[SCSI] zfcp: Replace local reference counting with common kref

Replace the local reference counting by already available mechanisms
offered by kref. Where possible existing device structures were used,
including the same functionality.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

11 files changed, 196 insertions, 258 deletions

diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index 883e139..8492cea 100644
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -96,13 +96,12 @@ static void __init zfcp_init_device_configure(char *busid, u64 wwpn, u64 lun)
 	adapter = dev_get_drvdata(&ccwdev->dev);
 	if (!adapter)
 		goto out_unlock;
-	zfcp_adapter_get(adapter);
+	kref_get(&adapter->ref);
 
 	port = zfcp_get_port_by_wwpn(adapter, wwpn);
 	if (!port)
 		goto out_port;
 
-	zfcp_port_get(port);
 	unit = zfcp_unit_enqueue(port, lun);
 	if (IS_ERR(unit))
 		goto out_unit;
@@ -113,11 +112,10 @@ static void __init zfcp_init_device_configure(char *busid, u64 wwpn, u64 lun)
 	flush_work(&unit->scsi_work);
 
 	mutex_lock(&zfcp_data.config_mutex);
-	zfcp_unit_put(unit);
 out_unit:
-	zfcp_port_put(port);
+	put_device(&port->sysfs_device);
 out_port:
-	zfcp_adapter_put(adapter);
+	kref_put(&adapter->ref, zfcp_adapter_release);
 out_unlock:
 	mutex_unlock(&zfcp_data.config_mutex);
 out_ccwdev:
@@ -244,7 +242,7 @@ struct zfcp_unit *zfcp_get_unit_by_lun(struct zfcp_port *port, u64 fcp_lun)
 	list_for_each_entry(unit, &port->unit_list, list)
 		if ((unit->fcp_lun == fcp_lun) &&
 		    !(atomic_read(&unit->status) & ZFCP_STATUS_COMMON_REMOVE)) {
-			zfcp_unit_get(unit);
+			get_device(&unit->sysfs_device);
 			read_unlock_irqrestore(&port->unit_list_lock, flags);
 			return unit;
 		}
@@ -269,7 +267,7 @@ struct zfcp_port *zfcp_get_port_by_wwpn(struct zfcp_adapter *adapter,
 	list_for_each_entry(port, &adapter->port_list, list)
 		if ((port->wwpn == wwpn) &&
 		    !(atomic_read(&port->status) & ZFCP_STATUS_COMMON_REMOVE)) {
-			zfcp_port_get(port);
+			get_device(&port->sysfs_device);
 			read_unlock_irqrestore(&adapter->port_list_lock, flags);
 			return port;
 		}
@@ -277,9 +275,20 @@ struct zfcp_port *zfcp_get_port_by_wwpn(struct zfcp_adapter *adapter,
 	return NULL;
 }
 
-static void zfcp_sysfs_unit_release(struct device *dev)
+/**
+ * zfcp_unit_release - dequeue unit
+ * @dev: pointer to device
+ *
+ * waits until all work is done on unit and removes it then from the unit->list
+ * of the associated port.
+ */
+static void zfcp_unit_release(struct device *dev)
 {
-	kfree(container_of(dev, struct zfcp_unit, sysfs_device));
+	struct zfcp_unit *unit = container_of(dev, struct zfcp_unit,
+					      sysfs_device);
+
+	put_device(&unit->port->sysfs_device);
+	kfree(unit);
 }
 
 /**
@@ -294,36 +303,39 @@ static void zfcp_sysfs_unit_release(struct device *dev)
 struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *port, u64 fcp_lun)
 {
 	struct zfcp_unit *unit;
+	int retval = -ENOMEM;
+
+	get_device(&port->sysfs_device);
 
 	unit = zfcp_get_unit_by_lun(port, fcp_lun);
 	if (unit) {
-		zfcp_unit_put(unit);
-		return ERR_PTR(-EINVAL);
+		put_device(&unit->sysfs_device);
+		retval = -EEXIST;
+		goto err_out;
 	}
 
 	unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL);
 	if (!unit)
-		return ERR_PTR(-ENOMEM);
-
-	atomic_set(&unit->refcount, 0);
-	init_waitqueue_head(&unit->remove_wq);
-	INIT_WORK(&unit->scsi_work, zfcp_scsi_scan);
+		goto err_out;
 
 	unit->port = port;
 	unit->fcp_lun = fcp_lun;
+	unit->sysfs_device.parent = &port->sysfs_device;
+	unit->sysfs_device.release = zfcp_unit_release;
 
 	if (dev_set_name(&unit->sysfs_device, "0x%016llx",
 			 (unsigned long long) fcp_lun)) {
 		kfree(unit);
-		return ERR_PTR(-ENOMEM);
+		goto err_out;
 	}
-	unit->sysfs_device.parent = &port->sysfs_device;
-	unit->sysfs_device.release = zfcp_sysfs_unit_release;
 	dev_set_drvdata(&unit->sysfs_device, unit);
+	retval = -EINVAL;
 
 	/* mark unit unusable as long as sysfs registration is not complete */
 	atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
 
+	INIT_WORK(&unit->scsi_work, zfcp_scsi_scan);
+
 	spin_lock_init(&unit->latencies.lock);
 	unit->latencies.write.channel.min = 0xFFFFFFFF;
 	unit->latencies.write.fabric.min = 0xFFFFFFFF;
@@ -334,16 +346,12 @@ struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *port, u64 fcp_lun)
 
 	if (device_register(&unit->sysfs_device)) {
 		put_device(&unit->sysfs_device);
-		return ERR_PTR(-EINVAL);
+		goto err_out;
 	}
 
 	if (sysfs_create_group(&unit->sysfs_device.kobj,
-			       &zfcp_sysfs_unit_attrs)) {
-		device_unregister(&unit->sysfs_device);
-		return ERR_PTR(-EINVAL);
-	}
-
-	zfcp_unit_get(unit);
+			       &zfcp_sysfs_unit_attrs))
+		goto err_out_put;
 
 	write_lock_irq(&port->unit_list_lock);
 	list_add_tail(&unit->list, &port->unit_list);
@@ -352,27 +360,13 @@ struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *port, u64 fcp_lun)
 	atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
 	atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);
 
