[RFC PATCH v2 04/19] scsi: scsi_error: Add helper scsi_eh_sdev_stu to do START_UNIT

[Wenchao Hao <haowenchao2@xxxxxxxxxx>]

Add helper function scsi_eh_sdev_stu() to perform START_UNIT and check
if to finish some error commands.

This is preparation for a genernal LUN/target based error handle
strategy and did not change original logic.

Signed-off-by: Wenchao Hao <haowenchao2@xxxxxxxxxx>
---
 drivers/scsi/scsi_error.c | 50 +++++++++++++++++++++++----------------
 1 file changed, 29 insertions(+), 21 deletions(-)

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 48ed035d44ce..64eb616261ec 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -1564,6 +1564,31 @@ static int scsi_eh_try_stu(struct scsi_cmnd *scmd)
 	return 1;
 }
 
+static int scsi_eh_sdev_stu(struct scsi_cmnd *scmd,
+			      struct list_head *work_q,
+			      struct list_head *done_q)
+{
+	struct scsi_device *sdev = scmd->device;
+	struct scsi_cmnd *next;
+
+	SCSI_LOG_ERROR_RECOVERY(3, sdev_printk(KERN_INFO, sdev,
+				"%s: Sending START_UNIT\n", current->comm));
+
+	if (scsi_eh_try_stu(scmd)) {
+		SCSI_LOG_ERROR_RECOVERY(3, sdev_printk(KERN_INFO, sdev,
+				    "%s: START_UNIT failed\n", current->comm));
+		return 0;
+	}
+
+	if (!scsi_device_online(sdev) || !scsi_eh_tur(scmd))
+		list_for_each_entry_safe(scmd, next, work_q, eh_entry)
+			if (scmd->device == sdev &&
+			    scsi_eh_action(scmd, SUCCESS) == SUCCESS)
+				scsi_eh_finish_cmd(scmd, done_q);
+
+	return list_empty(work_q);
+}
+
  /**
  * scsi_eh_stu - send START_UNIT if needed
  * @shost:	&scsi host being recovered.
@@ -1578,7 +1603,7 @@ static int scsi_eh_stu(struct Scsi_Host *shost,
 			      struct list_head *work_q,
 			      struct list_head *done_q)
 {
-	struct scsi_cmnd *scmd, *stu_scmd, *next;
+	struct scsi_cmnd *scmd, *stu_scmd;
 	struct scsi_device *sdev;
 
 	shost_for_each_device(sdev, shost) {
@@ -1601,26 +1626,9 @@ static int scsi_eh_stu(struct Scsi_Host *shost,
 		if (!stu_scmd)
 			continue;
 
-		SCSI_LOG_ERROR_RECOVERY(3,
-			sdev_printk(KERN_INFO, sdev,
-				     "%s: Sending START_UNIT\n",
-				    current->comm));
-
-		if (!scsi_eh_try_stu(stu_scmd)) {
-			if (!scsi_device_online(sdev) ||
-			    !scsi_eh_tur(stu_scmd)) {
-				list_for_each_entry_safe(scmd, next,
-							  work_q, eh_entry) {
-					if (scmd->device == sdev &&
-					    scsi_eh_action(scmd, SUCCESS) == SUCCESS)
-						scsi_eh_finish_cmd(scmd, done_q);
-				}
-			}
-		} else {
-			SCSI_LOG_ERROR_RECOVERY(3,
-				sdev_printk(KERN_INFO, sdev,
-					    "%s: START_UNIT failed\n",
-					    current->comm));
+		if (scsi_eh_sdev_stu(stu_scmd, work_q, done_q)) {
+			scsi_device_put(sdev);
+			break;
 		}
 	}
 
-- 
2.35.3