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Message-ID: <ea22efd7-3b46-e71c-c64f-0b593691e7e7@kernel.org>
Date:   Sun, 16 Apr 2023 23:02:00 +0800
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Subject: Re: [PATCH] f2fs: remove bulk remove_proc_entry() and unnecessary
 kobject_del()
Content-Language: en-US
To:     Jaegeuk Kim <jaegeuk@kernel.org>
Cc:     Yangtao Li <frank.li@vivo.com>,
        linux-f2fs-devel@lists.sourceforge.net,
        linux-kernel@vger.kernel.org
References: <20230406191629.63024-1-frank.li@vivo.com>
 <2e41d6e0-13bb-fa5d-00aa-75865b8e7c34@kernel.org>
 <ZDglzIoEp3dH3eOS@google.com>
From:   Chao Yu <chao@kernel.org>
In-Reply-To: <ZDglzIoEp3dH3eOS@google.com>
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On 2023/4/13 23:54, Jaegeuk Kim wrote:
> On 04/13, Chao Yu wrote:
>> On 2023/4/7 3:16, Yangtao Li wrote:
>>> Convert to use remove_proc_subtree() and kill kobject_del() directly.
>>> kobject_put() actually covers kobject removal automatically, which is
>>> single stage removal.
>>>
>>> Signed-off-by: Yangtao Li <frank.li@vivo.com>
>>> ---
>>>    fs/f2fs/sysfs.c | 15 ++-------------
>>>    1 file changed, 2 insertions(+), 13 deletions(-)
>>>
>>> diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
>>> index dfbd17802549..3aad3500a701 100644
>>> --- a/fs/f2fs/sysfs.c
>>> +++ b/fs/f2fs/sysfs.c
>>> @@ -1461,25 +1461,14 @@ int f2fs_register_sysfs(struct f2fs_sb_info *sbi)
>>>    void f2fs_unregister_sysfs(struct f2fs_sb_info *sbi)
>>>    {
>>> -	if (sbi->s_proc) {
>>> -#ifdef CONFIG_F2FS_IOSTAT
>>> -		remove_proc_entry("iostat_info", sbi->s_proc);
>>> -#endif
>>> -		remove_proc_entry("segment_info", sbi->s_proc);
>>> -		remove_proc_entry("segment_bits", sbi->s_proc);
>>> -		remove_proc_entry("victim_bits", sbi->s_proc);
>>> -		remove_proc_entry("discard_plist_info", sbi->s_proc);
>>> -		remove_proc_entry(sbi->sb->s_id, f2fs_proc_root);
>>> -	}
>>> +	if (sbi->s_proc)
>>> +		remove_proc_subtree(sbi->sb->s_id, f2fs_proc_root);
>>> -	kobject_del(&sbi->s_stat_kobj);
>>
>> - f2fs_register_sysfs
>>   - kobject_init_and_add(&sbi->s_stat_kobj, ..)
>>
>> /**
>>   * kobject_init_and_add() - Initialize a kobject structure and add it to
>>   *                          the kobject hierarchy.
>> ...
>>   *
>>   * This function combines the call to kobject_init() and kobject_add().
>> ...
>>   */
>>
>> /**
>>   * 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().
>>   */
>>
>> Am I missing something?
> 
> kobject_put -> kobject_cleanup was supposed to do it?

Yes, it seems so.

Reviewed-by: Chao Yu <chao@kernel.org>

Thanks,

> 
>>
>> Thanks,
>>
>>>    	kobject_put(&sbi->s_stat_kobj);
>>>    	wait_for_completion(&sbi->s_stat_kobj_unregister);
>>> -	kobject_del(&sbi->s_feature_list_kobj);
>>>    	kobject_put(&sbi->s_feature_list_kobj);
>>>    	wait_for_completion(&sbi->s_feature_list_kobj_unregister);
>>> -	kobject_del(&sbi->s_kobj);
>>>    	kobject_put(&sbi->s_kobj);
>>>    	wait_for_completion(&sbi->s_kobj_unregister);
>>>    }