-	zfcp_port_get(port);
-
 	return unit;
-}
-
-/**
- * zfcp_unit_dequeue - dequeue unit
- * @unit: pointer to zfcp_unit
- *
- * waits until all work is done on unit and removes it then from the unit->list
- * of the associated port.
- */
-void zfcp_unit_dequeue(struct zfcp_unit *unit)
-{
-	struct zfcp_port *port = unit->port;
 
-	wait_event(unit->remove_wq, atomic_read(&unit->refcount) == 0);
-	list_del(&unit->list); /* no list locking required */
-	zfcp_port_put(port);
-	sysfs_remove_group(&unit->sysfs_device.kobj, &zfcp_sysfs_unit_attrs);
+err_out_put:
 	device_unregister(&unit->sysfs_device);
+err_out:
+	put_device(&port->sysfs_device);
+	return ERR_PTR(retval);
 }
 
 static int zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
@@ -518,41 +512,44 @@ int zfcp_adapter_enqueue(struct ccw_device *ccw_device)
 {
 	struct zfcp_adapter *adapter;
 
-	/*
-	 * Note: It is safe to release the list_lock, as any list changes
-	 * are protected by the config_mutex, which must be held to get here
-	 */
+	if (!get_device(&ccw_device->dev))
+		return -ENODEV;
 
 	adapter = kzalloc(sizeof(struct zfcp_adapter), GFP_KERNEL);
-	if (!adapter)
+	if (!adapter) {
+		put_device(&ccw_device->dev);
 		return -ENOMEM;
+	}
+
+	kref_init(&adapter->ref);
 
 	ccw_device->handler = NULL;
 	adapter->ccw_device = ccw_device;
-	atomic_set(&adapter->refcount, 0);
+
+	INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);
+	INIT_WORK(&adapter->scan_work, _zfcp_fc_scan_ports_later);
 
 	if (zfcp_qdio_setup(adapter))
-		goto qdio_failed;
+		goto failed;
 
 	if (zfcp_allocate_low_mem_buffers(adapter))
-		goto low_mem_buffers_failed;
+		goto failed;
 
 	if (zfcp_reqlist_alloc(adapter))
-		goto low_mem_buffers_failed;
+		goto failed;
 
 	if (zfcp_dbf_adapter_register(adapter))
-		goto debug_register_failed;
+		goto failed;
 
 	if (zfcp_setup_adapter_work_queue(adapter))
-		goto work_queue_failed;
+		goto failed;
 
 	if (zfcp_fc_gs_setup(adapter))
-		goto generic_services_failed;
+		goto failed;
 
 	rwlock_init(&adapter->port_list_lock);
 	INIT_LIST_HEAD(&adapter->port_list);
 
-	init_waitqueue_head(&adapter->remove_wq);
 	init_waitqueue_head(&adapter->erp_ready_wq);
 	init_waitqueue_head(&adapter->erp_done_wqh);
 
@@ -565,10 +562,7 @@ int zfcp_adapter_enqueue(struct ccw_device *ccw_device)
 	rwlock_init(&adapter->abort_lock);
 
 	if (zfcp_erp_thread_setup(adapter))
-		goto erp_thread_failed;
-
-	INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);
-	INIT_WORK(&adapter->scan_work, _zfcp_fc_scan_ports_later);
+		goto failed;
 
 	adapter->service_level.seq_print = zfcp_print_sl;
 
@@ -579,54 +573,37 @@ int zfcp_adapter_enqueue(struct ccw_device *ccw_device)
 
 	if (sysfs_create_group(&ccw_device->dev.kobj,
 			       &zfcp_sysfs_adapter_attrs))
-		goto sysfs_failed;
+		goto failed;
 
 	atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);
 
 	if (!zfcp_adapter_scsi_register(adapter))
 		return 0;
 
-sysfs_failed:
-	zfcp_erp_thread_kill(adapter);
-erp_thread_failed:
-	zfcp_fc_gs_destroy(adapter);
-generic_services_failed:
-	zfcp_destroy_adapter_work_queue(adapter);
-work_queue_failed:
-	zfcp_dbf_adapter_unregister(adapter->dbf);
-debug_register_failed:
-	dev_set_drvdata(&ccw_device->dev, NULL);
-	kfree(adapter->req_list);
-low_mem_buffers_failed:
-	zfcp_free_low_mem_buffers(adapter);
-qdio_failed:
-	zfcp_qdio_destroy(adapter->qdio);
-	kfree(adapter);
+failed:
+	kref_put(&adapter->ref, zfcp_adapter_release);
 	return -ENOMEM;
 }
 
