[S390] dasd: fix reference counting in display method for proc/dasd/devices
Using the /proc/dasd/devices interface leaves the reference counter
of alias devices in an inconsistent state. A process that tries to set
such a device offline afterwards will hang.
The dasd_devices_show function returns immediately for alias devices
and this code path was missing a dasd_put_device call.
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/block/dasd_proc.c b/drivers/s390/block/dasd_proc.c
index 28a86f07..556063e 100644
--- a/drivers/s390/block/dasd_proc.c
+++ b/drivers/s390/block/dasd_proc.c
@@ -62,8 +62,10 @@
return 0;
if (device->block)
block = device->block;
- else
+ else {
+ dasd_put_device(device);
return 0;
+ }
/* Print device number. */
seq_printf(m, "%s", device->cdev->dev.bus_id);
/* Print discipline string. */