On 05/16/2013 11:33 AM, Chen Gang wrote: > On 05/16/2013 05:22 AM, Tejun Heo wrote: >> On Wed, May 15, 2013 at 02:13:14PM +0800, Chen Gang wrote: >>> >>> In workqueue_sysfs_register(), when failure occurs after called >>> device_create_file(), need call device_remove_file() to release the >>> related resources, then call device_unregister(). >>> >>> Or it will cause issue. >>> >>> For individual 'device_attributs' (just like our case), need call >>> device_remove_file() explictly and then call device_unregister(), >>> please reference drivers/base/*.c (e.g node.c or cpu.c). >> >> Hmm... isn't this already taken care of by __sysfs_remove_dir() which >> device_unregister() calls? That function removes all non-directory >> files under the directory being removed. >> > > It just like what you said: > device_unregister() -> > kobject_del() -> > sysfs_remove_dir() -> > __sysfs_remove_dir() -> > sysfs_remove_one() > But: > device_remove_file() -> > sysfs_remove_file() -> > ... > sysfs_attr_ns() -> > ops->namespace() (such as device_namespace() in workqueue.c) > ... > sysfs_hash_and_remove() -> > sysfs_remove_one(). > > So if not call device_remove_file() explicitly, the device_namespace() > may be not called. >
It seems, if not call ops->namespace(), it still is OK. To get a result, it still has much details to continue to read. But all together, reference the related code of another subsystems, we really need device_remove_file() before call device_unregister(). > > Even in device_unregister(), it still call device_remove_file() to > release the related attributes firstly, then call kobject_del(). > > > > Thanks. > -- Chen Gang Asianux Corporation -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
