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Date:   Thu, 23 Mar 2023 13:16:20 +0800
From:   Ming Lei <ming.lei@redhat.com>
To:     Yangtao Li <frank.li@vivo.com>
Cc:     clm@fb.com, josef@toxicpanda.com, dsterba@suse.com,
        xiang@kernel.org, chao@kernel.org, huyue2@coolpad.com,
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Subject: Re: [PATCH v3 01/10] kobject: introduce kobject_del_and_put()
Message-ID: <ZBvgpBzEuFuyOD/c@ovpn-8-16.pek2.redhat.com>
References: <20230322165830.55071-1-frank.li@vivo.com>
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On Thu, Mar 23, 2023 at 12:58:30AM +0800, 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@vivo.com>
> ---
> v3:
> -convert to inline helper
> v2:
> -add kobject_del_and_put() users
>  include/linux/kobject.h | 13 +++++++++++++
>  lib/kobject.c           |  3 +--
>  2 files changed, 14 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/kobject.h b/include/linux/kobject.h
> index bdab370a24f4..e21b7c22e355 100644
> --- a/include/linux/kobject.h
> +++ b/include/linux/kobject.h
> @@ -112,6 +112,19 @@ extern struct kobject * __must_check kobject_get_unless_zero(
>  						struct kobject *kobj);
>  extern void kobject_put(struct kobject *kobj);
>  
> +/**
> + * kobject_del_and_put() - Delete kobject.
> + * @kobj: object.
> + *
> + * Unlink kobject from hierarchy and decrement the refcount.
> + * If refcount is 0, call kobject_cleanup().
> + */
> +static inline void kobject_del_and_put(struct kobject *kobj)
> +{
> +	kobject_del(kobj);
> +	kobject_put(kobj);
> +}

kobject_put() actually covers kobject removal automatically, which is
single stage removal. So if you see the two called together, it is
safe to kill kobject_del() directly.


thanks,
Ming