isci: fix incorrect assumptions about task->dev and task->dev->port being NULL
A domain_device has the same lifetime as its related scsi_target. The
scsi_target is reference counted based on outstanding commands,
therefore it is safe to assume that if we have a valid sas_task that the
->dev pointer is also valid.
The asd_sas_port of a domain_device has the same lifetime as the driver
so it can also never be NULL as long as the sas_task is valid and the
driver is loaded.
This also cleans up isci_task_complete_for_upper_layer(), renames it to
isci_task_refuse() and notices that the isci_completion_selection
parameter was set to isci_perform_normal_io_completion by all callers.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/scsi/isci/task.c b/drivers/scsi/isci/task.c
index d00b4c9..d483680 100644
--- a/drivers/scsi/isci/task.c
+++ b/drivers/scsi/isci/task.c
@@ -67,39 +67,36 @@
#include "task.h"
/**
-* isci_task_complete_for_upper_layer() - This function completes the request
-* to the upper layer driver in the case where an I/O needs to be completed
-* back in the submit path.
-* @host: This parameter is a pointer to the host on which the the request
-* should be queued (either as an error or success).
-* @task: This parameter is the completed request.
-* @response: This parameter is the response code for the completed task.
-* @status: This parameter is the status code for the completed task.
+* isci_task_refuse() - complete the request to the upper layer driver in
+* the case where an I/O needs to be completed back in the submit path.
+* @ihost: host on which the the request was queued
+* @task: request to complete
+* @response: response code for the completed task.
+* @status: status code for the completed task.
*
-* none.
*/
-static void isci_task_complete_for_upper_layer(struct sas_task *task,
- enum service_response response,
- enum exec_status status,
- enum isci_completion_selection task_notification_selection)
-{
- unsigned long flags = 0;
- struct Scsi_Host *host = NULL;
+static void isci_task_refuse(struct isci_host *ihost, struct sas_task *task,
+ enum service_response response,
+ enum exec_status status)
- task_notification_selection
- = isci_task_set_completion_status(task, response, status,
- task_notification_selection);
+{
+ enum isci_completion_selection disposition;
+
+ disposition = isci_perform_normal_io_completion;
+ disposition = isci_task_set_completion_status(task, response, status,
+ disposition);
/* Tasks aborted specifically by a call to the lldd_abort_task
- * function should not be completed to the host in the regular path.
- */
- switch (task_notification_selection) {
+ * function should not be completed to the host in the regular path.
+ */
+ switch (disposition) {
case isci_perform_normal_io_completion:
/* Normal notification (task_done) */
- dev_dbg(task->dev->port->ha->dev,
+ dev_dbg(&ihost->pdev->dev,
"%s: Normal - task = %p, response=%d, status=%d\n",
__func__, task, response, status);
+ task->lldd_task = NULL;
if (dev_is_sata(task->dev)) {
/* Since we are still in the submit path, and since
* libsas takes the host lock on behalf of SATA
@@ -107,44 +104,36 @@
* before we can call back and report the I/O
* submission error.
*/
- if (task->dev
- && task->dev->port
- && task->dev->port->ha) {
+ unsigned long flags;
- host = task->dev->port->ha->core.shost;
- raw_local_irq_save(flags);
- spin_unlock(host->host_lock);
- }
+ raw_local_irq_save(flags);
+ spin_unlock(ihost->shost->host_lock);
task->task_done(task);
- if (host) {
- spin_lock(host->host_lock);
- raw_local_irq_restore(flags);
- }
+ spin_lock(ihost->shost->host_lock);
+ raw_local_irq_restore(flags);
} else
task->task_done(task);
-
- task->lldd_task = NULL;
break;
case isci_perform_aborted_io_completion:
/* No notification because this request is already in the
* abort path.
*/
- dev_warn(task->dev->port->ha->dev,
+ dev_warn(&ihost->pdev->dev,
"%s: Aborted - task = %p, response=%d, status=%d\n",
__func__, task, response, status);
break;
case isci_perform_error_io_completion:
/* Use sas_task_abort */
- dev_warn(task->dev->port->ha->dev,
+ dev_warn(&ihost->pdev->dev,
"%s: Error - task = %p, response=%d, status=%d\n",
__func__, task, response, status);
sas_task_abort(task);
break;
default:
- dev_warn(task->dev->port->ha->dev,
+ dev_warn(&ihost->pdev->dev,
"%s: isci task notification default case!",
__func__);
sas_task_abort(task);
@@ -152,6 +141,10 @@
}
}
+#define for_each_sas_task(num, task) \
+ for (; num > 0; num--,\
+ task = list_entry(task->list.next, struct sas_task, list))
+
/**
* isci_task_execute_task() - This function is one of the SAS Domain Template
* functions. This function is called by libsas to send a task down to
@@ -164,7 +157,7 @@
*/
int isci_task_execute_task(struct sas_task *task, int num, gfp_t gfp_flags)
{
- struct isci_host *isci_host;
+ struct isci_host *ihost = task->dev->port->ha->lldd_ha;
struct isci_request *request = NULL;
struct isci_remote_device *device;
unsigned long flags;
@@ -172,60 +165,23 @@
enum sci_status status;
enum isci_status device_status;
- dev_dbg(task->dev->port->ha->dev, "%s: num=%d\n", __func__, num);
-
- if ((task->dev == NULL) || (task->dev->port == NULL)) {
-
- /* Indicate SAS_TASK_UNDELIVERED, so that the scsi midlayer
- * removes the target.