 /**
- * zfcp_adapter_dequeue - remove the adapter from the resource list
- * @adapter: pointer to struct zfcp_adapter which should be removed
+ * zfcp_adapter_release - remove the adapter from the resource list
+ * @ref: pointer to struct kref
  * locks:	adapter list write lock is assumed to be held by caller
  */
-void zfcp_adapter_dequeue(struct zfcp_adapter *adapter)
+void zfcp_adapter_release(struct kref *ref)
 {
-	int retval = 0;
-	unsigned long flags;
+	struct zfcp_adapter *adapter = container_of(ref, struct zfcp_adapter,
+						    ref);
+	struct ccw_device *ccw_device = adapter->ccw_device;
 
 	cancel_work_sync(&adapter->stat_work);
+
 	zfcp_fc_wka_ports_force_offline(adapter->gs);
-	sysfs_remove_group(&adapter->ccw_device->dev.kobj,
-			   &zfcp_sysfs_adapter_attrs);
-	dev_set_drvdata(&adapter->ccw_device->dev, NULL);
-	/* sanity check: no pending FSF requests */
-	spin_lock_irqsave(&adapter->req_list_lock, flags);
-	retval = zfcp_reqlist_isempty(adapter);
-	spin_unlock_irqrestore(&adapter->req_list_lock, flags);
-	if (!retval)
-		return;
+	sysfs_remove_group(&ccw_device->dev.kobj, &zfcp_sysfs_adapter_attrs);
+
+	dev_set_drvdata(&ccw_device->dev, NULL);
 
+	dev_set_drvdata(&adapter->ccw_device->dev, NULL);
 	zfcp_fc_gs_destroy(adapter);
 	zfcp_erp_thread_kill(adapter);
 	zfcp_destroy_adapter_work_queue(adapter);
@@ -637,11 +614,30 @@ void zfcp_adapter_dequeue(struct zfcp_adapter *adapter)
 	kfree(adapter->fc_stats);
 	kfree(adapter->stats_reset_data);
 	kfree(adapter);
+	put_device(&ccw_device->dev);
+}
+
+/**
+ * zfcp_device_unregister - remove port, unit from system
+ * @dev: reference to device which is to be removed
+ * @grp: related reference to attribute group
+ *
+ * Helper function to unregister port, unit from system
+ */
+void zfcp_device_unregister(struct device *dev,
+			    const struct attribute_group *grp)
+{
+	sysfs_remove_group(&dev->kobj, grp);
+	device_unregister(dev);
 }
 
-static void zfcp_sysfs_port_release(struct device *dev)
+static void zfcp_port_release(struct device *dev)
 {
-	kfree(container_of(dev, struct zfcp_port, sysfs_device));
+	struct zfcp_port *port = container_of(dev, struct zfcp_port,
+					      sysfs_device);
+
+	kref_put(&port->adapter->ref, zfcp_adapter_release);
+	kfree(port);
 }
 
 /**
@@ -661,21 +657,24 @@ struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
 				     u32 status, u32 d_id)
 {
 	struct zfcp_port *port;
+	int retval = -ENOMEM;
+
+	kref_get(&adapter->ref);
 
 	port = zfcp_get_port_by_wwpn(adapter, wwpn);
 	if (port) {
-		zfcp_port_put(port);
-		return ERR_PTR(-EEXIST);
+		put_device(&port->sysfs_device);
+		retval = -EEXIST;
+		goto err_out;
 	}
 
 	port = kzalloc(sizeof(struct zfcp_port), GFP_KERNEL);
 	if (!port)
-		return ERR_PTR(-ENOMEM);
+		goto err_out;
 
 	rwlock_init(&port->unit_list_lock);
 	INIT_LIST_HEAD(&port->unit_list);
 
-	init_waitqueue_head(&port->remove_wq);
 	INIT_WORK(&port->gid_pn_work, zfcp_fc_port_did_lookup);
 	INIT_WORK(&port->test_link_work, zfcp_fc_link_test_work);
 	INIT_WORK(&port->rport_work, zfcp_scsi_rport_work);
@@ -684,32 +683,28 @@ struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
 	port->d_id = d_id;
 	port->wwpn = wwpn;
 	port->rport_task = RPORT_NONE;
+	port->sysfs_device.parent = &adapter->ccw_device->dev;
+	port->sysfs_device.release = zfcp_port_release;
 
 	/* mark port unusable as long as sysfs registration is not complete */
 	atomic_set_mask(status | ZFCP_STATUS_COMMON_REMOVE, &port->status);
-	atomic_set(&port->refcount, 0);
 
 	if (dev_set_name(&port->sysfs_device, "0x%016llx",
 			 (unsigned long long)wwpn)) {
 		kfree(port);
-		return ERR_PTR(-ENOMEM);
+		goto err_out;
 	}
-	port->sysfs_device.parent = &adapter->ccw_device->dev;
-	port->sysfs_device.release = zfcp_sysfs_port_release;
 	dev_set_drvdata(&port->sysfs_device, port);
+	retval = -EINVAL;
 
 	if (device_register(&port->sysfs_device)) {
 		put_device(&port->sysfs_device);
-		return ERR_PTR(-EINVAL);
+		goto err_out;
 	}
 
 	if (sysfs_create_group(&port->sysfs_device.kobj,
-			       &zfcp_sysfs_port_attrs)) {
-		device_unregister(&port->sysfs_device);
-		return ERR_PTR(-EINVAL);
-	}
-
-	zfcp_port_get(port);
+			       &zfcp_sysfs_port_attrs))
+		goto err_out_put;
 
 	write_lock_irq(&adapter->port_list_lock);
 	list_add_tail(&port->list, &adapter->port_list);
@@ -718,23 +713,13 @@ struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
 	atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status);
 	atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &port->status);
 
-	zfcp_adapter_get(adapter);
 	return port;
-}
 
-/**
- * zfcp_port_dequeue - dequeues a port from the port list of the adapter
- * @port: pointer to struct zfcp_port which should be removed
- */
-void zfcp_port_dequeue(struct zfcp_port *port)
-{
-	struct zfcp_adapter *adapter = port->adapter;
-
-	list_del(&port->list); /* no list locking required here */
-	wait_event(port->remove_wq, atomic_read(&port->refcount) == 0);
-	zfcp_adapter_put(adapter);
-	sysfs_remove_group(&port->sysfs_device.kobj, &zfcp_sysfs_port_attrs);
+err_out_put:
 	device_unregister(&port->sysfs_device);
+err_out:
+	kref_put(&adapter->ref, zfcp_adapter_release);
+	return ERR_PTR(retval);
 }
 
