Re: [RESEND,PATCH v2 01/10] kobject: introduce kobject_del_and_put()

[Damien Le Moal]

On 3/21/23 03:46, Yangtao Li wrote:
> There are plenty of using kobject_del() and kobject_put() together
> in the kernel tree. This patch wraps these two calls in a single helper.
> 
> Signed-off-by: Yangtao Li <frank.li@xxxxxxxx>
> ---
> v2:
> -add kobject_del_and_put() users
> resend patchset to gregkh, Rafael and Damien
>  include/linux/kobject.h |  1 +
>  lib/kobject.c           | 17 +++++++++++++++--
>  2 files changed, 16 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/kobject.h b/include/linux/kobject.h
> index bdab370a24f4..782d4bd119f8 100644
> --- a/include/linux/kobject.h
> +++ b/include/linux/kobject.h
> @@ -111,6 +111,7 @@ extern struct kobject *kobject_get(struct kobject *kobj);
>  extern struct kobject * __must_check kobject_get_unless_zero(
>  						struct kobject *kobj);
>  extern void kobject_put(struct kobject *kobj);
> +extern void kobject_del_and_put(struct kobject *kobj);
>  
>  extern const void *kobject_namespace(const struct kobject *kobj);
>  extern void kobject_get_ownership(const struct kobject *kobj,
> diff --git a/lib/kobject.c b/lib/kobject.c
> index 6e2f0bee3560..8c0293e37214 100644
> --- a/lib/kobject.c
> +++ b/lib/kobject.c
> @@ -731,6 +731,20 @@ void kobject_put(struct kobject *kobj)
>  }
>  EXPORT_SYMBOL(kobject_put);
>  
> +/**
> + * kobject_del_and_put() - Delete kobject.
> + * @kobj: object.
> + *
> + * Unlink kobject from hierarchy and decrement the refcount.
> + * If refcount is 0, call kobject_cleanup().
> + */
> +void kobject_del_and_put(struct kobject *kobj)
> +{
> +	kobject_del(kobj);
> +	kobject_put(kobj);
> +}
> +EXPORT_SYMBOL_GPL(kobject_del_and_put);

Why not make this an inline helper defined in include/linux/kobject.h instead of
a new symbol ?

> +
>  static void dynamic_kobj_release(struct kobject *kobj)
>  {
>  	pr_debug("kobject: (%p): %s\n", kobj, __func__);
> @@ -874,8 +888,7 @@ void kset_unregister(struct kset *k)
>  {
>  	if (!k)
>  		return;
> -	kobject_del(&k->kobj);
> -	kobject_put(&k->kobj);
> +	kobject_del_and_put(&k->kobj);
>  }
>  EXPORT_SYMBOL(kset_unregister);
>  

-- 
Damien Le Moal
Western Digital Research