[SCSI] libsas: async ata scanning

libsas ata error handling is already async but this does not help the
scan case.  Move initial link recovery out from under host->scan_mutex,
and delay synchronization with eh until after all port probe/recovery
work has been queued.

Device ordering is maintained with scan order by still calling
sas_rphy_add() in order of domain discovery.

Since we now scan the domain list when invoking libata-eh we need to be
careful to check for fully initialized ata ports.

Acked-by: Jack Wang <jack_wang@usish.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>

drivers/scsi/libsas/sas_ata.c

@@ -585,11 +585,10 @@ static struct ata_port_info sata_port_info = {
 	.port_ops = &sas_sata_ops
 };
 
-int sas_ata_init_host_and_port(struct domain_device *found_dev,
-			       struct scsi_target *starget)
+int sas_ata_init_host_and_port(struct domain_device *found_dev)
 {
-	struct Scsi_Host *shost = dev_to_shost(&starget->dev);
-	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
+	struct sas_ha_struct *ha = found_dev->port->ha;
+	struct Scsi_Host *shost = ha->core.shost;
 	struct ata_port *ap;
 
 	ata_host_init(&found_dev->sata_dev.ata_host,
@@ -607,6 +606,8 @@ int sas_ata_init_host_and_port(struct domain_device *found_dev,
 	ap->private_data = found_dev;
 	ap->cbl = ATA_CBL_SATA;
 	ap->scsi_host = shost;
+	/* publish initialized ata port */
+	smp_wmb();
 	found_dev->sata_dev.ap = ap;
 
 	return 0;
@@ -683,6 +684,38 @@ static void sas_get_ata_command_set(struct domain_device *dev)
 		dev->sata_dev.command_set = ATAPI_COMMAND_SET;
 }
 
+void sas_probe_sata(struct asd_sas_port *port)
+{
+	struct domain_device *dev, *n;
+	int err;
+
+	mutex_lock(&port->ha->disco_mutex);
+	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
+		if (!dev_is_sata(dev))
+			continue;
+
+		err = sas_ata_init_host_and_port(dev);
+		if (err)
+			sas_fail_probe(dev, __func__, err);
+		else
+			ata_sas_async_port_init(dev->sata_dev.ap);
+	}
+	mutex_unlock(&port->ha->disco_mutex);
+
+	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
+		if (!dev_is_sata(dev))
+			continue;
+
+		sas_ata_wait_eh(dev);
+
+		/* if libata could not bring the link up, don't surface
+		 * the device
+		 */
+		if (ata_dev_disabled(sas_to_ata_dev(dev)))
+			sas_fail_probe(dev, __func__, -ENODEV);
+	}
+}
+
 /**
  * sas_discover_sata -- discover an STP/SATA domain device
  * @dev: pointer to struct domain_device of interest
@@ -724,11 +757,23 @@ static void async_sas_ata_eh(void *data, async_cookie_t cookie)
 	sas_put_device(dev);
 }
 
+static bool sas_ata_dev_eh_valid(struct domain_device *dev)
+{
+	struct ata_port *ap;
+
+	if (!dev_is_sata(dev))
+		return false;
+	ap = dev->sata_dev.ap;
+	/* consume fully initialized ata ports */
+	smp_rmb();
+	return !!ap;
+}
+
 void sas_ata_strategy_handler(struct Scsi_Host *shost)
 {
-	struct scsi_device *sdev;
 	struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
 	LIST_HEAD(async);
+	int i;
 
 	/* it's ok to defer revalidation events during ata eh, these
 	 * disks are in one of three states:
@@ -740,14 +785,21 @@ void sas_ata_strategy_handler(struct Scsi_Host *shost)
 	 */
 	sas_disable_revalidation(sas_ha);
 
-	shost_for_each_device(sdev, shost) {
-		struct domain_device *ddev = sdev_to_domain_dev(sdev);
+	spin_lock_irq(&sas_ha->phy_port_lock);
+	for (i = 0; i < sas_ha->num_phys; i++) {
+		struct asd_sas_port *port = sas_ha->sas_port[i];
+		struct domain_device *dev;
 