 /**
diff --git a/drivers/s390/scsi/zfcp_ccw.c b/drivers/s390/scsi/zfcp_ccw.c
index aca2047..c89dbe2 100644
--- a/drivers/s390/scsi/zfcp_ccw.c
+++ b/drivers/s390/scsi/zfcp_ccw.c
@@ -128,13 +128,15 @@ static void zfcp_ccw_remove(struct ccw_device *ccw_device)
 	write_unlock_irq(&adapter->port_list_lock);
 	mutex_unlock(&zfcp_data.config_mutex);
 
-	list_for_each_entry_safe(port, p, &port_remove_lh, list) {
-		list_for_each_entry_safe(unit, u, &unit_remove_lh, list)
-			zfcp_unit_dequeue(unit);
-		zfcp_port_dequeue(port);
-	}
-	wait_event(adapter->remove_wq, atomic_read(&adapter->refcount) == 0);
-	zfcp_adapter_dequeue(adapter);
+	list_for_each_entry_safe(unit, u, &unit_remove_lh, list)
+		zfcp_device_unregister(&unit->sysfs_device,
+				       &zfcp_sysfs_unit_attrs);
+
+	list_for_each_entry_safe(port, p, &port_remove_lh, list)
+		zfcp_device_unregister(&port->sysfs_device,
+				       &zfcp_sysfs_port_attrs);
+
+	kref_put(&adapter->ref, zfcp_adapter_release);
 }
 
 /**
diff --git a/drivers/s390/scsi/zfcp_cfdc.c b/drivers/s390/scsi/zfcp_cfdc.c
index ef681df..856f82d 100644
--- a/drivers/s390/scsi/zfcp_cfdc.c
+++ b/drivers/s390/scsi/zfcp_cfdc.c
@@ -98,7 +98,7 @@ static struct zfcp_adapter *zfcp_cfdc_get_adapter(u32 devno)
 	if (!adapter)
 		goto out_put;
 
-	zfcp_adapter_get(adapter);
+	kref_get(&adapter->ref);
 out_put:
 	put_device(&ccwdev->dev);
 out:
@@ -212,7 +212,6 @@ static long zfcp_cfdc_dev_ioctl(struct file *file, unsigned int command,
 		retval = -ENXIO;
 		goto free_buffer;
 	}
-	zfcp_adapter_get(adapter);
 
 	retval = zfcp_cfdc_sg_setup(data->command, fsf_cfdc->sg,
 				    data_user->control_file);
@@ -245,7 +244,7 @@ static long zfcp_cfdc_dev_ioctl(struct file *file, unsigned int command,
  free_sg:
 	zfcp_sg_free_table(fsf_cfdc->sg, ZFCP_CFDC_PAGES);
  adapter_put:
-	zfcp_adapter_put(adapter);
+	kref_put(&adapter->ref, zfcp_adapter_release);
  free_buffer:
 	kfree(data);
  no_mem_sense:
diff --git a/drivers/s390/scsi/zfcp_dbf.c b/drivers/s390/scsi/zfcp_dbf.c
index 215b707..fe818cd 100644
--- a/drivers/s390/scsi/zfcp_dbf.c
+++ b/drivers/s390/scsi/zfcp_dbf.c
@@ -1067,6 +1067,8 @@ err_out:
  */
 void zfcp_dbf_adapter_unregister(struct zfcp_dbf *dbf)
 {
+	if (!dbf)
+		return;
 	debug_unregister(dbf->scsi);
 	debug_unregister(dbf->san);
 	debug_unregister(dbf->hba);
diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h
index e45a08d..55dc402 100644
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -446,9 +446,7 @@ struct zfcp_qdio {
 };
 
 struct zfcp_adapter {
-	atomic_t                refcount;          /* reference count */
-	wait_queue_head_t	remove_wq;         /* can be used to wait for
-						      refcount drop to zero */
+	struct kref		ref;
 	u64			peer_wwnn;	   /* P2P peer WWNN */
 	u64			peer_wwpn;	   /* P2P peer WWPN */
 	u32			peer_d_id;	   /* P2P peer D_ID */
@@ -501,9 +499,6 @@ struct zfcp_port {
 	struct device          sysfs_device;   /* sysfs device */
 	struct fc_rport        *rport;         /* rport of fc transport class */
 	struct list_head       list;	       /* list of remote ports */
-	atomic_t               refcount;       /* reference count */
-	wait_queue_head_t      remove_wq;      /* can be used to wait for
-						  refcount drop to zero */
 	struct zfcp_adapter    *adapter;       /* adapter used to access port */
 	struct list_head	unit_list;	/* head of logical unit list */
 	rwlock_t		unit_list_lock; /* unit list lock */
@@ -525,9 +520,6 @@ struct zfcp_port {
 struct zfcp_unit {
 	struct device          sysfs_device;   /* sysfs device */
 	struct list_head       list;	       /* list of logical units */
-	atomic_t               refcount;       /* reference count */
-	wait_queue_head_t      remove_wq;      /* can be used to wait for
-						  refcount drop to zero */
 	struct zfcp_port       *port;	       /* remote port of unit */
 	atomic_t	       status;	       /* status of this logical unit */
 	u64		       fcp_lun;	       /* own FCP_LUN */
@@ -656,47 +648,4 @@ zfcp_reqlist_find_safe(struct zfcp_adapter *adapter, struct zfcp_fsf_req *req)
 	return NULL;
 }
 
