Re: [PATCH V5 9/9] null_blk: serialize configfs attribute shows with the file-scope lock

[Zizhi Wo <wozizhi@huaweicloud.com>]

在 2026/7/25 5:16, Bart Van Assche 写道:
> 
> On 7/13/26 9:18 PM, Zizhi Wo wrote:
>> diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/ 
>> main.c
>> index 67cd32d28887..c8487a630e1a 100644
>> --- a/drivers/block/null_blk/main.c
>> +++ b/drivers/block/null_blk/main.c
>> @@ -345,8 +345,14 @@ static ssize_t nullb_device_bool_attr_store(bool 
>> *val, const char *page,
>>   static ssize_t                                \
>>   nullb_device_##NAME##_show(struct config_item *item, char *page)    \
>>   {                                    \
>> -    return nullb_device_##TYPE##_attr_show(                \
>> +    ssize_t ret;                            \
>> +                                    \
>> +    mutex_lock(&lock);                        \
>> +    ret = nullb_device_##TYPE##_attr_show(                \
>>                   to_nullb_device(item)->NAME, page);    \
>> +    mutex_unlock(&lock);                        \
>> +                                    \
>> +    return ret;                            \
>>   }                                    \
>>   static ssize_t                                \
>>   nullb_device_##NAME##_store(struct config_item *item, const char 
>> *page,    \
>> @@ -479,7 +485,13 @@ NULLB_DEVICE_ATTR(badblocks_partial_io, bool, NULL);
>>   static ssize_t nullb_device_power_show(struct config_item *item, 
>> char *page)
>>   {
>> -    return nullb_device_bool_attr_show(to_nullb_device(item)->power, 
>> page);
>> +    ssize_t ret;
>> +
>> +    mutex_lock(&lock);
>> +    ret = nullb_device_bool_attr_show(to_nullb_device(item)->power, 
>> page);
>> +    mutex_unlock(&lock);
>> +
>> +    return ret;
>>   }
> 
> The above changes would be much more elegant if guard()() would be used 
> instead of explicit mutex_lock() and mutex_unlock() calls.
> 
> Thanks,
> 
> Bart.

Thanks Bart. Will switch to using guard() in the next version :)

Thanks,
Zizhi Wo