Re: [PATCH v2 1/3] mm/shmem: check return value of shmem_init_inodecache

[Chen Wandun <chenwandun@huawei.com>]

在 2022/6/6 10:08, Matthew Wilcox 写道:
> On Mon, Jun 06, 2022 at 09:34:13AM +0800, Chen Wandun wrote:
>> On 2022/6/5 19:49, Matthew Wilcox wrote:
>>> On Sun, Jun 05, 2022 at 11:55:55AM +0800, Chen Wandun wrote:
>>>> It will result in null pointer access if shmem_init_inodecache fail,
>>>> so check return value of shmem_init_inodecache
>>> You ignored my suggestion from v1.  Here, let me write it out for you.
>> Hi Matthew,
>> I didn't ignore your suggestion,  some explanation is needed, sorry for
>> that.
>>
>> In V1, Kefeng point:
>> "kmem_cache_create return a pointer to the cache on success, NULL on
>> failure,
>> so error = -ENOMEM; is right :)"
>>
>> so, I look some similar code such as init_inodecache in kinds of file
>> system,  they all
>> return -ENOMEM on failure, so is it OK to return -ENOMEM on failure :)
>>
>> Besides,  kmem_cache_create return NULL on failure, maybe returning error
>> code
>> on failure is more proper, but it is another job.
> I literally wrote out what I think you should do instead.  Stop arguing.
>
>>> +static int shmem_init_inodecache(void)
>>>    {
>>>     	shmem_inode_cachep = kmem_cache_create("shmem_inode_cache",
>>>     				sizeof(struct shmem_inode_info),
>>>     				0, SLAB_PANIC|SLAB_ACCOUNT, shmem_init_inode);
>>> +	if (!shmem_inode_cachep)
>>> +		return -ENOMEM;
>>> +	return 0;
>>>    }
>>>
>>> ...
>>>
>>> +	error = shmem_init_inodecache();
>>> +	if (error)
>>> +		goto out2;
Oh, I misunderstood what you said, feel so sorry.
I will send a new version.

Thanks.
>>>
>>>
>>> .
> .