[SCSI] libata, libsas: introduce sched_eh and end_eh port ops

When managing shost->host_eh_scheduled libata assumes that there is a
1:1 shost-to-ata_port relationship.  libsas creates a 1:N relationship
so it needs to manage host_eh_scheduled cumulatively at the host level.
The sched_eh and end_eh port port ops allow libsas to track when domain
devices enter/leave the "eh-pending" state under ha->lock (previously
named ha->state_lock, but it is no longer just a lock for ha->state
changes).

Since host_eh_scheduled indicates eh without backing commands pinning
the device it can be deallocated at any time.  Move the taking of the
domain_device reference under the port_lock to guarantee that the
ata_port stays around for the duration of eh.

Reviewed-by: Jacek Danecki <jacek.danecki@intel.com>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 6 insertions, 6 deletions

diff --git a/drivers/scsi/libsas/sas_event.c b/drivers/scsi/libsas/sas_event.c
index 4e4292d210c1..789c4d8bb7a7 100644
--- a/drivers/scsi/libsas/sas_event.c
+++ b/drivers/scsi/libsas/sas_event.c
@@ -47,9 +47,9 @@ static void sas_queue_event(int event, unsigned long *pending,
 	if (!test_and_set_bit(event, pending)) {
 		unsigned long flags;
 
-		spin_lock_irqsave(&ha->state_lock, flags);
+		spin_lock_irqsave(&ha->lock, flags);
 		sas_queue_work(ha, work);
-		spin_unlock_irqrestore(&ha->state_lock, flags);
+		spin_unlock_irqrestore(&ha->lock, flags);
 	}
 }
 
@@ -61,18 +61,18 @@ void __sas_drain_work(struct sas_ha_struct *ha)
 
 	set_bit(SAS_HA_DRAINING, &ha->state);
 	/* flush submitters */
-	spin_lock_irq(&ha->state_lock);
-	spin_unlock_irq(&ha->state_lock);
+	spin_lock_irq(&ha->lock);
+	spin_unlock_irq(&ha->lock);
 
 	drain_workqueue(wq);
 
-	spin_lock_irq(&ha->state_lock);
+	spin_lock_irq(&ha->lock);
 	clear_bit(SAS_HA_DRAINING, &ha->state);
 	list_for_each_entry_safe(sw, _sw, &ha->defer_q, drain_node) {
 		list_del_init(&sw->drain_node);
 		sas_queue_work(ha, sw);
 	}
-	spin_unlock_irq(&ha->state_lock);
+	spin_unlock_irq(&ha->lock);
 }
 
 int sas_drain_work(struct sas_ha_struct *ha)