ -561,7 +571,8 @@ int isci_task_abort_task(struct sas_task *task)
 
 		dev_warn(&ihost->pdev->dev,
 			 "%s: %s request"
-				 " or complete_in_target (%d), thus no TMF\n",
+				 " or complete_in_target (%d), "
+				 "or IDEV_GONE (%d), thus no TMF\n",
 			 __func__,
 			 ((task->task_proto == SAS_PROTOCOL_SMP)
 			  ? "SMP"
@@ -570,7 +581,8 @@ int isci_task_abort_task(struct sas_task *task)
 				: "<other>")
 			  ),
 			 test_bit(IREQ_COMPLETE_IN_TARGET,
-				  &old_request->flags));
+				  &old_request->flags),
+			 test_bit(IDEV_GONE, &idev->flags));
 
 		spin_lock_irqsave(&task->task_state_lock, flags);
 		task->task_state_flags &= ~(SAS_TASK_AT_INITIATOR |
@@ -734,7 +746,7 @@ static int isci_reset_device(struct isci_host *ihost,
 			     struct domain_device *dev,
 			     struct isci_remote_device *idev)
 {
-	int rc = TMF_RESP_FUNC_COMPLETE, reset_stat;
+	int rc = TMF_RESP_FUNC_COMPLETE, reset_stat = -1;
 	struct sas_phy *phy = sas_get_local_phy(dev);
 	struct isci_port *iport = dev->port->lldd_port;
 
@@ -752,14 +764,15 @@ static int isci_reset_device(struct isci_host *ihost,
 	 * primary duty of this function is to cleanup tasks, so that is the
 	 * relevant status.
 	 */
-
-	if (scsi_is_sas_phy_local(phy)) {
-		struct isci_phy *iphy = &ihost->phys[phy->number];
-
-		reset_stat = isci_port_perform_hard_reset(ihost, iport, iphy);
-	} else
-		reset_stat = sas_phy_reset(phy, !dev_is_sata(dev));
-
+	if (!test_bit(IDEV_GONE, &idev->flags)) {
+		if (scsi_is_sas_phy_local(phy)) {
+			struct isci_phy *iphy = &ihost->phys[phy->number];
+
+			reset_stat = isci_port_perform_hard_reset(ihost, iport,
+								  iphy);
+		} else
+			reset_stat = sas_phy_reset(phy, !dev_is_sata(dev));
+	}
 	/* Explicitly resume the RNC here, since there was no task sent. */
 	isci_remote_device_resume_from_abort(ihost, idev);