s390/dasd: fix inability to set a DASD device offline

Fix ref counting for DASD devices leading to an inability to set a
DASD device offline.
Before a worker is scheduled the DASD device driver takes a reference
to the device. If the worker was already scheduled this reference was
never freed.
Fix by giving the reference to the DASD device free when
schedule_work() returns false.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/block/dasd.c

@@ -579,7 +579,8 @@ void dasd_kick_device(struct dasd_device *device)
 {
 	dasd_get_device(device);
 	/* queue call to dasd_kick_device to the kernel event daemon. */
-	schedule_work(&device->kick_work);
+	if (!schedule_work(&device->kick_work))
+		dasd_put_device(device);
 }
 EXPORT_SYMBOL(dasd_kick_device);
 
@@ -599,7 +600,8 @@ void dasd_reload_device(struct dasd_device *device)
 {
 	dasd_get_device(device);
 	/* queue call to dasd_reload_device to the kernel event daemon. */
-	schedule_work(&device->reload_device);
+	if (!schedule_work(&device->reload_device))
+		dasd_put_device(device);
 }
 EXPORT_SYMBOL(dasd_reload_device);
 
@@ -619,7 +621,8 @@ void dasd_restore_device(struct dasd_device *device)
 {
 	dasd_get_device(device);
 	/* queue call to dasd_restore_device to the kernel event daemon. */
-	schedule_work(&device->restore_device);
+	if (!schedule_work(&device->restore_device))
+		dasd_put_device(device);
 }
 
 /*

drivers/s390/block/dasd_eckd.c

@@ -1628,7 +1628,8 @@ static void dasd_eckd_kick_validate_server(struct dasd_device *device)
 		return;
 	}
 	/* queue call to do_validate_server to the kernel event daemon. */
-	schedule_work(&device->kick_validate);
+	if (!schedule_work(&device->kick_validate))
+		dasd_put_device(device);
 }
 
 static u32 get_fcx_max_data(struct dasd_device *device)