[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 <[email protected]>
Signed-off-by: Christof Schmitt <[email protected]>
Signed-off-by: James Bottomley <[email protected]>

Author: sswen

drivers/s390/scsi/zfcp_aux.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);
 }
 
 /**

drivers/s390/scsi/zfcp_ccw.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:

drivers/s390/scsi/zfcp_cfdc.c

@@ -1067,6 +1067,8 @@ int zfcp_dbf_adapter_register(struct zfcp_adapter *adapter)
  */
 void zfcp_dbf_adapter_unregister(struct zfcp_dbf *dbf)
 {
+	if (!dbf)
+		return;
 	debug_unregister(dbf->scsi);
 	debug_unregister(dbf->san);
 	debug_unregister(dbf->hba);

drivers/s390/scsi/zfcp_dbf.c

@@ -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 */

drivers/s390/scsi/zfcp_def.h

@@ -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;
 }
 

drivers/s390/scsi/zfcp_erp.c

@@ -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);

drivers/s390/scsi/zfcp_ext.h

@@ -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 @@ void zfcp_fc_port_did_lookup(struct work_struct *work)
  */
 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 @@ void zfcp_fc_link_test_work(struct work_struct *work)
  */
 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)
@@ -576,21 +578,19 @@ 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;
 
 	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) +