scsi: isci: Drop SAS_TASK_AT_INITIATOR check in isci_task_abort_task()

In the queue path, move around when we assign sas_task->lldd_task such that
this pointer and the SAS_TASK_AT_INITIATOR flag are set atomically.  It is
also not required to clear SAS_TASK_AT_INITIATOR in isci_task_execute_task()
error path as it is also cleared immediately after in isci_task_refuse()
call.

Now the following items may be considered:

 - SAS_TASK_STATE_DONE and SAS_TASK_AT_INITIATOR are mutually exclusive
   apart from possibly when SAS_TASK_STATE_DONE is set in
   sas_scsi_find_task(), but that is after .lldd_abort_task, i.e. the
   considered callback, is called.

 - If isci_task_refuse() is called in the queue path, then
   sas_task->lldd_task and SAS_TASK_AT_INITIATOR are cleared atomically in
   isci_task_refuse().

 - In the completion path, SAS_TASK_STATE_DONE is set and
   SAS_TASK_AT_INITIATOR is cleared atomically before the
   sas_task.lldd_task is cleared later.

So in isci_task_abort_task() if SAS_TASK_STATE_DONE is not set and
sas_task.lldd_task is still set, then SAS_TASK_AT_INITIATOR must be set -
so we can drop this check on SAS_TASK_AT_INITIATOR.

[mkp: checkpatch]

Link: https://lore.kernel.org/r/1644489804-85730-2-git-send-email-john.garry@huawei.com
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 6 insertions, 7 deletions

diff --git a/drivers/scsi/isci/task.c b/drivers/scsi/isci/task.c
index 3fd88d72a0c0..14738702d4c9 100644
--- a/drivers/scsi/isci/task.c
+++ b/drivers/scsi/isci/task.c
@@ -162,18 +162,18 @@ int isci_task_execute_task(struct sas_task *task, gfp_t gfp_flags)
 					 SAS_TASK_UNDELIVERED,
 					 SAS_SAM_STAT_TASK_ABORTED);
 		} else {
+			struct isci_request *ireq;
+
 			task->task_state_flags |= SAS_TASK_AT_INITIATOR;
+			/* do common allocation and init of request object. */
+			ireq = isci_io_request_from_tag(ihost, task, tag);
 			spin_unlock_irqrestore(&task->task_state_lock, flags);
 
 			/* build and send the request. */
-			status = isci_request_execute(ihost, idev, task, tag);
+			/* do common allocation and init of request object. */
+			status = isci_request_execute(ihost, idev, task, ireq);
 
 			if (status != SCI_SUCCESS) {
-				spin_lock_irqsave(&task->task_state_lock, flags);
-				/* Did not really start this command. */
-				task->task_state_flags &= ~SAS_TASK_AT_INITIATOR;
-				spin_unlock_irqrestore(&task->task_state_lock, flags);
-
 				if (test_bit(IDEV_GONE, &idev->flags)) {
 					/* Indicate that the device
 					 * is gone.
@@ -498,7 +498,6 @@ int isci_task_abort_task(struct sas_task *task)
 
 	/* If task is already done, the request isn't valid */
 	if (!(task->task_state_flags & SAS_TASK_STATE_DONE) &&
-	    (task->task_state_flags & SAS_TASK_AT_INITIATOR) &&
 	    old_request) {
 		idev = isci_get_device(task->dev->lldd_dev);
 		target_done_already = test_bit(IREQ_COMPLETE_IN_TARGET,