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Subject: Re: [RESEND PATCH] llist: Make llist_del_first return only the first
 node
To: "Huang, Ying" <ying.huang@intel.com>
CC: <akpm@linux-foundation.org>, <paulmck@linux.vnet.ibm.com>,
	<neilb@suse.de>, <chuck.lever@oracle.com>, <linux-kernel@vger.kernel.org>
References: <20240218065750.1241-1-liqiang64@huawei.com>
 <875xymtdy5.fsf@yhuang6-desk2.ccr.corp.intel.com>
From: Li Qiang <liqiang64@huawei.com>
Message-ID: <c4c95726-ad43-88d3-186c-28b192f0b9d4@huawei.com>
Date: Sun, 18 Feb 2024 17:23:44 +0800
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在 2024/2/18 15:43, Huang, Ying 写道:
> liqiang <liqiang64@huawei.com> writes:
> 
>> Set the next of the returned node of llist_del_first
>> to NULL, which can prevent subsequent nodes in llist
>> from being exposed, and is more consistent with the
>> logic of this interface.
>>
>> Signed-off-by: liqiang <liqiang64@huawei.com>
>> ---
>>  lib/llist.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/lib/llist.c b/lib/llist.c
>> index f21d0cf..c33fff5 100644
>> --- a/lib/llist.c
>> +++ b/lib/llist.c
>> @@ -61,6 +61,7 @@ struct llist_node *llist_del_first(struct llist_head *head)
>>  		next = READ_ONCE(entry->next);
>>  	} while (!try_cmpxchg(&head->first, &entry, next));
>>  
>> +	entry->next = NULL;
>>  	return entry;
>>  }
>>  EXPORT_SYMBOL_GPL(llist_del_first);
> 
> This isn't needed for functionality correctness.  Many users of llist
> ask for performance.  So, it may be better to let the users to decide
> whether to set entry->next to NULL.
> 

Ok, get it, thanks for your reply.

-- 
Best regards,
Li Qiang