s390/cio: use device_lock to synchronize calls to the ccwgroup driver
When calling set_{on,off}line of a ccwgroup device driver we hold
the module reference of the owner. This is pretty useless - we don't
want to prevent module unloading but driver unbinding. Use the
driver core's device_lock instead.
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c
index 959135a..fd3367a1 100644
--- a/drivers/s390/cio/ccwgroup.c
+++ b/drivers/s390/cio/ccwgroup.c
@@ -128,14 +128,14 @@
const char *buf, size_t count)
{
struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
- struct ccwgroup_driver *gdrv = to_ccwgroupdrv(dev->driver);
unsigned long value;
int ret;
- if (!dev->driver)
- return -EINVAL;
- if (!try_module_get(gdrv->driver.owner))
- return -EINVAL;
+ device_lock(dev);
+ if (!dev->driver) {
+ ret = -EINVAL;
+ goto out;
+ }
ret = kstrtoul(buf, 0, &value);
if (ret)
@@ -148,7 +148,7 @@
else
ret = -EINVAL;
out:
- module_put(gdrv->driver.owner);
+ device_unlock(dev);
return (ret == 0) ? count : ret;
}
