[PATCH 2/7] staging: erofs: code cleanup for option parsing of fault_injection

[cgxu519]

On 09/13/2018 10:15 AM, Chao Yu wrote:
> On 2018/9/12 13:10, Chengguang Xu wrote:
>> Define a dummpy function of erofs_build_fault_attr() when macro
>> CONFIG_EROFS_FAULT_INJECTION is disabled, so that we don't have to
>> check the macro in calling place. Based on above adjustment,
>> do proper code cleanup for option parsing of fault_injection.
>>
>> Signed-off-by: Chengguang Xu <cgxu519 at gmx.com>
>> ---
>>   drivers/staging/erofs/super.c | 33 ++++++++++++++++++++++-----------
>>   1 file changed, 22 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c
>> index 1aec509c805f..14dbb6517b8d 100644
>> --- a/drivers/staging/erofs/super.c
>> +++ b/drivers/staging/erofs/super.c
>> @@ -144,18 +144,33 @@ char *erofs_fault_name[FAULT_MAX] = {
>>   	[FAULT_KMALLOC]		= "kmalloc",
>>   };
>>   
>> -static void erofs_build_fault_attr(struct erofs_sb_info *sbi,
>> -						unsigned int rate)
>> +static int erofs_build_fault_attr(struct erofs_sb_info *sbi,
>> +					substring_t *args)
>>   {
>>   	struct erofs_fault_info *ffi = &sbi->fault_info;
>> +	int rate = 0;
>> +
>> +	if (args->from && match_int(args, &rate))
>> +		return -EINVAL;
>>   
>>   	if (rate) {
>>   		atomic_set(&ffi->inject_ops, 0);
>>   		ffi->inject_rate = rate;
>>   		ffi->inject_type = (1 << FAULT_MAX) - 1;
>> +		set_opt(sbi, FAULT_INJECTION);
>>   	} else {
>>   		memset(ffi, 0, sizeof(struct erofs_fault_info));
>> +		clear_opt(sbi, FAULT_INJECTION);
> Hmmm, if user mounts/remounts image with -o fault_injection=0, user can not
> check such info in anywhere, as we skip showing this option due to lack of
> EROFS_MOUNT_FAULT_INJECTION bit. How about keeping this bit?
>

IIUC, the purpose of fault_injection=0 is for disabling fault injection 
function,
so isn't it the same as default? Should we distinguish explicit setting 
value 0 and default value 0?

Thanks,
Chengguang