Some arrays may only capable of handling one STPG at a time,
so this patch adds a singlethreaded workqueue for STPGs to be
submitted synchronously.
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
---
drivers/scsi/device_handler/scsi_dh_alua.c | 21 ++++++++++++++++++---
1 file changed, 18 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index 5824c8a..4a3b0e7 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -64,6 +64,7 @@
/* 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
@@ -76,6 +77,7 @@ MODULE_PARM_DESC(optimize_stpg, "Allow use of a non-optimized path, rather than
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;
@@ -695,6 +697,7 @@ 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;
@@ -704,6 +707,8 @@ static void alua_rtpg_work(struct work_struct *work)
spin_unlock_irqrestore(&pg->lock, flags);
return;
}
+ if (pg->flags & ALUA_SYNC_STPG)
+ alua_wq = kaluad_sync_wq;
pg->flags |= ALUA_PG_RUNNING;
if (pg->flags & ALUA_PG_RUN_RTPG) {
spin_unlock_irqrestore(&pg->lock, flags);
@@ -712,7 +717,7 @@ static void alua_rtpg_work(struct work_struct *work)
if (err == SCSI_DH_RETRY) {
pg->flags &= ~ALUA_PG_RUNNING;
spin_unlock_irqrestore(&pg->lock, flags);
- queue_delayed_work(kaluad_wq, &pg->rtpg_work,
+ queue_delayed_work(alua_wq, &pg->rtpg_work,
pg->interval * HZ);
return;
}
@@ -730,7 +735,7 @@ 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(kaluad_wq, &pg->rtpg_work,
+ queue_delayed_work(alua_wq, &pg->rtpg_work,
pg->interval * HZ);
return;
}
@@ -759,6 +764,7 @@ static void alua_rtpg_queue(struct alua_port_group *pg,
{
int start_queue = 0;
unsigned long flags;
+ struct workqueue_struct *alua_wq = kaluad_wq;
if (!pg)
return;
@@ -776,10 +782,12 @@ static void alua_rtpg_queue(struct alua_port_group *pg,
scsi_device_get(sdev);
start_queue = 1;
}
+ if (pg->flags & ALUA_SYNC_STPG)
+ alua_wq = kaluad_sync_wq;
spin_unlock_irqrestore(&pg->lock, flags);
if (start_queue &&
- !queue_delayed_work(kaluad_wq, &pg->rtpg_work,
+ !queue_delayed_work(alua_wq, &pg->rtpg_work,
msecs_to_jiffies(ALUA_RTPG_DELAY_MSECS))) {
scsi_device_put(sdev);
kref_put(&pg->kref, release_port_group);
@@ -1002,10 +1010,16 @@ 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;
@@ -1014,6 +1028,7 @@ 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);
}
--
1.8.5.6
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