kobject: Improve docs for kobject_add/del

There is currently some confusion on how to wind back
kobject_init_and_add() during the error paths in code that uses this
function.

Add documentation to kobject_add() and kobject_del() to help clarify the
usage.

Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Tobin C. Harding 2019-04-28 10:48:10 +10:00 committed by Greg Kroah-Hartman
parent edb16da34b
commit 92067f8438

View File

@ -406,15 +406,19 @@ static __printf(3, 0) int kobject_add_varg(struct kobject *kobj,
* is assigned to the kobject, then the kobject will be located in the
* root of the sysfs tree.
*
* If this function returns an error, kobject_put() must be called to
* properly clean up the memory associated with the object.
* Under no instance should the kobject that is passed to this function
* be directly freed with a call to kfree(), that can leak memory.
*
* Note, no "add" uevent will be created with this call, the caller should set
* up all of the necessary sysfs files for the object and then call
* kobject_uevent() with the UEVENT_ADD parameter to ensure that
* userspace is properly notified of this kobject's creation.
*
* Return: If this function returns an error, kobject_put() must be
* called to properly clean up the memory associated with the
* object. Under no instance should the kobject that is passed
* to this function be directly freed with a call to kfree(),
* that can leak memory.
*
* If this call returns successfully and you later need to unwind
* kobject_add() for the error path you should call kobject_del().
*/
int kobject_add(struct kobject *kobj, struct kobject *parent,
const char *fmt, ...)
@ -589,6 +593,9 @@ EXPORT_SYMBOL_GPL(kobject_move);
/**
* kobject_del - unlink kobject from hierarchy.
* @kobj: object.
*
* This is the function that should be called to delete an object
* successfully added via kobject_add().
*/
void kobject_del(struct kobject *kobj)
{