- */
- isci_task_complete_for_upper_layer(
- task,
- SAS_TASK_UNDELIVERED,
- SAS_DEVICE_UNKNOWN,
- isci_perform_normal_io_completion
- );
- return 0; /* The I/O was accepted (and failed). */
- }
- isci_host = isci_host_from_sas_ha(task->dev->port->ha);
+ dev_dbg(&ihost->pdev->dev, "%s: num=%d\n", __func__, num);
/* Check if we have room for more tasks */
- ret = isci_host_can_queue(isci_host, num);
+ ret = isci_host_can_queue(ihost, num);
if (ret) {
- dev_warn(task->dev->port->ha->dev, "%s: queue full\n", __func__);
+ dev_warn(&ihost->pdev->dev, "%s: queue full\n", __func__);
return ret;
}
- do {
- dev_dbg(task->dev->port->ha->dev,
+ for_each_sas_task(num, task) {
+ dev_dbg(&ihost->pdev->dev,
"task = %p, num = %d; dev = %p; cmd = %p\n",
task, num, task->dev, task->uldd_task);
- if ((task->dev == NULL) || (task->dev->port == NULL)) {
- dev_warn(task->dev->port->ha->dev,
- "%s: task %p's port or dev == NULL!\n",
- __func__, task);
-
- /* Indicate SAS_TASK_UNDELIVERED, so that the scsi
- * midlayer removes the target.
- */
- isci_task_complete_for_upper_layer(
- task,
- SAS_TASK_UNDELIVERED,
- SAS_DEVICE_UNKNOWN,
- isci_perform_normal_io_completion
- );
- /* We don't have a valid host reference, so we
- * can't control the host queueing condition.
- */
- goto next_task;
- }
-
device = isci_dev_from_domain_dev(task->dev);
- isci_host = isci_host_from_sas_ha(task->dev->port->ha);
-
if (device)
device_status = device->status;
else
@@ -239,34 +195,28 @@
if (device_status != isci_ready_for_io) {
/* Forces a retry from scsi mid layer. */
- dev_warn(task->dev->port->ha->dev,
+ dev_warn(&ihost->pdev->dev,
"%s: task %p: isci_host->status = %d, "
"device = %p; device_status = 0x%x\n\n",
__func__,
task,
- isci_host_get_state(isci_host),
+ isci_host_get_state(ihost),
device, device_status);
if (device_status == isci_ready) {
/* Indicate QUEUE_FULL so that the scsi midlayer
* retries.
*/
- isci_task_complete_for_upper_layer(
- task,
- SAS_TASK_COMPLETE,
- SAS_QUEUE_FULL,
- isci_perform_normal_io_completion
- );
+ isci_task_refuse(ihost, task,
+ SAS_TASK_COMPLETE,
+ SAS_QUEUE_FULL);
} else {
/* Else, the device is going down. */
- isci_task_complete_for_upper_layer(
- task,
- SAS_TASK_UNDELIVERED,
- SAS_DEVICE_UNKNOWN,
- isci_perform_normal_io_completion
- );
+ isci_task_refuse(ihost, task,
+ SAS_TASK_UNDELIVERED,
+ SAS_DEVICE_UNKNOWN);
}
- isci_host_can_dequeue(isci_host, 1);
+ isci_host_can_dequeue(ihost, 1);
} else {
/* There is a device and it's ready for I/O. */
spin_lock_irqsave(&task->task_state_lock, flags);
@@ -276,12 +226,9 @@
spin_unlock_irqrestore(&task->task_state_lock,
flags);
- isci_task_complete_for_upper_layer(
- task,
- SAS_TASK_UNDELIVERED,
- SAM_STAT_TASK_ABORTED,
- isci_perform_normal_io_completion
- );
+ isci_task_refuse(ihost, task,
+ SAS_TASK_UNDELIVERED,
+ SAM_STAT_TASK_ABORTED);
/* The I/O was aborted. */
@@ -290,7 +237,7 @@
spin_unlock_irqrestore(&task->task_state_lock, flags);
/* build and send the request. */
- status = isci_request_execute(isci_host, task, &request,
+ status = isci_request_execute(ihost, task, &request,
gfp_flags);
if (status != SCI_SUCCESS) {
@@ -307,19 +254,14 @@
* SAS_TASK_UNDELIVERED next time
* through.
*/
- isci_task_complete_for_upper_layer(
- task,
- SAS_TASK_COMPLETE,
- SAS_QUEUE_FULL,
- isci_perform_normal_io_completion
- );
- isci_host_can_dequeue(isci_host, 1);
+ isci_task_refuse(ihost, task,
+ SAS_TASK_COMPLETE,
+ SAS_QUEUE_FULL);
+ isci_host_can_dequeue(ihost, 1);
}
}
}
-next_task:
- task = list_entry(task->list.next, struct sas_task, list);
- } while (--num > 0);
+ }
return 0;
}