-/*
- *  functions needed for reference/usage counting
- */
-
-static inline void
-zfcp_unit_get(struct zfcp_unit *unit)
-{
-	atomic_inc(&unit->refcount);
-}
-
-static inline void
-zfcp_unit_put(struct zfcp_unit *unit)
-{
-	if (atomic_dec_return(&unit->refcount) == 0)
-		wake_up(&unit->remove_wq);
-}
-
-static inline void
-zfcp_port_get(struct zfcp_port *port)
-{
-	atomic_inc(&port->refcount);
-}
-
-static inline void
-zfcp_port_put(struct zfcp_port *port)
-{
-	if (atomic_dec_return(&port->refcount) == 0)
-		wake_up(&port->remove_wq);
-}
-
-static inline void
-zfcp_adapter_get(struct zfcp_adapter *adapter)
-{
-	atomic_inc(&adapter->refcount);
-}
-
-static inline void
-zfcp_adapter_put(struct zfcp_adapter *adapter)
-{
-	if (atomic_dec_return(&adapter->refcount) == 0)
-		wake_up(&adapter->remove_wq);
-}
-
 #endif /* ZFCP_DEF_H */
diff --git a/drivers/s390/scsi/zfcp_erp.c b/drivers/s390/scsi/zfcp_erp.c
index 464f047..788fd3a 100644
--- a/drivers/s390/scsi/zfcp_erp.c
+++ b/drivers/s390/scsi/zfcp_erp.c
@@ -174,7 +174,7 @@ static struct zfcp_erp_action *zfcp_erp_setup_act(int need,
 
 	switch (need) {
 	case ZFCP_ERP_ACTION_REOPEN_UNIT:
-		zfcp_unit_get(unit);
+		get_device(&unit->sysfs_device);
 		atomic_set_mask(ZFCP_STATUS_COMMON_ERP_INUSE, &unit->status);
 		erp_action = &unit->erp_action;
 		if (!(atomic_read(&unit->status) & ZFCP_STATUS_COMMON_RUNNING))
@@ -183,7 +183,7 @@ static struct zfcp_erp_action *zfcp_erp_setup_act(int need,
 
 	case ZFCP_ERP_ACTION_REOPEN_PORT:
 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
-		zfcp_port_get(port);
+		get_device(&port->sysfs_device);
 		zfcp_erp_action_dismiss_port(port);
 		atomic_set_mask(ZFCP_STATUS_COMMON_ERP_INUSE, &port->status);
 		erp_action = &port->erp_action;
@@ -192,7 +192,7 @@ static struct zfcp_erp_action *zfcp_erp_setup_act(int need,
 		break;
 
 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
-		zfcp_adapter_get(adapter);
+		kref_get(&adapter->ref);
 		zfcp_erp_action_dismiss_adapter(adapter);
 		atomic_set_mask(ZFCP_STATUS_COMMON_ERP_INUSE, &adapter->status);
 		erp_action = &adapter->erp_action;
@@ -1177,19 +1177,19 @@ static void zfcp_erp_action_cleanup(struct zfcp_erp_action *act, int result)
 	switch (act->action) {
 	case ZFCP_ERP_ACTION_REOPEN_UNIT:
 		if ((result == ZFCP_ERP_SUCCEEDED) && !unit->device) {
-			zfcp_unit_get(unit);
+			get_device(&unit->sysfs_device);
 			if (scsi_queue_work(unit->port->adapter->scsi_host,
 					    &unit->scsi_work) <= 0)
-				zfcp_unit_put(unit);
+				put_device(&unit->sysfs_device);
 		}
-		zfcp_unit_put(unit);
+		put_device(&unit->sysfs_device);
 		break;
 
 	case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
 	case ZFCP_ERP_ACTION_REOPEN_PORT:
 		if (result == ZFCP_ERP_SUCCEEDED)
 			zfcp_scsi_schedule_rport_register(port);
-		zfcp_port_put(port);
+		put_device(&port->sysfs_device);
 		break;
 
 	case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
@@ -1198,7 +1198,7 @@ static void zfcp_erp_action_cleanup(struct zfcp_erp_action *act, int result)
 			schedule_work(&adapter->scan_work);
 		} else
 			unregister_service_level(&adapter->service_level);
-		zfcp_adapter_put(adapter);
+		kref_put(&adapter->ref, zfcp_adapter_release);
 		break;
 	}
 }
@@ -1224,8 +1224,9 @@ static int zfcp_erp_strategy(struct zfcp_erp_action *erp_action)
 	unsigned long flags;
 	struct zfcp_adapter *adapter = erp_action->adapter;
 
-	write_lock_irqsave(&adapter->erp_lock, flags);
+	kref_get(&adapter->ref);
 
+	write_lock_irqsave(&adapter->erp_lock, flags);
 	zfcp_erp_strategy_check_fsfreq(erp_action);
 
 	if (erp_action->status & ZFCP_STATUS_ERP_DISMISSED) {
@@ -1282,6 +1283,7 @@ static int zfcp_erp_strategy(struct zfcp_erp_action *erp_action)
 	if (retval != ZFCP_ERP_CONTINUES)
 		zfcp_erp_action_cleanup(erp_action, retval);
 
