Messages in this thread | | | Date | Thu, 16 May 2013 11:33:24 +0800 | From | Chen Gang <> | Subject | Re: [PATCH] kernel/workqueue.c: need call device_remove_file() when failure occurs after called device_create_file() |
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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.
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
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