-		if (!dev_is_sata(ddev))
-			continue;
-
-		async_schedule_domain(async_sas_ata_eh, ddev, &async);
+		spin_lock(&port->dev_list_lock);
+		list_for_each_entry(dev, &port->dev_list, dev_list_node) {
+			if (!sas_ata_dev_eh_valid(dev))
+				continue;
+			async_schedule_domain(async_sas_ata_eh, dev, &async);
+		}
+		spin_unlock(&port->dev_list_lock);
 	}
+	spin_unlock_irq(&sas_ha->phy_port_lock);
+
 	async_synchronize_full_domain(&async);
 
 	sas_enable_revalidation(sas_ha);

drivers/scsi/libsas/sas_discover.c

@@ -207,22 +207,22 @@ static void sas_probe_devices(struct work_struct *work)
 
 	clear_bit(DISCE_PROBE, &port->disc.pending);
 
-	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
-		int err;
-
+	/* devices must be domain members before link recovery and probe */
+	list_for_each_entry(dev, &port->disco_list, disco_list_node) {
 		spin_lock_irq(&port->dev_list_lock);
 		list_add_tail(&dev->dev_list_node, &port->dev_list);
 		spin_unlock_irq(&port->dev_list_lock);
+	}
+
+	sas_probe_sata(port);
+
+	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
+		int err;
 
 		err = sas_rphy_add(dev->rphy);
-
-		if (err) {
-			SAS_DPRINTK("%s: for %s device %16llx returned %d\n",
-				    __func__, dev->parent ? "exp-attached" :
-							    "direct-attached",
-				    SAS_ADDR(dev->sas_addr), err);
-			sas_unregister_dev(port, dev);
-		} else
+		if (err)
+			sas_fail_probe(dev, __func__, err);
+		else
 			list_del_init(&dev->disco_list_node);
 	}
 }

drivers/scsi/libsas/sas_internal.h

@@ -113,6 +113,15 @@ static inline int sas_smp_host_handler(struct Scsi_Host *shost,
 }
 #endif
 
+static inline void sas_fail_probe(struct domain_device *dev, const char *func, int err)
+{
+	SAS_DPRINTK("%s: for %s device %16llx returned %d\n",
+		    func, dev->parent ? "exp-attached" :
+					    "direct-attached",
+		    SAS_ADDR(dev->sas_addr), err);
+	sas_unregister_dev(dev->port, dev);
+}
+
 static inline void sas_fill_in_rphy(struct domain_device *dev,
 				    struct sas_rphy *rphy)
 {

drivers/scsi/libsas/sas_scsi_host.c

@@ -762,17 +762,10 @@ int sas_target_alloc(struct scsi_target *starget)
 {
 	struct sas_rphy *rphy = dev_to_rphy(starget->dev.parent);
 	struct domain_device *found_dev = sas_find_dev_by_rphy(rphy);
-	int res;
 
 	if (!found_dev)
 		return -ENODEV;
 
-	if (dev_is_sata(found_dev)) {
-		res = sas_ata_init_host_and_port(found_dev, starget);
-		if (res)
-			return res;
-	}
-
 	kref_get(&found_dev->kref);
 	starget->hostdata = found_dev;
 	return 0;
@@ -1012,16 +1005,6 @@ void sas_task_abort(struct sas_task *task)
 	}
 }
 
-int sas_slave_alloc(struct scsi_device *scsi_dev)
-{
-	struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
-
-	if (dev_is_sata(dev))
-		return ata_sas_port_init(dev->sata_dev.ap);
-
-	return 0;
-}
-
 void sas_target_destroy(struct scsi_target *starget)
 {
 	struct domain_device *found_dev = starget->hostdata;
@@ -1082,6 +1065,5 @@ EXPORT_SYMBOL_GPL(sas_task_abort);
 EXPORT_SYMBOL_GPL(sas_phy_reset);
 EXPORT_SYMBOL_GPL(sas_eh_device_reset_handler);
 EXPORT_SYMBOL_GPL(sas_eh_bus_reset_handler);
-EXPORT_SYMBOL_GPL(sas_slave_alloc);
 EXPORT_SYMBOL_GPL(sas_target_destroy);
 EXPORT_SYMBOL_GPL(sas_ioctl);