+	kref_put(&adapter->ref, zfcp_adapter_release);
 	return retval;
 }
 
diff --git a/drivers/s390/scsi/zfcp_ext.h b/drivers/s390/scsi/zfcp_ext.h
index b3f28de..3106c3b 100644
--- a/drivers/s390/scsi/zfcp_ext.h
+++ b/drivers/s390/scsi/zfcp_ext.h
@@ -15,15 +15,15 @@
 extern struct zfcp_unit *zfcp_get_unit_by_lun(struct zfcp_port *, u64);
 extern struct zfcp_port *zfcp_get_port_by_wwpn(struct zfcp_adapter *, u64);
 extern int zfcp_adapter_enqueue(struct ccw_device *);
-extern void zfcp_adapter_dequeue(struct zfcp_adapter *);
 extern struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *, u64, u32,
 					   u32);
-extern void zfcp_port_dequeue(struct zfcp_port *);
 extern struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *, u64);
-extern void zfcp_unit_dequeue(struct zfcp_unit *);
 extern int zfcp_reqlist_isempty(struct zfcp_adapter *);
 extern void zfcp_sg_free_table(struct scatterlist *, int);
 extern int zfcp_sg_setup_table(struct scatterlist *, int);
+extern void zfcp_device_unregister(struct device *,
+				   const struct attribute_group *);
+extern void zfcp_adapter_release(struct kref *);
 
 /* zfcp_ccw.c */
 extern int zfcp_ccw_register(void);
diff --git a/drivers/s390/scsi/zfcp_fc.c b/drivers/s390/scsi/zfcp_fc.c
index c7efdc5..6fa1bcb 100644
--- a/drivers/s390/scsi/zfcp_fc.c
+++ b/drivers/s390/scsi/zfcp_fc.c
@@ -134,6 +134,8 @@ static void zfcp_fc_wka_port_force_offline(struct zfcp_wka_port *wka)
 
 void zfcp_fc_wka_ports_force_offline(struct zfcp_wka_ports *gs)
 {
+	if (!gs)
+		return;
 	zfcp_fc_wka_port_force_offline(&gs->ms);
 	zfcp_fc_wka_port_force_offline(&gs->ts);
 	zfcp_fc_wka_port_force_offline(&gs->ds);
@@ -356,7 +358,7 @@ void zfcp_fc_port_did_lookup(struct work_struct *work)
 
 	zfcp_erp_port_reopen(port, 0, "fcgpn_3", NULL);
 out:
-	zfcp_port_put(port);
+	put_device(&port->sysfs_device);
 }
 
 /**
@@ -365,9 +367,9 @@ out:
  */
 void zfcp_fc_trigger_did_lookup(struct zfcp_port *port)
 {
-	zfcp_port_get(port);
+	get_device(&port->sysfs_device);
 	if (!queue_work(port->adapter->work_queue, &port->gid_pn_work))
-		zfcp_port_put(port);
+		put_device(&port->sysfs_device);
 }
 
 /**
@@ -426,7 +428,7 @@ static void zfcp_fc_adisc_handler(unsigned long data)
 	zfcp_scsi_schedule_rport_register(port);
  out:
 	atomic_clear_mask(ZFCP_STATUS_PORT_LINK_TEST, &port->status);
-	zfcp_port_put(port);
+	put_device(&port->sysfs_device);
 	kfree(adisc);
 }
 
@@ -468,7 +470,7 @@ void zfcp_fc_link_test_work(struct work_struct *work)
 		container_of(work, struct zfcp_port, test_link_work);
 	int retval;
 
-	zfcp_port_get(port);
+	get_device(&port->sysfs_device);
 	port->rport_task = RPORT_DEL;
 	zfcp_scsi_rport_work(&port->rport_work);
 
@@ -487,7 +489,7 @@ void zfcp_fc_link_test_work(struct work_struct *work)
 	zfcp_erp_port_forced_reopen(port, 0, "fcltwk1", NULL);
 
 out:
-	zfcp_port_put(port);
+	put_device(&port->sysfs_device);
 }
 
 /**
@@ -500,9 +502,9 @@ out:
  */
 void zfcp_fc_test_link(struct zfcp_port *port)
 {
-	zfcp_port_get(port);
+	get_device(&port->sysfs_device);
 	if (!queue_work(port->adapter->work_queue, &port->test_link_work))
-		zfcp_port_put(port);
+		put_device(&port->sysfs_device);
 }
 
 static void zfcp_free_sg_env(struct zfcp_gpn_ft *gpn_ft, int buf_num)
@@ -576,7 +578,7 @@ static int zfcp_fc_send_gpn_ft(struct zfcp_gpn_ft *gpn_ft,
 	return ret;
 }
 
-static void zfcp_fc_validate_port(struct zfcp_port *port)
+static void zfcp_fc_validate_port(struct zfcp_port *port, struct list_head *lh)
 {
 	if (!(atomic_read(&port->status) & ZFCP_STATUS_COMMON_NOESC))
 		return;
@@ -584,13 +586,11 @@ static void zfcp_fc_validate_port(struct zfcp_port *port)
 	atomic_clear_mask(ZFCP_STATUS_COMMON_NOESC, &port->status);
 
 	if ((port->supported_classes != 0) ||
-	    !list_empty(&port->unit_list)) {
-		zfcp_port_put(port);
+	    !list_empty(&port->unit_list))
 		return;
-	}
-	zfcp_erp_port_shutdown(port, 0, "fcpval1", NULL);
-	zfcp_port_put(port);
-	zfcp_port_dequeue(port);
+
+	atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status);
+	list_move_tail(&port->list, lh);
 }
 
 static int zfcp_fc_eval_gpn_ft(struct zfcp_gpn_ft *gpn_ft, int max_entries)
@@ -602,6 +602,7 @@ static int zfcp_fc_eval_gpn_ft(struct zfcp_gpn_ft *gpn_ft, int max_entries)
 	struct zfcp_adapter *adapter = ct->wka_port->adapter;
 	struct zfcp_port *port, *tmp;
 	unsigned long flags;
+	LIST_HEAD(remove_lh);
 	u32 d_id;
 	int ret = 0, x, last = 0;
 
