[SCSI] zfcp: Implement module unloading

With the reference counting for zfcp data structures, it is now
possible to implement module unloading again. Module unloading
requires to free all data structures in the module exit function. This
is done by unregistering zfcp from s390 cio and the SCSI midlayer
first in the module exit function.

Reviewed-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>

Author: Christof Schmitt

drivers/s390/scsi/zfcp_aux.c

@@ -189,7 +189,7 @@ static int __init zfcp_module_init(void)
 		goto out_misc;
 	}
 
-	retval = zfcp_ccw_register();
+	retval = ccw_driver_register(&zfcp_ccw_driver);
 	if (retval) {
 		pr_err("The zfcp device driver could not register with "
 		       "the common I/O layer\n");
@@ -218,6 +218,19 @@ static int __init zfcp_module_init(void)
 
 module_init(zfcp_module_init);
 
+static void __exit zfcp_module_exit(void)
+{
+	ccw_driver_unregister(&zfcp_ccw_driver);
+	misc_deregister(&zfcp_cfdc_misc);
+	fc_release_transport(zfcp_data.scsi_transport_template);
+	kmem_cache_destroy(zfcp_data.gid_pn_cache);
+	kmem_cache_destroy(zfcp_data.sr_buffer_cache);
+	kmem_cache_destroy(zfcp_data.qtcb_cache);
+	kmem_cache_destroy(zfcp_data.gpn_ft_cache);
+}
+
+module_exit(zfcp_module_exit);
+
 /**
  * zfcp_get_unit_by_lun - find unit in unit list of port by FCP LUN
  * @port: pointer to port to search for unit

drivers/s390/scsi/zfcp_ccw.c

@@ -279,14 +279,3 @@ struct ccw_driver zfcp_ccw_driver = {
 	.thaw	     = zfcp_ccw_activate,
 	.restore     = zfcp_ccw_activate,
 };
-
-/**
- * zfcp_ccw_register - ccw register function
- *
- * Registers the driver at the common i/o layer. This function will be called
- * at module load time/system start.
- */
-int __init zfcp_ccw_register(void)
-{
-	return ccw_driver_register(&zfcp_ccw_driver);
-}

drivers/s390/scsi/zfcp_ext.h

@@ -27,7 +27,6 @@ extern void zfcp_adapter_release(struct kref *);
 extern void zfcp_adapter_unregister(struct zfcp_adapter *);
 
 /* zfcp_ccw.c */
-extern int zfcp_ccw_register(void);
 extern int zfcp_ccw_priv_sch(struct zfcp_adapter *);
 extern struct ccw_driver zfcp_ccw_driver;
 extern struct zfcp_adapter *zfcp_ccw_adapter_by_cdev(struct ccw_device *);