From: Christoph Hellwig <hch@lst.de>
Date: Mon, 19 Jun 2017 14:27:24 +0200
Subject: [PATCH] scsi: scsi_dh_alua: remove synchronous STPG support
References: bsc#1061782
Git-commit: 6934be4f016311cf88c316dad5c75e4ccf8a7fc0
Patch-Mainline: v4.13-rc1

Since 9c58b395 ("scsi: scsi_devinfo: remove synchronous ALUA for NETAPP
devices") this code is unused.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/scsi/device_handler/scsi_dh_alua.c | 27 +++++----------------------
 include/scsi/scsi_device.h                 |  1 -
 2 files changed, 5 insertions(+), 23 deletions(-)

diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index c01b47e..0962fd5 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -57,7 +57,6 @@
 /* device handler flags */
 #define ALUA_OPTIMIZE_STPG		0x01
 #define ALUA_RTPG_EXT_HDR_UNSUPP	0x02
-#define ALUA_SYNC_STPG			0x04
 /* State machine flags */
 #define ALUA_PG_RUN_RTPG		0x10
 #define ALUA_PG_RUN_STPG		0x20
@@ -70,7 +69,6 @@
 static LIST_HEAD(port_group_list);
 static DEFINE_SPINLOCK(port_group_lock);
 static struct workqueue_struct *kaluad_wq;
-static struct workqueue_struct *kaluad_sync_wq;
 
 struct alua_port_group {
 	struct kref		kref;
@@ -380,8 +378,6 @@ static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h,
 	}
 
 	spin_lock_irqsave(&pg->lock, flags);
-	if (sdev->synchronous_alua)
-		pg->flags |= ALUA_SYNC_STPG;
 	if (pg_updated)
 		list_add_rcu(&h->node, &pg->dh_list);
 	spin_unlock_irqrestore(&pg->lock, flags);
@@ -785,7 +781,6 @@ static void alua_rtpg_work(struct work_struct *work)
 	int err = SCSI_DH_OK;
 	struct alua_queue_data *qdata, *tmp;
 	unsigned long flags;
-	struct workqueue_struct *alua_wq = kaluad_wq;
 
 	spin_lock_irqsave(&pg->lock, flags);
 	sdev = pg->rtpg_sdev;
@@ -796,8 +791,6 @@ static void alua_rtpg_work(struct work_struct *work)
 		kref_put(&pg->kref, release_port_group);
 		return;
 	}
-	if (pg->flags & ALUA_SYNC_STPG)
-		alua_wq = kaluad_sync_wq;
 	pg->flags |= ALUA_PG_RUNNING;
 	if (pg->flags & ALUA_PG_RUN_RTPG) {
 		int state = pg->state;
@@ -810,7 +803,7 @@ static void alua_rtpg_work(struct work_struct *work)
 				pg->flags &= ~ALUA_PG_RUNNING;
 				pg->flags |= ALUA_PG_RUN_RTPG;
 				spin_unlock_irqrestore(&pg->lock, flags);
-				queue_delayed_work(alua_wq, &pg->rtpg_work,
+				queue_delayed_work(kaluad_wq, &pg->rtpg_work,
 						   pg->interval * HZ);
 				return;
 			}
@@ -822,7 +815,7 @@ static void alua_rtpg_work(struct work_struct *work)
 			pg->flags &= ~ALUA_PG_RUNNING;
 			pg->flags |= ALUA_PG_RUN_RTPG;
 			spin_unlock_irqrestore(&pg->lock, flags);
-			queue_delayed_work(alua_wq, &pg->rtpg_work,
+			queue_delayed_work(kaluad_wq, &pg->rtpg_work,
 					   pg->interval * HZ);
 			return;
 		}
@@ -839,7 +832,7 @@ static void alua_rtpg_work(struct work_struct *work)
 			pg->interval = 0;
 			pg->flags &= ~ALUA_PG_RUNNING;
 			spin_unlock_irqrestore(&pg->lock, flags);
-			queue_delayed_work(alua_wq, &pg->rtpg_work,
+			queue_delayed_work(kaluad_wq, &pg->rtpg_work,
 					   pg->interval * HZ);
 			return;
 		}
@@ -874,8 +867,6 @@ static bool alua_rtpg_queue(struct alua_port_group *pg,
 {
 	int start_queue = 0;
 	unsigned long flags;
-	struct workqueue_struct *alua_wq = kaluad_wq;
-
 	if (WARN_ON_ONCE(!pg) || scsi_device_get(sdev))
 		return false;
 
@@ -900,12 +891,10 @@ static bool alua_rtpg_queue(struct alua_port_group *pg,
 		}
 	}
 
-	if (pg->flags & ALUA_SYNC_STPG)
-		alua_wq = kaluad_sync_wq;
 	spin_unlock_irqrestore(&pg->lock, flags);
 
 	if (start_queue) {
-		if (queue_delayed_work(alua_wq, &pg->rtpg_work,
+		if (queue_delayed_work(kaluad_wq, &pg->rtpg_work,
 				msecs_to_jiffies(ALUA_RTPG_DELAY_MSECS)))
 			sdev = NULL;
 		else
@@ -1166,16 +1155,11 @@ static int __init alua_init(void)
 		/* Temporary failure, bypass */
 		return SCSI_DH_DEV_TEMP_BUSY;
 	}
-	kaluad_sync_wq = create_workqueue("kaluad_sync");
-	if (!kaluad_sync_wq) {
-		destroy_workqueue(kaluad_wq);
-		return SCSI_DH_DEV_TEMP_BUSY;
-	}
+
 	r = scsi_register_device_handler(&alua_dh);
 	if (r != 0) {
 		printk(KERN_ERR "%s: Failed to register scsi device handler",
 			ALUA_DH_NAME);
-		destroy_workqueue(kaluad_sync_wq);
 		destroy_workqueue(kaluad_wq);
 	}
 	return r;
@@ -1184,7 +1168,6 @@ static int __init alua_init(void)
 static void __exit alua_exit(void)
 {
 	scsi_unregister_device_handler(&alua_dh);
-	destroy_workqueue(kaluad_sync_wq);
 	destroy_workqueue(kaluad_wq);
 }
 
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 7af3ffb..b41ee9d 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -181,7 +181,6 @@ struct scsi_device {
 	unsigned no_dif:1;	/* T10 PI (DIF) should be disabled */
 	unsigned broken_fua:1;		/* Don't set FUA bit */
 	unsigned lun_in_cdb:1;		/* Store LUN bits in CDB[1] */
-	unsigned synchronous_alua:1;	/* Synchronous ALUA commands */
 
 	atomic_t disk_events_disable_depth; /* disable depth for disk events */
 
-- 
1.8.5.6