@@ -652,9 +653,16 @@ static int zfcp_fc_eval_gpn_ft(struct zfcp_gpn_ft *gpn_ft, int max_entries)
 	zfcp_erp_wait(adapter);
 	write_lock_irqsave(&adapter->port_list_lock, flags);
 	list_for_each_entry_safe(port, tmp, &adapter->port_list, list)
-		zfcp_fc_validate_port(port);
+		zfcp_fc_validate_port(port, &remove_lh);
 	write_unlock_irqrestore(&adapter->port_list_lock, flags);
 	mutex_unlock(&zfcp_data.config_mutex);
+
+	list_for_each_entry_safe(port, tmp, &remove_lh, list) {
+		zfcp_erp_port_shutdown(port, 0, "fcegpf2", NULL);
+		zfcp_device_unregister(&port->sysfs_device,
+				       &zfcp_sysfs_port_attrs);
+	}
+
 	return ret;
 }
 
@@ -763,7 +771,7 @@ int zfcp_fc_execute_els_fc_job(struct fc_bsg_job *job)
 		}
 
 		els_fc_job->els.d_id = port->d_id;
-		zfcp_port_put(port);
+		put_device(&port->sysfs_device);
 	} else {
 		port_did = job->request->rqst_data.h_els.port_id;
 		els_fc_job->els.d_id = (port_did[0] << 16) +
diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index 9df62f6..3aad709 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -1492,7 +1492,7 @@ static void zfcp_fsf_open_port_handler(struct zfcp_fsf_req *req)
 	}
 
 out:
-	zfcp_port_put(port);
+	put_device(&port->sysfs_device);
 }
 
 /**
@@ -1530,14 +1530,14 @@ int zfcp_fsf_open_port(struct zfcp_erp_action *erp_action)
 	req->data = port;
 	req->erp_action = erp_action;
 	erp_action->fsf_req = req;
-	zfcp_port_get(port);
+	get_device(&port->sysfs_device);
 
 	zfcp_fsf_start_erp_timer(req);
 	retval = zfcp_fsf_req_send(req);
 	if (retval) {
 		zfcp_fsf_req_free(req);
 		erp_action->fsf_req = NULL;
-		zfcp_port_put(port);
+		put_device(&port->sysfs_device);
 	}
 out:
 	spin_unlock_bh(&qdio->req_q_lock);
@@ -2335,7 +2335,7 @@ skip_fsfstatus:
 	else {
 		zfcp_fsf_send_fcp_command_task_handler(req);
 		req->unit = NULL;
-		zfcp_unit_put(unit);
+		put_device(&unit->sysfs_device);
 	}
 }
 
@@ -2387,7 +2387,7 @@ int zfcp_fsf_send_fcp_command_task(struct zfcp_unit *unit,
 	}
 
 	req->status |= ZFCP_STATUS_FSFREQ_CLEANUP;
-	zfcp_unit_get(unit);
+	get_device(&unit->sysfs_device);
 	req->unit = unit;
 	req->data = scsi_cmnd;
 	req->handler = zfcp_fsf_send_fcp_command_handler;
@@ -2463,7 +2463,7 @@ int zfcp_fsf_send_fcp_command_task(struct zfcp_unit *unit,
 	goto out;
 
 failed_scsi_cmnd:
-	zfcp_unit_put(unit);
+	put_device(&unit->sysfs_device);
 	zfcp_fsf_req_free(req);
 	scsi_cmnd->host_scribble = NULL;
 out:
diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c
index 6feece3..39a621d 100644
--- a/drivers/s390/scsi/zfcp_scsi.c
+++ b/drivers/s390/scsi/zfcp_scsi.c
@@ -52,7 +52,7 @@ static void zfcp_scsi_slave_destroy(struct scsi_device *sdpnt)
 {
 	struct zfcp_unit *unit = (struct zfcp_unit *) sdpnt->hostdata;
 	unit->device = NULL;
-	zfcp_unit_put(unit);
+	put_device(&unit->sysfs_device);
 }
 
 static int zfcp_scsi_slave_configure(struct scsi_device *sdp)
@@ -335,8 +335,7 @@ void zfcp_adapter_scsi_unregister(struct zfcp_adapter *adapter)
 
 	read_lock_irq(&adapter->port_list_lock);
 	list_for_each_entry(port, &adapter->port_list, list)
-		if (port->rport)
-			port->rport = NULL;
+		port->rport = NULL;
 	read_unlock_irq(&adapter->port_list_lock);
 
 	fc_remove_host(shost);
@@ -356,7 +355,7 @@ zfcp_init_fc_host_stats(struct zfcp_adapter *adapter)
 		fc_stats = kmalloc(sizeof(*fc_stats), GFP_KERNEL);
 		if (!fc_stats)
 			return NULL;
-		adapter->fc_stats = fc_stats; /* freed in adater_dequeue */
+		adapter->fc_stats = fc_stats; /* freed in adapter_release */
 	}
 	memset(adapter->fc_stats, 0, sizeof(*adapter->fc_stats));
 	return adapter->fc_stats;
@@ -472,7 +471,7 @@ static void zfcp_reset_fc_host_stats(struct Scsi_Host *shost)
 		adapter->stats_reset = jiffies/HZ;
 		kfree(adapter->stats_reset_data);
 		adapter->stats_reset_data = data; /* finally freed in
-						     adapter_dequeue */
+						     adapter_release */
 	}
 }
 
@@ -517,7 +516,7 @@ static void zfcp_scsi_terminate_rport_io(struct fc_rport *rport)
 
 	if (port) {
 		zfcp_erp_port_reopen(port, 0, "sctrpi1", NULL);
-		zfcp_port_put(port);
+		put_device(&port->sysfs_device);
 	}
 }
 
