[RFC PATCH v2 05/19] scsi: scsi_error: Add helper scsi_eh_sdev_reset to do lun reset

[Wenchao Hao <haowenchao2@xxxxxxxxxx>]

Add helper function scsi_eh_sdev_reset() to perform lun reset 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 | 54 +++++++++++++++++++++++----------------
 1 file changed, 32 insertions(+), 22 deletions(-)

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 64eb616261ec..16888540b663 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -1635,6 +1635,34 @@ static int scsi_eh_stu(struct Scsi_Host *shost,
 	return list_empty(work_q);
 }
 
+static int scsi_eh_sdev_reset(struct scsi_cmnd *scmd,
+			      struct list_head *work_q,
+			      struct list_head *done_q)
+{
+	struct scsi_cmnd *next;
+	struct scsi_device *sdev = scmd->device;
+	enum scsi_disposition rtn;
+
+	SCSI_LOG_ERROR_RECOVERY(3, sdev_printk(KERN_INFO, sdev,
+			     "%s: Sending BDR\n", current->comm));
+
+	rtn = scsi_try_bus_device_reset(scmd);
+	if (rtn != SUCCESS && rtn != FAST_IO_FAIL) {
+		SCSI_LOG_ERROR_RECOVERY(3,
+			sdev_printk(KERN_INFO, sdev,
+				    "%s: BDR failed\n", current->comm));
+		return 0;
+	}
+
+	if (!scsi_device_online(sdev) || rtn == FAST_IO_FAIL ||
+	    !scsi_eh_tur(scmd))
+		list_for_each_entry_safe(scmd, next, work_q, eh_entry)
+			if (scmd->device == sdev &&
+			    scsi_eh_action(scmd, rtn) != FAILED)
+				scsi_eh_finish_cmd(scmd, done_q);
+
+	return list_empty(work_q);
+}
 
 /**
  * scsi_eh_bus_device_reset - send bdr if needed
@@ -1652,9 +1680,8 @@ static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
 				    struct list_head *work_q,
 				    struct list_head *done_q)
 {
-	struct scsi_cmnd *scmd, *bdr_scmd, *next;
+	struct scsi_cmnd *scmd, *bdr_scmd;
 	struct scsi_device *sdev;
-	enum scsi_disposition rtn;
 
 	shost_for_each_device(sdev, shost) {
 		if (scsi_host_eh_past_deadline(shost)) {
@@ -1675,26 +1702,9 @@ static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
 		if (!bdr_scmd)
 			continue;
 
-		SCSI_LOG_ERROR_RECOVERY(3,
-			sdev_printk(KERN_INFO, sdev,
-				     "%s: Sending BDR\n", current->comm));
-		rtn = scsi_try_bus_device_reset(bdr_scmd);
-		if (rtn == SUCCESS || rtn == FAST_IO_FAIL) {
-			if (!scsi_device_online(sdev) ||
-			    rtn == FAST_IO_FAIL ||
-			    !scsi_eh_tur(bdr_scmd)) {
-				list_for_each_entry_safe(scmd, next,
-							 work_q, eh_entry) {
-					if (scmd->device == sdev &&
-					    scsi_eh_action(scmd, rtn) != FAILED)
-						scsi_eh_finish_cmd(scmd,
-								   done_q);
-				}
-			}
-		} else {
-			SCSI_LOG_ERROR_RECOVERY(3,
-				sdev_printk(KERN_INFO, sdev,
-					    "%s: BDR failed\n", current->comm));
+		if (scsi_eh_sdev_reset(bdr_scmd, work_q, done_q)) {
+			scsi_device_put(sdev);
+			break;
 		}
 	}
 
-- 
2.35.3