Commit 00642a1b authored by Hannes Reinecke's avatar Hannes Reinecke Committed by Martin K. Petersen

scsi_dh_alua: Allow workqueue to run synchronously

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: default avatarBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarHannes Reinecke <hare@suse.de>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 03197b61
...@@ -64,6 +64,7 @@ ...@@ -64,6 +64,7 @@
/* device handler flags */ /* device handler flags */
#define ALUA_OPTIMIZE_STPG 0x01 #define ALUA_OPTIMIZE_STPG 0x01
#define ALUA_RTPG_EXT_HDR_UNSUPP 0x02 #define ALUA_RTPG_EXT_HDR_UNSUPP 0x02
#define ALUA_SYNC_STPG 0x04
/* State machine flags */ /* State machine flags */
#define ALUA_PG_RUN_RTPG 0x10 #define ALUA_PG_RUN_RTPG 0x10
#define ALUA_PG_RUN_STPG 0x20 #define ALUA_PG_RUN_STPG 0x20
...@@ -76,6 +77,7 @@ MODULE_PARM_DESC(optimize_stpg, "Allow use of a non-optimized path, rather than ...@@ -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 LIST_HEAD(port_group_list);
static DEFINE_SPINLOCK(port_group_lock); static DEFINE_SPINLOCK(port_group_lock);
static struct workqueue_struct *kaluad_wq; static struct workqueue_struct *kaluad_wq;
static struct workqueue_struct *kaluad_sync_wq;
struct alua_port_group { struct alua_port_group {
struct kref kref; struct kref kref;
...@@ -686,6 +688,7 @@ static void alua_rtpg_work(struct work_struct *work) ...@@ -686,6 +688,7 @@ static void alua_rtpg_work(struct work_struct *work)
int err = SCSI_DH_OK; int err = SCSI_DH_OK;
struct alua_queue_data *qdata, *tmp; struct alua_queue_data *qdata, *tmp;
unsigned long flags; unsigned long flags;
struct workqueue_struct *alua_wq = kaluad_wq;
spin_lock_irqsave(&pg->lock, flags); spin_lock_irqsave(&pg->lock, flags);
sdev = pg->rtpg_sdev; sdev = pg->rtpg_sdev;
...@@ -695,6 +698,8 @@ static void alua_rtpg_work(struct work_struct *work) ...@@ -695,6 +698,8 @@ static void alua_rtpg_work(struct work_struct *work)
spin_unlock_irqrestore(&pg->lock, flags); spin_unlock_irqrestore(&pg->lock, flags);
return; return;
} }
if (pg->flags & ALUA_SYNC_STPG)
alua_wq = kaluad_sync_wq;
pg->flags |= ALUA_PG_RUNNING; pg->flags |= ALUA_PG_RUNNING;
if (pg->flags & ALUA_PG_RUN_RTPG) { if (pg->flags & ALUA_PG_RUN_RTPG) {
pg->flags &= ~ALUA_PG_RUN_RTPG; pg->flags &= ~ALUA_PG_RUN_RTPG;
...@@ -705,7 +710,7 @@ static void alua_rtpg_work(struct work_struct *work) ...@@ -705,7 +710,7 @@ static void alua_rtpg_work(struct work_struct *work)
pg->flags &= ~ALUA_PG_RUNNING; pg->flags &= ~ALUA_PG_RUNNING;
pg->flags |= ALUA_PG_RUN_RTPG; pg->flags |= ALUA_PG_RUN_RTPG;
spin_unlock_irqrestore(&pg->lock, flags); 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); pg->interval * HZ);
return; return;
} }
...@@ -722,7 +727,7 @@ static void alua_rtpg_work(struct work_struct *work) ...@@ -722,7 +727,7 @@ static void alua_rtpg_work(struct work_struct *work)
pg->interval = 0; pg->interval = 0;
pg->flags &= ~ALUA_PG_RUNNING; pg->flags &= ~ALUA_PG_RUNNING;
spin_unlock_irqrestore(&pg->lock, flags); 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); pg->interval * HZ);
return; return;
} }
...@@ -751,6 +756,7 @@ static void alua_rtpg_queue(struct alua_port_group *pg, ...@@ -751,6 +756,7 @@ static void alua_rtpg_queue(struct alua_port_group *pg,
{ {
int start_queue = 0; int start_queue = 0;
unsigned long flags; unsigned long flags;
struct workqueue_struct *alua_wq = kaluad_wq;
if (!pg) if (!pg)
return; return;
...@@ -768,10 +774,12 @@ static void alua_rtpg_queue(struct alua_port_group *pg, ...@@ -768,10 +774,12 @@ static void alua_rtpg_queue(struct alua_port_group *pg,
scsi_device_get(sdev); scsi_device_get(sdev);
start_queue = 1; start_queue = 1;
} }
if (pg->flags & ALUA_SYNC_STPG)
alua_wq = kaluad_sync_wq;
spin_unlock_irqrestore(&pg->lock, flags); spin_unlock_irqrestore(&pg->lock, flags);
if (start_queue && 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))) { msecs_to_jiffies(ALUA_RTPG_DELAY_MSECS))) {
scsi_device_put(sdev); scsi_device_put(sdev);
kref_put(&pg->kref, release_port_group); kref_put(&pg->kref, release_port_group);
...@@ -990,10 +998,16 @@ static int __init alua_init(void) ...@@ -990,10 +998,16 @@ static int __init alua_init(void)
/* Temporary failure, bypass */ /* Temporary failure, bypass */
return SCSI_DH_DEV_TEMP_BUSY; 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); r = scsi_register_device_handler(&alua_dh);
if (r != 0) { if (r != 0) {
printk(KERN_ERR "%s: Failed to register scsi device handler", printk(KERN_ERR "%s: Failed to register scsi device handler",
ALUA_DH_NAME); ALUA_DH_NAME);
destroy_workqueue(kaluad_sync_wq);
destroy_workqueue(kaluad_wq); destroy_workqueue(kaluad_wq);
} }
return r; return r;
...@@ -1002,6 +1016,7 @@ static int __init alua_init(void) ...@@ -1002,6 +1016,7 @@ static int __init alua_init(void)
static void __exit alua_exit(void) static void __exit alua_exit(void)
{ {
scsi_unregister_device_handler(&alua_dh); scsi_unregister_device_handler(&alua_dh);
destroy_workqueue(kaluad_sync_wq);
destroy_workqueue(kaluad_wq); destroy_workqueue(kaluad_wq);
} }
......
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