@@ -559,23 +558,23 @@ static void zfcp_scsi_rport_block(struct zfcp_port *port)
 
 void zfcp_scsi_schedule_rport_register(struct zfcp_port *port)
 {
-	zfcp_port_get(port);
+	get_device(&port->sysfs_device);
 	port->rport_task = RPORT_ADD;
 
 	if (!queue_work(port->adapter->work_queue, &port->rport_work))
-		zfcp_port_put(port);
+		put_device(&port->sysfs_device);
 }
 
 void zfcp_scsi_schedule_rport_block(struct zfcp_port *port)
 {
-	zfcp_port_get(port);
+	get_device(&port->sysfs_device);
 	port->rport_task = RPORT_DEL;
 
 	if (port->rport && queue_work(port->adapter->work_queue,
 				      &port->rport_work))
 		return;
 
-	zfcp_port_put(port);
+	put_device(&port->sysfs_device);
 }
 
 void zfcp_scsi_schedule_rports_block(struct zfcp_adapter *adapter)
@@ -604,7 +603,7 @@ void zfcp_scsi_rport_work(struct work_struct *work)
 		}
 	}
 
-	zfcp_port_put(port);
+	put_device(&port->sysfs_device);
 }
 
 
@@ -622,7 +621,7 @@ void zfcp_scsi_scan(struct work_struct *work)
 				 scsilun_to_int((struct scsi_lun *)
 						&unit->fcp_lun), 0);
 
-	zfcp_unit_put(unit);
+	put_device(&unit->sysfs_device);
 }
 
 static int zfcp_execute_fc_job(struct fc_bsg_job *job)
diff --git a/drivers/s390/scsi/zfcp_sysfs.c b/drivers/s390/scsi/zfcp_sysfs.c
index 8430b51..b4a7e17 100644
--- a/drivers/s390/scsi/zfcp_sysfs.c
+++ b/drivers/s390/scsi/zfcp_sysfs.c
@@ -3,7 +3,7 @@
  *
  * sysfs attributes.
  *
- * Copyright IBM Corporation 2008
+ * Copyright IBM Corporation 2008, 2009
  */
 
 #define KMSG_COMPONENT "zfcp"
@@ -140,7 +140,6 @@ static ssize_t zfcp_sysfs_port_remove_store(struct device *dev,
 	struct zfcp_port *port;
 	u64 wwpn;
 	int retval = 0;
-	LIST_HEAD(port_remove_lh);
 
 	mutex_lock(&zfcp_data.config_mutex);
 	if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_REMOVE) {
@@ -154,23 +153,21 @@ static ssize_t zfcp_sysfs_port_remove_store(struct device *dev,
 	}
 
 	port = zfcp_get_port_by_wwpn(adapter, wwpn);
-	if (port && (atomic_read(&port->refcount) == 1)) {
-		atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status);
-		write_lock_irq(&adapter->port_list_lock);
-		list_move(&port->list, &port_remove_lh);
-		write_unlock_irq(&adapter->port_list_lock);
-	} else
-		port = NULL;
-
 	if (!port) {
 		retval = -ENXIO;
 		goto out;
 	}
 
+	atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status);
+
+	write_lock_irq(&adapter->port_list_lock);
+	list_del(&port->list);
+	write_unlock_irq(&adapter->port_list_lock);
+
+	put_device(&port->sysfs_device);
+
 	zfcp_erp_port_shutdown(port, 0, "syprs_1", NULL);
-	zfcp_erp_wait(adapter);
-	zfcp_port_put(port);
-	zfcp_port_dequeue(port);
+	zfcp_device_unregister(&port->sysfs_device, &zfcp_sysfs_port_attrs);
  out:
 	mutex_unlock(&zfcp_data.config_mutex);
 	return retval ? retval : (ssize_t) count;
@@ -224,7 +221,6 @@ static ssize_t zfcp_sysfs_unit_add_store(struct device *dev,
 	zfcp_erp_unit_reopen(unit, 0, "syuas_1", NULL);
 	zfcp_erp_wait(unit->port->adapter);
 	flush_work(&unit->scsi_work);
-	zfcp_unit_put(unit);
 out:
 	mutex_unlock(&zfcp_data.config_mutex);
 	return retval ? retval : (ssize_t) count;
@@ -239,7 +235,6 @@ static ssize_t zfcp_sysfs_unit_remove_store(struct device *dev,
 	struct zfcp_unit *unit;
 	u64 fcp_lun;
 	int retval = 0;
-	LIST_HEAD(unit_remove_lh);
 
 	mutex_lock(&zfcp_data.config_mutex);
 	if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_REMOVE) {
@@ -261,19 +256,16 @@ static ssize_t zfcp_sysfs_unit_remove_store(struct device *dev,
 	/* wait for possible timeout during SCSI probe */
 	flush_work(&unit->scsi_work);
 
-	if (atomic_read(&unit->refcount) == 1) {
-		atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
+	atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
+
+	write_lock_irq(&port->unit_list_lock);
+	list_del(&unit->list);
+	write_unlock_irq(&port->unit_list_lock);
 
-		write_lock_irq(&port->unit_list_lock);
-		list_move(&unit->list, &unit_remove_lh);
-		write_unlock_irq(&port->unit_list_lock);
+	put_device(&unit->sysfs_device);
 
-		zfcp_erp_unit_shutdown(unit, 0, "syurs_1", NULL);
-		zfcp_erp_wait(unit->port->adapter);
-		zfcp_unit_put(unit);
-		zfcp_unit_dequeue(unit);
-	} else
-		zfcp_unit_put(unit);
+	zfcp_erp_unit_shutdown(unit, 0, "syurs_1", NULL);
+	zfcp_device_unregister(&unit->sysfs_device, &zfcp_sysfs_unit_attrs);
 out:
 	mutex_unlock(&zfcp_data.config_mutex);
 	return retval ? retval : (ssize_t) count;