[SCSI] zfcp: cleanup unit sysfs attribute usage

Let the driver core handle device attribute creation and removal. This
will simplify the code and eliminates races between attribute
availability and userspace notification via uevents.

Reviewed-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/s390/scsi/zfcp_ccw.c

@@ -129,7 +129,7 @@ static void zfcp_ccw_remove(struct ccw_device *cdev)
 	zfcp_ccw_adapter_put(adapter); /* put from zfcp_ccw_adapter_by_cdev */
 
 	list_for_each_entry_safe(unit, u, &unit_remove_lh, list)
-		zfcp_device_unregister(&unit->dev, &zfcp_sysfs_unit_attrs);
+		device_unregister(&unit->dev);
 
 	list_for_each_entry_safe(port, p, &port_remove_lh, list)
 		device_unregister(&port->dev);

drivers/s390/scsi/zfcp_ext.h

@@ -158,7 +158,7 @@ extern void zfcp_scsi_set_prot(struct zfcp_adapter *);
 extern void zfcp_scsi_dif_sense_error(struct scsi_cmnd *, int);
 
 /* zfcp_sysfs.c */
-extern struct attribute_group zfcp_sysfs_unit_attrs;
+extern const struct attribute_group *zfcp_unit_attr_groups[];
 extern struct attribute_group zfcp_sysfs_adapter_attrs;
 extern const struct attribute_group *zfcp_port_attr_groups[];
 extern struct mutex zfcp_sysfs_port_units_mutex;

drivers/s390/scsi/zfcp_sysfs.c

@@ -357,10 +357,13 @@ static struct attribute *zfcp_unit_attrs[] = {
 	&dev_attr_unit_access_readonly.attr,
 	NULL
 };
-
-struct attribute_group zfcp_sysfs_unit_attrs = {
+static struct attribute_group zfcp_unit_attr_group = {
 	.attrs = zfcp_unit_attrs,
 };
+const struct attribute_group *zfcp_unit_attr_groups[] = {
+	&zfcp_unit_attr_group,
+	NULL,
+};
 
 #define ZFCP_DEFINE_LATENCY_ATTR(_name) 				\
 static ssize_t								\

drivers/s390/scsi/zfcp_unit.c

@@ -145,6 +145,7 @@ int zfcp_unit_add(struct zfcp_port *port, u64 fcp_lun)
 	unit->fcp_lun = fcp_lun;
 	unit->dev.parent = &port->dev;
 	unit->dev.release = zfcp_unit_release;
+	unit->dev.groups = zfcp_unit_attr_groups;
 	INIT_WORK(&unit->scsi_work, zfcp_unit_scsi_scan_work);
 
 	if (dev_set_name(&unit->dev, "0x%016llx",
@@ -160,12 +161,6 @@ int zfcp_unit_add(struct zfcp_port *port, u64 fcp_lun)
 		goto out;
 	}
 
-	if (sysfs_create_group(&unit->dev.kobj, &zfcp_sysfs_unit_attrs)) {
-		device_unregister(&unit->dev);
-		retval = -EINVAL;
-		goto out;
-	}
-
 	atomic_inc(&port->units); /* under zfcp_sysfs_port_units_mutex ! */
 
 	write_lock_irq(&port->unit_list_lock);
@@ -254,7 +249,7 @@ int zfcp_unit_remove(struct zfcp_port *port, u64 fcp_lun)
 
 	put_device(&unit->dev);
 
-	zfcp_device_unregister(&unit->dev, &zfcp_sysfs_unit_attrs);
+	device_unregister(&unit->dev);
 
 	return 0;
 }